Leptospirosis in Dogs

Vaccination May or May Not be Necessary


Our vet recommends Luke have a leptospirosis vaccine. In what specific areas are the large outbreaks of lepto occurring? Does a dog have natural immunities to lepto? Does the vaccine protect against the most lethal versions? Our dog is never off leash, so won’t come into direct contact with wildlife.


Dr. Nichol:

Luke is a lucky dog to have owners so concerned about his safety. Leptospirosis, an infectious disease of the kidneys and liver, is caused by an organism that is transmitted primarily through contaminated urine. It’s found most often in moist areas where infected pigs, cattle, horses, and wildlife live in large numbers. Free ranging dogs can be at risk; cats get a pass.


There have been more cases in recent years, including dogs infected by strains that had not previously caused canine disease. The latest vaccine covers all 4 of the problem strains but it has less than a perfect record of protection. And there have been adverse reactions, most often affecting small dogs.


It’s tough to get our arms around the lepto problem in part because it’s a moving target. In the past we have recommended vaccination for dogs in rural areas but recent studies have found the same strains in urban and semirural pets. Experts now advise vaccinating dogs who live where the prevalence is high-and that keeps changing.


There is no consensus on how often to vaccinate; the duration of immunity varies with the individual, ranging from no response to 12 months. According to Dr. David Lewis, board certified in veterinary internal medicine, “The rule-of-thumb is to use only those vaccines that are medically necessary and vaccinate as infrequently as medically appropriate.” Dogs in New Mexico are at low risk for leptospirosis right now. Stay tuned.