Prevention better than cure for canine leptospirosis
By Dr. Ruth MacPete, DVM
Leptospirosis can be an expensive disease to treat with a moderately high mortality rate, yet it is often not included in the differential diagnosis when veterinarians are presented with a dog with sudden onset of fever, depression, vomiting, diarrhea, or respiratory distress.
These clinical signs are not pathognomonic and suggest many more common conditions, such as gastrointestinal upset due to other bacterial infections, parasites, dietary changes, and toxins. Therefore, leptospirosis is often underdiagnosed. By the time some veterinarians decide to do a diagnostic test for leptospirosis, the clinical course may have already progressed to hepatic or renal failure, and it may be too late for effective antibiotic therapy.
"This is really unfortunate," says Larry Glickman, VMD, MPH, DrPH, "because leptospirosis can often be treated successfully with a tetracycline or a penicillinase antibiotic and supportive care in its early stages."
“The earlier the infected dog is treated with antibiotics, the more likely it is to survive,” adds Dr. Glickman, adjunct professor in the department of epidemiology in the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill and chief scientist at One Epi in Pittsboro, NC.
Even more important, leptospirosis can be prevented with yearly administration of a canine Leptospira vaccine (bacterin). LeptoVax® by Boehringer Ingelheim Vetmedica, Inc., protects against the 4 most common Leptospira serovars that cause canine disease.
Leptospira, a bacterial spirochete that is prevalent in animals worldwide, is the causative organism of leptospirosis, a zoonotic disease. Worldwide, about 300,000 to 500,000 severe human cases are recognized yearly, and the disease may be fatal in about 5% to 30% of human cases, according to Pedro Paulo Diniz, DVM, PhD, assistant professor in small animal internal medicine at Western University of Health Sciences in California.
To prevent the spread of the disease from an infected pet to family members, owners of a dog with leptospirosis should always be told to contact their physician for advice. In the meantime, they should be informed by the veterinarian of the zoonotic potential and advised to wear gloves when cleaning up after their dog. It would also be a good idea to leash walk the animal and to wash its bedding using bleach.
Despite a veterinarian’s best efforts, up to 20% of dogs that develop leptospirosis will die from this disease, according to Dr. Glickman. Therefore, both veterinarians recommend yearly vaccination as the best way to protect a beloved pet and its family. Puppies should receive 2 immunizations initially and then a yearly booster. The available vaccines are efficacious and have proven safe in clinical trials. They protect against the 4 most common serovars that cause leptospirosis in dogs.
Leptospirosis is a zoonotic disease and the number of dogs diagnosed is increasing. About 20% of canine cases can be fatal despite aggressive treatment. Therefore, it is good medicine, to vaccinate all dogs, since it is nearly impossible to identify any who are not at risk of becoming infected given the widespread nature of the organism in reservoir animal hosts in both urban and rural areas.