Thank you very much, Antony, and welcome to everyone that's joining us for this webinar. I just had to take a few minutes to share some exciting news about Next Nexard Specttra before we hand over to, Eric and Richard. So parasites are an ever present threat to our pets, but these risks can change over time.
And today, Eric and Richard are going to keep parasites that are very much evolving. But of course, we mustn't forget about fleas. They're always there and GI worms, especially toxicara, obviously has a zoonotic risk, and that's important, particularly when we have, pet owners with families.
When it comes to parasite control, as vets, we now have a very wide range of products to choose from, way more than when I first qualified. We have different active ingredients and combinations, different presentations, and they come with different treatment frequencies. It's great to have such a choice, but that can also create complexity and potentially confusion for staff and for clients, particularly if you need to use more than one product to cover a pet's antiparasitic needs, that could impact on compliance, if owners, start to forget which product they're supposed to use when and how.
So exciting news for the next S spectra, is that it's now licenced for prevention of lung worm disease, and that means you now have one single product that prevents lung worm and treats ticks, as well as killing fleas fast and treating GI roundworms, and that's in a single tasty chew. This makes it ideal for health plans and helps simplify parasite protocols both for your staff and, and for your clients. So next specer has two active ingredients, oxolan, which is one of the isoxazolines, and that's active against ectoparasites, and we have Milgamycin, which has end the parasite activity.
So go spectra is effective against the 3 main European ticks for 4 weeks and against fleas for 5 weeks. It's effective against the, the usual range of, of GI nematodes that includes Toxocaraus said that's really important for families, and 3 species of hookworm. And when it's given monthly, it prevents heartworm disease and now is also licenced for prevention of angiostrongylosis, lung worm disease.
We look at the studies that were done, in the next spectra and the angiostrongylus, this showed, nearly 95% efficacy against adult angiostrongylus worms and a 99.9% reduction in faecal larval output. Next Spectra has a proven safety profile.
Millions of doses have now been sold worldwide. Adverse events are uncommon, and they're usually mild and transient. So it's a very well tolerated product.
It comes in 5 strengths and that allows you to tailor the dosing for growing puppies. And the biggest size goes up to 60 kg. So it makes it really easy to use in a wide range of dogs.
You've got dogs over 60 kg, then you can use a combination of tablets if you need to. So Nextard Spectra is a very palatable, proper chew. Mariel's got a real, heritage in producing palatable chews, and Nextguard Spectra is yet another one in, in that portfolio.
We recently did a survey of, veterinary practise staff, using their own. Dogs, and we know how fussy but we practise dogs often are. And 4 out of 5 took the choose readily or like a treat, and over 90% of the vets involved said they'd be likely or very likely to recommend next Guard Specttra.
So it's certainly living up to its being a treat and being easy to give. So in summary, next Spectrum now offers you a very simple solution for your parasite needs. It's convenient because it covers lung worm and ticks as well as fleas and GI roundworms.
It's a very palatable chew, making it easy for clients to give, and as it's given monthly, it's easy for clients to remember. So thank you for listening to that. And, I'll now hand you over to Richard, who will give you some very interesting information about some of the evolving parasite risks.
Thanks, Esther. So passing over to Richard, Richard, I'm sure is well known to everybody on the call, but just in case those of you who don't know, Richard, Richard is the professor of zoology at the University of Bristol. He teaches entomology and parasitology to biology and veterinary undergraduates and postgraduate.
And is very involved in tick research. I think it's fair to say you just love parasites, don't you, Richard? That's very true, yes, indeed.
And I think we were saying before it's, it's not the best of weather for them at the moment with the heat, is it? Not for ticks, no, we wouldn't expect to see too many ticks today cos they just dry up too quickly in this heat. So thank you so much, Richard.
I will leave it over to you to to chat to us about the tick and tick-borne disease risk. Thanks, Anthony. Well, tonight I thought I'd talk about something slightly different.
We're particularly interested at the moment in tick-borne disease risk, trying to understand what the risks are, why some dogs get ticks and other dogs don't. And really our interest in this area came out of the various large scale trials that we've done. I just seem to.
My screen isn't moving. Oh, there we go, right, I'll get the hang of the technology. The large scale trials that we've done over the last few years where we've got vets to inspect dogs at random and look for ticks on those dogs, and we tried to establish what the risk factors are, which dogs are more likely to get ticks than others.
And we get some quite interesting results. The first survey that we did was in 2009, relatively small survey. We had, we looked at 35,000 dogs.
And we found that breeds such as hounds, utilities and working dogs were much more likely, significantly more likely to have ticks than other breeds. Interestingly, we found that dogs with medium hair lengths also had significantly more ticks than dogs with short or long hair. And unsurprisingly we found very strong seasonal effects and dogs were more likely to get ticks in May, June and July than other months.
Another interesting result is we found that there was a significant effect of whether dogs were neutered or not, and neutered dogs were much less likely to get ticks than intact dogs. And then we repeated that with a much larger scale survey in 2015 from the Big Tick project, where we looked at 12,000 dogs, and we got some intriguing differences. In this study we found that pastoral and gun dogs were significantly more likely to have ticks than other breeds.
Again, we had the same effect with neutered dogs. Dogs that were neutered were significantly less likely to have ticks than entire dogs. And in this study we looked at the effects of dog age, we found that the youngest dogs, 1 to 3 or 3 to 6 years of age, were more likely to have ticks from the very youngest age group or the older age groups.
And we began to think about whether this reflected something intrinsic in the biology of the dog, or there was some broader issue going something else driving this risk pattern, for example, due to the behaviour of the dogs. And so what I'm gonna tell you about today is, is studies we've done to try and quantify risk for various dogs and the conclusion that we sort of tentatively coming to at present. This story starts looking at a park just to the west of Bristol.
This is Bristol here. This is where I am at the moment, in the middle of Bristol. And immediately to the west of Bristol, we have a large park called Ashton Court.
