Good evening everybody, and welcome to another Thursday night members webinar. My name is Bruce Stevenson, and I have the honour and pleasure of chairing tonight's webinar. As you can see up on the screen, we have one of my all-time favourites, Simon Tappan with us again tonight, and he's gonna be chatting about the evaluation of the coughing dog.

We don't have any new members as far as I know. So all the normal rules apply. Pop your questions into the Q&A box and we'll hold those over to the end.

So for those of you who don't know Simon, he graduated from the University of Cambridge, and after 2 years in practise, undertook a residency at the University of Bristol in small animal medicine and intensive care, where he gained his European diploma, a diploma in small animal medicine. He's currently head of internal medicine at Dick White Referrals, where he sees cases in all areas of internal medicine. Simon, welcome back to the webinar vet, and it's over to you.

Thank you, thank you for the very kind introduction and welcome everyone to tonight's webinar. So we're talking this evening about how we evaluate the coughing dog, and coughing dogs form quite a, a large proportion of the case load that we see in practise. We see some of the more frustrating ones at referral level.

So it's really going to talk through this evening how we go through logically in terms of approaching those sorts of patients, trying to work out how we would treat the ones with self-limiting cough, what we do to try and evaluate those, and then the more frustrating coughs, the more chronic coughs, how we might try to localise the problem. Understand what the issues and the reasons why that dog is coughing, and then think about how we would go through the diagnostic process and think about some of the treatments that we might have in place. So to start off with, I just wanted to talk a little bit about what coughing is, because coughing is one of those things where owners will say the dog is coughing, but it's really important that we try and understand exactly what the dog is doing, because there can be lots of things that look like a cough.

So essentially the dog can be gagging, some of the reverse sneezing things sometimes are reported as coughing. Owers find it very difficult to understand what the dog is doing. And there is a difference between coughing and an expiratory reflex, which helps us to understand what's going on.

So a true cough is essentially a reflex action that helps us to move things out of the airway. So it's very normal for animals to cough occasionally as it is with ourselves, as we're trying to move mucus or material from the airway. And to do that, what we do is have a, a really deep inspiration.

So we breathe in and then a very powerful expiration. So we breathe out initially gets a closed glottis, so we build up pressure within the chest, and then we open the glottis and you have that cough, so material is expelled from the chest in a very coordinated reflex action. This is a little dog here, it's a video of a dog coughing.

It's quite a loud exscription noise so there's a. Inspiratory emotion, and then that expiratory forceful movement, where we get the movement of air out of the chest again to close. And at the end, you'll often see that sort of expiration.

Often there'll be something that may have been brought up. It doesn't necessarily need to be expelled from the body, but often there'll be material that comes up, often it is swallowed sort of subconsciously rather than we'll see this ex expirated material that actually comes up out of the airway. Sometimes we also see what's called an expiratory reflex, which is exactly the same as the cough reflex, but without the inspiration first.

And this is usually caused by irritation at the back of the, of the pharynx or of the larynx. So what we'll see is just that there's a, a, a really sort of . Less powerful sort of expiratory effort without that deep inspiration first.

So a cough will be coordinated. We know we're gonna cough because we breathe in first, whereas with the expiratory reflexes caused by irritation, you don't have that inspiration first, you just get that kind of coughing motion where material is brought up without that inspiratory phase first. So it looks a little bit different.

Oh, that's the same dog again. There we go. This dog at the bottom with the inspiratory reflex.

So this is the dog that's bringing up the material. It's that kind of, cough-like noise, but without the, inspiration to make it as forceful as we would expect. This is that kind of irritating cough-like noise that I guess really irritates owners and and causes us difficulty in terms of trying to localise where the problem is.

So coughing is, is gonna be caused by lots of different parts of the airway. That expiratory reflex is just caused by upper airway, laryngeal and pharyngeal inflammation, which is causing a problem, so that we know then it's gonna be an upper respiratory tract problem. So we've talked a little bit about coughing being a reflex and it being protective, and if we get something that goes down the wrong way, or if we get excessive mucus that's produced in the airway, it's gonna cause irritation, it's gonna cause a narrowing within the airway itself, and we're going to want to cough topeuate and bring that material up so we can keep the airway as clear as possible and move material out of the airway.

So this is a cough reflex. It's, there is a conscious override, so we can stop ourselves coughing, but it's quite hard to make ourselves go through the cough process without having that, that sort of stimulation, that, that initial triggering event. So looking at the cough reflex, if we were to get something to go down into the airway, so for example, this is a, a, a wheat of cornea that's down in one of the, the, the larger bronchi here in this, in this dog, that would obviously stimulate a cough.

It's gonna stimulate cough receptors. Those cough receptors feed into the vagal nerve, and so we go back to the, the, the brain. The cough centre is in the pond, so deep within the subconscious, the autonomic parts of the brain, and that's going to trigger off the nervous response to that to lead to this coordinated reflex action allows us to breathe in and then expirate against the closed losses to open it at the time.

So that uses various nerves in the current angio, the vagus nerve, the spinal nerves to elicit that cough. Now the sensitivity of that cough reflex can be markedly increased by inflammation. So if we have inflammatory airway disease, it's gonna be much more likely that the animal is gonna cough as a result of that.

So lots of inflammatory mediators that we see with inflammatory airway disease, so things like substance P. Neuroynin, tachyyins, the cal calcitonin gene related peptide, all can make that cough reflex much more sensitive by sensitising the cough receptors. And this is why you know animals that cough a lot, if there's lots of inflammation, they're going to cough more as a result of that.

And that's when coughing becomes less protective and less helpful and more of an irritation because we get the cycleway. Have more coughing, that coughing itself, because it's quite forceful, leads to quite a lot of inflammation within the chest, and then you get that continued cycle, what's called the cough cycle. And breaking that cough cycle sometimes is important in terms of reducing the inflammation, reducing the sensitization of those cough receptors and allowing things to settle.

So it's important to realise that there are those inflammatory mediators that feed into those cough receptors. And these contraceptors are found in different places within the the airway and the respiratory tract. So if we think about the airway, we, we obviously start at the naries and the mouth where air comes in.

So animals at rest will often breathe through their nose. So we think about the area, the nasal chambers, and then flows over the, the dorsal part of the soft palate through the larynx into the upper airway. And there are cough receptors at the back of the throat in terms of the pharynx and the larynx, really high density of cough receptors around that area.

If we get food or water in that area, and we want to, to bring it up, then coughing is helpful to clear the airway. And then as we start to move down to the trachea, we have again, a high density of, of cough receptors. These are mechano sensitive, so they're essentially triggered by material being in the wrong place, so foreign materials, so food, things that have been aspirated, or mucus or debris that's there, which we want to try and clear.

And then as we go further down the airway, we get to the bifurcation, so the trachea splits into the left and the right, main stem bronchi, and then obviously divides off a bit like the branches of a tree into the different lung lobes in the different areas and the bronchi will divide and divide and fight as we go down. And there's a lower density of coffin receptors, the further we further away we get from the, bifurcation. So if we get into the lower airways, we're gonna see a lower density of those cough receptors, and those tend to stop being mechano receptive, and start being chemo sensitive.

So they're responsive then to inflammation, to irritation, to bacteria, to, to other triggers that are present, rather than just having a, a mechanical trigger. And then once we get down to the bronchioles, a very small airways and into the alveoli, there there isn't actually cough receptors there, so they don't initially initiate the cough reflex. This is where we start getting to the arguments about, you know, what causes coughing in dogs with cardiac disease.

