Leptospirosis and its serovars: a re-emerging pathogen

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EP: 1.Leptospirosis and its serovars: a re-emerging pathogen

EP: 2.Mitigating leptospirosis with vaccines that reduce both transmission and circulation in the bloodstream

EP: 3.A paradigm shift to leptospirosis as a small dog disease

EP: 4.Tactics to assuage client vaccine hesitation

Content sponsored by Merck Animal Health

Adam Christman, DVM, MBA: So welcome back in this segment, we're going to be talking about leptospirosis. So we're gonna get in the know with lepto. Are you ready, everyone? Alright, so let's just kind of talk about a little general overview of leptospirosis and talk a little bit about their serovars. So, Dr Chatfield, kind of lead the way a little bit. Tell us a little bit about lepto and its serovars and what do we know?

Jenifer Chatfield, DVM, DACZM, DACVPM: So number one lepto is one of my favorite pathogens. So give me the hook, Dr Chrisman, if I'm carrying on. But lepto is actually I think pretty fascinating. In the United States, it's considered a reemerging pathogen, because we're starting to see a trend and an uptick of cases in humans and in pets. But it's a bacterial disease and it likes warm, slow-moving water, which is interesting for bacteria. Isn't that unique? No, it's not. Come on, friends. Bacteria, right, bacteria love warm, moist places. You guys know that, right? So anyhow, so that's its happy place, although it's pretty adaptable, because lepto is found worldwide. So if anyone ever asks you, "Do you have lepto in your area?" Your answer is, "Yes, yes we do, at all times." It's always there, not just during an outbreak, but it is one that has a cycle through wildlife. So the reservoirs [are] raccoons, possums, wildlife, squirrels, rats, pigs, all those sorts of things. And that's where we get into the serovars. So I think there's like 250 different serovars that have been identified. And they kind of go back and forth with the geneticists, whether or not they're going to be serovars, or species, or subspecies. I don't care clinically about that. But we do know that there is this very complex relationship between specific serovars and their maintenance host. So that's like a marriage. And so it's...they've adapted to not kill that host, right? They don't piss off the immune system in that creature, so that the creatures rocking along just fine and peeing out all that lepto, right? It's passed in urine. And so we don't want to have that happen, because then you don't see clinical signs, right? The dog can have lepto with no clinical signs, or very mild ones, if it's that perfect serovar match, right? And so for dogs, just for everyone who plays trivia, that's canicola.And in rats, it's ictero. Like you say the whole world because you said...

Adam Christman, DVM, MBA: Icterohaemorrhagiae?

Jenifer Chatfield, DVM, DACZM, DACVPM: Right, icterohaemorrhagiae, I just call it ictero because I'm not saying all that on camera. And then there's other ones, you know, that are paired perfectly, but those are the 2 big ones we worry about. And it's a disease that's zoonotic; we can get it. So this is like your number one reason when you talk to your 5 or 6 year old, or your husband, when you say we don't drink dog urine, right?

Kathryn Primm, DVM, CVPM: I say that all the time.

Adam Christman, DVM, MBA: I said that last night.

Jenifer Chatfield, DVM, DACZM, DACVPM: I mean, I don't care if the cool kids are doing it. We're not. We're not. Yeah, and so it is something to make all pet owners aware of. And I joke about drinking dog urine, but you know, if you've ever seen a kid pet a dog, they do it like this, right? So you want to keep your mouth closed.

Adam Christman, DVM, MBA: And Dr Primm, what are some clinical signs that dogs present for with lepto?

Kathryn Primm, DVM, CVPM: Well, they can be really sick, the ones that by the time I see them, right? They're really sick, and then the whole staff is like, "This can be lepto; this is zoonotic," because they've been trained on that. So when I go into the exam rooms to talk with pet owners, I always mention, "I want to vaccinate your dog for this, because of this and this and the fact that I want to protect you and your family too. Because even though your children may get a little dog urine, your dog is definitely drinking out of puddles, and your yard has squirrels. And in Tennessee, your yard has possums and raccoons, too."

Adam Christman, DVM, MBA: But Dr Mortsakis, you're in the city, so you don't see lepto, right?

Yasmine Mortsakis, DVM: We see lepto, yeah. We don't have any rats in New York. None are there. Yeah, no, we see lepto. And I think sometimes, you know, like you're talking about, we see them when they're really sick. And so, you know, it's top of mind. But sometimes, you know, dogs that are not so clinically sick with lepto can come in with sort of nonspecific signs of maybe not eating, not feeling so good, a little diarrhea, you know, a little vomiting. And I think those are the tough ones to diagnose. And, again, you know, there's a vaccine available so we can all be a lot safer.