That park is very heterogeneous in its inhabitats. It's got a sort of managed golf course, it's got lots of woodland, it's got ungrazed grassland. It also contains lots of deer.
There are red deer and fallow deer in managed populations and a wild population of row deer. So those deer, of course, are associated with very high tick densities. The park is hugely widely used.
Everybody from the west of Bristol goes and uses this park, and people use it for walking, there are lots of concerts and social events that take place in it, picnics, and of course lots of people take their dogs for walks. So what we did was we looked at the park and we broke it up into a number of different habitats. That was the managed golf course, these are the areas of woodland, and this is the area of unmanaged grassland, and we wanted to know how many ticks were in this area, wanted to quantify the tick densities in these different types of habitat.
So if you do that, and this is where there's gonna be a recurring theme in this talk, the first thing you do whenever you want to do any work is find yourself a student. So this is a student called Faith Smith. And Faith mapped the park, and the state of the art technology in tick research is called the blanket drag.
What you do is you get a 1 metre square of cloth wielded by a willing student, and you drag the cloth over the ground for about 10 metres. You turn it over and the ticks that have been looking for a host, they've been questing, grab a hold of the underside of the cloth. And that's the standard technique for surveying for ticks.
So Faith went out to the park and sampled twice a week, and she chose 5 different habitats represented here by the different colours. And within each habitat she sampled 5 times, 5 blanket drags every time she went out to the field, and she did that 1500 times over the course of a spring to autumn period. Every time she did her samples, she also took environmental readings, she measured the humidity and the temperature and the wind speed and the vegetation depths.
As a result of that, we can map exactly what the density of ticks was in the various habitats. Results are perhaps not completely unsurprising. Most of the drags that gave us ticks were in the woodland area.
Also, the edge of the woodlands, so lots of ticks where the the the trees meet the grassland, that's where areas where deer are moving between woodland and grassland. The unmanaged grassland with deer had a large number of ticks, and the unmanaged grassland without deer had relatively few, and you can see the impact the deer are making here on areas of grassland with and without deer allowed access. The mown grass and the very short grass had very few ticks at all.
In addition to knowing where the ticks are, if we look at, you know, some of the factors associated with tick abundance, the first thing we looked at was saturation deficit, and the waste saturation deficit, it measures the amount of water in the atmosphere and relatively low levels of saturation deficit equate to high levels of water in moisture in the atmosphere. And unsurprisingly, when the saturation deficit was low, there's lots of moisture, we had more ticks than when it was dry. When we looked at the map depth, the depth of the vegetation, where the map depth is is thicker, we also get more ticks when the map depth is thinner.
So essentially ticks are found in the woodland, the woodland edge, the unmanaged grassland. They like areas where there's lots of water, and they like areas where there's lots of vegetation, so they can crawl down into that massive vegetation and escape hot desiccating conditions. So we've got a really good picture in this one localised park area, exactly where the ticks are, and we know what the environmental factors that are driving tick abundance.
What we then needed to do was try and relate that to the way dogs are using the park. So again, the first thing you do is find some students, and this bit of work was done predominantly by Amy Jennett, owner Dennison, and Rachel Dixon. And what these students did was they hung around in the car park at Ashton Court, and essentially when people drove up with their dogs to walk the dogs in the park, they rushed up to them with a questionnaire, and they took a detailed history, clinical history of the dog.
And what it had been treated with, and how often it was walked in the park, and how often the owners found ticks on their dogs. And then for owners that were willing, they attached all these little satellite trackers on the collar of the dog, and essentially as the dog went off and walked, it would track the walk on that dog. And when the dog came back to the car park, the students would retrieve the tracker and then we could map the pattern of movement of the dog through the park.
Essentially we get traces like this, this, this purple one at the top here is a dog that's essentially wandered around this short grazed golf course area, touching the wood and a little bit here, but mainly on the short managed grassland. The light blue dog here has had a great long walk through predominantly the woodland, and you can see it tracking all the way through the woodland areas here. The dark blue dog has had a mixture of going through woodland, going through grass and a big long walk through a variety of different habitats.
And the light green dog here is just basically tootled around the car park and hasn't actually gone into any of the what we consider to be the at risk areas at all. Just one more track, this is a sort of detail you can get, you can see this dog's having a great time running around the woods backwards and forwards, and we can get detailed pictures of where the dogs are going during their walks. And of course what we expected to find, because we know where the ticks are, we know where the highest tick density is, we expected that the dogs that used the high risk habitats would be more likely to pick up ticks than the dogs that didn't.
Well, first of all, we can look at the distribution of or frequency distribution of dogs picking up ticks, slightly difficult difficult to interpret the data, to interpret these numbers, but essentially just under 30% of dogs or owners claimed their dogs never got a tick at all. So about 70% of the dogs that we use in the park found at least one tick over the course of the year. The peak frequency bar that we got is essentially the owners of the reporting about one tick every 20 visits to the park, and that's the most frequent pattern of tick infestation that we've found.
Some dogs, of course, were picking up ticks almost every time they walked in the park. So we expected this to be related to the environment that they visited, but it wasn't. Essentially we found absolutely no clear effects of the walk route or the duration of the walk.
It didn't matter where they went or how long they were in the park for, it didn't seem to make any difference. We didn't find any effect in this study of the breed or the sex of the dog. In addition, we didn't find any effect of the history of recent treatment.
So, you know, even if owners said that the animal was treated, it didn't seem to affect whether those dogs had ticks or not, and this would suggest either inappropriate products or poor compliance by the owners. The only thing that seemed to affect whether dogs had ticks or not, was the frequency of exposure, how often the dogs visited the park. And essentially what we found was there was a direct correlation between tick infestation and the number of visits.