Does pulmonary edoema cause cough? Because that material within the avi itself probably shouldn't elicit a cough material reflex, but if that comes up into the airway, then that does start to trigger a cough, and we see signs associated with that. So, coughing can be, difficult, firstly because it can be really annoying.

And it's one of those things that is quite hard, when owners come in, because it's not necessarily the dog that sometimes is the problem, it's the owner's quality of life and the fact that the dog is coughing all night, waking them up in 3 o'clock in the morning, and they're, you know, really grumpy because they haven't had a good night's sleep. So we need to get owners on board and help them to understand why the animal is coughing, and that cough is, is just a symptom of the abnormality. And actually it may be quite necessary, in some of the productive diseases that we'll talk about, so thinking about things like bronchial pneumonia, diseases where there's a lot of excessive mucus, it's actually quite necessary for the animal to cough to bring that material up.

But actually if we have things like tracheal collapse, for example, where we have extreme tracheal sensitivity, that can really affect the animal's quality of life, because they're not settling, and the owners are obviously going to to be upset as a result of that. So we have to balance treating the underlying disease, treating the symptoms of that disease, and making sure that the owners are happy with us, and really keeping everyone on board and making sure that we're addressing what the owner's actual problem is, this. Really helpful in terms of doing that.

So sometimes it may be the dog is coughing, that it's the problem. But when you get down to it, it's actually that the dog is coughing so much that the owner isn't having a good night's sleep, and that's obviously no good for the dog. But it's, it's something that we need to try to, to, to understand.

And when we think about coughing, often you will find that owners do report that the cough is worse at night. That's often because it's quieter and they notice it more. Not necessarily that's a true reflection.

When the cough is being presented. So often these animals will be coughing at a similar rate all through the day. It's just noted more that it's quieter, probably irritating during the early hours of the morning.

Often you will see that cough, but then potentially just as the animal gets up, it starts to move, if there's mucus or material in the chest, then that will often trigger a cough on on movement, which is that necessary cough to move that material to try and clear the airway, which is often quite helpful. So what, what causes coughing? What sort of disease processes would we think about?

Well, we can kind of break this down into different areas. So we can look at the upper airway, the lower airway, and then think about the ranula and the interstition. So the alveolar spaces and the space between the alveolar spaces, so the, the actual structure of the lung itself.

And if we look at different diseases, there are a long list of potential causes of coughing. If we're thinking about the upper airway, we've got things like laryngeal disease, so paralysis, and tumours, tracheal clamps when we're thinking about. The upper airway, the trachea is part of that, foreign bodies that are present within the trachea, neoplasia of the larynx, you know, infectious things, so, bacterial diseases, the kennel cloth complex, and thinking about parasitic infections.

And as we move down the airway, we're going to see that some of these processes still continue, so things like collapse. So with bronchialacia, the loss of the cartilage structure within the airway, you're gonna see that if the trachea is collapsing, the bronchia also gonna collapse as a result of that to some degree. They see Foreign bodies that have got further wedged, they tend to go to the right side of the lung because it's straight on, rather than the left side, probably 2/3 on the right, 1/3 on the left from the literature, because it's more straight on, and they'll get stuck there and cause a problem.

We also see that there are nearoplastic events that occur, so, bronchial carcinomas and masses that form and cause problems, and there's some sort of infections that we would think about as well in terms of bacterial disease, parasitic disease, and then a whole host of chronic inflammatories. Diseases that are often quite difficult to differentiate between things like chronic asthma, chronic bronchitis, and then thinking about things like bronneumopathy, where we have an overreaction to things that are normally present in the environment, and the animal is hypersensitized to that, and then we start to see, really quite severe inflammation in the case of those diseases, where we've got disproportionate inflammation and really very severe inflammation that triggers, you know, very reactive pattern with coughing. And then the, the pachial interstitial diseases, those that form problems within the alveoli or the interstitial space, the structure of the lung can have haemorrhage, so intertitial bleeding, associated with an stronglus infection, for example, we can see edoema, so the formation of fluid, most of the time that's going to be cardiogenic.

That often isn't a trigger to coughing, as we said, but if it makes its way up into the bronchioles on the airway, then that will trigger cough reflex. And the non-cardiogenic edoema, which is formed usually through, well, obviously non-cardiogenic causes, but, edoema within the lung as a result of that, things like near drowning, strangulation events, electrocution, those sorts of things will cause upon edoema to form. So they're quite unusual.

Usually, you know. That that's happened. It's, you know, you've got an event where that's occurred to cause that cartilagegenic edoema and usually differentiate them the cardiogenic ones have that alveolar pattern around the heart base, and the non-cardiogenic ones are much more peripheral pattern, which obviously what we see with anstroculosis as well lung worm infection, that patchy alveolar pattern, is, is really suggestive and non-card non-cardiogenic edoema as well.

The broken pneumonia, so infection that's affecting the different parts of the lung, fibrosis, you see, that's classic in Westies, where we have this interstitial fibrosis. So the elasticity of the lung is affected, so lungs a bit like a sponge, essentially. And if that sponge becomes tougher, you're not going to get that elasticity and movement.

So material isn't going to be cleared from the as well, we're going to get some secondary infections, and that's going to cause a problem. And if you look in textbooks, there's some unusual things as well, like torsions, lung torsions in pugs, the left, middle, and the the sorry, the left cranium, the right middle lung lobes, the ones that tend to cause, just because of the anatomy of the chest and the way that the lungs can sometimes move, it's going to be a bit more common if there's Some fluid in the chest as well, so often it's secondary to a pleural effusion as well. And then neoplastic events where we have tumours that are causing a problem.

So you can see some rare lymphomas and things going along that are causing problems. In the occasion we do see things like al space disease, diaphragmatic disease, thoracic cage, and vascular diseases, all that can feed in and cause coughing as well and cause problems. So when we think about the causes of cough, it's, it's really easy to blame the heart.

We've talked a little bit about this in terms of saying that cardiac disease is often blamed for being cause of cough, this kind of theory of a cardiac cough. But actually, it's not that often that the heart is. Responsible for the cough and heart murms are really common in animals as they get older, but heart murmurs are, are, are not all, well, they're very uncommonly associated with heart failure.

So, heart murmurs can be very incidental, don't reflect that the animals will develop cardiac disease or have congestive failure. So most animals that have mitral valve disease, for example, don't develop heart disease, heart failure during their lifetime. They have heart disease because their valves are abnormal.

The, the mitral valve isn't as, as sort of rigid, as we'd expect, and there's some reflux and the material moves in the wrong direction, but they don't go on to develop congestive heart failure. So murmurs are common in dogs that, that cough, but most coughing is not caused by heart failure. And just to mention cats, I know we're talking about dogs this evening, but cats and heart failure don't tend to cough at all.

And, and there's lots of sort of theory behind this in terms of, of sort of discussion around that. So you talked a little bit about pulmonary edoema causing a cough. There are some studies looking at that.

Congestive heart failure doesn't seem to be linked to coughing, so we don't think that, pulmonary edoema is the cause of a cough. If you have effusive fluid that's present within the lung, then it will trigger coughing. But pulmon edoema isn't often associated with cough, so it's essentially, doesn't tend to be a cause of, of the cough in these patients.

