Hello, everyone, it's a pleasure for me to share with you my experience regarding on-farm postmortem examinations or PMEs. And before starting, I wanted to give you a brief overview on how I got so passionate about this topic and also what what the journey has been for me. I'm Valentina Bozin and I graduated as a vet in 2007 and worked in mixed and farm animal practises for a few years before moving into postgraduate training.

First, I did a farm animal residency for the European College of Small Women and Health Management and then a PhD. During my time in practise, I did quite a few on-farm postmortems, and to be honest, I, I did find them, sometimes quite stressful and, and, and many times I wasn't entirely sure what I was looking for and, and what you can see in the picture here is, is exactly myself just about to start one. After I moved to the University of Glasgow in 2016 and I've taken on a position as a veterinary clinician, I've been heavily involved in farm animal postmortems, but also disease diagnostics and surveillance.

And I would say that was really an eye-opener for me. And I, I really realised fully that PMEs are such an important tool both for farmers and vets. But I've also got to understand how they relate to the bigger picture of surveillance and how we can promote animal and public health through this, through these channels.

And what I hope is that this webinar will, will actually convince you of this and will hopefully also provide some help, so, so you won't feel overwhelmed as I, as I maybe was sometimes when doing on-farm postmortems. Before we start with the actual content of the webinar, I thought it would be useful to provide an overview of what will be covered. So, I'm going to start with an overview of the general surveillance, what it means and why it is so important.

We'll then move to the juicy part of the webinar and obviously giving the topic, be ready for some what what they would call for the general public disturbing images as we call the on-farm postmortem examinations or PME. Firstly, when it is appropriate to do them, and then obviously how, how to do them. Once you're done with your PMs, I would say that things are definitely not over and probably in, in my opinion, this is actually the sample selection is actually the crucial part.

And then we'll conclude with putting it all together in what we can say would be the interpretation of findings. So, let's get started. Deterinary surveillance is an essential and dynamic tool designed to aid decision making, and it is the foundation of many crucial concepts, including food security, public health, and international trade.

Therefore, it represents a public good safeguarding public health. It reduces disease burden and poverty through improved animal health and protection of international trades. It is a global effort as pathogens do not respect borders or geographic and species differences.

And it allows to detect, respond, and mitigate the consequences through early detection and coordinate response of undefined or unexpected threats. In 2013, at the first international conference of animal health surveillance, a group of industry experts coined a standardised definition of animal health surveillance as the systematic, continuous, or repeated measurement collection, collation, analysis, interpretation, and timely dissemination of animal health and welfare-related data from defined populations. These data are then used to describe health as an occurrence and to contribute to the planning, implementation, and evaluation of risk mitigation actions.

Surveillance is supposed to provide real-time feedback to stakeholders and decision makers, allowing for continued improvement of strategies aimed at the control of disease. Surveillance, therefore, includes all the activities which provide effective and prompt or early detection of animal health and welfare problems, together with the tracking and analysis of the way they spread. The types of threat include novel pathogens, novel diseases, novel presentations of known diseases, or the occurrence of diseases in normal species.

Another remit of veterinary surveillance is also the monitoring of marked change in endemic disease trends. Surveillance is currently broken into two branches, active or targeted surveillance and scanning or passive surveillance on the basis of data collection methodologies. Active surveillance is a scheduled risk-based targeted approach.

It described patterns of disease more accurately, but it is commonly reserved for high risk notifiable diseases, significant implications like brucellosis and bovine tuberculosis, as it is costly and labour intensive. It is also not suitable for detection of new and emerging conditions. Scanning or passive surveillance is centred around the collection, analysis, and reporting of voluntary submissions of samples and carcasses to the veterinary investigation centres or the disease surveillance centres, and it is often a more cost-effective methodology.

It is well suited to monitoring levels of endemic disease and to identify new emerging and exotic conditions. Particularly those which could adversely affect animal health and welfare, trade, and public health. Its main limitations are that data are limited to case submissions without the availability of a denominator.

In Great Britain, food animal surveillance is publicly funded or subsidised. The collection of scanning surveillance data is done through diagnostic testing performed by the Animal Plant and Health Agency, Veterinary Investigation centres, by Scotland's Royal College Disease surveillance centres, and by partner postmortem providers. The sharing and analysis of the information obtained from all the centres is essential to accomplish the fundamental goal of surveillance.