I'll just show you some data demonstrating this, amongst the owners who never got ticks, they never thought they had a tick. Most of those dogs that never got a tick were only walking in this area once or twice a week, so fairly low frequency of visiting this fairly high risk site. Amongst the owners that got high levels of tick infestation, most of them were visiting far more frequently, so most of the owners who claimed that they got ticks more frequently were visiting 6 or 7 times, almost every day.
So the primary factor relating to whether or not dogs were going to pick up a tick was nothing intrinsic about the dog, didn't even matter where the dog went within the park, it was just how often it visited. And that sort of relates back to those risk tables I showed you right at the beginning. We don't think at the at the moment there's anything intrinsic about a particular dog breeds, it simply reflects the behaviour, it simply reflects whether dogs are more or less likely to be exposed to high tick risk habitats more frequently.
So it's more to do with the behaviour of animals, maybe entire dogs are simply going on more walks, or they're going on more extended walks than neutered dogs. We're not quite sure about that one, but it's something about the behaviour rather than the intrinsic biology of the different breeds of dog. Now what's quite fun is just to do, this is a very crude back of the envelope calculation, just to try and put some numbers on risk.
One of the common things that get asked is, you know, what is the risk of picking up a tick or, what's the risk of getting a tick-borne pathogen. So if we take the data that we've collected, I must emphasise this is extreme back of the envelope and just a crude ballpark estimate. If we look at the dog walked daily in this park, based on the data we've got.
Average it over a year, the risk per week is about 1 in 100, so 1 in 100 chance that if you walk daily in this park, you will pick up a tick during that walk. And just make it even more crude an estimate, if I look at the expected infection rate within ticks of Lyme borreliosis, we know it depends where you survey. We know we get between about 3 and 7% infection rates in different parts of the country.
And if we factor in an average 5% infection rate in the ticks, there's about 1 in 2000 chance of being bitten by an infected tick infected with Lyme borreliosis. Of course, you've then got to factor in what's the chance of that creating an infection in the dog, and what's the chance of that infection with pathogens resulting in clinical disease. So it's fairly crude sort of estimates, but it begins to allow us to put some numbers on what the sorts of risks are.
Exposing animals to relatively high risk habitats at different frequencies. So about 1 in 2000 chance of being bitten by an infected tick if you walk every day in a high tick at risk environment. Well, just to think about whether the results that we've got were specific to this Ashton Court estate where we were working, again, take a bunch of students, and we had some students that I sent out with tick blankets, and they spent a happy summer driving all over the south of England with their blankets, doing a survey of tick.
Densities in parks, these were urban or semi-urban parks in various cities around the southwest of the UK. You can see them dragging their blankets in different types of habitats. This one is not blanking, dragging a blanket on the tarmac, she's just counting the ticks.
So they surveyed these different habitats. And the map here shows the various parks that they surveyed, the red dots are the parks where there were no ticks, and the blue dots were parks where we found ticks. And out of 34 parks that were surveyed.
11 had ticks in them, mostly in the woodland, as you would expect from the survey we did in Bristol. 7, had ticks around the edge of the woodland, bordering with grassland, 3 had ticks in the unmanaged grassland, and 1 had ticks in the managed grassland. So showing that the results that we're getting in this park to the west of Bristol, Ashton Court, are not unique to that park.
We find ticks in a range of urban and semi-urban environments, semi-urban park habitats. And so the sorts of risks that we're seeing in this particular park where we sur surveyed intensely may also apply to a whole range of other parks around the country. So finally, I just have to thank the two main students who helped with most of the work I've described tonight, and that's Amy Jennet and Faith Smith, who really mustered the other gangs of students who went out and did all this blanket dragging and owner questioning and tick surveying over the last few years.
OK, I'm gonna leave it there and hand over to Eric. Thank you so much, much, Richard. Just before we pass over to Eric, just to give a little background to Eric, he, he did his degree in veterinary medicine and zoology, qualifying in 1997, has now, subsequently done a PhD in parasite ecology.
And since 2002 has been a reader in veterinary parasitology at the University of Bristol. I think I been at the University of Bristol since then and is now a reader. Just before we pass over to Eric, Richard, I think that is sometimes called child labour, almost using these students.
So I think you need to watch that because I'm sure there's some sort of, you could run into some sort of problems, but anyway, moving over to Eric, looking forward to the talk, Eric. Lungworm is an exciting area, and I'm really looking forward to hearing your perspective as one of the experts in lungworms, so I'm really looking forward to it. Over to you, Eric.
Thank you very much for the introduction. So I'm really going to try and update you on recent developments in lung worm, distribution, diagnosis, and how we can approach it in practise. I'm first going to run over the range of lung worms that we do find in cats and in dogs, to remind you that it's not only about angios strongluspoorum.
However, angiostrolus is probably the most important clinically, and so the bulk of this talk will concern this species. A run over the life cycle, transmission of disease, and also changes in distribution, that have occurred over the past 10 years or so, particularly in the UK and elsewhere in the world. I'll mention, as Richard has already for ticks, the risk factors, the things that make it more or less likely that individual dogs will be infected with angios stronglus, because obviously that's quite useful both for clinical diagnosis and for deciding on prevention strategies.
I'll introduce the diagnostic tools that are available and discuss then how we can use those tools in association with what we know about changes in epidemiology and in risk factors to, develop your own strategy in practise for detection and prevention of this disease. The picture there is obviously not a lung, and the reason that angios stronglus is so important is that it's clinical consequences are not restricted to. Cats also get lung worms.
They get a range of different species. Aleros stronglis abstrusis is probably the most common. This occurs as adult worms in the lung, in the parenchyma, in nodules, and also in the bronchi, and produces lots of larvae, and you can see the histological section there, showing a lot of larval sections, a lot of infiltration of inflammatory cells in the lung, and pneumonia.
Aura Strongli has become more important in varying practise, particularly in Southern Europe, but we certainly have slides like this in our histological collection going back 30 or 40 years in the UK, so it's been in the UK for a long time. I believe it causes some disease, but we don't really have any good surveys or, detailed studies showing either the prevalence or the level of disease that it causes in the UK. I'm not aware of any change, any increase in respiratory disease in catamul causes chronic respiratory disease, coughing, dyspnea, tachypnia.