People then think, well, maybe if the left atrium is enlarged because of congestive failure, we have distention of the left atrium because we've got forward failure, and that's gonna put pressure on the left main te bronchuss, and that's going to cause a problem as well. So this is a picture of a dog that has a really enlarged heart, through marked cardiogaly and quite marked compression of the left main stem bronchus, so that's gonna cause coughing as a result of that. But with this, we need to have an abnormal bronchus.

For that level of collapse to occur. So this will only occur if we have that bronchoalacia, where the airway structure is affected and that airway is effectively narrower than we would expect it to be, and that will obviously trigger some coughing as well. So the enlargement of the left atrium will worsen the cough, but it isn't the cause of the cough.

These animals have concurrent airway disease in the sense they have a loss of the cartilage structure. This Looking at the bifurcation, so that the right side is on the lower half of the screen, oops right down here, and this is the left main stem brons here. This should be nice and round, but it's collapsed due to the loss of the cartilage structure that is present, and essentially we're seeing that that area is collapsed as a result.

And there's some nice papers and reviews looking at this, so Luca Ferrison and Chris Lindley wrote this JSA review few years back now. But, essentially just reviewing all of that evidence. So coughing isn't really a sign of congestive heart failure.

Usually they will have animals that have concurrent airway disease that's the cause of the cough. So now we've talked about where the cough might be coming from, what the disease processes are, and what the coughing reflexes. We're going to think about how we approach the patient.

And when we approach the patient, we take a fairly logical approach. We'll define what the problem is, we'll try to define where the location is, and once we've defined where the location of the cough is, we'll consider what the differential diagnosis might be, for that individual patient. And it's really important whenever we're looking at a patient that we take a really clear history, and lots of time, you can get lots of clues from the history.

And we spend a lot of time in referral practise just listening to owners and helps us build a relationship with them and and just make sure we've got all of the detail. Lot of what they say isn't potentially useful, but there are lots of little nuggets sometimes that just help you to build the picture. And if you can build that picture that helps to explain and understand exactly what's happening, you're going to go in a much clearer.

A direction when you're going down your diagnostic pathway, rather than just kind of saying, yeah, the dog coughing, yes, it's coughing, and then you think you understand what the problem is, but it might not be exactly what the owner is describing. So, clarifying and really understanding what's going on, it's really helpful in these cases where, maybe not for the acute cases, but in cases where it's been going on for a while, or you've tried a few things that hasn't worked, really going back and trying to understand exactly what's going on is really important. So obviously you need all the background information, the environmental information, where the dog lives, what's happened, any previous problems, all of those sorts of things.

The presenting problems, so what is actually going on and the owner's main concern, as we said before, that may not, that may not be directly related to the animal. They may say maybe I don't have a good night's sleep, or I can't go for a decent walk with my dog because it's got airway disease and that's causing a problem. I'm really trying to understand what they want to achieve in terms of the treatment because you may, you know, do a fantastic job, understand what the problem is, but not fix their problem.

As well as what's going on with the animal, and that's really important when we think about veterinary medicines to balance those two things up. Obviously, we're not going to act irresponsibly when we reducing the doctor but we need to have everyone on board to get to where we want to be. And then think about systemic systems and make sure that we've reviewed all the body systems to localise the problems, so respiratory disease versus heart disease and really try and make sure we've understood that as much as possible.

So this history will allow us to define what the problem is. It helps us to understand where the location is, and then we can start to go through in terms of trying to, to problem solve and, and make it a plan in terms of how we might try and obtain a diagnosis. So what sort of clues can we have?

Well, from the background and the environmental history, obviously we need to know about previous history, in contact animals, vaccinations, worming, travel, diet, all of that sort of thing can be, can be useful. If they're in contact sort of coughing, that could be useful when we're thinking about things like kennel cough. Infectious trachea bronchitis, and whether they've been in contact with animals, if the animal is vaccinated with both borderella vaccines and parainfluenza, for example, it's going to make that a little bit less less likely.

Are they wormed on a regular basis? Is parasitic disease part of your differential list and those sorts of things. And then the current problem is really key to define that.

And now, most people have a mobile phone in their pocket with a really good video. That's a really good way of understanding what's going on. And sometimes, before we do any investigations, we will just say to the owners, Well, I need to see what your dog is doing, because I don't know where to look, and I don't know what tests we'll need to do as a result of that.

So just getting them to video 20 or 30 seconds of what's happening can be really helpful to understand exactly what is going on. And that's really useful and when we're trying to understand, is this a reverse sneeze, is this a cough? There's sort of gagging, what exactly is going on with the animal, because the words that the owners are using aren't necessarily the words that you would truly understand as the technical, explanation for what the dog is doing.

So having a video and understanding what's going on can be, can be, you know, absolutely, game-changing in terms of, of how we go forward. And, and it's, it's often the sort of, adding that a picture is worth 1000 words, but with a video, it's, it's very similar. It can be really time-saving and, and really make sure we go in the right direction.

So you need to understand what the problem is, how long it's been there, whether it's progressed, what makes it worse, what makes it better, whether there's been any response to treatments before, all of those sorts of things help you to build a picture of understanding, has it been antibiotic responsive, has it been steroid responsive, is it responsive to rest, when does the cough occur? All of those sorts of things help you to understand what might be going on with the outrageous disease. So loads of clues that you can get from taking out a decent history.

The coughing will probably be noticed more at night, regardless of the cause, exactly, exactly as we said at the beginning. And most courses of coughing are worse when the dog wakes up because there will be that irritation, that movement of material, and the dog is gonna expatriate and bring up that material as soon as it starts to move around. So there's a few cues that kind of help you to to understand a little bit and some questions that we want to try and ask and to understand.

So, is the dog, coughing? Is it well or is it sick? So understanding whether the animal has a cough and is just, just fine and is moving around all right and isn't having a problem, or is the animal unwell as a result of that, and really, you know, off colour as a result, because if the animal is sick, obviously it's going to be more proactive.

That most of the self-limiting causes of coughing, so they can be infectious things, you know, trachea bronchitis, thinking about parasitic infections are not going to be the animal sick. Because if the animal is sick, it generally sort of unlights that there might be more of a systemic problem, so bronchi pneumonia or some kind of infection that's causing an issue that we will want to be more proactive about investigating and symptomatic treatment probably isn't appropriate in those in those patients. To know whether there's been contact with other dogs, and whether those animals have been coughing in that regard in terms of understanding whether that's something that we will want to try and investigate.

So if there's a, you know, the animal's been into kennels recently, and the animals come back with a cough, then know, Sherlock Holmes isn't needed to understand that. Kennel cough might be the most likely of those differentials, especially if the animal is well, has positive pinch, all sorts of things we associate with that. The animal lives on its own, it's never in contact with other animals, for example, then maybe that's less likely on that basis.

So that helps us to sort of build a picture of exactly what's going on. And with foreign bodies, we will often see that they're sort of acute in onset, and that can be really helpful. And just to talk a little bit about kennel cough, canine infectious, tracheal bronchitis is this kind of group of of diseases where we have a mixture of bacterial and and viral triggers.

And usually it's a fairly self-limiting disease, and it's, it's more of a frustration, as coughs are with ourselves and their sort of serious medical illnesses, but, usually that sort of dry, harsh hacking cough tends to be paroxysmal, so we have bouts of coughing, occasionally it can be productive, often with water tolerances, it's associated with ocular and nasal discharge to some degree as well. We have lots of different agents that feed into that. So, parainfluenza, can anovirus, so both 1 and 2 can do that.

