The advice comes after a recent outbreak of strangles on horse properties in New South Wales, and a Hendra outbreak on a property near Rockhampton, in Queensland.
Several strangles cases in New South Wales arose after a new horse arrived on the property.
A horse can appear normal, but can be incubating the disease or be a source of infection.
Horses can incubate strangles infection for three to eight days before appearing sick. A horse that has had strangles can remain infectious for at least four weeks after they recover. Some may remain infectious for up to eight months.
For this reason, authorities are recommending owners keep new horses isolated from other horses on their property for at least two weeks and check them daily for signs of ill-health.
It is a good idea to ask the person who last cared for the horse whether it has been sick in the last few months, or if it has been in contact with sick horses, and get as many details as you can.
If the horse develops a fever, snotty nose or swellings under the jaw consult a veterinarian as soon as possible.
Strangles is a notifiable disease in New South Wales. It is caused by the bacterium Streptococcus equi equi.
Strangles is usually seen in young horses but it can infect older horses. Outbreaks sometimes occur when large numbers of horses are held in close contact.
It affects the upper respiratory system and lymph nodes of the head.
It rapidly spreads from horse to horse through coughing, or by eating feed or drinking water that has been contaminated by a sick horse.
Contaminated grooming utensils, rugs, feed bins, or humans (on hands or clothing) can also spread the infection.