And unlike Andrew Strong for Zora, it doesn't seem to cause non-respiratory signs. Eucoleus aerophilus is found in the bronchi also and similarly causes chronic long-term respiratory signs that are mild to moderate in severity. Troglotrolus revio is similar to a strong in that it Uses a snail or slug intermediate host, whereas you call this has a direct life cycle.
Trogla Stronglus appears to be more severe clinically. It's associated with wildcats as a reservoir, and it's quite important in parts of Italy, but as far as I'm aware, it is not in the UK. Osotrostratus is also not in the UK and cats do get angiotrolus, but they get a different species to dogs.
It's not vasorum, it's angiostroli chabodi. And again, there are no records in the UK. So in cats, really, it's a lustrous abstrusis, is around in the UK, possibly causing some chronic respiratory disease.
Nothing more than that, and I'm not aware of any particular changes in epidemiology that you should be aware of. Dogs get several different lung worm species, not just Andrewstrongushosorum. And the other, the second most common is probably Crenoso of vulpis.
Chrenosomealalpis occurs in the airways, and it also uses a slug or snail intermediate host, and it causes a respiratory disease which can be quite severe. It does, however, not cause the bleeding disorders that we see with angiotrolis. There are some Filaroides species, Filaroids oslori, which used to be osus osa, and the picture at the bottom shows the nodules in the trachea and bronchi, particularly the the bronchial bifurcation, where we see these nodules containing the adult worms, and they can cause inflammation and irritation there, some coughing, reduced performance in sport dogs, for instance, and that can be important.
In some cases, ferro her do not seem to be common in the UK. So these other lung worms really are more true lung worms than angios strongly in that they are restricted to the respiratory tract, and the clinical consequences are respiratory in nature. The panels of larval morphology just show that you can tell these larvae apart.
The top right image is crenosome of vulpes, and you can see the tail of the lava which tapers smoothly to a point, with no odd assortments or twists or turns. Whereas the other species have a characteristic little kink and a a notch in the tail of the lava. This can be useful to tell the species apart, when you have a faecal sample and we come on that when we discuss diagnosis.
So the rest of this talk is really about Angiostrong's sorum because unlike the others, it can cause much more severe and general and difficult to diagnose clinical disease. Apologies to those who already know the life cycle well, but it's worth recapping. So Angiostrongylus as the adult is actually in the heart, the right side of the heart, and in the pulmonary arteries.
It can be in quite small pulmonary arteries. So really it's more of a heartworm than a lung worm. But we don't want to confuse it with the diaphylaria imittis.
A strong is much smaller worm. It tends to be more peripheral in the pulmonary circulation. There are male and female worms and they breed and produce the females produce eggs, and those eggs are carried down into the capillary bed and they'll hatch into L1 or first stage larvae.
They will actually migrate across into the alveoli, and it's this migration that probably causes a lot of inflammation and pneumonia. Those larvae once they're in the alveoli are carried up by the mucociliary escalator and coughed up and swallowed, and they pass out in the faeces. When slugs or snails feed on those faeces, they ingest the L1.
And they must develop then to the 3rd stage, infective stage of larvae, the L3 stage. That occurs over a number of weeks and is temperature dependent, so it occurs more quickly at higher temperatures. The dog is then infected when it ingests a slug or a snail, which has a mature 3rd stage larvae in it.
The peculiarity of the and your strongest life cycle, as many parasites is what we call a pyrotenic host. So the slug or snail is an intermediate host. It's a necessary part of the life cycle.
There are other species, such as frogs, that if they ingest an infected intermediate host, carry the larva in their tissues for quite a long time. So no further development of the larva occurs, but those pararatetenic hosts, as we call them, are now infective if they're eaten. And er frogs have been shown to be pyroic hosts, for instance, for angio stronglis, which might be important in the natural cycle between foxes and slugs and snails, but possibly not so much in dogs we would expect.
Once the infected intermediate or parittenic host is ingested by the dog, the larvae will migrate out of the digested tissues and then penetrate the intestine, and then migrate through the lymph and blood, to get to their final site in the heart and pulmonary arteries. This takes some time, this takes, probably just over 1 month, say 5 weeks or so, and that period between ingesting the infective lava and producing L3 from the mature adults that are now breeding and and producing larvae, that is called the pre-patent period. And the period during which larvae are being shared before the old, the worms get old and die is or are killed, that is the patent period.
Those terms are important in what I say later. So we know that life cycle. I mean, most parasite lifecycles were worked out a long, long time ago.
One of the, the most recent is probably malaria, and even that was at the start of the 20th century. So surely we know everything about the life cycle. Well, not really, because people didn't realise the clinical importance of Andrew Strongless, and it's become more important lately.
There are many unanswered questions on the life cycle. And several groups are working on those, and there are new papers almost every year now, which add a little bit more knowledge of that life cycle, some of which might have clinical relevance. So for instance, last year it was proven that chickens can act as a parrotenic host.
So chickens eat slugs and snails. If those slugs and snails are infected, the larvae will be shed from the mollusk tissues and will end up in the chicken's muscle, liver, etc. And in theory, a dog could be infected by eating raw chicken if those chickens are infected.
If you, we don't know for sure ran strong, but almost universally, if you have meat borne, nematode parasites, if that meat is frozen or cooked, then that kills the larva and it's no longer dangerous to eat. So I suspect. A lot of the, the raw food diets that dogs are on, are frozen for distribution and so on.
So I'm not saying that this is a risk factor. I'm just pointing out that our knowledge of the life cycle is evolving all the time, and in theory, chickens could be a source of infection. The second bit of news, I guess, is there have been studies going on for several years, asking whether the infected larvae can leave the slug and snail into the environment and therefore whether dogs can be infected by licking grass or slime trails in their feed bowl and that sort of thing.
