Hi, everybody. Thank you for joining me, for this webinar on blood sampling in exotic species. I know that this, probably, might be a little bit of a refresher for some of you guys.
You're probably working with exotics day in and day out. And for some of you, this might be your attempt at branching out into something a little bit different. So I'm gonna do my very, very best at making sure that this is a, a useful webinar, and a little bit of something for everybody.
And, you can, my email's at the end so you can hit me with any questions at the end if you need to. So, what we are going to look at is we're gonna try and cement this calculation of how much blood can we take from an individual animal. So this will differ depending on the size of your patient, .
Excuse me, I will caveat this and say that the whole presentation is more designed towards, sort of small exotics. I'm not gonna teach you how much blood you can take off a rhino, because generally if you need to take that much blood off of something that big, you've probably got bigger problems and you probably by that point, know what you're doing with them. So, the, the same rules, do, loosely apply.
But we're gonna look at, calculating maximum blood volume that you can take from your smaller species, so. I'm talking your your small primates. I'm talking, rabbits, guinea pigs, chinchillas, lizards, birds, that sort of thing.
We are gonna look at being able to identify venna puncture sites in a variety of exotic species. Like I say, we're gonna be looking at the smaller of the exotic species, rather than giraffe, elephant, rhino, things like that. Mostly because they're not incredibly applicable in practise.
If I teach you, how to, I don't know, put an arterial line in a giraffe or something, that's not, not what you're gonna be doing every day. So, we're also going to have a quick look at key morphological differences, in exotic species blood cells. Now, I will admit haematology is not my favourite thing in the world.
I am more an anaesthesia and exotics kind of guy. So, It won't be too heavy, I promise, it will just be the key morphological differences that you will need to know, for when you are taking samples and for when you are, reviewing samples, as a, is this good enough to submit to the lab, kind of assessment. So there are key learning outcomes.
Now, for how much we can take, it does depend on the size and ideally, we want to take as little as possible. The theory being that the reason you're taking blood is presumably because your patient is already unwell. Now, if your patient's already unwell, especially when we are talking small exotics, they are largely prey species.
They are gonna hide that they are unwell for such a long time. They are evolutionarily designed to hide that they have a problem. Because otherwise they would get picked off first and they would get eaten.
So take a rabbit, for example, if a rabbit looks a little bit slow and a little bit weak, then that's dead easy prey for the fox, and he's gonna get taken out of the population, before you can even say, oh no. Now Because they hide it so well, that means that by the time clients or even by the time we've identified that there is a concern with this patient's health, that means that they really are quite unwell, and they are beginning to decompensate. Now, it's not always as obvious, as what it would be in a dog or a cat with decompensation, because again, they are a prey species.
It might be something as simple as, a rabbit with respiratory disease has just started to breathe, a little bit differently. Their inspiratory effort has increased, and their nostrils are a little bit more flared. That could be all you see.
And if you've got a client who isn't, necessarily keeping a very close eye on their, on their pets, then you might not get these sort of early warning signs. It might not be until that patient presents him severe respiratory distress, that you need to do something, with the animal because that's when it's presented to you. Now, If we're taking as little as possible, that's great, but what if you do actually need a decent size sample?
So, ideally, you don't want to be taking more than 10% of their circulating blood volume, OK? Excuse me. So if we are taking 10% of their circulating blood volume, we need to know roughly what their circulating blood volume is.
Now, these are all approximate mL per kilo, blood volume calculations. So for cats, you're talking 6, 56 mil per kilo for dogs. You're talking 85 to 90 mL per kg.
Rabbits, we're looking at around 70 mL per kg. Reptiles, there, there are about 60 mL per kg, and birds about 100 mL per kilo. Now, that sounds like a lot when we're talking dogs and cats.
It's some of those are, are much higher than dogs and cats. But remember that we're not talking about a lot of the time. We're not talking about a 5 kg bird.
We're talking about a 50 gramme bird. We're not talking about a 3 kg guinea pig, hopefully, because that would be a real concern. We're talking about a $300 to 500 gramme guinea pig.
Because, as I say, these guys don't always come in, as healthy, anaesthetic score one, preoperative blood test just for the sake of screening. These guys come in because they are already unwell. So being able to calculate what our patient's circulating blood volume is, is, it's a useful skill not just for how much blood can we take, but also for intraoperatively.
So if you routinely see rabbits or guinea pigs for spades, neuters, if you're seeing reptiles in, for, of if if you're seeing any of these guys and taking them to theatre, I would be calculating their circulating blood volume. And then you can work from there from what blood losses do you have, because all it would take, for, let's say. So if you've got a healthy patient, that is, a rabbit, it's coming in for a spay and you've got a very diligent owner who wants to come in, and get preoperative blood tests done.
If you have got, I don't know, you've taken the blood tests and. You've got what you would consider a little bit more oozing, than normal, during your stay, you could actually end up accidentally, creating a significant blood loss in that patient without even realising it. I mean, what looks like a lot of blood on one swab might be fair enough.
That's a little bit of blood for, I don't know, a 50 kg Rottweiler. But when we're talking, a 2 kg rabbit, that could be significant. So, and even surgeries with the most minor blood loss, you wouldn't anticipate more than, 10% of blood loss, realistically.
So just be very, very aware of how much we can take before we get all needle happy, and I'll give it a go. That's a cool species. I'll take blood from it.
So if we are calculating maximum sampling volume, I'm not gonna make you do maths while you are watching this, I promise, but our maximum sampling volume is approximately 10% of our circulating blood volume. So if our circulating blood volume is going to be. I don't know, 70 mLs, then in theory, you could take 7 mLs.
