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0:00Welcome to the VET Podcast by the VET Gurus, Brendan and Mark. Get ready for the latest veterinary news, information and entertainment. Don't forget to visit us at the VET Gurus website, vetguruus.com. Now sit back, relax, it's over to the VET Gurus, Brendan and Mark. Welcome to the VET Gurus, Brendan here with Mark. Before you jump in, Mark, I am awesome, amazing, fantastic. How are you? We're a matching set, Brendan. Anybody likes? Good to hear your voice. Now, bit of housekeeping, Mark. We need to thank our main sponsors for all these years, our three main sponsors, specialised anyone, nutrition, Jen and the crew and the wonderful Oxbow products and every expanding other products at Jen and her team produce, Micah Chips Australia, the best value and the best

1:06Micah Chips available, Mark. And those little mini chips, we don't know, it'll be scary to look at how many we've implant. Are you trying to get chemical essential? Yes. And chemical essential. Where have you gone? Brandon. I'm here. Mark, I think you lost it then, Mark. So I am here. And yes, I was just thanking Micah Chips Australia and their wonderful chips and also chemical essentials, Andrew and the team and F10. F10, drink it every night, Mark, as a nightcap to keep my guts healthy. What about you? I also take it off the wonderful F10. And I quickly mentioned, we've been going so long, this podcast has been going so long that we're going to have to, our contacts at these wonderful organisations are going to start retiring soon. And we're going to have to build new relationships with the new people in those organisations. So that's right, we might have, or we might have a new sponsor, a sponsor, so leave it to

2:14me, Mark, I will chase that. Yes, we have been going a while. OK, so hello to everybody. Thank you for listening and to our new listeners and subscribers. Very much appreciated. Now, you wanted to jump into an email, Mark. You've already replied to Hannah, but she sent us an email about an ongoing discussion we had. Because it's going to segue to our main topic, I reckon we talk about the spiders first. OK, let's do that. I have an article. I was surprised by an article, a news article, in National Geographic. Yes, in a geo. And it talks about the use of fireflies trapped in spiderswebs, particularly orb weavers in some Southeast Asian countries, whether the spiders use the fireflies, flashing their little neon light.

3:16As bait, Brendan, and not only did the whole idea seem amazing to me, but it reminded me of one of my experiences up in Cape York, where I saw exactly the same thing, where we had, in our outdoor area, at our camping, we had a spidersweb, and there were lots of fireflies up there, and inevitably one of them did get tangled in the spidersweb and continue to flash. And this story, which we will link to in our show notes, highlights the fact that the spiders use the fireflies as bait and catch more insects when they have fireflies in their web. Very sneaky. Here, the article hints that the spiders may inject venom into the fireflies to control their flashing signals, but they still need a little bit more research to confirm their hypothesis. So the thought is that they manipulate the flashing signals of the male fireflies to lure

4:20other males to their death, so they make the flashing like a female, I presume, the flash rate of a female, whatever that is, we won't go there. Very interesting. And the fact you've seen this sort of process or something similar out in the wild, they're not so, no wonder you picked up on this particular article there, Mark. Cunning little bugger, isn't there? It is amazing, Brendan, and I actually had my doubts that it actually made any difference because I thought the fireflies were not pleasant to eat, not having eaten any myself, but I thought that, you know, I know that many lizards will get very sick after they've eaten the fireflies. Yep. And I know the geckos up where we were would not eat them at all, they would leave them alone, even if they're right in front of them, and those geckos eat anything. But obviously the spiders do manage to get around their toxic nature and enjoy using them

5:28as bait and catching a few more. That is fascinating, Mark, it is fascinating. So we look forward to, we'll probably be around by the time they do the follow-up research, Mark. Hopefully, how many episodes, 700 or something or other? Yes. Look forward to that. Now, you want to take my shirt about Hannah's hair, yes. So you will remember that in a couple of months ago we discussed Toad Euthanasia, and this was stimulated by person, my personal experience with Toads up in the Northern Territory, and also by questions that were asked by the wonderful Hannah, who works at the YARC Animal Hospital in Darwin, and Hannah had a bit of a follow-up question. She sends us an email that says, hey again, we've been having lots of discussions around pain relief in frogs. Do you guys have any insights? There are huge dose ranges and a very broad range of options discussed, especially opioid

6:29wise, in all of our drug books, things in advance. Hannah, so I thought we would launch into a bit of a discussion about analgesia in amphibians Brendan. Okay, take it away, Mark, you start. So, the first thing is that it does matter, pain does matter. Amphibians, first of all, increasingly presented at veterinary practices, an increasing number of people here in Australia have amphibians as pets. There is a lot of wildlife rehabilitators who work with injured amphibians, and there's a growing amount of conservation medicine done on those species which are affected by the Kittred fungus or other environmental problems. And so having a good grasp of amphibian analgesia is a good thing, I think. So, historically there's been some confusion about whether amphibians experience pain similarly

7:29to our other patients. But I think modern neurobiology and behavioral research indicates that all the tools, all the structures that provide noce reception and the central processing of that information from noce receptors, that is pain, all those structures are there. And even more than that Brendan, the amphibians behave as if they are feeling pain. And I think having all the structures there and all the behaviours that come in, you're up with it is a pretty good argument to say that those animals do feel pain. And if they do, we need to do something about it. Yep. Well said, Mark. Well said. So Brendan. Assume all animals feel pain and let's prove another good role of some of our other amyerecans. Yes. Okay. So, I'm trying to find your agenda here. I'm up to two. I'm up to two. You have to number two. Two recognises.