And recently, there have been some important papers showing that larvae of some of these lung worm species can leave snails and actually go and find other snails and infect them, as well as leaving into the environment. And this has worried people relating to angiostrongylus risk, that the environment is a risk and a reservoir of larvae. Actually, those studies were on the cat lung worms that I've just discussed, Eurostronglis and Troggostrongylus.
There are very few examples of larvae leaving snails in the case of Angiostronglus vasorum. There are some, but you have to really try very hard to get those larvae to leave the snails. We've looked at miles and miles of slime trails and both morphologically and using molecular tools to try to find these larvae, leaving the snails, and they just don't really do it when the slugs and snails are alive.
When the slugs or cells die, that's a different story. So actually, as soon as the tissues start to degrade, the the L3 larvae do migrate out of the slugs in large numbers. And so this kind of image where we've maybe worried about slugs and snails in the garden, we set out beer traps, that sort of thing, and then slugs are attracted to that and die.
Then those, those, bodies of water could be full of larvae. So the last thing you want to do if you're worried about angios strongiss is set out beer traps and let the dogs drink it. Also, if you're going to try to reduce slug populations using slug pellets, that's a bad idea because of the toxicity of the pellets, but it's also a bad idea because you're now facilitating the exposure of dogs actually to any infections in those slugs.
So what happens if a dog er eats an infected intermediate host? Well, we see a variety of clinical signs and broadly they're split into respiratory and bleeding disorders. Although how they manifest can be quite confusing.
So, The main consequence, the most common consequence of infection with your stronglus is inflammation around the alveoli, infiltration of inflammatory cells and a pneumonia. And that is probably caused by larval migration. So it occurs in patent infections.
It's, it's probably in proportion to the numbers of worms that are present and the, the weight of that infection, and also how long it's been going on. So this typically leads to a chronic cough, respiratory disease, dyspnea, tachypnea, which may be building up for some time. It can present very acutely, but usually it's been building up for some time.
That manifestation can usually be treated fairly successfully. The reason Angiostrong has risen to prominence is that it's not just respiratory disease that it causes. For reasons unknown, that worms can in some dogs interfere with clotting, and then we get bleeding disorders.
And that can manifest in a variety of ways. Here, you've got a scleral haemorrhage in this picture, but it could be a nose bleed, it could be bleed into the central nervous system, and then you get neurological signs. It could be a bleed into the gastrointestinal tract, leading to vomiting or bloody diarrhoea.
It could be a post-surgical bleeding and death following even elective surgery. So this can be very difficult to pick up if you're not very aware of find you strong risk. The Venn diagram in the middle is from some studies that we did some time ago from Bristol in first opinion practise.
So, One question when Andrew Strongli first became prominent was whether we are seeing these strange clinical manifestations published just from referral cases, and actually, we don't see them so much in first opinion practise, but we do. And there are a large number of respiratory cases, some of which also have other signs, and then of the bleeding disorders, some will also have respiratory disease, but some won't. And those are the ones that threw people in.
Newly colonised areas where they were thinking of lung worm, they were thinking it must be a respiratory component as well as something else, and that's not the case. And that goes for other signs like syncope, like neurological disorders. Some will have respiratory disease also and some won't.
So this from the same study, main presenting sign by far, are respiratory, but we do see this wide variety, lethargy, haemorrhage, exercise intolerance, neurological signs, etc. Even larvae migrating in larvae migrating into the eyes and other tissues. So, it can be very hard to diagnose, and I think this has made it popular with vet students who can put Andrew Strongli onto almost any differential diagnosis list that they like and not be wrong.
But it also means that some cases have been missed, and certainly there have been fatal cases of Andrew Strongli, that were not treated for lack of clinical awareness, really. Once it is diagnosed, treatment, can involves anthemintic, moxidectin, lamycin, oxy are the two licenced drugs in the UKenbendazole was popular before these drugs are licenced, but it's not licenced for this use. And so under the cascade, it shouldn't really be used.
Supportive therapy just depends on the presentation. So, for example, if it's respiratory signs, it could be oxygen, if it's, clotting disorders, there isn't much that's shown to be useful in supportive therapy. Some authors have proposed the use of anti-inflammatory steroids to reduce some of the respiratory consequences, but there's no real evidence for or against that.
And the prognosis is variable. And the good news is that some of the severe cases that present can actually be treated quite successfully. So if there's a disseminated intravascular co.
Ation for example, and the causes Andrews stronglus, then removing the worms should remove that cause and make what is normally a very severe and potentially terminal condition treatable. And the same goes for neurological conditions. If there's a clot in the central nervous system, then by removing the worms and the cause of that bleeding, then you can get successful resolution.
In other cases, in spite of diagnosis and and correct treatment, then you do get fatality. We don't know the case of Talcarate for angios stronglus. There have been no good studies on that.
Prevention and well, removing the worms by using oxidectin and milbamycin. And there is a bit of a misconception with worming, whether it's angio stronglus or other worms like toxicara, that we are preventing and actually, usually, we're just repeat treating in order to remove any worms that are required. And if we do that, and make sure there are no worms there, certainly not many worms there, then we would expect to avoid these clinical consequences.
Because we are effectively repeat treating, then doing that more frequently is going to be most effective. And because the pre-patent period of angios strongis is about 5 weeks, then doing it monthly is very logical. However, some people are reluctant, some vets are reluctant to do that unless there's good evidence that this is a risk in your local area, and this has caused some controversy.
Because of that, I want to insert a few slides really and talk about the distribution of smugglers and where it's found, what's happening to it, is it really spreading. This global map shows in green boxes where we know Angios strongis is present, and in red circles where we think climatically the conditions are suitable for transmission. So you can see it's very patchy at a global level, but if you zoom in on Europe, then most of Europe, apart from the very extreme north, east and south, is very, very suitable for aniotrous transmission.
