Ross river fever

Mosquitoes are on the rise, with many of them carrying diseases that are harmful to both humans and horses. One of these illnesses is Ross River Fever (RRF) which is commonly spread through the warmer months in Australia, peaking during January to March when mosquito’s populations are highest.

Months of heavy rainfalls often see the biggest number of RRF cases as mosquito population’s rise with wet breeding grounds. Areas also surrounded by stagnant pools of water (dams, puddles, open water tanks) or damp areas see a rise in the number of mosquitoes and therefore are a bigger chance of contracting the disease.

What is Ross River Fever?

Ross River Fever is an insect-borne virus (commonly carried by mosquitoes) that can affect both humans and horses in a number of ways. The most common of symptoms are a number of neurological, musculoskeletal, behavioural, and respiratory problems in horses. It is a very common disease across Australia, and although not lethal, it is extremely debilitating and once infected can last a lifetime.

In humans, RRF will often mean that the carrier will suffer joint pain and arthritis while others can experience cases of chronic fatigue.

Symptoms

When it comes to symptoms of RRF, most horses will differ strongly as they can be affected in different ways.
In saying this, some of the initial signs will include:

• Fevers
• Joint pain
• Swelling of the lower limbs
• Reluctance to move or cooperate
• Stiffness and soreness
• Respiratory signs – increased respiratory rate and an early stages cough
• Lethargy
• Gastrointestinal problems including diarrhoea and spasmodic colic
• Behavioural changes – more time spent lying down, loss of appetite, weight loss, poor exercise performance or an inability to exercise
• Loss of coordination and lameness
• Nervous signs – wobbliness or staggering when walking

Treatment

When it comes to Ross River Fever, there is, unfortunately, no treatment readily available. In this case, prevention is the best form of treatment. However, giving your horse antibiotics and anti-inflammatory agents will help with the swelling and stiffness along with making the horse more comfortable in general.

To help with alleviating the symptoms, you should put your horse under minimal stress and be allowed to rest as much as possible. In most cases, after 18 months or so the horse will overcome the disease and build immunity to RRF, therefore allowing them not to be reinfected later on in life.

Prevention and control

Controlling the breeding of mosquitoes around your horses is the best bet to reduce the chances of contracting RRF. It is important to be extra vigilant after heavy rainfalls as mosquitoes thrive in these types of environments. Other precautions that you can take include covering your horse with mesh or cotton rugs (particularly during the morning and evening as mosquitoes are prevalent at these times), as well as general maintenance around the stables such as removing still water sources where mosquitoes can breed.

When dealing with insect-borne diseases, prevention and control is the best way to cope. As RRF doesn’t have a treatment, it is much safer to avoid the disease and all costs through preventative measures. Although, if your horse is showing signs of Ross River Fever, contacting your vet immediately should be a top priority.