8:30See where professionals aren't we, Mark? Recognising pain and amphibians. Which is much the same as our many other exotic and unusual species. It's difficult because they challenge us. So don't necessarily show all the things that we recognise as painful responses. And they do have maybe a little bit more limited behavioural repertoire in the way that they can respond. So the sorts of things I look for are unusual body position, particularly if the animal is hunched or won't move as much. It isn't sitting right on the perch, isn't sitting right on the ground. That's a bit of an alert. Secondarily, if there's decreased activity, if they stay in that abnormal posture, if they fail to write as quickly as they might otherwise, if that writing reflexes subdued,

9:34then I start to worry about a painful interference to their mobility. Yes. So often go off their food and choose the way that healthy frogs hoe into their prey. If that starts to disappear and there's less feeding, reduce feeding or feeding absence, I start to look aggressively for a cause and pain is one of the possible causes. They might exhibit increased escape behaviour, trying a voiding contact, avoiding exposure, avoiding everything just to remain still and has pain free as they can be. And while vocalisation isn't always a clear indication, there is variability amongst the species, but particularly with acute pain, there are some species that will vocalise quite noticeably and suddenly. So it's important to take home the message that they will, being largely prey animals,

10:40mask most of those behavioural responses, so they will be subdued and difficult to identify. You have to have strong observational points to refer to. I think it's like our reptiles, pain may be distinctly under recognised and therefore under treated in our amphibians. I think you are spot on their mark, yes. So assume they can and will and do feel pain and that we're missing a lot of the cases when they are in pain mark, but we're going to address that now, aren't we? So tell me about how, how does it all work in an amphibian mark? What is no seception look like in amphibians? What does it look like? Yes. What does it feel like? Well, I've described it. I think the key thing is that those, the receptors that mediate the painful things that you and I feel, what have they got?

11:41The mere receptors, the capper receptors, the delta receptors, they have them all. They have the same ones that we have and they show functional responses to opioids that are similar to mammals. Now, there is one important thing that I always mention here when we talk about the opioids is that there are some receptors that are situated in various parts of the reproductive system and mediate some of the reproductive processes seasonally in our amphibians. So in that conservation management aspect, we have to be careful of the use of opioids in amphibians that we're trying to breed. But in all the others, circumstances where we think there's a painful thing, they certainly have the appropriate receptors to mitigate the painful pathways that we would normally

12:41treat in mammals. And it's very difficult trying to study this, isn't it, both in a research model and experimental pain models with amphibians trying to work out what dose rates etc and which of the drugs that we cannot or should not use. So do you want to jump in and just mention some of the opioid analogies, the analogies X, that we can use in amphibians, the ones that have been best studied? Well, there's fortunately for you and I that the drugs that have been most extensively studied, other ones that are usually we have access to in our practices. So morphine, butorphenol and fentanyl are clearly the biggest three that have been studied. The experiment or work that has been done suggests that the mu receptors, that is the ones

13:43that morphine would attach to. By far and away, they're predominant in most of the species that have been studied. And so there is a regularly reported strong analogies that response to morphine and fentanyl and I think it's safe to assume the other mu agonists, the new, is it antagonists? One's the mu receptor. Yes. They are very effective analogies X and the doses do vary widely. It's tricky isn't it? Sometimes an order of magnitude and so trying to use the best scientific evidence you have for the species you're dealing with is something that I really focus on, Brendan. Yep. Now, another difficulty with it is we need to make sure we factor in as we do with reptiles mark temperature dependent and autesia.

14:44So the metablet, we need to make sure that we have them at their preferred temperatures. And if they aren't, mark if they're at a really prolonged cool environment, the drug clearance will be markedly different, won't it? And it's interesting with our amphibians because a lot of those have a preferred optimal temperatures zone that's a good deal cooler than our reptiles. White temperatures can be as consequential and problematic as low temperatures. So you are correct in focusing on that preferred optimal temperature zone. I was going to quickly mention while we were talking about the different drugs that while we were talking about the new medications and I mentioned butyl formal had been studying in a number of species, it's less effective. There's no doubt in the world. There are in the test that have been done, there's some evidence that it provides moderate analgesia but certainly for severe pain, I would be looking straight to those, if that

15:49new group of drug signs hit the muirosectus. Yep. Okay. So what about non-opiod analgesics? Well, Brendan, Brendan, Brendan. This isn't the area that really highlights the level of research that's been done in amphibians because honestly, the evidence for the use of maybe the non-stroidles or the regional anaesthetics like lignacane, evidence is really, really limited and largely absent. So while the systems are there for us to assume that they are going to work, published pharmacological evidence on doses or how effective they're going to be, really, really limited. Now I would definitely be happy to use molybpsicam in my amphibians but the evidence backing