At a European scale, in the last 10 years or so, a large number of new countries have reported angios stronglus. And these have mainly been in areas that we predicted some years ago would be suitable for transmission, that's really mild, temperate, humid kind of areas. In the UK, before 1990, it was really restricted to a couple of focal areas in South Wales and in the southwest of England.
And then in the 190s, a number of cases reported from, from London and the surrounding areas, and it became clear that the worm was actually present much more widely than in those original foresite. Over the next 1015, 20 years, Andrew Strong has spread, it popped up in Glasgow in 2009, for instance, and now there are reports from all over the UK. However, this is also the period where clinicians have become more aware of it, the teaching hospitals have become more aware of it, and so the question remains whether this is real spread or really increased awareness and better diagnosis.
We addressed that by sampling a large number of foxes that were being killed for other reasons, recovering the worms from them and mapping and your strongness of foxes, you would expect are not influenced by things like awareness or new diagnostic tests, or CPD and they're probably a fairer reflection of distribution. We did this, 2005, and again, nearly 10 years later, and the red markers here are positive foxes, and the white markers are negative foxes, and we found between the two, sampling occasions that in the first, We had no positive foxes, despite a large number of being sampled in the north of the country. And in the second study, where some of these markers overlie each other, there were quite a large number of positive fossils.
So there's been definite northward spread of angio strongness, irrespective of any differences in awareness. What we also saw further south was some areas, such as around Bristol, where there wasn't any evidence of infection before, and they seem to have been colonised by the parasites. So there's spread.
Both northwards and filling in these areas that were previously negative. In every area that we sampled, we found an increase in prevalence. So even in the Southeast here on the right, where angiostrois is common, we thought before, 23% of foxes.
Now it's over 50% of foxes. So in every single area that was sampled, then prevalence increased. So even if you're in an area that's long been known to be endemic, the background numbers of worms are probably increasing.
If we look at another Fox survey recently published in Ireland, we found very little evidence of patchiness. It seems that, I mean, every single county was positive, and it seems that over time, because it's been present in Ireland for longer, we think, over time this patchy distribution settles down into really widespread distribution. And this is what we might expect in the UK.
What about slugs before we talk about risk factors and ingestion of slugs? Well, unlike things like liver fluke that have very specific intermediate host species, angios stronglus is really not choosy. It will infect every species of slug or snail that's ever been attempted in the laboratory.
And when we go out here in Swansea, a long standing endemic focus, and we sample slugs and snails. Random. It's really slugs carrying most infection.
Every single species really carries it. But the large slugs, large black or orange slugs that you see are in a group, are the ones that are both most commonly infected, and the ones that have the highest numbers of larvae, and some of them come and have hundreds of larvae. So in theory, ingesting a single, heavily infected slug or snail could cause clinical disease.
Although most of them aren't so. Mhm I've just told you that Andrew Strongli really has spread northwards, so surely geography is becoming less of a risk factor. Well that might be so.
But the level of risk probably still varies locally. So the maps you see here are from Cook's study, which was a veterinary practise survey. And if they asked those practises if they've ever seen a case of angio strongness, there was very wide distribution geographically they said yes, but if they asked them if they'd seen more than 5 cases in the past year, then it was much more common to get a yes for Southeast and from Wales, where we already know the parasite is common in foxes.
So where you are in the country should influence the level of your concern of Andrew Strongli and the, the degree of suspicion when you're faced with a clinical case. You'll notice the breed is not listed here in my risk factors. There have been some studies pointing to certain breeds, but those breed associations are not consistent between studies, so I don't think there's enough evidence to really take that into account, when you're presented with the case.
Young age, however, is quite strongly associated with infection. So in our studies and several others, dogs that are less than 18 months of age are at least 4 times as likely to test positive for angio stronglus. That said, older dogs, 1114 years of age have been diagnosed.
Some of those dogs have been diagnosed twice in their life, so it seems there's no strong immunity to angiostronglu and older dogs can also be affected. Season, well, slugs are very seasonal, and you like transmission to be quite seasonal, but because the disease can develop for quite a long time, over quite a long time and be chronic, there doesn't seem to be a very strong seasonal pattern in the presentation of cases. And behaviour we might expect to be a factor, because some dogs are scavengers, for instance, might encounter slugs much more commonly.
Others chew grass, maybe drink out of puddles more. So you might expect behaviour and the amount of walks like the ticks, to be a, a predictor, but there are no studies proving that. So our risk factors can help in diagnosis, they don't give the whole story, and of course we have to take the diagnosis further.
And the launch of the Angio detect test a couple of years ago is a real boost to that. For the first time we have, an in-clinic point of care test. Becomes as you.
You know, I know the dog is infected by strong. It's a lateral flow immunoassays, you put a drop of Assum or circular part, you look for. And line and if you get Rs positive.
So Surely make a big difference to practises wondering whether on issue in individual cases and generally in their practise. How does it perform? Well, the alternative we had was what we call a bearman's test, and that simply consisted of putting some dog faeces into a, a, a onto a sieve or into a muslin gauze bag, suspending in water, letting the larvae migrate out, and then petting them onto microscope slides and looking for larvae.
And the angio detect test performs fairly similarly actually to the Bearman's. If it's positive, then it's really positive, so the specificity is very high. The sensitivity though, is not all that great.
So Bearman's, we know, is probably around 50% sensitive and angioect compares well to the Bearman's, but it's not, not infinitely superior. In terms of the timing, there have been some studies on experimentally. The res you detect over time.
Well, it becomes positive more or less as the worms mature in the lung. So if the dog's only recently infected, then it might be a false negative. But those dogs are unlikely to be showing.
That and the number of Harvey and the Bearman's method drop off quite quickly. And you detect becomes negative over about 4 or 6 weeks. So, compared to the Bearmanman's really, its main advantage is it's more convenient.