Now, we can equate this roughly to 1% of body weight. So if you have something that weighs 700 grammes, you could take 7 mL in the sorry, 0.7 of a mL in theory.
So if we have a guinea pig that weighs 300 grammes. How much are we going to be able to take from this patient? Let's have a quick look.
So, I said I wasn't gonna make you do maths, but you will have to follow me through, so that I can do this maths. Now, 10% of 300 grammes is 0.3 kg times by 0.1.
That gives you a circulating blood volume of 0.03 kg. Yeah?
We don't talk about kilos with circulated blood volume, we talk about millilitres. So if 1 gramme is approximately 1 mL. Squint at it, I know it's 1.1, but let's squint at it and say for easy maths, then we can say that 0.03 kg is the same as 0.03 litres.
And so a circulating blood volume in our 300 gramme guinea pig is 30 mL. Yeah, 30 mLs is minuscule. So 10% of this 30 mLs is our minimum sampling volume, so the MSV.
30 mLs times by 0.1, trying to get 10% of it is 3 mLs. So the, maximum sampling volume for this patient is 3 mLs.
OK? Now, that is the absolute maximum we could take. It doesn't matter too much when we are thinking about, oh, we just want to check his, kidney values, or we just want to check his liver values.
That's fine. But if we are talking about serial sampling, that is when we potentially run into, well, hang on a minute, how quickly can I take the next sample, or this patient was in for X and now he's got worse and I want to take more blood, how much can I take now? So there is a little bit of nuance in knowing how much you can take and when, and that is why I always say that if you can take the minimum amount possible, so if you, if you don't already.
Have the privilege of the half mL, blood tubes, so the half milli lithium heparin and the half mL EDTA tubes. I would definitely, speak to your lab or speak to whoever your exotics lab is and ask what their recommendations are, get them to send you some over, because then that means that rather, even if you only needed, like, I don't know, 0.3 of a mL of serum in order to test what you needed, if you are having to take a whole mL of blood in order to get that 0.3 mL of serum.
You're still taking a whole meal of blood. So, just have a think, have a very quick calculation of it's roughly 10% of body weight, sorry, roughly 1% of body weight. And if you want to be, really, really good, then you can calculate your, circulating blood volume as per on the previous slides.
So, now, I feel like this is the bit that everybody came for. We're gonna talk about how to get blood and where to get blood from with these guys. So, with rabbits, we've got a variety of options.
We haven't just got the lateral ear vein. Now, I know that that seems to be everybody's favourite, and I'm not saying that it is bad choice at all. I just think that decisions, can be better informed when we are using this site.
So first off, this, I don't know if I can use my . My little buzzy pen, here we go, laser pointer, that's what I need. So.
This vessel here, so the rabbit's head is this side, the rabbit's body is over here. So the rabbit is facing to the right. Now this central vessel here is your auricular artery, OK?
This little vessel is your marginal or lateral oricular vein, so that is your lateral ear vein, OK? Now, your ariular artery, you don't, you don't want to catheterize that unless you are looking to achieve an invasive blood pressure measurement in this rabbit, OK? I have had on previous occasion, people mistakenly say to me, oh, why, why wouldn't you just choose the nice big vessel in the middle?
The reason being, it is an artery. I don't want to be putting any drugs in that because they are immediately going to hit the heart like a train. And potentially cause a fatality.
I also don't want to, put a catheter in there without knowing, because it is going to, cause blood loss, because if you can place a beautiful blood-free arterial catheter, please come and teach me because mine always end up with at least some blood everywhere. So, there it is. It's not something that you want to do unintentionally, because you will, you will cause blood loss.
The other thing is, if you inadvertently end up with a clot or a thrombus inside the oricular artery, you can actually end up with ear tip necrosis. It's very rare. I've never seen it, but if you are assuming that what you've put in is a venous catheter and you're flushing it every 4 hours, then you might think that that's not a problem.
But with an arterial catheter, you need to be flushing it more frequently than every 4 hours. And so that would increase the risk of a thrombus forming and it tip necrosis developing. So just make sure that you know your anatomy.
Now, the marginal ear vein, absolutely no problem with catheterizing this guy. Just be aware that you need to make sure that you have supported the ear without making it too heavy. Rabbits get incredibly stressed if they feel that they are wonky, and if they feel that they've got something big and weird on their head.
So I'm all for supporting with, a roll of vet wrap or a watch of swabs or soft ban or something underneath the pinna. But. I'm not necessarily, for, OK, and then we'll tape it, and then we'll tape it again.
OK, and now we'll soft ban it, and now we'll put some vet wrap on. To be honest, 9 times out of 10, I would tape it in, and then I would just put a single, sort of strip of vet wrap over the top of it to protect it. And that's mostly because if I am in a hospital and I've got my rabbits, I will be able to have, a much closer eye on them.
I'm fortunate enough that I, will be able to, if I'm on. That ward, he'll be able to be with them pretty much the entire day and keep a very, very close eye on them if they are, messing with their, with their catheter site, but also I don't want to make it too heavy, because as soon as it's heavy, that is an invitation to mess with it. Now.
The other good thing with the air vein is that you don't have to put a, a buster collar on, to prevent them from chewing it, because it's quite difficult for them, to get round to chew it unless they are sort of a, a giant lo breed. But it does mean that they have both front paws free to just grab hold of it and rip it out of their ear, which I'm sure we've all seen after a beautifully placed catheter, the rabbit goes back in its kennel and just sits up and rips it off its ear, and it's always a white rabbit, and then there's blood everywhere, and it's a nightmare. So, Just be aware, you don't wanna make it too heavy, but also you don't wanna restrict the the patient's normal behaviours.