It's associated with inflammatory changes and herpes viruses can also be present as well, which cause problems. And Boatello is is quite tricky because it can survive for quite a while in the environment, which makes it quite difficult to get rid of, which is why it's a problem within kennels. Bordella lives on the surface of the flageidity in the airways, so it's also quite difficult for the immune system to get rid of as well, which is why it's difficult.

It produces these toxins that cause paralyzation of those hagei, so it makes it difficult for mucus clearance, damages the endothelium. As a result of that, we get secondary infections, mucus becomes static. It isn't clear in the airway and where we would expect to get secondary infections within that mucus layer that then causes problems.

So we need to be aware of that and understand that that is a potential problem when we see these animals, but most of the time they get better on their own, occasionally we'll treat with antibiotics if we are worried that there's underlying disease. So for example, the animal is elderly or immunosuppressive disease, has neoplasia and is on chemotherapy, all of those sorts of things will feed into decisions about using antibiotics, but it's really key that we try Not to, because there is a developing problem with resistance with border teller to lots of antibiotics. So when we, when we will use it, we want to try and use things like doxycycline, because there is a growing comoxi and TPMS resistance problem.

So doxycycline would be the treatment of choice, and they do tend to try and do cultural sensitivity for teller, whereas historically we we perhaps wouldn't have done that. So there's kind of 30 to 40% of ice that's have a reasonable degree of resistance, which is a little bit of a concern. Then the respiratory parasites, there's quite a few, so the, the worms that we see within the airway, so this is bronchoscopy of capillary aerophilia, this little wiggly worm that is present, sort of snakelike that is moving, blossus oslori and chrorisom of olpeorum, all airway infections that will cause irritation and will cause problems.

All of them. Responsive to most of the commercially available and antiparysticides, so from Beazole, for example, all of the sort of topical ones that that we, well, there's various topical ones that in terms of application that will cover this. So there's quite a number of products that will have quite broad parasitic control, which would be appropriate for use for for lung wormodectin and thinking about milkycin will have quite broad cover for these parasitic diseases.

So those are the sort of infectious causes. I jumped ahead a little bit and start talking about airway thrombodies, and airway foreign bodies usually have this really acute type onset, and we showed the airway foreign body in the beginning that have been stuck in the bronchus. This is usually associated with acute onset during exercise, the animals come leaping through a field of barley or corn field or growing.

Feel has come back coughing, usually that coughing is, is immediate in onset, so it's quite profound when it starts off. Generally then gets better over time. So over a few days, it tends to resolve.

But then as the foreign body starts to disintegrate and break down, it's often then associated with halitosis, so we have a horrible pungent smell as a result of that decomposition. And that sort of gradually gets worse. So these are often sort of active breeds that are doing a lot and, and, and really involved in terms of exercise.

Those usually have to be removed because they're not going to be able to be coughed out of the airway. So essentially you're thinking about bronchoscopy to, to go in and grab them, and take them out and and remove them. You can see that there is some suspicions a foreign body on, on X-rays, and then be able to go down to the.

A way to remove it. So this is just the bronchial foreign body, so that same wheat just within the right mainstem bronchi. I gonna go in with our endoscope so we can retrieve it, and you can see it's here, and then we've got sort of irritation around that area where we've got sort of an alveolar pattern as a result of bacteria moving down into the area bronchialmonia associated with it, and we can go ahead and grasp it and remove it.

And often we will see that things are pretty, pretty horrible after we've done that. So there's often a lot of sort of airway inflammation, possibly a little bit of bronchiectasis, where the airway has become a little bit more dilated around where the foreign body was. But generally, they resolve quite well.

We usually would treat them with antibiotics for 5 to 7 days, for example, and usually you'll find that there's really good recovery as a result of that. Some of these really chronic ones that can be more difficult if they've been in place for a while, we will see that there's more dilation, so more bronchiectasis, that can be a focus for infection, that can be more tricky in the longer term. If they can't be removed endoscopically because they're really well wedged, or if they're too deep within the airway, then surgery would be something that would be considered.

It's quite unusual with the endoscopes we have now and the ability to remove things that that would be the case. Often the problem is when things are quite fresh, so if the er of wheat has gone in. Often it's quite stiff and at that stage it's quite difficult to remove, and it's horrible as it may sound, often leaving those for a couple of days to to kind of decompose a little bit and become softer, makes them easier to remove.

So if you can't remove it on the first occasion, make the animal more comfortable, treat with antibiotics to make sure we're not seeing signs of bronchial pneumonia, but going back a couple of days later, often it is possible to remove it at that stage where it hadn't been initially, so it's obviously not so nice for the patient, but it then means that they don't have to have a surgical intervention to try and remove it at that stage. We need to think about what the exercise tolerance is like, and there's obviously different things that feed into that. If there's airway obstruction that's going to affect air exercise tolerance.

Is that cardiac failure, so is it more of a perfusion problem rather than a respiratory problem. There's a ventilator problem. So is there interstitial fibrosis?

Is there a difference in in in ventilatory function because we can't get oxygen to diffuse through the alveolar wall could expect. So there are lots of different components to that. And from our clinical exam that will come on to in a second, it helps us to understand which part of that might be the case.

Is the cough, loud and harsh or soft and wet? Is the cough worse with excitement? All of this sort of thing can be really helpful when we're thinking about the sort of cough that might be present, is the kind of Classic goose walking cough that we see with collapse.

So that kind of non-productive irritative cough is is quite common in those sorts of circumstances, and that's sort of cough that will associate with the airway instability that we see with cattrial caps. So that, sort of goose honking cough will be really common in that sort of circumstance. In bronchial pneumonia, when we've got a really effusive or or sort of fluidy component, then that's going to be a much sort of softer, wetter cough, and we're going to see that there's potentially production as a result of that.

Is there any problem with eating and drinking? So is there a cough or spluttering that's present associated with that? So dysphagia will be a, a common cause of aspiration.

You can see in the aspiration pneumonia with a very ventral alveolar pattern and, and really clear bronchanneograms as a result of that. So dysphagia will potentially trigger that off if you've got micro oesophagus, for example, which is present in the story, you see the esophageal outline, sorry, it's not gonna project very well, that's the ventral border just here, the dorsal border is just up here. So there is esophageal distention, and you're going to get aspiration as a result of that.

You'll also see that with new problem. With deculousination in terms of actual formation of bones in the mouse and that that swallowing motion causes problems. So al dysphagia, where we have problems with the pharyngeal muscles that affect swallowing in in young dogs, and that's going to cause problems, and will cause aspiration mania.

Is there any change in the barks? Is the dysphonia, often that will happen with laryngeal paralysis, Labradors that have a horse bark over time and then stop barking, and that, that will be a key clue potentially that we have laryngeal paralysis that might be causing a problem. And is there any noise during exercise?

Essentially what's happening to the airway itself during the dynamic phases of exercise. So is the trachea collapsing, the larynx collapsing, is that causing a problem? So this is a dog that has laryngeal collapse.

And, and you can see that the light is becoming really quite narrow as a result of that the sacculs at the bottom are very, very large and they're causing obstruction, but that airway noise is, is really suggesting that someone is having a problem breathing air in and out. It's gonna suggest that we have an Apple airway type problem. So really key to trying to understand things when we're thinking about coughing is defining the problem, and we have a huge number of potential problems that can affect the airway.