Diagnosis reached are logged into the veterinary investigation diagnosis analysis, or BDA database, a national database providing analysis of all diagnostic submissions. Diagnosis follows strict agreed criteria. Outline is the wider diagnostic criteria, which describe what tests should be performed to reach a specific diagnosis.

These criteria are regularly reviewed and validated. Submissions in which a diagnosis is not reached after reasonable testing are also analysed to determine whether there is any evidence of a new or re-emerging threat. After analysis of this data from the species expert groups, information are reported.

Reporting is done in multiple ways. The number of positive diagnostics submissions from the VIDA database is used to create an interactive map called the GB Disease Surveillance dashboard, which is available for sheep, cattle, pigs, and avian. In addition, the APHA publishes its quarterly GBide livestock surveillance reports in an annual interactiveIDA report.

All of which are available to the public through their website. There are also monthly reports from both APHA and SOUC published on the website and on the veterinary record, which also features focus articles. Many people are involved in veterinary surveillance, and for it to work, everyone needs to take responsibility and understand the crucial importance of it.

Farmers, stock workers, and animal keepers are ultimately the responsible for their animal health and welfare. They should identify diseased animals, prevent and control disease on their premises, ensure their skills and competence levels are appropriate, and employ private veterinarians to help them in safeguarding animal health and welfare. By involving their private veterinary practitioners, they also allow for scanning surveillance data to be collected.

Veterinary practitioners are obviously responsible for animals under their care, but also for knowledge transfer and exchange and for having a proactive role in health planning and preventive medicine. The role of vets is traditionally focused on the treatment of diseases, and this is still a crucial aspect of their of their responsibilities. However, there needs to be a shift towards preventive medicine with provision of specialised advice.

By submitting diagnostic samples to veterinary laboratories, they allow for scanning surveillance data to be collected. Veterinary investigation officers are purposely trained veterinary surgeons. Their primary responsibility is to support veterinary practitioner through discussion of cases and help with disease investigation and diagnostics.

If samples are submitted for diagnostic testing, either through clinical or anatomical pathology services, diagnoses are uploaded into the vital system. They're also responsible for dissemination of surveillance information through reporting. Epidemiologists are responsible for analysis of data, providing expertise for the interpretation of the surveillance data.

Academia and researchers in general are responsible for producing practical evidence-based information and that the advice is available to the end users. It should also be seen as an independent body which can avoid biases and a source of expertise and networking. The government is overall responsible for supporting the rural economy, ensure food security, and protect public health.

It is the power of setting regulations and legislation and can empower local authorities to intervene. Scanning surveillance is currently subsidised by the government, with farmers paying toward testing services like veterinary fees, laboratory tests, and postmortem, while the government subsidise the cost of testing and funds other initiatives like collation and communication of information. The industry, which depends on the supply of live animals and animal products, is a duty to care for those animals, but also for responsible sourcing of the food they provide.

Agribusiness is a large and important global industry, and they are directly responsible in supporting animal health. They can also be involved in surveillance, for example, by collection of data at abattoirs or markets. Pharmaceutical companies have a duty to ensure that animal medicines are used responsibly.

They are involved in surveillance, for example, in cases of suspected lack of efficacy or adverse reactions to therapeutics. Finally, the general public is not only the ultimate beneficiary of veterinary surveillance, but also responsible for their behaviour and environment, respecting disease prevention and biosecurity practises. We'll now move into the second topic which is the main part of the webinar on farm postmortem examinations.

First of all, I would say you need to decide when to do them. I would definitely not recommend to do a non-farm PM, every time. So, in my opinion, the, the main reasons to a non-farm PME are often logistics.

So as you can see here, the geographical absence of PME facilities, so there's no access to it, or, maybe the, the, the facility is closed on that day. The other reason would be for the client, not being able to transport the carcass to the facility. You might also want to do it for your own interest, and sometimes if you want to show the farmer there and then the pathology.

Is, where to draw the line, I would say that, obviously small carcasses are a good candidate for on-farm postmortems. So I would say probably all sheep unless you have a, a very big ram. And for calves, probably, again, all of them up to about 150 kg are, in my opinion, doable on farm.

The other thing would be to do bigger carcasses at knacker yards, especially if you obviously have physical health and the carcass can be lifted. And what I would say that once the carcass is open, I, I don't think there is much less difference, or much difference between, you know, a 500 kg cow and a small calf as you, as you lay the organ on the floor. You can see here, yes, so on Farm PM for sheep is definitely, your top choice.