Having said that, we've also got lateral sofina and we've got cephalic veins. Now, I know that these might seem like a wild idea in a rabbit, but they definitely exist. They are definitely able to be catheterized and they definitely work.
So, the lateral sofius vein, I quite like because of the minimal effort, on the rabbit's part with regards to positioning. So, whereas, with a, with a marginal air vein, they can sit on the table and you can, if you need to, you can towel wrap them. Then you can pretty, pretty easily get hold of their ears.
The cephalic vein and the jugular vein take a little bit more manhandling, and I find that can be quite stressful for them. Whereas the lateral sofius vein, what I would do is I would have a rabbit with all four paws on the table, and I would shuffle them right up to the edge of the table. Obviously with somebody holding them.
We don't want any broken backs or broken legs. And whichever leg I wanted to catheterize, whichever hind limb I was going to catheterize, I would just have the, the person holding, drop that back leg off the table, so that you've then got 3 legs on the table and one leg sort of dangling off. And it does mean that I have to then sit on the floor or kneel down, to get the catheter in.
But for the rabbit, it means that they've only got one leg that is compromised, and so they feel much safer, and they are much less likely, to panic and kick off. So, you definitely, definitely can do lateralsopenous vein in these guys. I wouldn't recommend, unless they're already sedated or anaesthetized, I wouldn't recommend trying to pin them down on their side to do it because that's just stress for them.
It's stress for you, they're gonna kick you, somebody's gonna get a hole in their gloves, a hole in their hand, and it's just, it's a little bit too stressful. I wouldn't recommend that. So valet Bain is a little bit, a little bit more manhandly, so you would position them in the same way that you would a dog or a cat.
The only thing I will say is that because you are having to restrain their head with rabbits being obligate nasal breathers, that they can find that incredibly stressful, that you are holding their head out of the way, especially as the vast majority of rabbits that come in may or may not have, subclinical respiratory disease. Depending on, sort of their, their housing and especially because, in more recent years we've got a lot more brachycephalic rabbits as well. So if you're an obligate nasal breather and you're brachycephalic, imagine somebody trying to manhandle you while you have got a really bad cold, you're really bunged up, snotty, and you're having an asthma attack and someone's trying to hold your head out of the way, of course you would want to punch them in the face, or die trying.
And so. Just be very aware that the cephalic vein is, it is entirely possible to be accessed, but in some patients can be incredibly stressful. The jugular vein, it is, I've seen it used, it's more common for blood sampling than for catheterization.
But I would just be aware, to use it with caution. It's not necessarily, wrong to use a jugular vein. I just think that you need to be aware of the fact that, there can be potential issues.
And the same as anything we do. If we can assess the risks versus the benefits effectively, then we can make informed decisions. So, the jugular vein runs, obviously.
Down either side of, the rabbit's neck. What you also have in rabbits is the lymphatic drainage from the back of their eye, runs almost sort of alongside the jugular veins. Now, that's all well and good.
However, that is the only lymphatic drainage system that comes from the back of the eye. So if you take a sample from the jugular vein, and you end up with a hematoma there, you are potentially going to cause a blockage of that lymphatic drainage. A lymphatic drainage system.
Now, because it is draining from the back of the eye, what is that gonna cause? That's obviously gonna cause a buildup of pressure behind the eye, and that can actually cause ocular proptosis. So you can actually cause the eye to bulge out, and we're more at risk of ocular injuries and things like that then.
It's not something that I have ever seen. It is something that is reported in, in textbooks. But I just think that it is something that when we are looking at where are we taking a sample from, I would use jugular vein last.
So I kind of have put them in the order that I would use them, but not exactly, because it would be very, very patient dependent as well. So, small mammals, I think kind of underrated for taking bloods from, . Only because they are effectively small fluffy potatoes, they don't have anything as easy to access as a rabbit's ear, or anything like that, however.
Anything that looks like a potato with a, a decent sized tail, so rats and mice, you will be able to get the lateral tail vein. Now, I don't think, yes, I do on the next slide, I'll show you. So the lateral tail vein is relatively easy to catheterize, in rats and mice.
It's not something that I would be doing without sedation or anaesthesia, mostly because they are wiggly. Their tail is obviously, it's used for quite a lot of, Well, their day to day life, it's like taking a limb off them and given that they are prey species, they want to feel in control, so pinning them down just to stab them in the tail, is an extremely stressful. Full incident, so I wouldn't be unless they were moribund or edily well behaved, it's not something that I would really consider doing without sedation.
You can in smaller things that look a bit more potato-ish, well, aside from ferrets, then you can use the cranial vena cava. So hamsters, guinea pigs, ferrets, and chinchillas. Some people, in ferrets, I know that you can use the jugular vein, but some people prefer the cranial vena cava because the .
The skin around that area, isn't quite as thickened as it is over the jugular vein. Personally, I would prefer the jugular. There is a little bit of a grey area, with nurses about, are we or aren't we entering a body cavity if we are sampling from the cranial vena cava.
But as far as I'm aware, there's no, There's no black and white distinction in that grey area, so. Do with that information what you will. Hamsters and guinea pigs, and chinchillas, well, for, for all of these guys, if you're doing cranial vena cava, they need to be anaesthetized.