So, Bearman's faecal sample, results are better if you collect faeces over 3 consecutive days. That could be very difficult. In an inpatient or a dog that's, that's, where you require an urgent diagnosis, it's more convenient to take a blood sample and test it there and then.
And the false negative rate is fairly similar. Behman's is polyvalent by that, I mean, it will pick up the other lung worms. Angio detect will not pick up things like crenosoma, which is an advantage in some cases.
The Bearman's will, and if you see larvae on a faecal examination, then it's some kind of lung worm, and most of the drugs will get rid of that. So how should you use angio detect? Well, it's up to you really, but obviously for clinical diagnosis.
What makes sense to me, this is a a recommendation from Jacob Willison in Copenhagen, where the parasite is also spreading beyond endemic areas to new, new regions. And he recommends that in areas where you're uncertain of whether the parasite is a big issue, you should really use it quite routinely for common presentations like respiratory signs and bleeding disorders. Whereas if you're in a non-endemic area, you're probably pretty comfortable diagnosing drugs quickly in those cases, and an angio detect test which has a reasonably high false negative rate, might not be that helpful, but it would be really helpful for unusual presentations like neurological signs and lethargy and syncope where you, you really are not sure and you want to use it even as an experienced clinician.
It can also be used as a response to treatments. So in the past, the Bearman's test and even now the angio detect test is often not used because the response is, well, you might as well worm it, it's cheaper to just treat it and see. But of course, you don't know what your diagnosis was, you can't respond, you can't monitor the response to treatment.
There is an argument for, for testing, particularly in non-endemic areas, patients before they undergo surgery to avoid consequences of poor clotting for their recovery and treat positives and wait 4 to 6 weeks, before the surgery, if that's possible, of course. And really, I would encourage practises to use Angie Detect quite routinely to build an evidence base. The most common question I ever had when Andrew Strongli rose to prominence was vest phing from around the country asking if they change their, their prevention regimes for worm, for worms, and, most of them didn't really have a good idea of whether Andrew Strongli was there and how common it was, and this is a chance really to build that evidence base.
Bear in mind that if you find that there isn't a lot of angios strong in your area, it is spreading, so that might change. I'd encourage you to persist with the strategy of building that evidence base. So to summarise, there are several lung worm species in dogs and cats, but really it's angiotros in dogs, that's the most serious clinically, because of these bleeding disorders and because of the difficulties in diagnosing the various clinical presentations.
The main route of infection is ingestion of slugs. We don't really need to go looking for other things like pyrotenic hosts and larvae leaving in the environment. There's plenty of opportunity for dogs to ingest slugs while scavenging, while chewing grass, that sort of thing, and it's very hard to prevent.
There has been significant northward spread in the past 10 years. I would say all of the UK is certainly now endemic for anis strongness, although the level of risk probably varies still somewhat. And that is a changing picture, generally it's increasing once it reaches a new area and gets into the fox population, it's unlikely that it'll ever be got rid of from that area.
And there are new diagnostic tools, which should be helpful, not only clinically, but also to monitor the local status. And thankfully, good options for prevention are available, so it's difficult to prevent infection through ingestion of slugs, but by treating and removing those wounds regularly, we have a very good hope of avoiding clinical disease. That's all I have to say.
Thank you. Thanks Eric, that was fantastic, really interesting, fascinating, of course, you guys are obviously in Bristol looking for it. Suddenly you're seeing big clusters there.
I, I suppose it's one of those if, if it's not on your list, you never make the diagnosis, do you? That's right. So interesting because of course, you know, I stopped practising about 67 years ago in general practise, carried on with my dermatology, and in the North, we were really not seeing it, but then.
You know, in the dermatology field, I would often say, my parasite control was more to do with good control of fleas, . But obviously listen to what's happening in your local area because if lung worm is significant, clearly, you know, fleas are not really gonna kill you, whereas lung worm can. So we have got a few questions, let's see what's coming in there, .
Richard is, sorry, so Robert is asking Richard, have you spotted any ticks in cats with beef Ellis if yes were? Well, we carried out our cat tick survey last year, and we're still really going through those samples and identifying them. So at the present moment, we're double checking what we've got.
So it's not really possible for me to say definitively that we do have it or where it is, but certainly our suspicions are aroused that we may well have it. And we won't be able to confirm that until we've double checked all the samples. But as I say, you know, it certainly looks like we may have it in the UK.
Fantastic, thank you, Richard. Zhao is asking to Eric, does Angio Detect have cross reactivity with other migrating parasites? Right, I'm not sure which migrating parasites you mean, but it, it has been tested extensively, particularly as the in lab allies against a wide range of parasite species, and there was very little cross reactivity, almost none actually.
So that's why they went forward with that particular test into the Android detect. So no. Great, OK, and then somebody else is asking, can dogs become infected by contact with infected faeces?
So if the faeces have angiostrongylus larvae in them, they will be first stage larvae and they won't be infected, however, as we know from the life cycle, we know that slugs and snails like feeding on faeces, particularly slugs, and it's possible that those faeces will have a slug feeding on them that is infected with 3rd stage infected larvae. So yes, if there are slugs on the faeces, but no, if there aren't. Thanks Eric.
Obviously we, we've had a few questions which are off licence. If we get those sort of questions, you know, I would actually ask those questions directly to Mary Al, by ringing them. We have got a question for Esther, however, that says, how quickly does nextgu spectra kill fleas and ticks?
Does the parasite need to bite to get the active ingredient? If the. Is it the prompt removal of the ticks using O still important?
Thank you, great webinar, and that's from, an anonymous attendee. So that one's for you, I think, Asther. Yeah, thank you.
Really good question. Yeah, so the azoxazolins are systemic products. So yes, the parasites do have to feed in order to be killed.
But of course, even with the topical products, although the parasites don't have to feed to be affected in practise, they often do feed before they're killed. To be licenced, all the antiparasitic products have to kill fleas within 24 hours and ticks within 48 hours in order to get a licence. So all the isoxazolins are fast-acting products.