And this one is an example that I, that I had recently where they said it was a calf who had died, suddenly, and actually when it turned out it was over 170 kg. So just be a bit aware of the definition of calf, which can range from, you know, 50 60 kg to something, definitely bigger. And the situation where I would probably really discourage, doing a non-farm postmortem examination are when there are neurological signs is these, often almost always should, you know, will require the brain and potentially the spinal cord removal, which is quite difficult in the field.

If you are faced with a Legal or forensic case or for example, a very high value pedigree animal if you suspect a zoonotic or a notifiable disease, and finally when there is a contentious issue, so for example with a drug company or a client complaint, in which case probably a third party would be more appropriate. Like everything in life, I would say preparation is the key. I don't always get the time, but it makes a huge difference, and believe me, it's the best investment of your time if you can get everything ready before you start.

So what you see in the picture is how I would get ready before doing a PME again, if I get the time to do it. And I would highly recommend having a, a, a PME kit ready in your car and lay out all the sampling pots before you start. So what you see on the left is what I would use for the opening of the carcass in the in the sampling.

So I would have a couple of very sharp knives, the one with the, with the black handle or alternatively a postmortem blade, which is the, the, the, the blue handle with the blades separately. The preference for the latter one is that you have disposable blades and so they're always very sharp while you would need to sharpen your knives quite often. But I would say again, sharp knives do really make a difference.

So again, take the time to regularly sharpen them. Then you want something that would allow you to cut through the ribs. And so if you have a young animal, you might be able to do that just by cutting between the sternum and the ribs with your knife.

But for older ones, I really like using the garden loopers that you see in the picture. So again, you could buy a set to keep in the car or at the practise. And these are, these tools are really for opening the carcass, for dissecting the organs and for your sampling, then I would suggest you have a pair of forceps, a pair of scissors, and a scalpel blade and scalpel holder.

Moving to the right, at the bottom, so that's how I would lay out, my samples, sorry, my sample, pots and and I would say, again, if you have the time to, to do it in advance of your, of your postmortem. So, I would have few few plain sample pots of different sizes. So if we start from the left and there's a taller one which is quite good for milk and faeces, then you have a chunkier one which is good for pieces of fresh tissue that, that require larger size like the liver or the kidneys.

And then a smaller one which can contain, for example, intestinal contents or a small fresh sample like the spleen or the tracheal rings. Then I would have a plain tube for blood or, or other fluids like the virus humour. I would have some needles and syringes, and then, I would have the urine dipsticks at hand, and if you have the pH strips as well.

And on the, on the right of that picture you can see there's a, there's a plastic bucket, quite a big one. So that's for your histology, for your fixed tissue. So you need quite a big pot because you need a ratio of 10 times the formal in the tissue.

So my suggestion is to have quite big plastic pots for that and with a good lead that would prevent any leakage. So again, I'll, I'll explain a bit more about the, the histology sampling further on that, and I'll also say it here, it's whether you want to carry around or you have the possibility to carry around a packet that's already got the formalin or just have one empty and then place the tissue and place the formalin as soon as possible. What you see still in the picture on, on, on the top left is a, is a gas can, that you can use to basically have a flame.

And the idea here is that you want, maybe to sear the tissue and send a swab rather than a fresh tissue for, for culture, but I know that that's not always possible for for our on-farm PME. So if you have the possibility to have a flame and a spatula, which you see in the picture again with your blade and scalpel blade, then you could heat up the, the spatula to seal the tissue, then heat up your blade to cut through the tissue and then swab it with the charcoal swab that you see in the picture again. But that's not always possible in, in, on farms.

So if you cannot do that, then send a piece of fresh tissue rather than a swab. The the final picture at the top right, so that's my phone. Which has obviously got a camera, so, that's probably the, the, the, the most useful thing because you can take lots of pictures, you can check things, but what I would suggest is buying one of these waterproof cover, and then, you're sure that first of all, you are not damaging, you're not ruining your, your phone, but also that you can wash it properly after you've done the P&E so that you are not carrying out.

Around, you know, pathogens or things like this. So it's, it's really something very useful to, to have. So definitely have your phone or a camera handy because you can take lots of pictures, but try and protect, well, both yourself and other farms when you move into them and also your phone.

And now to the action. After all this talking, we finally get to the juicy bit, the, the reason you're probably all, all here. So how do we actually perform a non-farm postmortem examination?

