Veterinarians are reporting a potential cluster of leptospirosis cases in dogs near Lake Aquitaine in Mississauga (Winston Churchill Blvd. & Derry Rd. area). Leptospira gryppotyphosa has been confirmed in one dog, with other cases being suspected but not confirmed because owners declined testing.

Leptospirosis is a bacterial infection caused by different types Leptospira spp. These bacteria like to live in water and in moist conditions, and infections in dogs most often result in kidney disease. The bacterium is shed in the urine of infected animals. Leptospira gryppotyphosa is mainly found in wild voles, raccoons, skunks and opossums, and these animals can infect various environmental areas. Any animals exposed to outdoor environments in endemic areas can become infected from ingesting infected water or from contact of infected water with the mouth, eyes or nose, or cuts or other broken skin.

People in the area where these cases have been found should take particular care and probably avoid letting their animals wander into the water or wet areas. A vaccine is available to reduce the risk of leptospirosis, including disease caused by this Leptospira type. Vaccination of pets that are exposed to water or wet habitats in areas where lepto is present is a good idea. People in the Lake Aquitaine area should be particularly vigilant and vaccination of pets would be a good idea.

(click image for source)

Veterinarians are reporting an apparent spike in cases of leptospirosis in dogs in southern Michigan. Leptospirosis is considered a re-emerging disease in many areas of North America. This disease, caused by various types of the Leptospira bacterium, can affect many different species, including dogs and people. A wide range of illnesses can result, including fatal infections. In dogs, kidney failure is a common problem. 

Classically, leptospirosis is diagnosed in dogs that spend time in the woods and similar areas, where they may be exposed to the bacterium from contact with the urine of infected wildlife. Different types of Leptospira have different animal hosts, and infected hosts can shed large numbers of bacteria in urine. These bacteria can survive in wet conditions for long periods of time, and other animals can be infected through ingestion of urine-contaminated water or contact of urine-contaminated water with broken skin (e.g. tiny cuts or open sores on their feet) or mucous membranes (eyes, mouth, nose).

Michigan vets have suggested that the recent spike in cases is the result of local highway construction, which may have driven rats out of their normal habitats and into areas that people and dogs frequent. That’s possible, but it could also be increasing natural re-emergence of the disease, or increasing recognition of the disease, as more attention is being paid to it. Regardless, an understanding that this disease is a problem in the area is important to allow for prompt diagnosis (and proper treatment), as well as preventive measures.

A vaccine is available, but it is not 100% protective and only protects against certain strains of Leptospira. Nonetheless, it’s still a good idea in areas where disease is caused by the strains present in the vaccine and when dogs have a reasonable chance of being exposed.

People can also get leptospirosis. Most often, they are exposed just like dogs: from the outdoor environment. However, pet-to-human transmission has been reported, mainly involving pet rats (since rats are an important reservoir host). People who have contact with an infected dog must take precautions to reduce the risk of transmission. This includes avoiding contact with urine, good attention to personal hygiene (especially hand washing), and proper cleaning and disinfection of any areas potentially contaminated with urine. Prompt diagnosis of canine lepto is very important because treatment rapidly stops the animal from shedding the bacterium. The earlier it’s diagnosed, the quicker it can be treated, and the less contamination can occur.

More information about leptospirosis and Leptospira is available on the Worms & Germs Resources page, and in our archives.

(photo by costi)

When we have a -30C windchill and snow on the ground, my first thoughts usually aren’t about survival of bacteria in the outdoor environment. However, some microorganisms are well adapted for survival in various adverse conditions and we shouldn’t assume that cold=dead for every bug of concern. Along that line, we received a question recently about survival of Leptospira and I passed it along to our lepto expert, Dr. John Prescott. Here’s his guest post:

A reader in Ohio owns a dog that had leptospirosis, and had some questions about leptospirosis that may be of general interest.

