Categories: Horses

About equine leptospirosis

Although a vaccine for horses has been developed, we first need to know just how prevalent this bacterial disease is…

Leptospirosis is a zoonotic bacterial disease caused by small spirochete bacteria. The signs of disease vary according to the type of animal and the Leptospira germ responsible.

In humans, if infection leads to kidney failure and bleeding, it’s known as Weil’s Disease. Surveys conducted in South Africa show exposure of humans, dogs and cattle to infection. Indeed, human serum sampled in various parts of the country between 2006 and 2011 showed a prevalence of Leptospira antibodies that varied between 6% and 19%, indicating that the organism is fairly common here. However, horses in South Africa have not been extensively tested.

In the US, it was recently found that up to 75% of horses in certain areas have been exposed to leptospirosis; however, clinical cases are rarely seen and it is suspected that they are often misdiagnosed.

Also in the US, a close link has been found between leptospirosis and uveitis (inflammation of the inner parts of the eye), especially in Appaloosas and warmbloods. Uveitis is often caused by swelling and is probably linked to an auto-immune reaction, rather than leptospirosis itself.

Other signs of leptospirosis include late abortions (at about nine months) and kidney disease in both foals and adult horses.
In a postmortem, aborted foals often show enlarged yellow livers and white spots on their kidneys.

One reason for misdiagnosis may be that initial signs of leptospirosis in horses are fairly mild and respond well to a number of antibiotics, including penicillin and doxycylcine. Both of these are registered for use in horses in South Africa.

Rats are the main carriers of the disease and their urine can contain a high level of spirochaetes. This said, the urine and faeces from any infected animal (including humans) can also pollute water sources.

In South Africa, horses are likely to become infected through rodent faeces and urine contaminating horse feeds, or if they drink or wade in polluted water. In the US, horses are mainly affected by Leptospira interrogans serovar Pomona. This was the main serovar found in cattle sampled in KwaZulu-Natal between 2001 and 2003.

Vaccines available in South Africa to prevent leptospirosis in dogs and cattle are not effective in horses. US animal vaccine and medicine manufacturer, Zoetis, has developed a specific vaccine to protect horses against the disease.

However, before vaccination can be recommended here, more information is needed on whether leptospirosis is an important disease of horses in South Africa.

Until then, rodent control in stables and providing horses with potable water rather than allowing them to drink from wetlands, are probably the two most important prevention strategies under South African conditions. Diagnosis is relatively expensive and leptospirosis is unlikely to be routinely considered by a vet unless your horse has aborted a foal, shows uveitis or has severe kidney failure.

Published by
Caxton Magazines
Tags: bacterial diseasehorsesvaccine

Recent Posts

Damara sheep: No environment too tough

Since importing his first Damaras from Namibia in the late 1980s, stud breeder Frank Blumenthal has firmly believed in the…

20 hours ago

Court case over expropriation recommendation looming

While Parliament's Joint Constitutional Review Committee (CRC) is preparing its final parliamentary report on the possible amendment of Section 25…

22 hours ago

Leafroll virus in vines can be beaten – here’s how

Leafroll virus is a serious threat to South Africa’s viticulture industry: it shortens the lifespan of vineyards and has a…

3 days ago

SA Chardonnay deserves better prices – experts

It was evident at this year’s Chardonnay Celebration, hosted by De Wetshof near Robertson, that Chardonnay had come a long…

3 days ago

Farmers welcome sharp decline in fuel prices

The large drop in the diesel price that can be expected for December, as announced by the Automobile Association (AA)…

4 days ago

A healthy profit from pasture-raised eggs

As a technician specialising in the installation and repair of gates, Rico Vergotine had little reason to be interested in…

4 days ago

This website uses cookies.