You don't want them to move, move at the wrong moment because you can potentially cause, haemorrhage in there. And especially, I mean, we, I think we've all been bitten by a hamster at this point in our careers. They're not gonna let you do that conscious anyway.
You can in guinea pigs, ferrets, and chinchillas, so the, the larger of the small mammals, you can use cephalic or lateral sofina veins again. I mean, I've had quite a few ferrets that are very good, actually, and would let you catheterize a cephalic. With chinchillas and guinea pigs, I think I would rather them have a little bit of sedation first, even if it was just midazolam buttrophenol.
Just a little bit of something to take the edge off, because, again, You're very up in their face when you're doing a cephalic, and lateralopinus. Yes, again, you, you can do conscious and I would still try to do in the same way as I would with a rabbits. They try to keep all of their legs on the table, and then just drop the hind limb off, whichever, .
Whichever one you're going to categorise. Ferrets, a little bit more of a law unto themselves, little cat snakes. Usually the owners are very good at holding, or you might find that, one of your nurses is very good at holding, ferrets, but they are wiggly little cat snakes.
And so it might be easier, if you're taking bloods from, any of these guys to go jugular vein. Guinea pigs, it's gonna be a little bit tougher to go jugular vein because they are potatoes, in the nicest way, that is what they are designed to be. They are designed to be compact little units, and getting to their jugular vein is not gonna be easy.
So for me, if I needed to take blood off a guinea pig, I think I would prefer a mild sedation, place a catheter in cephallic or lateralopenus, and I would take blood from there. Jugular vein and cranial vena cava, I'll probably consider if that wasn't a possibility. But either way, they're gonna need some kind of sedation for me to allow those because the manhandling and obligate nasal breathers, as we've said before, is gonna be stressful.
Ferrets, I've taken blood off ferrets, from the jugular vein without sedation. It depends how good they are. If they're not particularly well handled, or if they're just a little bit feisty, and yes, sedation, or anaesthesia, might be necessary.
And chinchilla's the same, ideally with chinchillas, because their fur is so thick, when we are taking blood from them, we either want to use a really good. A pair of clippers and make sure that we are not just going to shear their skin off, because they really do have delicate paper skin, paper thin skin. If you think rabbits are bad, chinchillas are, they're basically just made of fairy dust.
But when we are wetting down the area to take the sample, the same applies in all species, but we obviously, we want to minimise heat loss in that area. So we don't want to be dousing the animal, in spirit or whatever it is that we're using to, to prep the skin. But chinchillas, especially, if we get the, the deep layers of that fur very wet, because their fur is so thick, you're actually not going to be able to notice, it's not gonna dry properly.
And they can develop mould within their fur, so just be very aware of how much we are clipping and how much we are wetting down these areas, because it's all well and good saying, yeah, well, I got the bloods. But if your patient's actually woken up with the most ridiculous haircut in the world and he's absolutely freezing, that's not ideal. Sedation or just gas.
Now this is a question that I get asked all the time. So, for me personally, I would prefer sedation, mostly because you you've got a little bit. A little bit more manoeuvrability.
You've got less, staff exposure to anaesthetic gases. And I think you've got a little bit better control over things because you are dosing the patient based on their weight, rather than just stick them in the chamber, turn the IO or placebo up to 5 or 8, whatever you've got, and sit and wait for them to fall down. Having said that, there are some patients that injecting them for a sedation is just too incredibly stressful for them, and I appreciate that.
In that case, yes, you could consider, just volatile agent, and so just gaseous anaesthesia, but I will say, I will say two things, OK? First off is I would rather, if we're doing this, I would rather do that with sevoflurane rather than isoflurane, mostly because iso stinks, and so they're gonna breath hold. And Sivaflurane is less of a potent smell.
So you're not necessarily going to get that breath holding, as dramatically. The other thing I will say is, don't just turn on your oxygen and then ramp up your volatile agent to the maximum. Make sure that you are gradually increasing that volatile agent, because if you walk into a room and it immediately smells different, or, I don't know, you hate the smell of, pasta or you hate the smell of whatever, you walk into a room and you immediately are like, Oh my God, what is that?
And you, you hold your breath, don't you? Whereas if someone was cooking pasta and you were sat at the other side of the room, it takes a while for that smell to get to you, but it's not as offensive. Now, we all know that pasta isn't the example that I wanted to use, but I think, in the, in the interest of keeping things clean, let's use that as an example.
So when we're talking sedation or just gas, it is patient dependent. The only other thing I will say is that if you are using isofluoran to, gas down ferrets, I mean, first off, it can be quite stressful, so sedation in those guys isn't, isn't the end of the world. So I, I would opt for that where you can.
But you can cause, a, an inadvertent anaemia with, isoflurane due to red blood cell sequestration in, short term isoflurane anaesthesia in ferrets. So if you suddenly find, that you look like you've got an anaemic ferret, . It on the bloods, but nothing about its clinical presentation is telling you that they're anaemic.
It is potentially just that red blood cell sequestration. So, that would be my other reason for voting for sedation for ferrets, rather than gassing them down, because, you will, you'll get a better quality sample. And also, you will, potentially avoid that, falsely altered hematocrit.
Now, lateral tail vein, in a rat is what I have done on the right here. So this was a rat that, sadly came in for, euthanasia, but the client wanted to be with him. And so we said, well, why don't we sedate him?
And I'll put a catheter in, and then the vet has access while, while the client holds him. So this was a, I want to say this was a 2, that was a 24 gauge catheter, in the rat on the right. I've done it quite cranially, because, you can go more distal, but I've done it quite cranially in this case, just for stability.