Jenifer Chatfield, DVM, DACZM, DACVPM: Because there are...there's really like there's 2 presentations for lepto. And if you get to pick, you pick having the renal version, the kidney version, right? Because the mortality rate for the hepatic version of lepto is actually still like 40%, even in the face of treatment. And and that's true of people too, right. So don't pick that one. Whereas the urinary tract infection can be just that, like you mentioned. And we're seeing a bit of a trend, anecdotally—paper to come out in a year or 2. But anecdotally, it seems like we're seeing dogs that are 6 months old, or a little younger that are presenting with that first UTI and those are more and more being found to be lepto. And so I think that's interesting that one of the things about medicine, especially infectious disease. You can't sleep on it because just when you think you get it, the dynamic shifts. And Dr Primm, how are you diagnosing lepto?

Kathryn Primm, DVM, CVPM: It depends on what the owner let me do. But you know, I would like to do all of the gold standard tests, but I don't always get to. So mostly vaccinate for it. I mean not every dog [but for my hospital, Leptospirosis is considered a core vaccine, just because it is.

Adam Christman, DVM, MBA: And there are point of care services that are now available for leptospirosis, right, in terms of diagnosing it. So because we kind of know that time is really important when you're concerned about that. So is point of care, something to consider to those that are tuning in about that?

Jenifer Chatfield, DVM, DACZM, DACVPM: Yeah, absolutely. So there's a couple of benchtop tests you can do, right? So there's, I think...one's a snap test and I think the other one is, too. But what's critically important is to understand which test you're using, and whether or not that test is looking for IgM or IgG. And now everyone's gonna have a flashback to immunology first year. Fight through it because one of the tests on the market doesn't differentiate and the other one does. So, if we remember, you can develop antibodies because you're vaccinated, because you've been exposed, or because you're infected. And so if you're doing an in-clinic test, you want to have a test that looks for IgM. Because IgM, if you remember, is the immunoglobulin that spikes early, and then it falls off. And IgG is the one that takes a little bit longer to build, but it lasts longer, right? So it's typically when that you'll get with vaccination. And you can remember that because IgM is "meh." It comes up and then goes away. And [IgG] is "good." It lasts longer. And so you want to make sure of what your test is telling you so that you know how to interpret that. IgG is good.IgG is good.

Adam Christman, DVM, MBA: I'm stealing that one.

Jenifer Chatfield, DVM, DACZM, DACVPM: Well actually it was given to me. I did not steal it. They gave it to me.

Adam Christman, DVM, MBA: So have you heard of leptospirosis in the shows? What's your experience been when you when you hear about lepto?

Laura Anderson: So [we] definitely have heard about leptospirosis. I mean, we live in an area that's heavily wooded and whatnot. My veterinarian always spoke to me about it. I remember, I think was like second or third Siberian Husky. The breeder that I got the dog from was like, "Don't do lepto; don't do lepto," you know, because at the time, it was this vaccine that had a high reaction. Now the good news is like, you only need an antihistamine to deal with the reaction. It wasn't like it was a deadly reaction. You just give it an antihistamine and the dog was fine, but the face would puff up and whatnot. But she was convinced that all of the dogs out of her breeding were gonna die if you gave it leptospirosis. I got yelled at when I did give one to my dog. So I was like, mortified. That was before I was even breeding dogs myself. I've since learned that they've come up with new vaccines, and I was giving that to my dogs. Or I do give that to my dogs. When we train sled dog racing, they're running through puddles. Okay, my yard in the springtime when it rains, there's puddles of water everywhere. My recommendation as a breeder, again, weigh the risk with where you live. I mean, you say it's everywhere in the world, but you know, obviously, you need water in most cases. And so if you live in the desert, you're not as likely you have it.

Jenifer Chatfield, DVM, DACZM, DACVPM: So what's funny is it's totally counterintuitive. So in Arizona, but this is but this is what everyone thinks, right, because it does like water. But I tell you it's it's counterintuitive. In Arizona, they have outbreaks almost every year. And so they finally they put together a paper that talked about what are the risk factors in low prevalence areas, and one of the risk factors was dog parks. Does your dog go to a dog park? So even without water, but I'm so glad you bring that up, because when we talk about the characteristics for environmental survival of lepto, everyone instantly does that. They're like, "Oh, Florida's got it, but the desert won't." And sometimes it doesn't come across. But yeah, that's crazy town, but it's true.

Laura Anderson: I mean, if you're definitely gonna be exposed to puddles of water and where these with this disease can rest. I mean, certainly that's, that's something you want to get that done, you know, our personal recommendations have been to do them in and again, I I hear that, you know, you guys might do them with the core puppy vaccines or whatnot. My personal preference is to separate it after the the last puppy vaccine, come back a month later start looking at doing the leptos Mostly to see if you do get a reaction. If you combine it all together, and you get a reaction. You don't know if it's the core vaccine, you know, with the Parvo and distemper and everything else, or if it's a lepto, but it gives you a chance then to say, "Hey, my dog's reacting to that particular vaccine, I will be prepared with the antihistamine before they go the next time to get the vaccine." So we never say don't give it because I don't want to be the one that gets called this the breeder said, "Hey, you told me not to do this now my dog’s dying of lepto."