So those problems that affect the upper part of the airways, so the nose, the pharynx, the larynx, affecting the upper part of the airway through to those diseases that affect. The lower airways and the pranky more spaces and the plural spaces. We'll see different signs as a result of that.

We'll investigate all of those things in different ways. So we're going to focus mostly on coughing, but when we're thinking about respiratory problems and and how cough might fit in with that, we often see associated signs, and it's really useful to run to understand exactly what that is and making sure that we understand exactly what we're going to diagnose is going to take us in the right direction. So hopefully now we've got a good idea as to what the problem is.

We've taken some history and we understand how long that problem has been present and where it is, and we need to then think about looking at our patient before we go down the diagnostic pathway of doing some tests. And different people do clinical exams in different ways. It doesn't really matter, but we're gonna focus really on the respiratory tract when we're thinking about coughing.

So we're gonna want to look at mucous membrane colour, assess its ventilator function looks OK. So the colour should be good, we should have nice pink mucous membranes. This shouldn't look horribly cyanosed.

This dog in this picture, cyanosis is a sign of hypoxia. You need about 5 to 6 grammes per deciliter of unoxygenated blood to see cyanosis. So that's about half the normal haemoglobin in a normal animal.

So you need quite marked hypo hypoxia to see that. So if we see cyanosis, you need to be really proactive about how we manage it. And if we're worried about hypoxia, we don't wait to see cyanosis before we're proactive in terms of understanding how we try to, to treat those disease processes.

And then we think about looking at the respiratory patterns, so how the animal is breathing. So it's their inspiratory effort, it's their expiratory effort, which phase of breathing is causing a problem. And we'll we'll look at that a little bit later with some videos and some understanding of of what phase might be causing a problem.

And then we'll listen to the chest, and we'll listen to the lungs to hear whether we've got normal noises. We should hear normal sort of. With icular sounds as the animal breathes in and out.

They should sound like rustling of leaves as backwards and forwards, which should be very quiet. We should see them in all four quadrants of the lung on both sides, so top and bottom front and back on both sides. But then we have abnormal noises, and there's a huge number of abnormal noises that were reported, and we could talk about individual ones, but in terms of of the kind of Common ones, they either break down into wheezes or crackles.

Wheezes are caused by the arrow being narrower than we'd expect. So thinking about things like asthma or bronchitis, whereas crackles are caused by the alveolar snapping open and closed and would be caused by the lung being wetter than we would expect. So those are the things we see with alveolar, fluids, so pulmary edoema with bronchial pneumonia that cause that fluid to accumulate.

Percussion's really useful if we're thinking about pleural space disease, where we've got fluid or we might have air which is present within the pleural space which is compressing the lung, which is going to then cause problems with the way that that lung is going to be able to be ventilated. Percussion is going to help us to understand whether the resonance has changed. So if you've got more air there, it's gonna sound hyper resonant.

If it's got fluid or there's consolidation of the lung, it's going to be very dull. So it's a bit like sort of knocking on a hollow box. It's going to sound very resonant if there's air there, and it will sound quite dull, so it's like a Full box if you, if you haven't got sort of aerated lung or if you've got fluid that's present in the plural space.

And then listening to the heart's really important. So do we have a murmur, what the rate is, what the rhythm is, we're all going to give us good clues as to what might be causing a problem. So that auscultation is, is really key and really important to what's going on.

So the respiratory pattern in a normal animal is usually between sort of 10 to 30 breaths per minute. You panting, it's gonna be a bit higher, and obviously we need to differentiate between panting and tipa and in the sense that panting is a normal physiological response to stress or exercise to cool down, dissipate heat, can also be something we see in nervous patients where To get obviously is essentially trying to to get more oxygen and it's usually associated with more effort as well. In the normal animal, we should see that that respiratory pattern is fairly even between inspiration and expiration, and they'll often be an expiratory pause.

So, you breathe in, breathe out, there's a pause and then you breathe in, breathe out again. So there's often a pause between that. And usually the rib cage comes out and slightly goes forward during inspiration, and then expiration is just passive as everything relaxes, and the chest will will empty as a result of that.

If we have abnormal respiratory patterns, they tend to break into two groups. We have slow and forceful breathing, and we have rapid and shallow breathing. Slow certain forceful breathing is the forceful bit might suggest, is usually obstructive, and usually that's either because we have an inspiratory problem, which is usually obstruction of the upper part of the airway.

So problem with the larynx or the trachea, which is making it difficult to get air in, or we have obstruction which is an expiratory dys which means it's hard to breathe. Out, and this is usually a problem with the compliance of the chest. So pranki based diseases making it difficult for air to be moved out of the chest.

So what we see with pulary edoema, with problems with haemorrhage within the lungs, so problems with bronch pneumonia that make that restriction and change much more difficult. And then rapid and shallow breathing is usually where we see problems where we have a restrictive issue. Usually that's pleural space disease, for example, the lung can't expand as much as we would expect or if there's fibrosis.

So it's just choppy, so essentially we're seeing there's more effort involved as a result of that, or paradoxical breathing, where the phase of breathing has changed, as a result of the respiratory muscles becoming very tired. So this is an example of obstructive inspiratory dysia where we have narrowing of the large airways or the larynx. This is sort of has laryngeal paralysis.

It's gonna have a stor associated with so start to associated with that which is a noise associated with trying to get air through the upper airway, essentially you can have a narrow larynx, and an inspiratory effort that's going to increase as a result of that and really characteristic noise associated with. Yeah. I It's really obvious that dog can't breathe very well, and that that's an upper airway-based problem.

It's it's finding it very difficult to breathe air in, but it can breathe air out. So the larynx is getting sucked into the air, which is causing it to narrow as it breathes in, and then as it breathes out, those kind of curtains that that are the larynx open allow the air to move more normally. Obstru exspiratory dysmear, as we said, it's caused by problems within the rancua itself.

And this is a dog that has bruising within the lung. So this is pulmonary contusions. So there's bruising because of an RTA.

The dog's obviously got a nasal oxygen catheter in here and it's making an expiratory effort, so it can breathe in quite nicely. The air is getting in quite well, but it's much more effort. It's much more forceful to move that air out of the chest, so it's more difficult for that to happen.

And then the restrictive pattern is what we see with pro pleural effusions or with the fibrosis, that kind of very rapid restricted movement backwards and forwards, and that very choppy pattern that we see here, it's very suggestive that we have plural space disease if we were to auscultate, probably hear that there's a resonance change as a result of that and potentially then want to do point of care ultrasound or potentially tap some fluid from the chest, which would help us to understand what's going on. And then lastly, there's paradoxical breathing, which isn't really helping us to localise where the problem is, but it helps us to understand if there is hypoxia and that this has been present for a period of time. So normally as we have normal movement, as you said, the chest expands, the diaphragm moves back, so the abdomen will fill as the animal breathes in, and then as we breathe out, everything relaxes.

But here what we've got is paradoxical breathing, so as the. Chest expands, what's happening is the diaphragm gets sucked into the chest. The diaphragm is getting sucked into the chest because it's a weaker muscle in comparison with the intercostal muscles.

So you can kind of see when we look at the phase of breathing there, that it looks a little bit abnormal. So as the chest expands, the diaphragm is getting sucked into the, into the chest. So it's it's the wrong way around.

