PODCAST TOPIC: Leptospirosis
TIME: 10:09
INTRO: Welcome to K-State's Pet Health Podcast. Today's topic -- Leptospirosis. Today's Pet Health expert is Dr. Ken Harkin, associate professor at K-State's College of Veterinary Medicine. Leptospirosis is a serious disease that can be fatal if not treated in time. Dr. Harkin talks about some of the signs your animal may have if it is suffering from Leptospirosis and what kind of treatment is available.
HARKIN: "Leptospirosis is a bacterial infection -- a group of spirochaete bacteria similar to Lyme disease or syphilis is also a spirochaete bacteria. It's transmitted in the urine of both wild animals and domestic animals and cattle, and pigs are some common domestic carriers. And then raccoons, possums, and rodents, rats are common carries for wildlife hosts. And then they can transmit that disease to man and dogs. Cats don't really seem to come down with that disease. We don't really recognize the disease in cats, but for dogs it can be a significant infection. It can result in kidney failure, which is one of the more common manifestations of the disease we see in dogs."
"There is a study -- Mike Ward and Lynn Guptill -- did a large study using the Purdue Veterinary Medical data base where they certainly showed an increase in the prevalence of the disease from the mid 80s through the year 2000. There are a variety of possible reason for that. One might be improved recognition of the disease, not that we have more of the disease, but more improved recognition and diagnosis. People making the attempt to make the diagnosis, but there certainly could be an increase in the prevalence of the disease as you see communities and new housing developments start to encroach on areas that were just inhabited by wildlife. The wildlife have to go somewhere and they often integrate into those neighborhoods, and you see raccoons and rats and all sorts of wildlife that are not normally integrated or have close contact with domestic pets suddenly have more contact. So that's certainly a possible reason for prevalence of the disease. It's usually some water source, although not always. It could be something as simple as a dog bowl, water bowl out in the back yard. Maybe the rodents decided to take a bath in that, and urinated in the water bowl. It could be a puddle of water anywhere in the back yard after some rainy weather. Farm dogs are going to be exposed because there are typically ponds on the farms and other bodies of water that are there constantly. So those are always a source of infections for the dogs. It's possible, but not likely to have infection from ingestions. In fact, eating an infected rodent would be a possibility but certainly far less common of a source than contaminated water source.
"We tend to see cases year around but I would say when it's as brutally hot as it has been, we don't see too many cases. We see more cases in winter, spring and fall pretty consistently. When there is a little more water we tend to see a few more cases."
"Most people aren't aware that their animal has contacted it because you don't think there is necessarily anything different in the environment. It's typically the same environment that the dog has had the last three years, four years or five years and no dramatic changes -- so we're usually not aware that the dog has had exposure. But clinical signs we often see – some early joint pain and muscle pain. The dogs will have a reluctance to move around. They may be lethargic. They may not want to eat; you could see some vomiting. Dogs may exhibit some back pain - reluctance to go up the stairs. This can be related to swelling of the kidneys from the kidney failure. Fever is not really common, although we see it on occasion. Typically the dogs are ill with anorexia and vomiting."
"For those who have kidney failure, or more severe cases, they usually need to be put on some intravenous fluids. They need to be hospitalized and treated with intravenous antibiotics and ampicillin -- probably the most common one we start with. Typically we treat them with Doxycycline. There's another clinical syndrome that we also see in dogs where they tend to be drinking a lot and urinating excessively. There are a lot of diseases that can cause that same clinical sign. When you rule out everything else, leptospirosis is a potential cause for that one too. Those dogs are usually fairly healthy – eating well and not vomiting, they're just drinking and urinating excessively. Those dogs we just treat with doxycycline. They wouldn't need to be hospitalized and put on ampicillin.