Q1. Since the yard is likely contaminated with leptospires, she asked “How cold does the temperature have to get before the Lepto organisms are killed?

A1. Once it’s frozen, as it is now in January, they’re dead. Leptospires are fragile bacteria that are killed by dry heat and by freezing. They survive well in moist or wet environments, with moderate temperatures. In some countries leptospirosis is called “mud fever” or “fall fever” since this description captures so well the environmental conditions under which they thrive.

Although leptospirosis in dogs can occur at any time in the year, it mainly causes disease in the fall, late September to December, peaking in November. The increasingly mild and prolonged falls that we have experienced in the last decade are thought to be an important reason that leptospirosis has resurged in dogs. Interestingly, there is often a “blip” of leptospirosis in dogs in March in Ontario (and likely Ohio), since this is when the snow melts and conditions are wet, even though we can still get freezing at that time. I suspect that this is also the time when the raccoons that are thought to be the main source of leptospirosis for dogs are again active after the winter, and are foraging for food for themselves and their babies.

Q2. Do dogs still shed leptospires after they’ve been treated?

A2. No. Leptospires are quickly killed by the antibiotics used in treatment, amoxicillin or doxycycline. There is no danger that dogs treated for a week with these drugs are a risk to people or other animals. You may read in otherwise very reputable textbooks that these antibiotics “do not eliminate the carrier state” but I have no idea where this misunderstanding comes from.

Q3. Where can I find out more about leptospirosis in dogs?

A3. I like the web site http://www.leptoinfo.com, which is maintained by a vaccine company. I was surprised how many web sites devoted to leptospirosis that there are, but like much on the internet some contain highly misleading information. The “Worms & Germs” site has good past blogs about canine leptospirosis and is usually (just kidding, Scott) a reliable source of information.

One very common entrenched misconception, which is very hard to kill, is that vaccination does not stop animals shedding the organism. This is quite wrong. I suspect this misconception came from an experimental study half a century ago when dogs with pre-existing kidney infection with a leptospiral serovar called Canicola were vaccinated. It would not be expected by anyone that these animals would stop shedding since antibodies don’t penetrate into the place in the kidney where the leptospires live and from which they are shed in the urine. What vaccination does incredibly effectively is to prevent leptospires from actually reaching the kidney and setting up home there. The leptospires are removed by antibodies in the blood, so they never reach the kidney.

Back in the 1980s, Vietnamese Pot-Bellied Pigs were a popular fad pet.  These stout little oinkers are still out there, though they’re not quite as popular as they once were.  Potbellied pigs are cute (at least to some people… to each their own!), supposedly quite smart, and can even be house trained/litter trained.  As with any new pet though, it’s very important to do your research before going hog-wild and getting yourself a pot-bellied pig.  Talk to your veterinarian about what your pig will need in terms of medical care – vaccines, deworming, spay/neuter, hoof trimming, tusk trimming… Because they are uncommon pets, some veterinarians may not be comfortable treating a pig.  Make sure you ask ahead of time so you know to which veterinarian(s) in your area you can (and will!) take your pig.

We recently received a question about vaccination of pot-bellied pigs.  Just like dogs, in some areas pigs need to be licensed by the city, and certain vaccines are required in order to obtain a license.  In this particular case, pigs are required to be vaccinated against rabies, swine erysipelas and leptospirosis.  Regular visitors to this site are no doubt familiar with the issues around rabies and why it’s important to vaccinate for this deadly disease.  (More information about rabies is available on the Worms & Germs Resources page and in our archives.)  Swine erysipelas is a systemic bacterial infection caused by Erysipelothrix rhusiopathia, which can rarely cause a skin infection known as erysipeloid in humans.  This is not to be confused with human erysipelas, which is a skin infection caused by various species of Streptococcus (particularly Streptococcus pyogenes). 