It takes a little bit of time to Actually sort of get your head around what's occurring. But actually what this suggests is there's been prolonged dyspnea, and as a result of that, we've got since you tiredness of the respiratory muscles, therefore, we're seeing that always using just its intercostal muscles to breathe, and it's not being able to expand its chest as much as we would expect, which obviously going to be making the hypoxia worse as a result of that. So those are the sort of patterns of breathing that are helpful, and then we're going to think about auscultation to to listen to the chest itself and to try and hear those normal vesicular sounds that we talked about.

So the front and the back, the top and the bottom of the chest on both sides, and often we'll listen then over the Shakira as well. So in the front of the chest, so we can hear if there's any serter or stridorous noises from the upper alley, they're going to be much more obvious in those areas. So those are the sort of normal noises that we would hear.

We've also talked about sort of crackles and wheezes. People call them all different things. The crackles are often called ras and and wheez are called wrongky, but there are also for other descriptions as well.

So those crackles are those alveoli opening and closing, wheezes in the airways becoming constricted and us having narrowing and restriction of airflow through the lower airways as well. And then listening to the heart sounds is really important, and cardiac auscultation, you could do a whole couple of lectures thinking about that, but listening for normal noises, so you've got the lub dub sounds that you'd normally expect, as we have with every heartbeat in terms of the cardiac valves opening and closing, but then the abnormal noises. So is there an additional heart sound that's causing a murmur?

Is there blurring of those heart sounds? Does there appear to be a murmur that that might be causing a problem? So when we're thinking about listening to the heart, the first thing we usually do is think about the, the rhythm that's present.

So listening for a while, is important, and listening to see whether we have a sinus arrhythmia is really important. And the sinus arrhythmia is normal. Essentially, we have a, a decrease in vagal tone and inspiration, which increases the heart rate, and then an increase in vagal tone during expiration so the rate should go down.

So this kind of wandering heart rate that goes up and down during respiration, so, going up in rate during inspiration and down in rate during expiration, could be really helpful to understand that there is actually normal cardiac cycle, and that's really helpful to understand that there's good cardiac health actually having Sinus arrhythmia, sort of excludes the dog from being congestive heart failure. There isn't that vagal reaction that's asking the heart to do more work to maintain perfusion. So having a sinus arrhythmia essentially excludes that the, the heart is having a problem that would be potentially the cause of, of the cough that's present in the patient.

So, really listening to that and, and making sure that we, we know, understand what the rhythm is, and if we hear a sinus arrhythmia, then we can be really happy that the animal isn't in congestive heart failure that's causing a problem. And they're listening to murmurs, how we describe them is really important. We grade them 1 to 6 in terms of the intensity of the murmur that we hear, and we grade them according to the, the S1 sound, which is, the, the, the, usually associated with the QRS type complex.

And in that respect, you know, we can listen hear a noise, localise them to the side of the heart, try and associate them with which valve they might be associated with left on the left, on the right, cranially or cordially. Associated with different valves that might be present in most occasions, whether we have a thrill that is palpable, whether we can hear with the stethoscope just off the chest in that regard, we will have differences in that regard, which will help us to understand and know exactly what's happening and whether we have a murmur that we can help to quantify and then grade that. So if it's grade 1 at the moment and then grade 2, grade 3, grade 4, we have progression of the disease process, and that helps us know when we might want to intervene and do further investigations.

So hopefully now we can define where the where the disease process is, we can define the location. Is this upper respiratory, is this lower respiratory, or is this space disease or is there something else going on? We've got cardiac disease or have we got multiple areas that might be causing a problem?

And we can think about how we might try to, to investigate and then go forward in terms of trying to understand how we might want to to approach the dog. So it's symptomatic, so with self-limiting disease, so with those acute coughing cases, a young dog that is well, then we'll probably try to, to treat them supportively. So we might treat with some antiussives, we might get some anti-inflammatories, we might get some anti-parasitic medication and watch and wait is sent to you and see if the animal gets better.

But if it's not getting better, or if the animal is unwell, so it's pyorexic, it's lethargic, it's got respiratory issues in the sense that it's a neck or it's dyspne, then we're gonna want to try and investigate a little bit further and really try and understand what the cause of the problem is, so we can address it, proactively and also specifically to understand what the cause of the problem is. So in these instances, the key differentials would be things like foreign bodies, chronic bronchitis, which by its nature is going to be chronic, so more than 4 weeks in duration. Bronchopneumonia, so a deeper seated infection within the lower airways, is sinophilic bronchi neuropathy or EPP, parasites, that list that we were talking through, those can mimic chronic bronchitis, it's really important that we consider that and we treat them if we do have a chronic persistent cough.

And then infectious trachea bronchitis, that can sometimes lead to something we call tracheobronchial syndrome in the sense of, if you've got an infectious cough that triggers the cough, then signs improve, but there's an airway sensitivity that stays for a number of weeks, sometimes months, and that can be quite irritative, and that often will settle with steroids over time. And then things like bronchialacia causing tracheal or bronchial collapse that sort of affect airway stability, and that can really make More difficult then to decide what the right forward is. So we then have to decide, in these instances, do we make a decision to symptomatically treat or do we make a diagnostic investigation?

Because sometimes those diagnostic tests don't necessarily change how we would treat things. And if we have a Yorkshire terrier that's had a long standing goose honking cough, and it's getting a little bit worse, and a bit irritative, it would be reasonable to assume that that was to kill cops and treated as soon as the dog gets well. Whereas if that dog was pyrexic, there was, it was struggling to breathe and it's exercise to was an issue, and we definitely want to think about diagnostic evaluation, but there are lots of things that feed into that in terms of owner inclination, finances, the other comorbidities that the animal might have in terms of the safety of doing some of those investigations.

So trying to balance those things up is sometimes difficult to work out what the right way forward is, and what the, the right decision for the dog and for the owner might be in those sorts of situations. So how do we approach what diagnostic tests we might want to do in these instances? Well, the tests that we have would be to think about doing diagnostic imaging, so radiographs of the chest, to look and see what pattern might be present, and look and see what's happening with the airway itself, to directly visualise what's going on with the airways, so to look at the larynx, to look at the, the soft palate, to go down into the airway itself with endoscopy, so we can go into the trachea, go down to the bifurcation, look to the left and right side and see what's happening.

But usually we would combine visual inspection with taking some samples. It's really hard sometimes unless there's structural change, so if there's collapse, or there's a mass or there's a foreign body to understand what the cause of inflammation is. So thing just looks a little bit hyperemic or there's excessive amounts of mucus, sampling that, so doing bronchialveolars is really important to understand that.

We don't have to do bronchos to be able to do it, but having a bronchoscope means you will get better. Be samples, because you can wedge your scope, flood the alveolar space with fluid and then collect that with suction. But you don't have to do that.

You can use a urinary catheter through the down as far as it will go. Usually we use for a reasonable sized dog, so if it's over 10 kg, probably using 10 mLs as as a total dose, if it's less than that, maybe 5 mLs for bigger dogs, so 30 kg, maybe 20 mLs would be fine as well. And you put the fluid in, to pass the chest, so you're And to sort of tap on both sides quite forcefully to agitate the fluid and then using suction to get that material back.

Using a wash trap like it's it's documented here, it's really helpful in terms of trying to make that a much more rewarding yield, because if you're just trying to suction back with the syringe, for example, it can be really tricky to do that. So having active suction being proactive in how you're containing that sample, it's really helpful in understanding what that material might be and what the cause of that inflammation is. So radiographs are usually the starting point for airway investigations.

