Biosecurity / Infectious Diseases
Why is a biosecurity plan important for your property? Until 2007, Australia was one of a handful of countries that had never experienced an outbreak of Equine Influenza (EI), a highly contagious viral disease of the respiratory tract. In animals that have been exposed to the virus previously and have, therefore, developed some degree of immunity, infection with the EI virus generally causes only mild disease.
Upper respiratory infections are a significant problem across all equine industries and within the racing industry, in particular. Studies have demonstrated considerable economic losses resulting from subclinical disease (when horses don’t look obviously sick, but are performing below expectations), from acute infection (when horses have nasal discharge, a cough and obviously need rest or a reduction in training), and from the hypersensitivity and chronic inflammatory airway disease that develops in the lungs as a result1,2.
A new study challenges the tenet that herpes viruses, like most enveloped viruses, are relatively unstable outside their host. Under a variety of conditions, Equine Herpes Virus remained stable and infectious over a three week period. This suggests that untreated water could be a source of infection by some herpesviruses. The results are reported in the scientific journal Scientific Reports.
On August 5th, Zoetis announced the Hendra virus vaccine, Equivac® HeV, has received registration from the Australian Pesticides and Veterinary Medicines Authority (APVMA) and released the data on reported side effects. In a press release issued last week, General Manager for Zoetis Australia and New Zealand Lance Williams, said: “We are pleased that after nearly three years of positive uptake, Equivac® HeV vaccine has successfully been registered."
Equine Infectious Anaemia (EIA) is an incurable viral disease that is spread by biting insects. It is a rare disease in Australia, found most commonly in isolated pockets, particularly in Queensland.
Equine Herpes Virus (EHV) causes horse owners and breeders a large amount of concern due to its potentially devastating effects. The virus is ever-present in the horse population worldwide and cases of Herpes virus infection are seen sporadically across Australia. It can cause mild to life-threatening disease affecting the respiratory and neurological systems, as well as being responsible for abortions in all ages and breeds of horses and donkeys.
The HHALTER Project is examining how virus-related knowledge, attitudes and practices change over a two-year period through a series of five surveys circulated to horse owners around Australia. This project aims to ensure that horse people are central to Hendra Virus-related policy development and research.
Strangles is a bacterial infection caused by the organism Streptococcus equi subspecies equi (S.equi). Fever is generally the first clinical sign seen, followed by enlargement of the lymph nodes of the head and neck. These swellings can be severe enough to impede respiration completely, hence the name ‘strangles’. A profuse thick nasal discharge is also likely to occur.
A positive outcome of the media focus on Hendra Virus, Murray Valley Encephalitis and Kunjin virus is that owners and veterinarians are becoming more diligent in observing horses for signs of disorders affecting the brain, spinal cord and nerves. In this article, Dr Natasha Hovanessian, from the Canberra Equine Hospital explains what neurologic disease looks like in the horse and how your veterinarian may diagnose the cause, as well as discussing some of the more common neurologic problems seen in Australia. Signs of Neurologic Disease
Early in 2011, an increase in the number of horses suffering from neurological disease was detected in NSW and Victoria. Blood samples from over 200 cases were submitted to the NSW State Veterinary laboratory, Elizabeth Macarthur Agricultural Institute. The brains of some of the few horses that died from the disease were also examined. Initially, an Arbovirus (a virus carried by insects) was suspected, with Murray Valley Encephalitis, Ross River Fever and Kunjin virus being investigated as the possible cause.