But the question was about leptospirosis vaccination in pot-bellied pigs.  Pigs are susceptible to infection by Leptospira interrogans, just like dogs and people, and if infected a pet pig would be equally capable of shedding the bacterium in its urine and potentially transmitting the disease.  The issues around requiring vaccination of pigs for leptospirosis are very similar to those around making leptospirosis a "core" vaccine in dogs.  More information about this is available in the Worms & Germs post entitled "Should all dogs in Ontario be vaccinated for leptospirosis?"  A pet pig would likely be exposed to the same serovars of Leptospira as a dog kept in the same area, typically by coming in contact with urine from infected wild animals such as raccoons and skunks when they go outside.  However, the risk of exposure for a pig that rarely or never leaves the house would be extremely low compared to a pig that has outdoor access.  Another important consideration is whether or not the pig vaccine is against the same serovars that a pet pig, instead of a commercial pig, might encounter.  This will also vary depending on in what area the pig lives.  The Leptospira servoars pomona and bratislava are actually host-adapted to pigs.

It is also important to vaccinate an animal with vaccines that are labeled for use in its own species.  Vaccinating a pig with a vaccine meant for dogs could have unpredictable results – it may increase the risk of an adverse reaction, or it may not adequately stimulate an immune response, thereby leaving the pig essentially unvaccinated.  Your veterinarian can discuss the pros and cons of vaccination in your pet with the available vaccine products.

More information about leptospirosis is also available on the Worms & Germs Resources page.

From Guest Author Dr. John Prescott, Professor, Department of Pathobiology, University of Guelph.  More information about Leptospira and leptospirosis can be found on our Resources page.

The last decade has witnessed a surge in leptospirosis in dogs throughout much of North America. Ontario and Québec have been part of the surge, which is associated with two serovars of Leptospira, grippotyphosa and pomona.

The reasons for the dramatic increase relate to: 1. The apparent spread of infection in raccoons and to a lesser extent skunks; 2. A changing climate that favours prolonged survival of these bacteria outdoors in the milder fall temperatures; 3. Perhaps to a minor extent increased awareness of the disease by veterinarians. Gillian Alton, a Masters student at the University of Guelph, has shown that the increased infection rate observed in recent years appears to have leveled off, which may be the result of widespread vaccination.

Leptospirosis should be suspected whenever there is kidney or liver inflammation of unknown origin, particularly in the fall of the year. In 2007, there were about 80 positive and 170 suspicious cases in Ontario based on blood tests submitted to the Animal Health Laboratory (AHL), University of Guelph. Since not all such blood tests go through the AHL, it is likely that there would have been about 160 positive and 350 suspicious cases based on this testing throughout Ontario, and an unknown number of cases diagnosed by PCR (a DNA-based test). If one includes cases diagnosed based on clinical signs but without laboratory testing, and about half the suspicious cases as positive cases, then there may be about 400 clinical cases (i.e. cases where the animal actually gets sick) of leptospirosis in dogs occurring annually in Ontario. Clinical leptospirosis in dogs is a serious disease and this number, if the assumptions are correct, represents a high burden of infection.

Arguments for recommending the new 4-way leptospiral vaccines as a “core” vaccine (i.e. all dogs should be vaccinated) in Ontario are:

  1. The suggested size of the problem;
  2. The often serious nature of the disease;
  3. The zoonotic potential of the infection (a small number of human infections acquired from dogs have been recognized in Ontario and Québec in recent years);
  4. The ongoing widespread presence and sometimes large numbers of raccoons in suburban and urban Ontario;
  5. The diagnosis of canine leptospirosis throughout the province;
  6. The diagnosis of the disease in dogs of all types, not just the “male hunting dog” which is sometimes conventionally regarded as “high risk”.

Arguments against recommending the new 4-way vaccines as a “core” vaccine are:

  1. The sporadic nature of the infection, including the lack of exposure of some dogs to raccoons and other wildlife sources;
  2. The number of vaccine reactions associated with leptospiral vaccines (this is not a significant problem with at least one of the vaccines);
  3. The considerable confusion caused by the (almost certainly totally unfounded) suspicion that serovar autumnalis causes canine leptospirosis, but is not in the new vaccines;
  4. The lack of inclusion of serovar bratislava in the vaccine (although this serovar seems to cause only mild disease in dogs);
  5. The annual cost of revaccination.