"The thing is, you have to protect your other pets and protect yourself. The other dogs likely have been exposed too, although that's not necessarily true. You have to assume that all dogs that are sharing the same environment probably have had the same environmental exposure. What we would typically recommend if you have a dog that is diagnosed with leptospirosis would be to test the other dogs to see if they show evidence of conversion to show they've been exposed but didn't get sick. If the dogs are negative, it probably would be a good idea to vaccinate them at that point in time. You'd hope that starting to treat the infected dog would be antibiotics and the doxycycline would decrease the risk or eliminate the risk that that dog would transmit the disease to the other dogs."
"Concern for the owners is that if there are other dogs in the house maybe transmitting the disease but not showing the signs, we certain can test their urine to see if they're transmitting the organism. That's particularly important where you have households where you have children or pregnant women in the household -- or anyone where they're more prone or predisposed to developing disease.
HUMANS CAN CATCH LEPTOSPIROSIS FROM THEIR PETS.
"They can get it from the dogs, which is not real common, but it certainly can happen. They're more likely to get it from a primary source, whether it's from rodent, cattle or pets. If you look at all the retrospective in dogs, and the fatality rate in dog is about 20%, which is relatively high, I think a lot of time failure to survive is more related to delayed therapy more than anything else. But in most cases for people, it's a survivable disease, although there's a potential for it to be fatal. The fatality rate is much lower in people than it is in dogs."
"We tend to see the disease just about everywhere, although the places in which we see less would be more like in the desert southwest. You probably wouldn't see the disease very much out there – San Diego, the Los Angeles area is probably not a big area. Phoenix, Albuquerque -- probably not a huge disease there, although they certainly can see it there. Obviously there are lakes and rivers and ponds even there. Really good areas would be the Midwest, upper Midwest, east coast and west coast as you get further north on the west coast – those are great areas for it -- even in the southeast. Actually the southeast would be a pretty good area for it because it's relatively wet there. The desert southwest would be the lowest incidents of disease there."
"Dogs that have high exposure would absolutely be dogs you would want to vaccinate from the disease - farm dogs, dogs that have high recreational exposure, dogs that spend a lot of time outdoors. I think those would be dogs you would vaccinate from the disease. If you lived in the desert southwest, you probably wouldn't do it because the risk of disease is relatively low. If your dog was primarily a housedog and you lived in an apartment, you would probably not choose to do it at that time. A lot of people are concerned about the vaccine reaction and that's traditionally been a problem with the vaccine. Although I think there is - at least in my opinion - it's not necessarily the lepto vaccine that's causing a reaction these days. It's just more of a function that we give so many vaccines at one time. I typically recommend separating the lepto vaccine and giving it at a separate time from the other vaccines. One -- if there is a vaccine reaction you can document which vaccine does it; and two -- it decreases the risk for vaccine reactions.
IN ORDER TO IMPROVE DIAGNOSIS OF THE DIESEASE, DR. HARKIN HAS DEVELOPED THE PCR TEST.
"What our goal was to look at improving our diagnosis of the disease. The traditional way is to use a blood test where they often times test between five and seven and eight different serovars of the Leptospirosis. One of my concerns was that some dogs with lepto were being missed because they were infected with serovars that didn't test positive for the standard panel of five to seven serovars, or they just didn't zero convert. Also likely, they just hadn't zero converted yet, and we might be missing the diagnosis. What our test looks at is looking for the organism in the urine, because that's where the organism is excreted. As a test, we collect the urine. We just do the test to see if there is leptospiral DNA in the urine, and if it's positive it at least helps to confirm the diagnosis of leptospirosis. It's not a test that can be set up in your own office. It would be something you would have to send the urine to a lab that would specialize in and requires equipment that you just wouldn't be able to afford in your average practice. But the average practice can collect the urine and send it to a laboratory that performs the test."
"There are vaccines that are made that just protect against two serovars, and are two companies that make vaccines that protect against four serovars. And the four-serovar vaccines are preferred because they tend to include the serovars that we tend to see the biggest problems with these days. So I guess if you are going to vaccine, I would encourage using the four-way lepto vaccine and not the two way."
OUTRO: And that's another K-State Pet Health Podcast. Check back later for more important information for your pet.