16:51my action in that course of action is much more limited. I freely admit that. I do feel that least clinically, the local anaesthetic agents particularly lignacane, they seem to be very, very effective at, you know, if I have an anaesthetic and an incision to the abdomen using lignacane clearly makes a difference but I think the key thing there, Brendan, is likely to be lignacane in our other species. We have to be very careful about the dose and in those small animals it's very easy to overdose them and cause cardiac problems. Yep. Now, it's tricky isn't it? There's a lot of rubbery figures out there. There's a lot of amphibians out there also. Okay. So let's chat about what you do practically, Mark.

17:53It's a nice point that you make because I think we forget sometimes when we look at, say we're looking at dogs and cats and there are profound differences in the way that we would use opiates between dogs and cats or the way that we would use non-steroidal between those species. Yep. You know, the toads that we see here in Australia are more distantly related to our frogs than dogs to cats and eggs, a lot of, one of the other common amphibians we see here in Australia, they're more distantly related than cattle and dogs. And so I think it's really important to keep in mind that while there are guidelines to use for a lot of the species that we get to see, there's just no data to use. And so you do have to be a little bit cautious, I suppose, use the best data you can get and extrapolate carefully.

18:54Yep. So when I'm doing surgical procedures, I definitely employ opioid analgesics. I almost invariably use very carefully titrated local anaesthetic doses, generally in full training it into the, if I can get it in with an insulin through engine to the muscular region associated with the surgical procedure. And then superimposed on that is an appropriate anaesthetic protocol for that animal. So it sort of does follow the same sort of ideas and patterns of multi-modal analgesia and anaesthesia that we use in our other species, but tailored specifically to these animals. Yes. It's almost, you really have to concentrate and sit back or sit down Mark and look at the individual what species of amphibian do we have here, what potential analgesics will work, what non-steroidal will work, what opets will work on this one, is there any references

19:58to any use of those products in this species and more often than not we end up extrapolating don't we? It's a best guess in a lot of the cases even with some of the well, I was wasn't going to say well research, that very commonly kept species Mark. Yep. Look, I think there's increasingly a recognition that their sentient sensitive vertebrates that they definitely feel pain and therefore require analgyz or whatever we know pain for potentially painful procedures are to be performed. And so I think it's a rapidly developing area and it's one of the things I think unusual and exotic veterinarians should continually refer back to the literature because things are changing on a year to year basis as we get more information. Yep. Okay. What about how does this all relate to welfare and ethics Mark?

21:01Well, I think that that we're the advocates, Brendan, we keep saying this whenever we have a talk about many aspects of animal welfare and I think the long and the short of it is that where the agents in the whole system that have the best understanding of the potential that pain can cause these animals. And so we have to be powerful advocates for for their welfare and for the process of providing analgyz when we know there's going to be pain. I know that there are international standards. The world organization for animal health has welfare principles that now include standards for reptiles and amphibians. And I expect to see those increasingly be taken on board both in husbandry circumstances and research circumstances.

22:03Well said. Well said. It's a challenge though, isn't it? Luckily we do have a couple of things that help with the practical approach to analgyz in our amphibians mark. One is Vin and they're excellent exotic animal formality which online also has for some not all of the drugs I think but a little calculator mark. When we're tired trading down doses for our little animals mark we can ensure that we're not making a big mistake and a decimal point error of a couple of thousand or so with them. The other one needs the exotic animal formality because the thing I like about that is at the end of every chapter and a lot of people forget it does have references to published papers mark on the species involved in that individual chapter so you can look up then

23:04the details of whatever study they did in that analgyzia for that amphibian mark. So if there will be those major knowledge gets we have and we'll start to be filled in over the next few years we will see more species specific pharmacokinetics. I expect to see a lot of work on non-steroid alls in amphibians. I wouldn't be surprised there's species with the behavioral pain squaring systems and of course as we have more pharmacokinetics we'll have optimal dosing intervals as well as dose rates. So yeah I see conservation medicine, veterinary field work, research animals as well as exotic and unusual pets all benefiting from us staying across this research. Maybe even contributing to it Brendan over the next few years and just making the life of those amphibians much better. Yes and would you like to summarize that in well you have summarised it but perhaps

24:09summarised it in another way madam I think you had a little line that you're going to suggest to close out this episode. The line I'd written was amphibian analgesia who is one of those areas where our ethical responsibility has moved ahead of our evidence base. The good news is that the neurobiology supports analgesic use and the challenge of the next few years is to refine how we do it. Excellent let's do it and let's get out of here Mark. Thanks for listening we'll talk to you all next week. Thanks for listening to the VET podcast by the VET gurus. Don't forget to visit us at the website vetguruos.com where you can subscribe, view show notes, listen to previous episodes and more. You can contact us via email and vetguruosatgmail.com to ask the question or just say hi.

25:12Thanks again and see you next time.