The vaccine manufacturers have the responsibility to provide the supporting data on which a “core vaccine” recommendation should be based, by testing dogs in Ontario for exposure to the different serovars. In the absence of such data, but knowing the possible extent of the problem, veterinarians should always discuss the pros and cons of leptospiral vaccination with dog owners. My opinion is that, barring problems of vaccine reactions and hypersensitivity in individual dogs, annual leptospiral vaccination with a 4-way vaccine should be recommended.

Lots of things you can get at a convenience store aren’t great for your health, but I wouldn’t have thought we’d have to add rabies to the list of concerns.

Public health officials in Niagara Falls, NY, are trying to track down nine baby raccoons that were handed out by someone outside a 7-Eleven store. Rabies is the big concern, raccoons being an important rabies reservoir species in this area. However, the list of potential diseases that could be transmitted by these raccoons is longer than that, with leptospirosis and the raccoon roundworm (Baylisascaris procyonis) being two other important issues.

As of the last report I saw, seven of the nine (too bad there weren’t eleven… that would have been funnier to report) baby raccoons had been recovered.

The list of reasons that handing out (or accepting) baby raccoons is bad is long, but to name just a few:

  • Wildlife belong in the wild.
  • Often, “rescued” baby wildlife are actually animals that were perfectly fine and temporarily left alone by their parents. Baby wildlife rescued by the public rarely survive and make it back to the wild.
  • Possession of wildlife is illegal in many areas, including New York state. Only licensed wildlife rehabilitators can posses wildlife, so that they are cared for properly and, when possible, re-introduced to the wild.
  • Baby raccoons are cute. However, they grow up to be large, curious and destructive adult raccoons that often end up being abandoned – but then they think they belong with people which makes them even bigger nuisances.
  • Baby raccoons rescued by members of the general public are often handled a lot in the process, leading to a lot of potential rabies exposures.
  • Wildlife belong in the wild.

More information about rabies (as well as leptospirosis) can be found on the Worms & Germs Resources – Pets page.

I did a talk recently for Third Age Learning in Guelph, and there was an abundance of questions. I didn’t get through them all at the time, so I figured I’d address some of them here:

Do mice carry rabies?

Mice aren’t rabies reservoirs like raccoons, skunks or bats, as they don’t have a rabies virus strain that circulates in the mouse population. Like any mammal, they are susceptible to rabies and can be infected. However, most often when a mouse tangles with a rabid animal, it doesn’t end well for the mouse. If a mouse survived a bite from a rabid animal it could get rabies, but since that’s pretty uncommon, mice are low risk.

Can you talk about foot-and-mouth disease? I heard of someone recently dying from it.

This is another one of those situations where diseases have confusing names.

Foot-and-mouth disease is a viral disease that affects cloven-hoofed animals such as cattle, sheep and pigs. It’s a devastating disease for those species, but of very limited risk to people. The odd human infection has been reported but it’s not really considered to be a significant human health risk.

Hand foot and mouth disease is a completely different disease caused by a completely different virus.  It only affects people, and usually, it causes mild disease characterized by oral lesions and a rash on the and feet in kids. Adults can sometimes become infected and serious infections (including death) can occur, but that’s very rare.

Do skunks pose a problem for cats that walk in the same area?

Not really. Rabies is a concern with skunks but that’s transmitted by bites, not by simply being in the same area (and cats are generally smarter about avoiding skunks compared to dogs).

A more realistic concern would be leptospirosis. Skunks can shed Leptospira bacteria in urine and that can contaminate the environment. We uncommonly see (or at least diagnose) leptospirosis in cats. It’s much more common in dogs, and can also affect people. Overall, though, the risk to cats posed by skunks being in the vicinity is pretty low.