However, you're absolutely right. If, you know, if you need to be absolutely sure that you haven't got a tick problem, particularly if you're worried about, tick-borne disease transmission, then definitely checking the dog. And using a tick hook is absolutely the right thing to do.
I mean, if you're worried about tick-borne disease transmission in it, while some of the, diseases are quite slow to transmit the Bia, for example, it's 3 to 4 days, but ali here is very fast. So, you know, none of your products are going to kill the ticks fast enough. So absolutely checking and using a tick hook is still a really good idea.
It's a, it's a belt and braces approach. Thanks, Esther. Just perhaps while we're waiting for some more questions to come in, it'd be interesting to know, you know, if any of you have seen Lungworm in your practise, perhaps if you say yes, you have seen it, where you're based, perhaps if any of those cases actually died, you know, that would be interesting just to see where you're, where you're seeing it, so please feel free to.
To do that. Alison is saying, and I suppose this is a question for Richard, humans are also at increased risk, re ticks, government UK data re Lyme disease is suggesting that that's obviously on the increase. We are not treated with ectopparasitics, parasiticides.
Why such a difference in approach, unless it's to Richard. Blimey, I don't know where to start with that one. Certainly, I mean, the official clinical data is that there are about 2 to 3000 cases of Lyme disease in the UK, but it's probable that the actual true figure.
It's about 10 times that in terms of the prevalence of Lyme disease, and that prevalence does appear to be increasing. I think there's fairly good evidence that it is going up, but we really don't know because there is so much Lyme disease that never goes through full clinical diagnosis. It's treated symptomatically.
We don't have good data on exactly how fast that change is. Why humans aren't aren't treated, that is a question entirely outside my remit, I'm afraid. OK, that's fine, Richard.
. We've got Sue asking if using mogamycin monthly as a lung worm preventative, is this as good as moxidectin monthly? Does moxidexin have a residual activity to give continual protection through the whole month? Thanks for the excellent talk, and I'll, I'll leave you all to decide who should answer that.
I mean, I guess if I take that to, to start with. So both the products are both min and mmycin are licenced for prevention of, lung worm, and they're both fully effective in preventing lung worm disease. They do work slightly differently, in terms of how long they're active for, but they both kill the lung worms, and prevent lung worm disease from occurring.
I don't know, Eric, if you've got anything you want to add to that. Well, I guess I'm taking a step back and thinking about how lung one cause or angios strong causes disease. If many of the respiratory signs are caused by larvae, then by wiping out those adults within the pre-paiding period, you would expect to stop that.
What we, we don't know much about is the mechanism of the bleeding disorders, and and I'm not aware of any published information that compares the effectiveness of those drugs in that regard. And David is saying, yes, he's seen lung worm in the Surrey Berkshire borders. Sue is saying yes in Southampton, one fatality in the last 3 years, regularly offering testing with angio tests before surgery, very few positive, .
If we've got anybody else, perhaps from the north of the country who wants to talk about lung worm, that would be great. Robert, in the meantime, has got a question for Eric. In your opinion, is, is it better to swap worm as and spot-ons to avoid worms to get used to the drugs, or no worries if we use the same drugs for years.
Thank you for the answer. I guess that's a question about developing drug resistance. And there's a, there's a lot of concern about that obviously with wormers in livestock, for instance.
It's a bit more tricky in companion animals because to avoid impacts of wormurs on resistance, you would have to intentionally let some of those infections produce eggs or larvae. And that's not very ethical when something's potentially fatal, like Andrew St strongly. So if a dog is not infected and give it a wormer, that's not doing anything in terms of encouraging drug resistance because the worms are not there.
What you'd have to do is have an infected dog that you intentionally don't treat or swap around drugs, and I, I think that's probably the risky approach for the dog. Because there's such a refuge or there's such a reservoir of infection in foxes, it's very unlikely that exposure of a particular dog to repeated treatments of a particular type is gonna make any difference to the population's level of drug resistance. Thanks Eric.
We've got another attendee saying that they see lots in outer London. And then, Ian had a positive case in a dog in northeast Derbyshire and it lived, somebody else saying South Wales frequent clinical infection, regularly diagnosed preGA several fatalities per year, so that's South Wales, that obviously seems that sort of South Wales Bristol Channel seems to be a bit of a hotbed, Eric. Well, of of course it's been around in South Wales for decades, and I would hope that any clinician practising there would be very attuned to pick it up early, and it's interesting that in spite of that, there are still some fatalities.
Yeah, no interesting. Esther, have you got any more comments before we perhaps close the webinar off? Yeah, there was, I think it was just one other question which is about whether you have to treat monthly for prevention of, of lung worm, and yes, it is a monthly treatment for prevention.
And I think that's all the other questions covered. Great. Esther, thank you so much for making this possible.
Thanks to the kind sponsorship of Mary Maryal, which is of course now part of the Boringa at Ingle High. And also thank you to Eric and Richard for, for giving the talks. I, I found it really fascinating.
I, I must admit, Richard, I, I just seem to fall in love with ticks more and more each time I hear you speak. Which is, which is great, and Eric, you know, it's fascinating to hear about what what's happening with lung worm, clearly becoming more and more of an important parasite. And I think it's so important that vets are hearing about it and just continuing to have it on their list of suspicions when they're seeing any of these sort of slightly nebulous, difficult.
As you say, it's, it's one of those that's almost now coming onto the differential list almost all the time, apart from maybe if you're a dermatologist. Ah, I'll stop you there. There have actually been cases of of skin disease from Angios strong also.
Oh well there we go, so we've got everything. Thanks Eric, thanks Richard, thanks, Esther, thank you so much and the person here has just said, magic, thank you all, much appreciated. So, I really appreciate that, appreciate that and looking forward to hearing you all on another webinar very soon.
Thanks everyone.