But effectively, if you, if you are looking. Pretend you're looking at a rat's bum, and that is a clock. So the rat is facing away from you, and their tail is the centre of the clock, OK?
So you are gonna find the lateral tail veins at approximately somewhere between 10 and 2 and. 9 and 3. OK?
You can raise them. It, it doesn't have as a dramatic effect as it would in a, in a dog or a cat. So just a little bit of pressure might help you be able to, to visualise something, but often it is a blind stick.
. Equally, in these, especially in smaller, species, so you murodacce or mice, it probably is just going to be a blind stick, and I would certainly recommend. If you have, I don't know, a, a rat brought in, like a, a, a wildlife patient, or, to be honest, any wildlife patient, I would certainly recommend, rather than just, doing the, oh, we'll get it over and done with and doing, an intracardiac stick, I would certainly recommend anaesthetizing them, and having a look at, OK, what are my options here? If this species was, owned.
So, for example, this rat, the reason that I'm happy placing lateral tailbone catheters in rats is because I've done it in wild rats. I've also obviously done it in domesticated rats, but it's, it's practise. It's the same as anything.
Now this is not me saying go round and anything you pick up off the street, try and get a catheter in it. But if, if a, a wildlife animal is brought in, and you have the time and the facilities to anaesthetize them and place a catheter prior to euthanasia or whatever treatment it is, that you are needing to do with that patient, then give it a go and, and practise. Now this on the left is a medial venous, IV placed in a European hedgehog.
This guy came in, he was severely, severely underweight. He had a multitude of issues and he was sadly put to sleep. But again, we attempted a medialsopenous, catheter in this.
It, we did, obviously, we managed, so we would have been able to take blood from him, but obviously because we've got quite a lot of the, the actual catheter, extruded from the leg, we wouldn't be able to, to maintain that as an indwelling catheter. But we would be able to take blood from that. The other thing that's quite good, let me find my pointer again, so the blood that's welled up in this hub here.
If you find that the minute you attach a syringe that all of the blood disappears, what you can do is I would get a, a 1 mil syringe, first off, for all of these guys, I would be using a one mil syringe. But I would get a 1 mil syringe with a needle on the end and. You can use the needle to suck out the blood from the hub rather than trying to use the catheter as the middle man, if that makes sense.
So this is a 26 gauge cannula. Don't be fooled that that is a blue, that is not, that is a purple, just so that you're aware. But what it means if we are able to do, things like this, so this, hedgehog was obviously anaesthetized for exam, and then it was made, the decision was made as the team, that he was not going to be viable for re-releasing into the wild, and he was sadly euthanized.
But the reason why we attempted catheterization in this guy is because, one, he was already anaesthetized, there was nothing to lose. And two, it means that if and when a client brings in their own hedgehog, albeit likely a pygmy. And African pygmy.
It means that we will be more able, and better practised to get a catheter in them. So, yes, it might be easier to just gas down the hedgehog and do an intracardiac stick. And that, I'm not saying that that is wrong, but if, getting into exotics and, exotic animal blood sampling is, and placing catheters in them is something that you want to be better at, then that's certainly what I would be, recommending you practise.
Birds, a little bit different, but by and large the same. So remembering our maximum sampling volume, birds have a circulating blood volume of around 100 mL per kilo, but that can, can be very species dependent. Birds, albeit they get lumped in together, they are extremely diverse, and sadly, I don't have enough time to go through the ins and outs and the differences, of, penguins versus parrots versus water birds, but.
As a, as a sweeping overview. Birds, their right jugular is often larger. And so it is, more often than not people's first choice.
You can, if you are incredibly skilled, you can handle them in a way that you, especially if they're a, a small bird like a budgie, you can handle them in a way, that means that you're able to hold them, and also take the sample at the same time. The only thing I will say is that, in restraint with birds, remember that they need to move their keel, because that is how they respire. If you, restrict their keel, so their breast bone, basically, then you will effectively suffocate them.
Birds are almost impossible to strangle because of their complete tracheal, cartilaginous rings, but you can suffocate them, if you are not allowing them that, that keel movement. So. Jugular vein, right hand side is often larger.
You can also use the medial metatarsal vein. Now, I've put this second on my list because I find it a more robust vessel than the brachial wing vein. So this here is an African grey, that I put, a catheter in whilst he was anaesthetized, for, what, oh, we were, we were X-raying him because of a wound on his leg.
That's what we were doing. And, His wings, he was a little bit of a self-traumatiser, and I didn't want to have to pluck, his feathers if I could help it because I knew he was gonna wake up and mess with them. Obviously, birds from a stress perspective and from a, I'm going to mess with myself perspective.
Birds are quite complex, and I'm not the person to be talking to about bird behaviour. That's not my, my specialty. But just be aware that birds being incredibly intelligent.
Whatever you do that is different, they're gonna want to mess with it, OK? So jugular vein, dead easy if you just want a blood sample. If you need to place a catheter, medial metatarsal vein, especially in water birds, so swans, ducks, anything like that, they have a really quite pronounced medial metatarsal vein, and so it's quite easy to get in, and, and catheterize there.
Obviously, this was in an African grey parrot, so it is possible to catheterize a medial metatarsal vein in something that isn't, a water bird. But you are generally gonna struggle if you've got like a a finch or something like that. If you were gonna need to take bloods off like a zebra finch, you would be looking at jugular vein.
