Leptospirosis in Dogs: Symptoms, Treatment and Vaccination

Leptospirosis is a serious bacterial infection that dogs catch from water and soil contaminated with the urine of infected animals. Rats are a common source. It can also pass to people.

How dogs get infected

Infected animals shed Leptospira bacteria in their urine. In Denmark the brown rat is the main carrier. A dog can pick up the bacteria by:

• Drinking from puddles, ponds or streams
• Swimming or wading in contaminated water
• Walking through contaminated mud or puddles, where the bacteria can enter through cuts or soft skin
• Touching urine from infected animals

Cases are more common after heavy rain. Dogs that live near water, farm animals or wildlife are at higher risk, but city dogs can be exposed too.

Symptoms

Early signs:

• Fever
• Tiredness and weakness
• Loss of appetite
• Vomiting or diarrhoea
• Muscle pain and stiffness
• Drinking more than usual

Later signs can include yellow gums, eyes or skin (jaundice), changes in how much the dog urinates, breathing difficulty and bleeding. The kidneys and liver are the organs most often harmed, and the lungs can bleed.

Some dogs have a mild illness. Others get much worse within days. Call a vet about any of these signs.

Diagnosis

Leptospirosis looks like many other illnesses, so vets combine several things: the dog's history and signs, blood and urine tests, and tests for the bacteria itself. Antibody testing usually needs two blood samples taken a couple of weeks apart. PCR looks for the bacteria's DNA in blood and urine. Culturing the bacteria is slow and isn't used for routine diagnosis.

Treatment

Most dogs need to stay in a clinic or animal hospital. Treatment includes:

• Antibiotics. Doxycycline for about two weeks is the standard recommendation, and it also clears bacteria from the kidneys. A dog that is vomiting may start on injectable antibiotics.
• Fluids through a drip
• Anti-nausea medicine and pain relief
• Monitoring of kidney and liver function
• Intensive care for the sickest dogs, which may include dialysis at a specialist hospital

The sooner treatment starts, the better the chance of recovery. Dogs with severe kidney, liver or lung damage have a more guarded outlook, and some are left with long-term kidney or liver problems. After recovery, your vet will tell you which follow-up tests your dog needs.

Vaccination

Yearly vaccination is recommended for dogs at risk. Vaccines used in Europe cover four strains of the bacteria. They protect against those strains, not against every strain.

• A puppy gets two injections a few weeks apart, then a booster every year.
• Whether your dog needs the vaccine depends on its life: swimming, drinking from ponds, farm or countryside walks, and areas with rats all raise the risk.
• Ask your vet to go through your dog's risk and set the schedule.

Lowering the risk

• Keep your dog out of stagnant water, puddles and ponds, especially after heavy rain.
• Bring fresh water on walks so your dog isn't tempted to drink from puddles.
• Keep dogs away from rats and rat droppings.
• Store food and bins so rats can't reach them.

Risk to people

Leptospirosis can spread from animals to people through infected urine or contaminated water and soil, via small wounds, the eyes or the mouth. In Denmark, about 10 to 30 people are diagnosed each year, mostly in jobs with exposure. Most infections are mild or cause no symptoms, some cause a flu-like illness, and a few become severe. There is no human vaccine.

If your dog has leptospirosis:

• Wear gloves when you clean up urine, and wash your hands afterwards.
• Keep children away from the dog's urine.
• Follow your vet's advice on caring for the dog at home.
• See your GP if you develop a flu-like illness, and tell them your dog has leptospirosis.

When to see a vet

Contact a vet the same day if your dog has fever, tiredness, loss of appetite, vomiting or diarrhoea, yellow gums or eyes, difficulty breathing, or a big change in how much it drinks or urinates. Tell them if your dog has been in water or near rats. Outside our opening hours, contact an emergency vet clinic.

Book a visit

Our veterinary service can go through your dog's risk and its vaccination schedule. We're open Monday, Thursday and Friday 10:00 to 16:00, and Tuesday and Wednesday 09:00 to 17:00. Contact the clinic to book.