Why you should vaccinate your dog against leptospirosis in Ontario

When Helen Da Silva’s six-year old Maltese Charlie refused his dinner one recent Friday night, she couldn’t have anticipated how quickly the situation would escalate or the harrowing ordeal that was to follow.

When he still looked ill the next morning, she decided to take him to the vet.

“He was looking very mushy, just not like himself at all. Because he was a very playful puppy,” she tells CityNews.

Initial tests showed some inflammation in the dog’s stomach and bowels so a blood test was done and a broad-spectrum antibiotic was prescribed.

That night, Charlie continued to refuse food and by noon the next day, Da Silva received news that his kidney levels were “elevated.”

A visit to the emergency clinic and ultrasounds followed along with more bloodwork which revealed that Charlie had contracted a disease called leptospirosis.

“I’d never heard of it,” says Da Silva.

“[Thereafter] we were referred to the Ontario Veterinary College (OVC) Animal Hospital in Guelph because I was told that they’re the only ones that offer kidney dialysis and that there was a good possibility that Charlie would require [it.]”

Charlie spent two weeks at the OVC hospital and had two dialysis treatments there.

“Just when we thought that he was going to make it, unfortunately he didn’t,” she says.

“My family’s heartbroken, but aside from that, I’m just so angry. I’ve now been reading articles from 2018 about people who went through the same thing. And here we are in 2023 and there’s no one making the public aware of this bacteria.”

What is leptospirosis?

Leptospirosis is a bacterial infection that can affect both humans and animals.

Dr. Scott Weese, infectious disease specialist and professor at OVC, explains that the bacterium that causes the disease is carried by farm animals like goats, pigs and horses and wild animals like raccoons, rats, skunks and possums.

“They eliminate the bacterium in their urine and humans can get exposed, dogs can get exposed through contact with urine-contaminated areas,” he says.

“We can get a wide range of disease in dogs — we can see kidney disease, liver disease which would be the most common combination.”

Other symptoms could include fever, a low platelet count, bleeding and lung problems.

The bacteria thrive in moist and wet environments like water bodies and wet soil.

“So if the bacterium is peed out and it’s an area that stays fairly moist, that bacteria will stay there and a dog can encounter it,” says Weese.

How common is leptospirosis?

Dr. Weese says several decades ago, only dogs in rural and farm areas were considered at high risk for leptospirosis because the chance of coming into contact with wild or farm animal urine was higher.

However, it is now also common in small urban dogs.

“The main reservoirs [for the bacterium] we see in Ontario are probably raccoons and rats. There are a lot of those in cities, particularly around Toronto. So these small dogs that live in a condo tower, for example, they’ve got a small green space where they go out to run around and pee. And what happens at night? A lot of raccoons come out and do the same thing,” explains Weese.

“So we’re really condensing the contact between wildlife and our pets — even though they don’t have direct contact very often, they’re living in very close environments.”

He adds that there can be seasonal spikes of leptospirosis.

“This is a disease we see more often in the spring and the fall because it likes moist environments. So in the dry summer, the bacterium dies really quickly, in the winter it doesn’t survive as well either. It doesn’t go to zero, we can see it all year, but we see waves of it,” he says.

Given the annual weather conditions and presence of wildlife that make it conducive for the disease to spread, Weese says he considers leptospirosis endemic in Ontario.

Treatment and vaccination against leptospirosis

Toronto Humane Society’s Chief Veterinary Officer Dr. Karen Ward says the disease is very treatable if caught early.

“If you’re on board early, it currently is still responding well to antibiotics,” she says.

If the disease progresses, hospitalization could be required for treatments like dialysis. If the dog recovers, it could suffer from long-lasting kidney damage.

There is a vaccine to protect dogs from leptospirosis and Dr. Weese explains that dog vaccines are broadly classified across the world as “core” and “elective.”

Core vaccines are those needed by all dogs everywhere — like distemper or parvovirus. Electives are based on the risk of exposure.

“For leptospirosis, there are some really dry areas of the world where it’s not much of a concern. That’s not Ontario. So anywhere in Ontario, we’ll see leptospirosis. So I consider it a core vaccine for any dog in Ontario,” he says.

“There’s always going to be risk. If your dog never goes outside, there are still actual risks because rodents can bring leptospirosis inside. And we’ve seen that where someone finds a mouse in their dog food bag and that’s how the dog got it. So there’s not a good way to absolutely prevent exposure.”

Dr. Ward says in the past, there were some concerns about giving the leptospirosis vaccine to smaller dogs.

“Smaller dogs have a higher incidence of vaccine reaction than larger dogs … and we used to think that the leptospirosis vaccine was more likely to be a vaccine that you would have an adverse reaction to. Those vaccines have really evolved over time and now they are very, very safe. So that is no longer a concern,” she says.

She adds that the leptospirosis vaccine is a “killed” vaccine as opposed to a “modified live” one.

“Modified live vaccines, which is like distemper and parvo, they have a really strong immune response and it lasts a really long time. So those are the vaccines that once [dogs have] had all of their appropriate initial vaccine series, it can be given every three years,” she explains.

“The leptospirosis one is different because it’s a killed vaccine. So we give it the first time, and then we give [a booster] two to four weeks later, and then it’s once a year thereafter. So, unlike some of the other vaccines, it does need to be repeated more frequently.”

Dr. Weese adds that while pet owners are free to assess their own level of risk and take costs into account, “the cost of a leptospirosis vaccine really pales in comparison to the cost of having to treat leptospirosis, which can run into the thousands if they’re really sick.”

Guidelines and awareness of leptospirosis

Da Silva says the shock of her beloved dog’s death was made that much worse by the fact that the disease she lost him to was preventable.

“How did I not know this? How did I not help him not get sick?” she says.

“I don’t think I’ve ever seen a poster in a clinic, any of the clinics — my regular vet, the emergency clinics — about leptospirosis and the dangers of it. All you see is ticks, fleas, and heartworm.”

Her other dog, Charlie’s littermate Mia, is now vaccinated against leptospirosis. She feels that as the learnings about the disease, as well as the vaccine, have evolved, more needs to be done to spread awareness among both vets and pet owners.

“There has to be a larger body that takes responsibility for this and brings awareness to the public,” she says.

Dr. Weese explains that there is no single authority that sets out dog vaccination requirements in Canada.

Experts look to the guidelines set out by organizations like the American Animal Hospital Association and the World Small Animal Veterinary Association and gather pertinent information relevant to Canada to help people make informed decisions for their pets.

The only legally required vaccine for dogs and cats is rabies.

“[The province is] doing that for the public health component. We don’t have things that cover more of the animal health component. We have recommendations, we have guidelines, we have information that we put out, but we don’t have ‘requirements,’ just because there’s no real body that’s gonna take that on from an animal health standpoint,” says Dr. Weese.