Leptospirosis - What is it?

Leptospirosis is a bacterial disease, with many forms affecting both animals and people. In New Zealand one form of Leptospirosis causes most of the disease we recognise in our dogs – Leptospirosis copenhageni. Fortunately for cats they are far less susceptible to this disease and as a result rarely become unwell.

Leptospirosis is most commonly spread via the urine, where the bacteria can live in large numbers. The disease remains in the environment in “host animals”. Host animals are those which carry the disease and spread it without becoming unwell themselves. The host animal for Leptospirosis copenhageni is the Brown Rat. Each year a small number of dogs are diagnosed with leptospirosis, usually in the northern half of the North Island.

If you dog contacts an affected Brown Rat, or its urine, they may become infected. Young dogs are usually more severely affected, but it is more common in mature dogs as their roaming and outdoor activity is more likely to put them in contact with Brown Rats.

Severe illness can rapidly result in death with only a few signs such as lethargy, muscle tenderness and shivering being shown. More commonly infection results in the dog being off its food, lethargic and reluctant to move. Vomiting is often seen, as is increased thirst. These signs may be present in many other illnesses but a detailed examination and blood testing by your veterinarian will aid in the diagnosis of leptospirosis being made. The sooner the disease is diagnosed and treated the better the likely outcome for your dog. Aggressive treatment and supportive care in hospital may save some dogs with this disease, but sadly death as a result of Leptospirosis is not uncommon.

Leptospirosis is a potential “zoonosis”. This means that the disease can be transmitted from animals to people, usually via the urine. Fortunately this is not commonly recognised with the disease in dogs, but has quite commonly been seen in farmers and freezing workers after they have been infected from pigs or cattle, different strains of leptospirosis are involved.

Your dog can be protected in most instances from Leptospirosis through vaccination. We recommend this is given as part of your routine puppy vaccinations at 9 and 12 weeks of age. Annual boosters are required thereafter for life to ensure best possible protection for your pet. If your dog commonly has access to areas where rats are likely to live (bush, abandoned properties, commercial areas, refuse tips), check to make sure they have been vaccinated for Leptospirosis. If you are unsure, please don’t hesitate to contact your vet.