Reaction to the leptospirosis vaccine?


Q: We have had three Shetland sheepdogs over the last 15 years, and all of the breeders have told us not to give a sheltie the leptospirosis vaccine. We complied but recently purchased another sheltie puppy — and were again given the warning. However, after speaking with our vet — and living in Portland, Oregon, where leptospirosis is fairly common — we decided to get her the shot. Following the inoculation, she became so hyper-aroused that training is nearly impossible. We have taken her to a veterinary behaviorist, who prescribed both trazodone and gabapentin for short-term treatment and Prozac for over the long haul. Despite her being on all these medications, we have seen very little improvement in her behavior. Our breeder insists the behavior is the result of the lepto vaccine, but our vet is unaware of a connection. We were wondering if you are aware of similar reactions after this vaccination
in shelties.

Juanita Petersen
Portland, Oregon

Dear Ms. Petersen,

A: “Never say ‘never,’” comments veterinary internist and Your Dog editorial board member Michael Stone, DVM, “although I’ve not seen or heard of long-term behavioral side effects in any breed in my 35 years of practice, nor could we find any accounts in scientifically validated literature.

“Vaccination against leptospirosis has had a bad reputation because the first-generation vaccines caused a lot of reactions in dogs, including discomfort and swelling at the vaccination site, hives, facial swelling and, in rare cases, collapse. Newer leptospirosis vaccinations, in widespread use for the past 10 years, are much safer.” Side effects, which are short-lived, include lethargy — the opposite of hyperactivity. Additionally, there is sometimes a transient loss of appetite, which like a change in energy level bounces back within a few days. Such reactions may occur with vaccinations in general. They are not specific to the leptospirosis vaccine.

Incidentally, a cursory online search for reactions to the leptospirosis vaccine in shelties shows a number of sites recommending against the vaccine for that breed. One sheltie rescue organization recommends “NOT giving this vaccine to your sheltie,” citing reports of liver and kidney failure “and even death.” But it doesn’t give any information about the reports or where they appeared. (Indeed, the lepto vaccine protects against kidney failure.) And a forum on the subject has someone weighing in that the vaccine “can cause very dangerous side effects.” But again, no references are provided. A magazine article goes so far as to say the vaccine “doesn’t work.”

That’s not true. The vaccine has most definitely been proven to protect against canine leptospirosis, which tends to affect those dogs living in warm, moist environments with stagnant puddles, ponds, and mud. The bacteria that cause the disease also thrive in the urine of wildlife that includes skunks and raccoons. For people whose dogs live or romp in areas where they might contract the disease, Dr. Stone says he would “absolutely recommend vaccination against leptospirosis.” The illness causes symptoms ranging from fever to severe muscle pain, shivering, overall weakness, and sometimes organ failure. And it can jump from dogs to people, as we explained in the January issue of Your Dog.

As far as your own dog, we suspect a workup for an unrelated medical condition may be in order, particularly since psychotropic drugs are not helping to calm her. Perhaps a consult with a veterinary neurologist might be scheduled to see if she has a disease such as meningitis. Please bear in mind that it can sometimes seem like one thing leads to another — for example, it can look like a vaccine causes an illness. But frequently, what appears to be cause-and-effect is simply an unfortunate and potentially misleading coincidence.


  1. My Maltese got Lepto from the vaccine and died. My dogs will never have that vaccine again. The drug company sent me a check for $400 saying they are not basically admitting fault. The hospital bill was $12,000. My dogs are small Maltese and Maltipoo. It is not recommended for small dogs so search the small print. Mine are both under 9 pounds. Bella who I lost was 5.5 pounds.


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