Equally, brachial or the wing vein, very, very fragile. So it is entirely possible, that you can, that you can take blood from there. And, and I have done, but they are extremely fragile, so catheterization of them is a little bit more difficult, because even if you hit the vein, the advancement can sometimes blow the vein, and that's just the advancement of the catheter itself, not even movement of the style.
And this is even more pertinent, in dehydrated birds, because obviously, you lose that venous integrity, if you are dehydrated. We've all seen it in sort of old hyperthyroid cats or old kidney cats, so they get a bit crispy and they get old lady veins. And then we say to the client, Oh, she's just, she's got such little old lady veins, bless her, when actually it is because the dehydration has compromised that venous integrity.
Equally, the maintenance of a catheter, in the brachial wing vein is a little bit more difficult. You will probably find that if you need to give, if you need to maintain a catheter in a bird, you will often find that these are placed intraosseously. They're a little bit more stable and a little bit, easier to prevent patient interference with, but for the sake of access under anaesthesia, the median metatarsal and the brachial wing vein are absolutely fine.
Just make sure that when you, are removing the catheter, particularly with, the brachial vein, that you are, providing adequate compression over the top, because these guys do like to create significant hematomas. And remember that anything that is a hematoma, that's blood that's been removed from the circulatory system. So you might have only taken 1% like you were supposed to, but if there's another 1% sat under that patient's skin.
That's not within their circulatory system, so you've accidentally orchestrated an anaemic patient again without meaning to. So just be aware of that as well. Snakes, a little bit different.
I, I've done, I've tried to split up the reptiles a little bit. But snakes, a little bit different if you go under their scales, please don't try to go through their scales because #1, it won't happen. And number 2, if it does happen, you're going to cause some significant damage to their scales, which is potentially going to introduce infection.
I will say here that for the reptiles, I would be skin prepping with iodine. To be honest, if you, if you wanted to be safe, you could also, do the same, with, with the birds is, . Not dilute your spirit, but get a, you know, like the little swabs.
So you're not spraying the whole bird, you're sort of wiping the specific area. So, and the same for your reptiles because these guys are ectotherms. Number one, we don't want to put anything on their skin that is gonna immediately evaporate because that's all of their heat gone.
But also because of the type of bacteria that's on their skin, we want to use iodine, when we are prepping, snake skin or reptile skin. So ventral tail vein, you can do this, well, with snakes being the shape that they are, and you can do this with them. Almost sat up, the other option is to do it so that they are on the table, or in the handler's arms, and then you come from underneath, as if you are pointing towards the ceiling.
So you can, you can do that. You can also use the Palatine vein that is only used under anaesthesia or sedation unless you want to be stabbing the inside of a snake's mouth whilst it's conscious and see what happens. Don't do that on my recommendation, do not come for me if you decide to do that.
It's not possible. The Palatine vein needs to be, because it's basically it's the inside of the mouth, . At the inside of the roof of the mouth, you'll only be using that under anaesthesia or sedation.
You can catheterize the jugular vein, but because of the scales, you will need to do a cutdown. And usually they would then get sutured in. So rather than just taping, the catheter in, you would suture it in.
For better stability. And you can also take intracardiac samples from snakes. Again, this isn't something that you would be doing conscious because a little movement and you've potentially lacerated something important.
So just being aware of how much you can take and where you can take it from can give you a lot of information regarding, OK, well, this animal doesn't have a cephalic or a sinus. Now what? It still has a tail, so we know we've still got a ventral tail vein.
Still has a jugular, so we know we can get a jugular vein, and intracardiac. I will accept that the Palatine vein is a little bit left field, and maybe not what you were expecting. But, there are definitely options, for venal puncture in snakes.
And equally, if you've got a snake that's feisty or stressed outside of its environment, sedation. Sedation is, it's your friend, OK? There's no point fighting these guys.
Like I say, they're already stressed, they're already, compromised their, homeostatic balances already, on the rocks. So, sedation is your friend. Just because something is, a little bit unwell doesn't mean that you can't sedate it.
It just means that we have more careful consideration when we do sedate them, OK? Stress can be as detrimental, or even more so than sedation, particularly in our smaller species. So just hold that in the, in the front of your mind.
I was gonna say in the back of your mind, but no, hold that in the front of your mind, please. So lizards, these guys are a little bit similar, but there are species that will exhibit autotomy. As you can tell, I struggle to say that word, but basically what that means is they can drop their tail.
So this is things like leopard geckos. There is no point, trying to get a blood sample, from something that is about to drop its tail out of stress. I did have somebody at a talk once, ask me, well, if they dropped their tail, could you not then take blood from that?
And I suppose that that is a very good question and something that I can't say for sure I've ever seen any studies in. But I would potentially argue, that it starts to clot the minute it leaves the patient's body, because obviously when they do exhibit autotomy, they don't then bleed to death. So, because I, I don't know the full haematological ins and outs of how autotomy works and how they don't bleed to death from it, I would say I don't know.
But, . I, I basically would say, if they've got to the point that they're so stressed that they've dropped their tail, that's a, we're done for today, try a different day, kind of job. In this picture here, you can see that, this is presumably a bit dragon, but they've flipped him up onto his back.
I would, it's entirely possible, you can do that, but I would more likely recommend that you keep them the correct way round, the same as with rabbits, and you come from underneath. So again, you are sort of sat on the floor looking up at the tail. And so you can do it that way.
The other option is you can use a cut down to access the cephalic vein. But again, you've then got to glue it back together. It's then a little bit of an issue, with regards to, keeping the catheter in place.
