Horse’s Catch Colds Too! Written by Dr John Kohnke Reprinted with the kind permission of Weekly Times Now www.weeklytimesnow.com.au FROM advanced medicines to good old-fashioned TLC, there are a number of ways to care for a horse with a cold, as DR JOHN KOHNKE explains Like humans, weanlings, horses in training and aged horses are at risk of “catching a cold” during winter, as aerosol viruses are more easily spread and the animal’s immune system may be compromised by the stress of cold weather. The respiratory system is paramount to a horse’s ability to exercise and perform. Many horses exhibit only very subtle signs, such as a slight wheeze or cough, as the only outward indication of a potentially debilitating airway disease. The lower respiratory tract in the lungs is subjected to heavy assault during exercise from a variety of inhaled bacterial and viral micro-organisms, as well as allergens including moulds and dust. These can increase airway reaction and excess mucus production as a form of bronchitis. Other threats can come from pollutants such as ammonia, an irritating gas released from stable bedding which lowers lung immunity, and cold air inhaled during early morning training without adequate pre-exercise warm-up, especially in winter. There are a number of infective organisms that can cause inflammation and low-grade infection in the respiratory tract. In Australia, the Equine Herpes Virus (EHV-1, EHV-4 sub-types), commonly referred to as the “stable virus”, is the most widespread viral disease, producing “flu-like” symptoms. Recognise respiratory symptoms early IT IS important to recognise the symptoms of EHV before the virus multiplies in the throat lining and tonsil cells and breaks out to be inhaled. The normal incubation period is from four to seven days before an infected horse develops the external symptoms of a “runny nose” or a cough when exercising. The earliest signs, within the first 36-48 hours after infection, include a slight loss of appetite, reduced ability to exercise, depression and an increased early morning (before exercise) body temperature above 38.5°C. Resting the horse in this initial early stage can help the immune system fight the virus and limit its multiplication in the nasal cells and throat lining. Diagnosis of a ‘cold’ SIGNS of a nasal discharge, reduced appetite and an occasional cough develop four to six days after the initial EHV infection. Once the virus has multiplied, it triggers an immune reaction, with increased airway-cleaning mucus and fluid in the lungs. Managing a ‘cold’ MONITOR the horse’s temperature and appetite daily. Ensure the horse has shelter and a warm rug. Separate it from other horses in the immediate vicinity – especially in stables and yards, where horses can come into nose contact over a fence. Place all feed on the floor – dampen all feed, including hay, to assist nasal and throat drainage. Damp feed will be less likely to irritate an inflamed tonsil or throat and often helps to lift the appetite.
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