How do we do it? So, well, I would say that's not much different than anything else we approach in our working life, and that's with a systematic approach. So it doesn't matter if it is alive or dead, if you have a calf or a pig, the same systematic approach, and I would say is, is really the key to success.

So I've Develop my way of doing it based on lots of practise and by reading and studying exactly like you're doing now. You also need to develop your own approach and obviously, you would have modification and add to the, to the one I'm describing here. What I would say is there's no necessary right or wrong thing to do, more that you make sure everything is examined thoroughly and you can do your best in that situation.

So first of all, I would start with the taking a note of the ear tags, so that's what you see on the, on the left hand side, and if it's obviously present and I would do an external examination that usually includes the body condition of the carcass, the state of the coat or the skin, and I would assess the feet. And then I would examine the head, look at the eye and the mucosa, and look inside the mouth. I would check the perineal area and the caudal hindlings for a staining, and then you you can also check, for example, the umbilicus in lambs and calves and, and also have a look if for example, the iodine has been applied correctly.

At this stage, you can also collect sample of Beatrice humour from, from the eye. If for example you think is needed and, and so, but definitely we have a good look at the carcass from the outside first. The second picture is basically your next steps, so I would place the carcass on its back and cut at the base of the shoulder and through the hip joints to reflect the limbs and stabilise the carcass.

And I would definitely recommend you don't skip stage and actually make sure the carcass is stable. You can stay as you see in the picture before starting. That's, yeah, that's something that might take you a couple of minutes, but I've been guilty myself to try and rush through this and, and ended up with a wobbly carcass, which it's really hard to do anything properly.

So, definitely, I've learned from my mistakes. And then finally, the third picture is what's probably your 3rd step before we, we dive into the carcass. And that's the reflection of the skin exposing the body walls.

I usually start at the pubis and then work my way up to the chin, but again, you can, you can do either way. Like the previous step, you actually might be tempted to skip this, to go faster, but exactly like before, I think it's worth the extra 5 minutes it takes, in the long run, when, when, you know, when you're trying doing the p.m.

And the fleece of the skin is in the way. And again, I've been there, I've done that and, and got the t-shirt, so I, I definitely think it's a good investment of, of your time. And during this step when you're reflecting the skin, and you can also check the subcutaneous tissue for changes in colour.

So have a look if the carcass is jaundice or it's anaemic, if you see haemorrhages, if you see edoema, and then you can have a look at the amount of fat that is present. Next is the opening of the cavities. I personally start with the abdomen, but others might start from the chest.

Again, there's not a right or wrong answer here. It's just preferences, really. So to open the abdominal cavity, I make an incision quite coudially around the pelvic region.

Mainly to avoid the rumen and the gas intestine, and try to be careful not to incise them, and that will make your PM a bit messy. If it happens again, no worries, I've done it myself a few times. You just, you just need to be aware of contamination and it's just, just makes things a bit more difficult.

And I then extend all the way to the sternum, as you can see here. And at this stage, really check for the presence of excessive or altered peritoneal fluid, remembering that a small amount of clear straw coloured fluids is normal, and this is also your chance to check that the organs are in the correct anatomical position and once you've removed them, it won't be possible anymore, so make sure you check at this point. Moving to the chest, which is the pictures in the, in the middle, I would make an incision along the ribs, roughly midway with, with my knife, to remove the soft tissue as the bone cutters won, won't cut through that.

I would then cut through the ribs from the back toward the front with the garden loopers, and that's the, the other picture at the bottom. Then I would move, to the head and I would run the knife along either side of the mandible to free the tongue. Again, that's the, the picture on the right.

The hardest part here is to cut through the through the bones, through the higher bones, so. Just look for the junction of the joints rather than, than trying to cut through the, through the bones itself. And, and then by holding the tongue, I would dissect the oesophagus and trachea all the way to the thoracic inlet.

I would then free the rib cage from the underlying attachments and expose the chest cavity. And again, here, you can check for the presence of excessive or altered thoracic fluid. Once the carcass is fully open, I would remove all the organs before examining them rather than doing it in situ.

So I would start with the plaque by holding the tongue and while lifting up and dissecting with the knife all the way to the base of the lungs, cutting through the big blood vessel and the oesophagus at the base of the diaphragm. Then we have the tongue, the trachea, the oesophagus, the lungs and heart as one. And ideally, I would try and lift the pericardium, and then I would put my side.

