Article and Guides

Dogs - How Dogs Catch It, How We Cure It, How We Prevent It

What Causes Leptospirosis?
Leptospirosis is a disease that affects many kinds of animals besides dogs. It occurs throughout the World. The organism that causes leptospirosis belongs in a group of spiral organisms called spirochetes. They are similar to ordinary bacteria in many ways. However, they move and wriggle about in a spinning motion using their wavy membrane called a flagella.

They are divided into serovars or strains, based on the characteristic of their surface proteins. Eight of these are known to cause disease in dogs and cats. They are:
  1. Leptospira icterohaemorrhagiae
  2. L. canicola
  3. L. grippotyphosa
  4. L. pomona
  5. L. bratislava
  6. L. automnalis
  7. L. bataviae
  8. L. hardjo and L. grippotyphosa
The first four are the most common ones that infect dogs.

The disease is always present in the environment for your dog to pick up. This is because it is perpetuated in rats, and wildlife, as well as domestic livestock. More cases also occur after heavy rainfalls. The disease is most common in places around the World with mild or tropical climates. It is seen more frequently in states with heavy rainfall. They are killed rapidly by drying but the persist in standing water, dampness, mud and alkaline conditions.

How Would My Dog Catch Leptospirosis?
Most of the infected wild animals and domestic animals that spread leptospirosis do not appear ill. In these animals, the leptospira have taken up residence in their kidneys. The type of infected reservoir animals varies from area to area. In some areas it is raccoons, in others, skunks, in some, rats. When reservoir animals void urine, they contaminate their environment with living leptospira. These carrier wildlife shed leptospira intermittently. Sometimes they shed for months and sometimes for life. Pets can become infected by sniffing this urine. More often, the leptospira are washed by rains into standing water. Then pets wading, swimming or drinking the contaminated water, develop the disease. Although this is the way that leptospira usually pass from animal to animal, they can also enter through a bite wound or through the pets eating infected materials.

Because of these dynamics, pets and working breeds that spend time in wooded or swampy areas are more likely to catch leptospirosis. Dogs that spend their lives indoors or in areas that are not contaminated by carrier wildlife are less likely to become infected.

Why Do Leptospira Persist In The Kidneys Of Carrier Animals?
Each species of wildlife has serovars (strains) of leptospira that live in relative harmony with it. We call these their “primary reservoirs hosts”.

Early in infection, these, leptospira are found throughout the carrier animal’s body. This includes their liver, spleen, kidneys, eyes and genital tract. As the animal produces antibodies, these spirochetes are cleared from most organs. However, within the kidneys, of carrier species (vectors), these leptospira are hidden from the animal's antibody and continue to live in the microscopic tubes that carry urine out to the bladder (the proximal renal tubules). There, they are protected by a poorly understood membrane-bound protein mechanism. These leptospira and their host animals have learned to live together in harmony. However, when these leptospira find their way into a new animal - such as your dog - the harmonious relationship does not occur.

What Happens When My Dog Catches Leptospirosis?
When leptospirosis does cause sudden disease in dogs, it tends to be most severe in unvaccinated dogs that are younger than 6 months old. These are the pets most likely to suffer life-threatening liver and kidney damage. In these cases, L. grippotyphosa is often responsible. It takes about 4-12 days after exposure for the pet to feel ill.

In dogs of any age that become ill, the leptospira spread rapidly through the pet’s blood stream, usually causing high fevers, depression and joint pain. Leptospira produce powerful toxins that can attack the liver and kidneys, leading to failure of these organs. Strains of lepto vary in their intensity and in the portions of the body they attack most severely. Some varieties primarily cause liver damage, while others concentrate in the kidneys. In other pets, blood fails to clot normally - leading to bleeding.

What Are The Signs I Would See In My Dog?
There are typical symptoms that veterinarians associate with leptospirosis. But because no two cases proceed exactly alike, not all of the typical signs are likely to be present in any one pet. The most common signs are fever and depression. These pets are cold, shivery, and stiff. They may carry their tummies tucked up do to pain. Some drool and vomit and most loose their appetite. Fever causes many dogs to drink excessively.

Later in the disease, a few pets will develop eye inflammations (uveitis), nervous system abnormalities or pass red-tinged urine. As the disease progresses, the pet may become dehydrated due to the fever, vomiting and disinterest is drinking. A drop to subnormal body temperature is a very grave sign. A few dogs, particularly juveniles, will die suddenly before many of these signs occur. When the liver has been damaged, the pet’s skin may take on a yellowish tinge (jaundice) and show all the symptoms of hepatitis. When the kidneys have been severely damaged, the pet may show the signs of uremia. These organ changes can be temporary – or permanent.

Diagnosis of Leptospirosis
One of the typical signs found in blood tests as leptospirosis progresses, is an elevation in the number of white blood cells in the pet’s blood.

There are a very large number of diseases of dogs that can give test results identical to that seen in cases of leptospirosis. These include ehrlichiosis, babesiosis, autoimmune disease, infectious canine hepatitis, canine herpes virus, canine brucellosis and certain poisonings. This test is extremely sensitive in finding the presence of leptospira in your pet’s body. The antibody test can be positive in pets due to previous vaccinations or a prior exposure to lepto that has nothing to do with your pet’s current health problem. Occasionally the diagnosis can be made by seeing leptospira microscopically in the pet’s urine.

Exposure to humans
If the organism gets into your body, you can also become ill. You could experience any of the same symptoms described in your pet. The most common ways people contract leptospirosis is from primary or secondary exposure to infected dog or rat urine. However, it is found that you are very unlikely to be exposed if you take proper sanitary measures.

Since urine is the most common spreader of leptospirosis, it is very important that you take hygienic steps not to expose yourself to your pet’s urine. Recovered pets can shed lepto in their urine for months, you need to continue to observe strict hygiene even after your pet has recovered.

Minimize your risk:
Have only one, healthy, family member care for the dog. Confine your pet to an easily-sanitized area of your house. Prevent exposure of other pets. Wear protective latex gloves whenever cleaning up after your dog. Take your dog out on a leash frequently to urinate. Only allow the pet to urinate on dry concrete surface that can be easily sanitized with bleach. When you are potentially exposed to any secretions or waste from your pet, disinfect your hands liberally with an iodine-based disinfectant. Doing these things will considerably lower your risk but not eliminate it entirely. Should you feel ill, you need to inform your physician about your ill pet.

Treatment of Leptospirosis In My Pet?
How Can I Prevent My Pets From Catching Leptospirosis?
Limiting your pet’s access to contaminated water is the best way to avoid leptospirosis. Feeding pets and wild critters outside your home attracts rodents and possible wildlife-carriers and should be avoided.

The immunity that leptospirosis vaccinations give is short lasting – perhaps a year, perhaps less in some dogs. Occasionally, the vaccine does not protect at all. Vaccine manufacturers have known the drawbacks of their leptospirosis vaccines for years.

Vaccination does not always prevent infection – but it tends to make the disease mild, if infection occurs. There is the potential for vaccinated dogs that do become infected to become long-term carriers of leptospirosis. Some long-term carriers have a more frequent incidence of reproductive failure and stillbirths.