As a native of the Canadian prairies, for much of my life I was oblivious to the glory of fall, and the wonder of cooler nights, warm (but not hot) days AND brilliant red, orange and yellow foliage. However, now that I live in a part of Canada with a fall season > 1.5 weeks, my thoughts turn to the colour yellow for a more sinister reason than 5-star Atlantic Canada leaf-peeping.
Yellow is the colour I associate with leptospirosis, and it’s a rather nasty bug (bacterium) that can infect and cause a range of illness in dogs. Vets typically diagnose leptospirosis as kidney (urine) and/or liver (jaundice) disease...which is why (for me), lepto = yellow. The bacterium is formally known as Leptospira interrogans, and in dogs we usually think about 4 serovars (strains of the bug) as key: L. canicola, icterohaemorrhagiae, pomona and grippotyphosa.
Typically, lepto is shed in the urine of animals like raccoons, rats and other rodents. These wildlife hosts also frequently populate urban (city and suburbs) environments, (e.g. Toronto where I think a raccoon is running for mayor), and then urinate into puddles or other water sources that dogs splash or wander through, thus becoming infected.
Lepto’s also a bug we tend to find in geographic ‘hot spots’ in N. America, and there’s been a few publications (from the U.S.A.) indicating these higher risk lepto locations (links below). A number of articles also show an increased risk during specific seasons, such as in northern climes, where we tend to see more lepto in late summer/fall…hence the title of this post and my hope to increase awareness and reduce dogs getting sick.
Spatial and spatio-temporal clustering of overall and serovars-specific Leptospira microscopic agglutination test (MAT) seropositivity among dogs in the United States from 2000 through 2007. Gautam, et al. https://www.sciencedirect.com/science/article/pii/S0167587710001649?via%3Dihub
Hotspots of canine leptospirosis in the United States of America. White, et al.
Seasonality of canine leptospirosis in the United States and Canada and its association with rainfall. Ward, et al.