So, these are blood sampling sites only. So elonians, so this is anything that looks like a tortoise, anything that looks like a turtle. So these guys obviously are a little bit more anatomically challenging, because they've got that great big shell.
But it is entirely possible to still get blood from these guys. If we are looking at, taking, a, a blood sample, and to be honest, this works in, most, most species, to be honest, this would be my first choice. We can go jugular vein.
In chelonians, we are more commonly looking at the left jugular vein, mostly because that one is usually larger, and more obvious in the same way that in birds, the right jugular vein is a little bit larger. These guys, the left jugular vein is a little bit larger. I don't know why.
I, if anybody does know why, please, email me and let me know because I've always wondered and never been able to find a real answer. But I would love to, I'd love to find out. You can also use the subcaripacial sinus, which is what I've done here, in the sea turtle.
So the subcaripacial sinus is, it, as with any sinus, it's basically a little pool, of, of blood, but it also mixes with lymphatic fluid. And what you can do is, when you take the sample, you can potentially get lymphatic, infiltrate. So you can potentially get lymphatic contamination.
So if it looks a little bit fatty and looks a bit white and a bit, mm, that's not quite just blood, is it? Then you would take, take that sample, but then take a second sample and you would use that second sample. So you can also use the dorsal coccygeal sinus, so that is, rather than here, we've we've gone above the head where the subcapacial sinus is, you can use the dorsal coccageal sinus, so that is the same sort of area, but on the back of the turtle or the of the tortoise.
You can also use the brachial vein, in very large chelonians. But again, that is something that, I mean, you could, you could use it in, things as, as big as sea turtles. But it is a challenge, particularly from restraint point of view.
I mean, these guys don't go back into their shells like a, a box turtle might or, a snapping turtle or something like that, but just pick your species and be very aware, of where you're getting that sample from. The other thing that I will say with the jugular vein is you might be able to lean on, some of the species, . I, I, I usually say pre-programmed reflexes, but that's maybe the wrong word, but .
Evolutionary, reflexes. So, in, Galapagos tortoises, they have been known, to exhibit something called the finch response. So, if for whatever reason you need to take, blood from a Galapagos tortoise, if you, gently scratch over there, over their, carapace, then they will, in theory.
If they exhibit the finch response, they will stick their neck out and you'll be able to take a sample while someone is scratching, over there, over their shell. It doesn't work for all of them, and it's not, a hypnotic type of effect. So it is entirely possible that they will turn around and bite you.
And believe you me, if a Galapagos tortoise comes for you, you better move because they will bite through your finger like it's nothing. So, just be aware, that Obviously, if we need to sedate them to get blood, that is OK, but usually, we can either restrain them or we'll be able to lean on those evolutionary, idiosyncrasies, shall we say. So, primates, a little bit different.
I'm not gonna spend too much time on them because they are not particularly common in the UK. I, I have feelings about captive primates, but we'll leave those out of this. You can use the jugular vein in these guys, depending on how close to the face, the bitey end you need to be.
The cephalic vein is also possible, more commonly accessed in, in larger species, so like your great apes and things like that. You can use ventral tail vein as well, and you can also use the femoral vein, which is what I'm doing here. This was a cotton top marmoset, that we were, I think he was, blood for a pre-release, I want to say, or, or a transfer, something like that.
And ideally, we would have sedated or anaesthetized patient. To reduce stress. This was a project abroad, and basically the situation didn't lend itself to easily sedating or anaesthetizing these patients.
So, Weighing up the stress of handling versus the, do we have the appropriate facilities, to, to deal with these patients if they are anaesthetized or sedated. Largely, I assume that I'm talking to people who are, practising in, in the UK or at the very least, within a, a clinic, a veterinary clinic, and so you should have the facilities to appropriately manage, sedated and anaesthetized animals. So it is, it's very.
Situational, very, individual, and it's certainly something that we need to consider. But wherever we can reduce stress with these guys, it can actually save their lives, so just making sure that we are doing what we can. Sample handling, I'm not gonna touch too much on, like I said, but just so that you are aware, if you want to screenshot this slide or take a picture or whatever, just so you are aware, EDTA is the preferred preservative for blood samples in birds.
That is because lithium heparin, so your orange top tubes, if you use, most of the UK labs, they will cause red blood cell clumping, so they will cause clotting. So EDTA is your preferred preservative for birds, so think birds are pink, or if you've got purple, birds are purple. EDTA will, however, cause hemolysis, in some reptiles, so it will burst the red blood cells, particularly, with tortoises, or with turtles.
So EDTA is not what you want to be using for reptiles. Lithium heparin is what you want to use for reptiles, so you want to use orange for your reptiles, . If you are sending samples away externally, ask your lab what they need and what sample they would prefer.
It's always good if you are seeing exotics. Please get to know who you're sending your bloods to, whether it be IEX, whether it be pals, like wherever you are sending them to, if you know, if you know them well enough, then you are able to ask questions of, OK, well, ideally I want this, this and this, but which one, which should I prioritise? And they might say, Oh, well, because I do the test this way, I can do this and then this, and you'll only need to take X amount of blood.
So get that relationship with them. Don't assume that just because it says that in the book, or just because you've read online that you should take this amount of blood or whatever, don't assume that that's the case for every single lab. Get a good relationship with them, go and visit them.
Like, have a, a little conversation with them on the phone. They're usually more than happy, to find that people are interested in this sort of thing. So.
Definitely, strike up a conversation with your lab and make sure that you know what you're sampling for, what tube do they want it in. And do they or don't they want a blood smear is always a good one, because, I, I'm pretty sure I can hear them cursing me, from all the times I've sent them a sample without a blood smear, and they did want one. So.