How do you test a raccoon population for rabies?

It involves testing a sample of individual raccoons. Rabies testing in animals requires a brain tissue sample, meaning the animal can only be tested after it’s dead. Raccoon testing is routinely performed when there has been exposure of a person (or sometimes a domestic animal) to the raccoon. It’s done in these cases to make sure the raccoon wasn’t rabid, as that influences management of the person or animal that was bitten/exposed. Beyond that, testing of dead raccoons is sometimes performed for surveillance purposes, to see if raccoon rabies is present in a region. Because of the cost of testing, surveillance testing of this kind is mostly reserved for situations where there’s a concern that raccoon rabies is spreading or where the extent of the disease is being discerned.

More Q&As to follow.

Not surprisingly, “should my dog be vaccinated against flu?” has been a very common question over the past few days. Here’s my take on vaccination of Canadian dogs, with the assumption that the recent H3N2 flu cluster in southwestern Ontario has been contained (something that is likely but is still to be determined).

Who should be vaccinated?

  • Dogs that will be travelling to areas in the US where there is canine flu activity (or more broadly, dogs that travel to the US, since canine flu is present in various regions).
  • Dogs that may have contact with dogs imported from Asia. This includes mainly dogs in rescues and kennels that are actively importing dogs, as well as dogs in households of people thinking about adopting a dog from Asia.
  • Dogs that may have contact with dogs imported (or travelling) from the US. The risk here is lower, but if dogs are coming from US shelters, in particular, it’s not a bad idea to vaccinate the dogs that will have contact with them.

When else might vaccination be useful?

The benefits of vaccination decrease as the likelihood of exposure decreases. There are a few more groups where vaccination could be considered:

  • Dogs at increased risk of exposure. This includes dogs that have frequent contact with lots of other dogs, especially dogs from a wide geographic range, such as those that travel for shows or other similar events.
  • Dogs at increased risk of serious consequences. This includes dogs with pre-existing heart disease or lung disease, potential senior dogs, and brachycephalic breeds (i.e. smushy faced dogs like bulldogs).

What about everyone else?

On one hand, it’s easy to say that the risk of exposure is very low, so vaccination is of very low utility (because it’s true). The tricky part is the fact that you never know when (and it’s probably when, not if) canine flu will revisit Canada. It takes two doses of vaccine given a couple of weeks apart for good vaccine effectiveness, so by the time a problem is identified, dogs in the immediate area may already be exposed before vaccination has time to work.

That’s an inherent problem with emerging diseases.

H3N2 canine flu could pop up in any given city tomorrow, but it also might not happen for years. At the moment, it’s hard to say that vaccination is broadly indicated in Canadian dogs, but if people are particularly worried about flu, it’s a safe vaccine and there’s no reason not to get it.

What about my dog, Merlin?

He’s pretty low risk. We live in the country and he doesn’t see other dogs at home. However, he goes into work with Heather regularly and mixes with a few other dogs there. It’s a fairly small population, but those dogs presumably regularly meet other dogs (who meet other dogs…), so if flu emerged in this area, he’d be at some degree risk. At the moment, I don’t have a plan to vaccine him against flu. (Leptospirosis is a different story. He’s getting that booster tonight.)

More information about canine influenza can be found here.

Minus 20C weather is supposed to have some benefits – at least that’s what we try to tell ourselves. (Maybe we’re just trying to justify why we haven’t migrated south.)

I’ve written about leptospirosis a few times recently, given the horrible lepto season we’ve been having. This bacterial disease isn’t new, but there have been two big differences this year: one was the number of cases, which was well beyond what we’ve ever seen here in Ontario; the other was the timing of cases. I’ve been saying, for weeks, that the lepto season has to be over soon. The bacterium is shed in urine of certain wildlife hosts and likes wet – but not frigid – environments. Yet, we’re still seeing new cases.