And then I would pull the abdomen organs to one side and start in front of the liver behind them at the base of the spine to remove this one, leaving behind the bladder and the reproductive tract. So you can see the the picture on the left, that's just with the carcass open and then once the the all the organs have been removed. At this, at this stage, I quite like to finish with the carcass.

Again, that's my preference, so I would, do the, the last, or I would check a few things in the carcass before moving to the organ. So I would check the bladder in the reproductive tract, which you can see in the, in the picture, the first smaller one on the right, . I would, for example, you can collect a urine sample if it's, if it's needed at this point.

I would then open the mouth and that's the, the, the picture far down by making a cut from the corners of the lips and incise the muscle till the joints and then you forcefully open them. And now you can have a proper look at the mouth, especially at the molar and pre-molar teeth. And then finally, that's the last picture on the right.

I would check a couple of joints so if you don't have any suspect of joint deal, then I would just check the easiest one to access, which in my opinion are either the carpal or the tarsal joints or the stifle. And then I'm basically done with my carcass said no, I've, I've taken away all the organs and I can move to them now. Now that we have all the organs, you want to make sure you examine them properly, and that applies to all of them.

So make a note or, or even better, as I said before, take a picture of everything that seems abnormal. So let's start from the back, open the oesophagus along the whole length using a pair of scissors and examine the mucosa. And that's the, the, the picture on the top left.

Then I would incise the trachea at the epiglottis and run all the way to the bifurcation and again examining the surface and evaluating the amount of froth and, and some of it is normal and that's the next feature. I could then observe the lungs for adhesions, for obvious lesions, for their size and the colour of all of the lobes, and really palpate the lungs thoroughly for any change in texture. So that could be either just a diffuse change or localised to some areas.

And I would do that before cutting through them. So the next step, which you see is the next picture is with the scissor, I would extend the cut from the bifurcation of the trachea going into the main bronchi all the way in on both sides. And here, look here.

For, for lambworms. And then finally I wouldize them with multiple cuts multiple times in, in what we call a bread slice cuts and you can see here just to look for any lesions within, within the lungs. And then if you find something or if you have felt something, obviously I would cut through that lesion as well.

What I would suggest if you think you might want to sample for microbiology, for cultures, so then sample the tissue before you handle them, you handle it too much, or what you can do is remove a decent side piece and then put it aside as all this handling could result in contamination and then the pathogen present might not be easily cultured. The next thing, so I forget about my, my lungs and I moved to the heart and I would open the pericardium to check for excessive or altered pericardial fluid. And again, just remember that a small amount of this straw coloured fluid is normal.

I will look for additions or any other change. And then I would observe the heart on both sides, and I would look for things like, as you can see in this picture, and then cut through all the four chambers by starting at the right oracle all the way up to the pulmonary artery and then moving on the left. Side, I would make an incision along the side, opening the atrium and the ventricle, and that would expose the micron valve and then with the scissors, I would cut through to open the aortic valve.

So basically you want all your chambers and all your valves to be visible at this stage, and that's the last picture and at this stage what you want to check is specifically for any septal defects or other things within within the heart. Moving to the abdominal organs, I would start with the solid organs, so the liver, kidney, and spleen, and I have a similar approach to all of them. Starting with my sight, I would evaluate their size, observing them on both sides, looks, look for changes on the surface, like a lesion or all these lesions or approaching and changes in colour.

Then use your touch and palpate them thoroughly. And finally, I would incise them by making multiple parallel cuts in the liver. So you can see an example in the left picture, and I would also open the gallbladder at this stage and do the same with the spleen, and then opening the kidney along the middle and to visualise the cortex and the medulla and the renal pelvis, which is the picture on the right.

As for the lungs, if you think you might want to sample for microbiology, I would suggest you do this before the tissue is handled too much or you've made multiple cuts, and, and then as I said, your results might be compromised. Normally, I would leave the digestive tract at the end unless the animal is freshly dead and I, and I'm investigating obviously a gastrointestinal problem and I want the histopathology to be as fresh as possible. In that case, it would be the first part examine.

So starting by observing them again as a whole, for any obvious lesions or addhes or any change in colour, and again, this can be as a whole segments, whole parts of the intestine, for example, or a localised change. And then starting by opening the room, so that's the picture on the, on the left and the reticulum, I would either empty the content and really look through them to assess the content or I would at least just go through them within the room and ideally if you can, if you can. Remove them, that would be, that would be the best and really look through the contents for grains or poisonous plants because sometimes you just need a small amount of that.

