Leptospirosis FAQs
Reviewed by Dr. Daniel Hebert
Leptospirosis is a serious but preventable disease that’s especially relevant here on the South Shore. At Duxbury Animal Hospital, we consider the leptospirosis vaccine a core vaccine for dogs, and we’re often asked why. Below, we’ve answered the questions we hear most so you can make an informed decision for your dog.
Leptospirosis FAQs
What is leptospirosis?
Leptospirosis is a bacterial infection that’s very common in our area. The bacteria live in wet environments such as damp soil or puddles and can enter the body through small cuts and scrapes on the feet. Because the bacteria have a strong affinity for iron — a component of blood — they tend to target the liver and kidneys, where they can cause serious damage.
Are the new vaccines effective?
Yes. The current vaccines protect against the four most common types of leptospirosis affecting dogs and are highly effective, with efficacy rates between 92% and 97%. Outbreaks tend to occur when vaccination rates drop — as seen in a recent outbreak in Santa Monica, where unvaccinated dogs became very ill.
Why do some breeders advise against the leptospirosis vaccine?
Some breeders caution against it because of historical issues with an older vaccine. About 30 years ago, a vaccine was pulled from the market for causing severe allergic reactions, but that was the result of a production problem. The vaccines available for the past 25 years or so are very safe.
How does leptospirosis infect dogs?
Dogs are typically infected when the bacteria enter through small cuts or scrapes on their paws. Once inside, the infection targets the liver and kidneys, and as the body works to clear it, significant organ damage can occur. Treatment is often intensive and costly, sometimes requiring ICU care or dialysis.
A bit of local history
Leptospirosis even played a role in the early history of the Duxbury and Plymouth areas. Rats carrying the bacteria from colonizing ships infected local wildlife and Native American populations, contributing to a significant decline in that population — which, in turn, facilitated the establishment of these colonies.
Why is the leptospirosis vaccine considered a core vaccine?
Given how common the bacteria are in local wildlife and how severe an infection can be, we consider lepto vaccination a core vaccine for dogs in our area. The cost and risk of the disease make prevention a crucial, worthwhile step.
Still Have Questions?
If you have other questions about leptospirosis or whether the vaccine is right for your dog, we’re here to help. Our team can talk through your dog’s risk and answer anything you’re unsure about.