Dog daycare outbreak exposes gaps in puppy leptospirosis vaccinations

Leptospirosis is a bacterial disease that can cause severe illness in dogs, including acute kidney injury. In severe cases, dogs can die. Humans can also contract the disease through contact with contaminated animal urine (especially from rodents or livestock) or contaminated water. Human cases often result in flu-like symptoms that can be treated with antibiotics.

Jane Sykes, lead author, professor of small animal internal medicine at the UC Davis Weill School of Veterinary MedicineWe know that the boarding itself was a risk factor. It might have been rodent problems in those facilities, or it might have just been really overcrowded facilities with lots of dogs in close contact with one another."

The study was published in Journal of Clinical Microbiology, an American Society for Microbiology journal.

Daycare environments accelerated spread

"The outbreak was massive," Sykes said. "It might have been the biggest outbreak of leptospirosis in dogs that's ever been recognized."

Researchers analyzed 59 confirmed cases from two specialty veterinary centers and compared them with more than 15,000 control patients. The study confirmed the infections were caused by Leptospira interrogans serovar Canicola, one of the four strains the dog leptospirosis vaccine protects against.

Lack of vaccinations played key role

The findings underscore the importance of vaccinations and vigilance in settings where dogs congregate.

"At the time, Los Angeles area veterinarians rarely offered leptospirosis vaccinations because the bacteria thrive in water from heavy rainfall and L.A. is an arid climate," Sykes said. "It was considered a low risk."

As vaccination rates increased and some dog daycares temporarily closed, the outbreak subsided. Major veterinary organizations now recommend annual leptospirosis vaccination for all dogs.

Disease not limited to Los Angeles

While the westside of Los Angeles outbreak was centered in high-end dog day care facilities, researchers are now investigating cases in homeless encampments in Berkeley and Oakland, where dogs, wildlife and environmental conditions are creating new pathways for transmission.

"This disease - there's no boundaries for it," Sykes said. "We're talking about dogs with this disease owned by wealthy people in L.A. and dogs that are in homeless encampments on the streets of Berkeley dying with this disease because of rodent exposure."

Public health implications

Dogs in encampments often roam between locations and may end up in shelters, increasing the risk of exposure to other animals and people. Although no human cases were linked in the Los Angeles outbreak, experts say the disease is likely underdiagnosed in people, and in recent years, leptospirosis has been recognized in people in large U.S. cities, albeit rarely.

"This is a really important One Health problem," Sykes said. "It affects dogs and it affects people."

Source:

University of California - Davis

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