And then I would check the mucosa, remembering that in carcasses they're not very fresh, that would probably peel off normally. At this stage, you can collect a sample of ruminal fluid by squeezing the content into a pot, and either you can do it yourself if you've got pH strips or, or you can, you can send away the the sample. I would also open the omain with a single incision and look for the content and the general appearance.

The next, next in line is the Abome. So for that, for aboma, so for that, I would open it in its full length and collect the contents if you want to do a warm count, although, I would say that's not easily, that's not always easily done for an old farm postmortem. And then you would expose the mucosa.

And, and what I would suggest here, you, you would probably want to wash away the, the what's left and really have a good look at the mucosa of thema but sometimes that requires you to wash away the contents to really have a proper look. Finally, I would move to the small and large intestine. So again, this is preference, but I usually start with y by opening and collecting a faecal sample, and observing its content and mucosa.

I would then move to the column and open it in multiple sections again to look at the content and the mucosa, and then I would track back from the sequence to identify the EU, which is the the branch of intestine that finishes in the sequence. So that's how you, you would find it. I would open it to evaluate the content again, collect a sample, and then evaluate the new cause.

I would then observe the mesoteric lymph nodes and open the dejunum in multiple sections. You, you don't have to open the entire Denum because that's quite long, but I would do multiple sections or if there are lesions, obviously changes in colour, I would, I would examine that area. And again, I would then move to the duodenum, so we'll do a, a section of the duodenum as well just to cover everything.

For this stage, what I would say is just remember to be very careful when handling the intestine is overhandling and the tissue might compromise your histology, so you would want them to sample, maybe not where you've, you've made your cut, so you, you've handled the mu cause it too much. So once you've finished with the systematic cross postmortem, and it's time to think about your sample collection. Unless you have something very obvious, like an intestinal torsion or acute fluke, you probably always need to take at least a few samples.

And I would say it's not possible and probably not very useful here, to list all the samples you need for each condition. So, I'd rather share with you a comprehensive list of samples that I, I would suggest you take to cover all the most likely diagnosis. And so my suggestion would be for you to collect all the samples and then either store them or discuss with the colleagues at the lab, what are the most appropriate to send to reach a diagnosis.

And as you can see from the slide, this is for your fresh sample. And then you have a picture and a list that, that gives you, that gives you the the list of of fresh samples that I would suggest to collect. So, what I would definitely always take is a blood sample, and you can see it's just in a, in a plain red tube and that can be used for serology.

And this can be collected when you stabilise the leg as you cut through the front limbs. Then definitely a faecal samples, that's the next one, in the, in the chunky plastic pot. And as I mentioned, I would take it from the secum, you can take it from the rectum as long as you remember to do it.

And I would say to collect enough to fill at least half of that pot. I would also take a sample of the terminal contents, which is good for clostridial disease. You can do culture and you can check, for example, for joys, and I would use the small plastic tube on, on the left.

Because you're only going to get a small amount of fluid. And then I would have one set of samples from lungs, liver and spleen that can be used for culture. So that, that usually is quite a, a, a chunk, as you see in the picture.

And then another set for other tests. So, like PCR and lungs and spleen, and those are smaller ones that can fit into the, the smaller pots, the smaller plastic pot. And then I would have a a piece of lever for trace element.

So again, quite another, another good chunk. And the kidney that can be used either for culture or if you suspect poisoning. So this should be all, a size to fit in one of the, as I said in one of the, the bigger plastic apart from the spleen which can in, in the, in the second piece of lungs, which can fit in the smaller one.

You place them fresh without anything else and then as I said before, try and sample them before there's too much handling or contamination. So this is the one you see here, the one I've mentioned is the standard list that I think it would cover most of your diagnosis. The one in brackets are the one that you would probably collect quite often, but they are more specific.

So for example, in case of sudden death, and I would also take a sample of virus humerus, and especially in older animals, so that's for a beta hydroxy butyrate calcium and magnesium. If there's a respiratory problem, I would also take a trachea ring, which is quite good for PCR and obviously, if it's lactating anymore, I would probably take a mammary, some mammary tissue as well. The other set of samples I would always take is the fixed one for histology.

All these samples, need to, need to be no bigger than 1 centimetre square, and you need to place, you need to place them in 10 times the volume of formalin. So that's for all of them, and that's very important so that they get properly fixed. You can put them all in the same pot.

