Leptospirosis: Updated Vaccination Recommendations for Dogs

Laurie Anne Walden, DVM

Photo by Rafaëlla Waasdorp on Unsplash

All dogs are at risk for leptospirosis and should be vaccinated for it every year, according to updated recommendations from the American College of Veterinary Internal Medicine (ACVIM).
 
Leptospirosis is caused by infection with Leptospira bacteria. The infection spreads from animals to humans, so leptospirosis is a public health hazard. Leptospirosis is a serious disease that damages the kidneys and other organs.
 
The leptospirosis vaccine for dogs has previously been considered a lifestyle vaccine, given to dogs with certain risk factors but not necessarily to all dogs. Information about how the disease spreads has improved over the years, so the ACVIM now says that all dogs, regardless of their lifestyle and location, should receive the vaccine.
 
Transmission
Leptospira spread mainly through urine. Many wild and domestic animal species carry the bacteria and deposit them in the environment. Rats and other rodents are the most common carriers.
 
Leptospira grow best in water and wet soil. Dogs with access to bodies of water, especially in warm climates, are at higher risk than others. However, the infection can also spread by direct contact (for example, when dogs hunt rodents) and in other ways, so outbreaks have happened among people and dogs living in urban areas and in drier and colder climates.
 
Cats seem to be resistant to leptospirosis, and cases in cats are extremely rare. However, cats might be able to spread the bacteria to other animals.
 
Disease
Leptospirosis affects many organ systems. These are some of the most serious problems it causes:

• Kidney injury
• Liver damage
• Bleeding in the lungs
• Inflammation of the lungs, heart, pancreas, and eyes
• Impaired blood clotting

 
These are some of the signs of infection:

• Fever
• Lethargy
• Vomiting and diarrhea
• Painful abdomen
• Increased thirst and urine volume
• Jaundice
• Labored breathing
• Blood in urine, vomit, or stool
• Red eyes

 
Diagnosis and Treatment
Leptospira can be hard to detect with laboratory tests. Definite diagnosis might require multiple blood and urine tests to isolate bacterial DNA and measure antibody titers. Dogs with suspected leptospirosis also receive baseline bloodwork, urinalysis, and chest radiographs.
 
Leptospirosis is treated with antibiotics. Additional treatments depend on the individual patient’s course of illness and the organ systems affected. Some dogs with kidney injury caused by leptospirosis need dialysis.
 
The risk of a person contracting leptospirosis directly from an infected dog is low because dogs don’t shed many Leptospira organisms in their urine. However, people caring for a dog with leptospirosis need to take precautions like avoiding contact with the urine, wearing protective clothing, and washing hands.
 
Vaccination
The doctors at Mallard Creek recommend that all dogs receive a leptospirosis vaccine starting at 9 weeks of age. Dogs need a booster vaccine 3 to 4 weeks later and then once a year.
 
Leptospirosis vaccines are not all the same. Leptospira have many different variations, or serovars, and vaccines target only specific serovars. However, some don’t cover the serovars currently causing disease in dogs in the United States. Your veterinarian can advise you on the best vaccination plan for your own dog.
 
Source
Sykes JE, Francey T, Schuller S, Stoddard RA, Cowgill LD, Moore GE. Updated ACVIM consensus statement on leptospirosis in dogs. J Vet Intern Med. 2023;37(6):1966-1982. doi:10.1111/jvim.16903
 
Image source: https://unsplash.com/photos/a-dog-running-through-a-field-of-yellow-flowers-SEGsw2Kmd08

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