  • We’re currently trying to figure out why this is, but I guess the key message I have for people at this point is “vaccinate,” since avoiding exposure is tough when we really don’t understand the main exposure risks.
  • The other thing is to consider lepto in sick dogs, even this time of year. Rapid treatment is important for management of this potentially serious disease, and it’s easy to understand how it would be overlooked in late December, since it’s considered a fairly seasonal disease.

Another area we’re working on a lot is tickborne diseases. The general dogma regarding ticks is that the will begin to quest (search for a host) when the temperature hits at least 4C. That’s a distant memory around here, as it hasn’t been above -10C in a while. Yet, I got a report from a reader about a feral cat carrying engorged ticks, from an area north of here that’s snow covered and even colder than here (currently sitting at -27C). It’s been well below freezing there for a long time, and well beyond typical adult tick attachment times. So, where did this cat pick up a tick? Maybe in a warm area such as a barn? Or, is 4C not really the right threshold.  It’s probably a matter of some ticks finding warmer microenvironments and cats seeking out those same warmer (or less cold) spots.

  • Regardless, this reinforces the message we’ve been saying: even in many cold climates, tick exposure is a 12-month-a-year risk. Even using the 4C threshold, it’s not unusual to get a few few days of 4C weather in the middle or winter around here. If the exposure threshold is even lower (or irrelevant if ticks can be questing in some isolated, warmer locations during cold periods) then even that gets tossed out the window.
  • For lepto, the main message is “vaccinate and be aware.” For ticks, it’s “use tick prevention and don’t stop tick-checks.” The risk is presumably quite low in winter, but low doesn’t mean zero, and tick avoidance practices aren’t particularly hard or expensive.

I guess I need to come up with a different “on the bright side…” excuse for this weather.

1) Pick up baby raccoons and take them away

  • Raccoon litter JVGRarely does this end well. It’s illegal in many areas (including Ontario). Raccoons don’t do well long-term in households for various reasons (their curious and destructive nature being a big one). And, they are potential sources of a number of zoonotic diseases (rabies being a big one but not the only concern).

2) Take them to a bar

  • This could be simplified to “take them anywhere.” The more people encounter the raccoon, the more people might be exposed to the pathogens it carries.

Seems like common sense, and yet people picking up cute raccoon kits and taking them somewhere (though not necessarily a bar) seems to happen all the time. A recent incident in Pendletown, NY, highlights the issues. A woman picked up a baby raccoon from a litter of 13 and took it to Mr. Quiggley’s Dead Dog Saloon, where it interacted with multiple people.  Because raccoons are rabies reservoirs, the raccoon had to be euthanized for testing. The rest of the litter was also tracked down and euthanized for testing, apparently, but that doesn’t make a lot of sense to me. If the raccoon to which people were exposed could be tested, that provides all the information that is needed from a rabies exposure standpoint. Maybe there was concern that other people would pick them up or maybe she put the baby back in with the litter after it’s trip to the bar and no one could tell which one it was. Regardless, the raccoons probably didn’t have rabies but the person’s actions led to their deaths.

Beyond rabies, there are a few other potential concerns:

  • Baylisascaris procyonis: The raccoon roundworm is very common, and it’s likely that eggs of this parasite were being shed in feces, or that the haircoat of the raccoon was contaminated with feces containing the eggs. The latter is the main concern because eggs that have been in the environment are the ones that can infect people. Infection in people is rare, but the parasite can cause very nasty neurological disease so it’s one to be aware of.
  • Leptospirosis: Raccoons are a host of Leptospira bacteria, which are shed in urine. Contact with urine isn’t uncommon when handling young animals, and urine that gets into cuts or the eyes, mouth or nose can result in transmission.

Hopefully not many people actually handled the critter and they washed their hands (but sometimes common sense is surprisingly uncommon).

Take home message: Leave wildlife in the wild.