Sometimes we will think about CT, but I think radiographs give us a lot of information, and usually good enough to understand what's going on in most circumstances where we have inflammatory airway disease. If we're thinking about neoplastic disease or plural space disease, then CT will be more useful because you lose some of the three dimensional information you can get from radiographs if there's a material obscuring what's happening in the chest. So we've tried to do this under general anaesthesia, so we'd often combine that with sampling.

So we will do that at the same time that we're doing our our bronchoscopy and we're, we're doing our BAL samples, but they allow us to assess the lung path and they allow us to look at the cardiac silhouette, they allow us to do vers heart scores, assess the vessels, all of those sorts of things are really key to understanding what might be happening with the patient. So radiographs are usually my starting point for a chronic cough. I usually go for a CT scan, unless we were concerned that it was underlying the plasia, or we've taken some radiographs and there's something, you know, a bit weird that doesn't look quite right.

And we can't define whether an alveolar area is, you know, actually a mass or not and in that instance of CT scans would be helpful, but CT scans are expensive things to do, and they require contrast, which is a little bit of a risk in terms of that to the patient and can often get the information we have from well positioned, well inflated chest ratedgrass. And I guess that's the key. They have to be good rated grass.

If they're not good rated grass, and I'm sure we've all seen, maybe some of the, the radiographs that are taken, if, if the animal isn't sedated, if it's not in the right position, it's got legs overlying the chest or it's rotated, it can be really difficult to actually interpret those images. So they have to be good to be able to understand what's going on. And then we would always take the lateral radiograph, and there are, there are breed differences that we need to be aware of.

Obviously, lurch's chests are going to be deeper, compared with more barrel chested bulldogs or, you know, springertis. So the heart sort of shape and size is gonna look different in those animals. So understanding what normal chests looks like is really important.

So with digital radiography, obviously we have a little bit more definition of things. These are normal radiographs that we've shown in the last two slides, and you will see a little bit more edge, depending on what . sort of settings you've got the machine set to, so it's sort of attempting to overinterpret these images a little bit in that regard.

But, yeah, sort of understanding what is normal is always the key to understanding where you are with abnormal results. So thoracic radiographs would be my starting point. If we're concerned at all about the cardiac silhouette, then echocardiography would be the next step.

And also sound can tell us lots about what's happening with the heart. You don't have to be a cardiologist to be able to do an echo that is useful. Through your patient.

Essentially, when you're doing any diagnostic test, and also, I guess is is key to that is is really trying to understand what the question you're trying to answer is. So with ultrasound, is there plural fluid, is that air that's present in the ural space? We can answer that question with echocardiography.

Is that pericardial effusion again, we can answer that question with echocardiography. Is there evidence of congestive change, then yes, we can look at that and we can look at any evidence of the aortic to FH. Dimension changing and that ratio between the aorta, so this is theorta here with that sort of classic Mercedes Benz sign, against the dimension and diameter of the left atrium is really helpful.

It should be less than 1.6 in a dog, slightly lower than a cat, so less than 1.4.

And we can look at the function and make sure we're happy that the function is OK and that there is contractility and that the heart is beating away, but we don't have dilated cardiomyopathy as we have here. And if we're good at ultrasound and we can look at the valves, and we can interrogate. The valvular function, then we can understand what the cause of the murmur is.

But it's sort of very easy, very straightforward way. We're just using ultrasound to collect that information. Is there pleural effusion?

Is that pericardar fusion? Is there any evidence of congestive failure if we're concerned about that? And there's a lot of information that we can get just with a few really straightforward views I'm doing cardio and again, a little bit outside of what we can talk about this evening, but there's lots of really useful information that we can have, just by getting those views and looking at those few images.

If we don't have that, then people often will look at cardiac biomarkers, and cardiac biomarkers are difficult because people kind of use them as the, the panacea to give us an answer as to, is there a cardiac disease or is there a respiratory disease, and they can be really useful pro pro BMP, anti-ro BMP, and it's released from cardiac muscles. So if we've got volume overload, hypoxia or this hypertrophy, then it will be increased, and it is a nice screening test to differentiate between cardiac and respiratory disease and snap tests are available in practise will help us to do that. But it's not definitive.

We can see that it's increased by other factors, so anaemia, renal disease, other systemic inflammatory diseases, so other inflammatory respiratory diseases sometimes can increase that as well. So it needs to be interpreted in conjunction with other tests. So we don't tend to use anti pro BMP very much because we're using more definitive diagnostic tests.

But if you, if you've got that and you're happy with using it, then it's, it's very helpful in some instances where we're not sure whether we have cardiac or respiratory disease. So I'm not not saying it's not useful. But usually it needs to be used alongside something.

And if you have the confidence to interpret what you're doing alongside that very well, often the pro the BNT isn't that useful in terms of, of making a diagnosis with good radiographs, good echo, good understanding of your clinical exam information, then often the pro BMP isn't that helpful in terms of making a decision, but, it, it is, in some instances helpful if you, if you haven't got those tests available or you're not able to take radiographs or do more investigations, then it will be useful adjunct to that investigative process. Talked about CT, CT is obviously great. It gives us three dimensional images of the chest, allow us to really understand what's going on.

So it's just some quick images of a bronchial thrombody, but we can understand where we have masses, we can understand whether we have plural space disease, we can understand if there's any evidence of tumours or growth that are present within the lung, and using contrast in various ways, we can look at the lymphatics, we can look at the. Vessels, we can understand really the true anatomy that is going on in the chest. So that three dimensional structure that we'll see from from CT is really useful in terms of understanding what exactly what's going on.

With chronic cough, we will really only use it if we're concerned about underlying neoplasia, where as I said, if the radiograph suggests an area that we need to look at in more detail, we can't see that because there's plural space disease that's causing a problem. And then lastly, bronchoscopy is, it's really useful to actually visualise and look down into the airways, so it allows us to assess the nasopharynx at the top, it allows us to look at the dynamic change to whether we've got any collapses present. If we have got foreign bodies we can remove them, and it allows us to more effectively collect bronchial alveolus, the var samples.

So we can look down into the airway assess the structure. So at the top here we have tracheal collapse. You can see what the trachea.

It is flattened and the dorsal membrane at the top of the screen is is moving at the bottom of the screen, we've got bronchial collapse where you can see that the bronchi itself should be a nice round circle, and that's also collapsing as a result of that. So we're seeing that there is a structure labmaty with the strength of the bronchus is lost, and we're seeing that the airway is collapsing and reduced airflow through that as a result of the sensitivity that's present. So these are the sort of investigative tests that we would do, and just finishing off in the last 5 minutes, I just want to talk about, you know, a couple of potential causes of chronic cough and been outside of being able to talk about all of the differentials and and thinking about things like to kill labs and some of the other things we managing in slightly separate ways and there's more information that's available both in different Webinars.

But chronic bronchitis would be inflammatory disease that we see in dogs, and mainly dogs as they're a little bit older. It's caused by chronic airway inflammation, and usually that airway inflammation leads to, to, to mucus, hypersecretion. And with chronic bronchitis, we'll see that occur over the course of usually 4 weeks is the minimum we'll make for a diagnosis, but we'll often see that over 2.

Months, a year, really long process where it becomes a really quite a chronic and an ongoing process. Because of the excessive amounts of mucus, we see that there's reduced functional clearance of that, mucus that mucci escalator becomes a problem. We see that a secondary infection as a result of that, so materials becomes static, and we see inflammation and bacterial infection within that.