I know that I've er sort of spitted and spotted this a little bit through through everything but the welfare considerations. There are adverse effects to stress, it will and it can impact your blood results, particularly glucose as we know, but. It can also cause adverse effects, as a, as a whole.
So if you've got a patient that needs to come in for repeated sampling, are you actually developing sort of a an anxiety in that patient? Are they then gonna struggle, are they not gonna trust their handler, are they not gonna trust coming into the practise? So there are, there's potential knock-on effects of stress in these species.
Anaesthesia, what, what risk compared to stress? Yes, we have all this beautiful, beautiful data. And ideally, we would have more, but we have beautiful data saying what, anaesthetic risks, percentages and statistics and all of that for anaesthesia in our exotic species.
But I don't think we have enough, data that says how stress is impacting our small animals, and our small exotic species. So, If patients are dying because of stress, then that is certainly something that we need to look at. Equally, if the patient came in and they didn't look that unwell, that stress could tip them over the edge.
Whereas if you're anaesthetizing them and you have got access, to their airway, so they're intubated or you've got a tight fitting mask on, and, and you've got access to advanced monitoring equipment, then you can potentially save their life. Whereas stress, just pushing them over the edge. I'm not saying that you will get them back if you attempt CPR in either situation, but I do think that you are more likely to if you've got immediate airway control and you've got access to advanced monitoring.
So just weighing up the, are we anaesthetizing them? Are we stressing them out too much? Do we need to try this again, or is there another way to do this?
Equally, frequency of sampling and why are we sampling? So are we taking a little bit extra because we think this patient's difficult and so we might as well get the blood now? How often are we taking the sample?
If this patient's got renal disease and we're assuming that it's gonna take. I don't know, 110 days for the life cycle of a red blood cell in a mammal. Then, if this patient's got renal disease, is it not gonna take longer for that anaemia to come back?
Is it not gonna take longer for that erythropoietin to generate, the same number of red blood cells that we had prior to sampling? So, again, I can't tell you a hard and fast rule of how frequently you should or shouldn't be sampling these guys. I, I'm sure there probably is data in, in lab research.
About what the impacts are of, sequential sampling in various species. But those animals will largely be healthy. So when we are talking sick animals, I would say, let's take as little as possible, as infrequently as possible, and thinking about why we're sampling, so.
If all we need is a PCV or all we need is a blood type, we don't need to take a whole meal. So having a think about how important is this sample, and if it's something that I don't know if it was a pre-operative blood test, but. These patients are getting incredibly, incredibly stressed.
Well, how about we have a chat with the client and explain that these are the risks of stress, these are the risks of anaesthetizing without a pre-op panel, and then weigh up the two and help the client to make an informed decision. Positive reinforcement training is a big, big, big, big, big topic, it's something that I could talk to you for another whole hour on, but generally positive reinforcement training is, I mean, it does what it says on the tin. The patient exhibits, a behaviour that you like and you reward that.
So I have seen, conscious blood sampling from several big cats, so snow leopards, tigers, I've seen, hand injections given to gorillas, chimpanzees, I've seen conscious blood sampling in polar bears and brown bears, and so positive reinforcement training really does work. Now, that's not me saying that you're going to be able to positively reinforce the behaviour of a hamster to have its cranial vena cava sampled, but positive reinforcement training is anything from as small as the animal being used to being handled, which in a lot of cases of small animals, small exotic animals, stress is a big one, particularly from being handled, so. Positive reinforcement training begins with how handable they are, and that starts at home.
So if you, are, I don't know, part of the practise Facebook, social media, whatever it is, if you're part of that team, then there's your next idea is some research on positive reinforcement training and some posts for those people with exotic small animals, so that they can go and do some positive reinforcement training. Something that I did with one of my hamsters that I used to have is I would put water in a syringe and a little bit of jam on the end of the syringe. And I would basically teach her to take medication if she ever needed it.
Fortunately, she didn't, but it meant that if I ever came to give her medication, the sight of a syringe wasn't terrifying. So, positive reinforcement training is, it's a, a blanket thing that we can do for everything. It's like when a dog's been a good boy after we've done a conscious ultrasound scan and we give him a gravy bone.
It's exactly the same thing. But you can use it, to be able to do cool things, like take blood off a polar bear or a snow leopard. So, in summary, just because they're not a cat or a dog, it doesn't mean that we can't take blood.
It doesn't mean that they are impossible, and it doesn't mean that we can't run their sample. We need to calculate the maximum sampling volume before any attempts though, because I think we need to be aware of the fact that if we take, I don't know, we've managed 0.1 in a, a, a stick that was unsuccessful.
But then we've managed 0.5 in the successful stick. Well, actually, we've taken 0.6 off this patient then, haven't we?
So, before you have any attempts, successful or otherwise, calculate your maximum sampling volume. Encouraging low stress and fear free handling, that is 100% underpinning and should be underpinning everybody's, practise, and everybody's, conduct, through their work. But knowing your species means that you are able to, appropriately apply low stress and fear free handling techniques.
There is no point, treating a rabbit like a snake and expecting it to be a, a fear-free, a fear free, handling session, you need to know your species, because what might be incredibly stressful for one is actually super chill for another one. So just be very aware that you do have those interspecies idiosyncrasies. And there are all my references.
If anybody wants to drop me an email, you can message me on Instagram, or my email is, the veterinary [email protected]. And you can hit me up with, all your questions.
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