What is leptospirosis?
Leptospirosis (lepto for short) is a serious bacterial disease of dogs, multiple animal species, and humans that occurs in countries around the world. In recent years, leptospirosis has become an increasing concern of pet owners and veterinarians in the United States, especially in cities and suburbs. The primary reason is growing populations of wildlife, like raccoons and skunks, which carry disease and infect dogs indirectly. Dogs can get sick even if they never come into direct contact with infected animals.
Lepto has been diagnosed in all types of dogs. All breeds and sizes of dogs are at risk. Lepto can be a very serious disease and can be fatal if not diagnosed and treated early. It generally attacks a dog's liver and kidneys and can lead to organ damage or failure. However, if lepto is caught early, it responds well to antibiotics. Preventative measures, such as vaccinations, are available to pet owners as well.
A bacterial disease
Leptospirosis is caused by the bacterium L. interrogans, part of a group of corkscrew-shaped bacteria called spirochetes.
Leptospira spirochetes are further divided into multiple "subfamilies" called serovars or strains. Around the world, there are more than 200 serovars of lepto. Although there are many serovars, only a few are known to cause disease in dogs. Newer vaccines contain four serovars for protection against today's most common serovars.
Lepto serovars are maintained in nature by "reservoir hosts" that have subclinical infections and shed the organisms for long periods of time. Dogs can be reservoire hosts for the serovar L. canicola. Many academics consider L. canicola the least frequently isolated serovar in dogs. Dogs are "incidental hosts" and generally develop more severe clinical disease for L. grippotyphosa, L. pomona, and L. icterohaemorrhagiae.
How is leptospirosis spread to my pet?
Lepto is usually spread through the urine of an infected animal. Most dogs that venture outdoors are at risk for lepto. Dogs typically become infected when they come into contact with wet grass, soil, puddles, streams, or ponds contaminated with the urine of infected animals. The bacteria can enter through a cut in the skin or mucous membranes, such as the eye, nose, or mouth.
Here's how easy it is for a dog to become exposed to lepto: An infected rat urinates in a puddle of water on the sidewalk or an infected raccoon urinates in the dew-covered grass along a walkway. You walk your dog in these areas and the dog steps in the contaminated material. Once home, your dog licks his feet during normal grooming and is exposed.
Wildlife and domestic animals commonly infected with lepto include: Raccoons, Skunks, Rats, Mice, Squirrels, Foxes, Coyotes, Deer, Horses, Cattle, Pigs, Dogs
Signs in dogs
Some dogs never display any signs of illness. Others may suffer from a lack of energy and show signs of depression. Some may display any or all of the following signs:
- Lack of interest in eating
- Abdominal pain
- Jaundice (yellowish color in the mouth or gums)
- Changes in urination patterns or frequency
A recently published retrospective study5 showed that just over 18% of dogs admitted to a university with renal pathology had undiagnosed leptospirosis. If the disease is not treated, some dogs become very ill and can even die. Lepto kills up to 1 in 5 clinically infected dogs.4 Even if the dog recovers, long-term consequences can include reduced kidney or liver function.
Safety precautions for confirmed cases
If your dog is sick, make an appointment immediately with your veterinarian. If your dog is diagnosed with lepto, follow your veterinarian's recommendations that commonly include the following steps:
- Avoid coming into contact with your dog's urine or blood.
- Wash your hands thoroughly after handling your pet or materials that might be contaminated with your pet's urine, blood, or excrement.
- Keep other pets and children away from the dog's urine or blood.
If a diagnosis of lepto has been confirmed and your dog has recovered enough to return home, be sure to follow your veterinarian's instructions to protect yourself and your family. Most importantly, if your dog has been prescribed antibiotics, be sure to finish all the medicine. Do not stop when signs disappear.
Annual vaccination for leptospirosis is an affordable means to help protect your dog from a disease than can be very costly to treat. Ask your veterinarian if they use a vaccine that protects against 4 serovars.
Your veterinarian will determine an appropriate vaccination series, depending on your dog's vaccination history and risk factors. Your dog may require an initial vaccination and a booster a few weeks later. Annual vaccination is needed for continued protection.
Vaccination is extremely important, but in addition, you may want to consider the following steps you can take to prevent leptospirosis:
- Have your dog vaccinated against the 4 serovars of Leptospira
- Wash your hands after direct contact with your pet or its urine.
- Where possible, avoid exercising your dog in wildlife habitat areas.
- Prevent your children from playing in areas used for exercising dogs.
- If you have been around a dog diagnosed with lepto, seek medical information from your veterinarian or medical provider.