The one I showed you, earlier on, the, the big plastic pot with a lid, that's absolutely fine. I, I've used, for example, the, the 1 kilogramme yoghurt pot that they are, they, they, they work quite well. And, and I think as I mentioned before, you can, you can fill the pot with the formalin before leaving the surgery, which probably is the ideal thing.

Or if you don't have any formalin, place the tissue there, and then, and then add the formalin as soon as you, as you, as you can. So again, this is my list that I would say cover most of your diagnosis. So I would take a sample from the muscle, either the leg or the diaphragm.

I would take 4 pieces of lungs from 4 different lobes, and I would take a sample from the heart, one from the spleen, liver, and the kidney. From the guts, I would suggest a sample from the Abomeium and then for the small intestine, I would sample one each from duodenum, dunum and illium, and then one each from the yum and the colon. So as I said, this would be to cover pretty much, you know, most of your likely diagnosis.

And the other thing I was gonna say is that this is for tissue they look normal, look, you think they're looking anatomically or grossly normal. If you see any lesion, I would then sample that as well on top of this list. Ideally, you want to leave the tissue in the formalin for 48 hours and then post them so you don't need to post them in the formalin, but you can just discard the formalin and send them away.

But if that's not possible, then you might want to place the tissue in the smaller pot. You can see this in this picture and send them that way into the formalin if they aren't fixed yet. And now that you're done with your on-farm P&E, what's next?

So when it comes to putting it all together and to interpreting your actual postmortem. I would say this requires a high level of skills and knowledge and experience, and, and, and just to put things into context, to become an accredited pathologist, you would need a 3-year full-time resident in a very tough exam. So, don't beat yourself up for, for not knowing exactly what's going on.

And my suggestion here is, don't consider yourself a pathologist. Use your clinical knowledge, what you remember from that school, and, and your gut feeling and experience to really put all the information gathered together. In this case, I'm not just talking about the, the PME but also the history you've taken, the knowledge of the area and the farm, and your own knowledge, plus, obviously, you can, you can have a good search on Google.

And so I would say, an important thing is definitely the history taking, that's a fundamental part of an effective postmortem examination as it is of any clinical examination. The main things to, to try and determine from your PME are, things like what is normal versus what is abnormal. So, obviously, having a good idea of the anatomy, both for the position of organs, so for example, adhesions versus normal attachment, what is an Normal colour, was it a normal size and texture, and that would obviously help a lot.

And the other big thing that you would see with that with PME is if the changes you are noticing are actually due to autoholysis or it is a, is a pathology, there's something pathological going on. My suggestion in this thing, as I said, it's, it's not easy to sometimes to determine whether one thing is normal or not and whether it's autolytic changes is take pictures, take plenty of pictures and then sample what you think are the lesions and then you can discuss whether that needs to be sent or not or, or if it's significant or not. When you put everything together, you also want to consider if the lesions you've seen are incidental findings.

So the typical example is adult rumen flu that you can find in the rumen, or they are actually significant. And so that's another, another important thing, and again, same thing, and you can make a note, you can take pictures and, and sample the lesion and, and then discuss, or decide whether this is significant or not. And then the, the, the, the other thing I would, I wanted to point out is that you also would, would try to determine if the, what is the cause of death.

So let's say what eventually killed the animal could be septicemia, but what might be an underlying condition. That has led the animal to the septic, which is the important thing. So the typical thing would be, for example, a failure of passive transfer or, or if you have a management problem that has led to the cause of death, but we need to address the underlying issue, primarily.

And so, so this would be what I think are the most important thing from, from your PME and, and at the end of the day, really what you're doing with your postmortem examination on farm is to create a list of differential diagnosis, like you could do after a clinical examination, and from the most likely to the least likely diagnosis, you start your ancillary testing to rule them in or out. So, so that's pretty much the same process. .

And as I mentioned before, apart from a few cases which are pretty straightforward, the actual opening of the carcass is, is really just the beginning of, what I think it's, an exciting discovery. And with this, we've come to the end of this webinar. I hope you enjoyed your time with me.

Thank you very much for it and, and for your attention. It's really been a pleasure to, for me to share my experience and, and I really hope it will be useful when you'll be standing hopefully in a, in a shelter space, ready to perform your own farm PME and to, to have listened to this webinar. You can see my email address and the Twitter account if you would like to ask for further information or you, you would like to connect with me.

And I've also added a link to our resource that we've created with, with colleagues that might be useful for you to. And so, well, bye for now.