And most of these dogs will cough, that they'll gag, they'll have dry retching, we'll see signs of bronchial inflammation. So on our reindeer graphs, we'll see a bronchial pattern. So here we've got doughnuts and tramlines, sort of indicating that we've got really sort of obvious margination of the airway itself, which is causing a problem.

And to make a diagnosis, we're going to want to do some endoscopy to to look down to the airway itself so we can visually. The airway, looking for signs of inflammation. So this is the trachea, this is the dorsal membrane, so the pitch is the wrong way up, but we've got a very bumpy appearance to it, and the wall looks bumpy.

There's some mucus here. It looks quite hyperremic. So this would suggest that we have inflammatory change that is present.

Want to exclude that there's other disease, so we wanted to make sure we've got rid of parasitic things, and we'll look with washes to look to see if we've got a larvae. That are present, looking at 3 day pool faecal samples with paracytology to make sure that it's not allow for excretion, and a trial treatment with famendazole or appropriate product to make sure we've treated for parasitic disease, that would be really helpful. But if there's no response, and we've not found any evidence of bacterial disease, and we're often going to be thinking about immunosuppression to try and damp down that inflammation and overcome that.

And it's really important when we're thinking about chronic bronchitis that we understand that this is a chronic problem. It's not gonna be something that gets better. So this is managed, not cured, and that's kind of the mantra of medicine most of the time that we're, that we're not like the surgeons, we can't go in and make a big difference and fix something.

So often we're trying to manage something to try and improve it over time. So managing the weight control is important. Often nebulization will be helpful to make that mucus a little bit less thick, so it's easier to be brought up.

Bronchodiassis can be useful to improve airflow. And then steroids are really helpful to reduce the degree of inflammation that's there, and often we'll use them orally to start with, and then taper them to the lowest dose that controls the clinical signs. A lot of people like using inhaled steroids.

It depends a bit on the dog as to whether they'll tolerate it or not. If they'll tolerate all steroids and so they don't get cushing side effects as a result of that, we usually stay with the oral steroids, and not move to an He steroids, but some owners will like them, and there are some dogs that will do better because you can get higher airway doses with, you know, fluticasone inhalers, for example, Becamethasone, into the airway to, to, to really increase the concentrations, and that will help to reduce the airway irritation when you're thinking about breaking that cough cycle by reducing the inflammation, desensitising the cough receptors, often that will work quite well. The opposite of that, I guess, is where we have bron bronchopneumonia, where we have an infectious cause.

And usually this will be upper GI or or gastrointestinal in origin essentially sort of aspiration of material because the upper respiratory tract is incompetent, so the larynx isn't working, for example, or we've got micro oesophagus where we have regurgitation, and then the larynx is sort of flooded with material. So that's aspiration. Secondary infection of the majority of fairly normal GI commensals, so things like Paella, E.

Coli, but there will also be, you know, anaerobes and other potential causes as well. We can see viral causes, proceal causes, and pneumocystis, which is common in cavalaking our spaniels, because they have a defective IGE immune system, which can cause problems. And this is an infectious cause.

It's going to cause infection within the alveolar space. So our treatment is going to be based around antibacterial infections. So where possible, we'll try to base that on culture sensitivity.

If we don't know if we're treating these we're pending cultural sensitivity results, then potentially tamoxicillin is usually our starting point. So sort of following from the protectomy BSAVA guidelines on what would be good options. This is based on some of the SCAD work as well and.

Antimicrobial choices in that in that sort of setting. If the animal hasn't responded to that, then a flower only clindamycin would be, would be reasonable, being more aggressive, and thora, that's now the recommendation because of resistance to some of the bugs, so, act y is to, for example, we tend to to use a flu tender mice in those instances, and generally the recommendation. To treat for reasonably long periods of time.

There's some discussion about that as to whether that's the right way forward. Usually, we would treat these to radiographic cure or to where we get to the C reactive protein being normal, treat for a few days beyond that. So usually 7 to 10 days beyond that.

So often we're treating for 4 to 6 weeks historically, more recently, perhaps we've been treating for a little less time than that, but it makes us a bit nervous, I guess, to treat for maybe 2 to 4 weeks and and Or longer in human medicine, you have very short courses, so maybe 5 to 7 days of antibiotics and, and not longer courses, because it has been linked to to problems with recolonization of the airway, which isn't sterile in the first instance. And then all the other things that are helpful when we're trying to move mucus, so nebulization, cappa, hydration, analgesia, because coughing can be quite uncomfortable, opioids and, and non-steroidals as well can be, can be very helpful. And when we're thinking about trying to manage coughing and limit coughing, the antittasters that we use are usually fall into the category of opioids.

So we're thinking about things like codeine, or buorphenol, or, diphyoxalate, which would be helpful to sort of limit that cough response, and then that can be really helpful, in terms of managing things. So that's pretty much what I wanted to say. Hopefully that gives us a good understanding of how we approach coughing and how we evaluate it.

It talks a lot about history, making sure we've got good information about approaching where the problem is, what the problem is, having a good understanding of those historical clues, what to look for on clinical exam, and how we can use our adjunctive tests to try and understand what would be the best way of approaching the problem and what treatment options we might have in specific circumstances. So thank you very much for listening, and I'm very happy to answer any questions. Simon, thank you very, very much for that fascinating talk.

It's as I said in the beginning, you are one of my favourite speakers because everything is always very logical and methodical and whenever I listen to you, I always think So why didn't I know that? You know, it's fascinating, it's lovely. So thank you for your time and thank you for sharing your knowledge with us tonight.

Thank you. You're welcome. We, we have just a couple of comments coming through from various people thanking you and agreeing with me, on your presentation.

There are no specific questions, but 11 thing I would like to say is it's quite funny how one gets memories triggered. And when you were talking about that grass seed and not being able to get it out the first time, it reminded me Many, many years ago, a complaint I had to deal with. Because the vet had tried to get it out and obviously couldn't get it out.

Referred it to the specialist who, obviously, a couple of days later, just popped it out, and the owner could not grasp that, why they had to pay, and why we shouldn't pay the specialist when they did the job that we were supposed to do in the first place. So it's yeah, sometimes it's just the knowing those little nuances to be able to explain the difference. Yeah.

And, and just, just another day sometimes, is it, so, you know, you're trying to remove something, and it, it doesn't want to move. Just, you know, trying to balance when to stop and trying again on another day is often a good way forward. But, yeah, we've, we've had a couple of those over the years where vets couldn't get things out, not through any fault of their own.

And then we've seen them a few days later, and they've been really, know, easy. And obviously, we have the luxury of having beautiful endoscopes and, and, and the expertise to be able to do it. But, but often it is just the course of a few days rather than anything that we've done differently.

Yeah, it's, I just, it, it, it's fascinating knowledge to have because obviously, that was something I, I learned tonight, which I didn't know when I was handling the complaint. But it also is nice to sometimes be able to, to talk to the vets on the ground and the younger vets especially, and to say, you know what, it's OK. I remember Simon saying, let's give it a day or two and retry or something like that.

So that's, it's a really handy tip to know. But Simon, there are no other questions coming through, so it is just up to me once again to thank you for your time tonight. And to all of those people that attended.

I hope you enjoyed it as much as I did. And, to Kyle, my controller in the background, thanks for helping everything run seamlessly and from myself, it's good night.