It's not really a new disease . Many years ago there were a few hunting dogs that may have picked up an occasional illness from close contact with deer or infected cattle, but it never became a "dog" disease. In the late '90s it started to appear in dogs in increasing numbers. It was still considered a disease of "outdoorsy dogs", rural dogs or those who explored wild areas. Between 2000 and 2005 there has been a 400% increase in the number of positive cases. Most of these were "lap dogs" with no known exposure to wildlife.

It is assumed that raccoons, one of the primary carriers that live in cities are now infected. Many surveys have shown that there are more raccoons per square mile in populated areas than in rural/wild settings. This close proximity of sick raccoons and large numbers of dogs is a bad combination.

The bacteria gets access to dog's systems usually by drinking water that has been contaminated by raccoons, but simply walking in a puddle and licking its feet can put a dog at risk. Once in the body, the dog's immune system rapidly clears most of the bacteria within 24 hours. Usually this phase of the disease lasts about one to two days and the dogs may appear a bit feverish or lethargic, but they regain their health quickly so many people miss this part of the disease.

Remaining bacteria settle in the liver or the kidneys, and stay hidden away in these sheltered areas and multiply until the sheer number of organisms can cause failure of these organs. Unfortunately the dogs become critically ill at this time and often cannot be successfully treated. Those that do survive often have serious damage done to the kidneys. In some cases, the bacteria can stay in a hidden low level state causing mild kidney disease that may be identified on blood tests or urine tests.

There is a new vaccine that gives very good protection against the strains of the bacteria that are now causing disease in our area. Older vaccines were made from whole bacteria and were not effective against the new strains. This older style vaccine was also very prone to adverse reactions. As a result, many veterinarians and pet owners discontinued this vaccine. In 1998 a new subunit vaccine was introduced that protects and is much safer for your dog. Given the current dynamics of the disease, it is important that all dogs who go outside should now receive this vaccine. In order to ensure that there are no adverse reactions to this vaccine, we recommend that it be given to your dog separately from the annual vaccines. The usual program is to get the first leptospirosis vaccine 2-3 weeks after the annual visit, and a booster 2-3 weeks later.