Tue, 26 January 2016

Many of us have been warned in the social media about sightings of strays/suspected rabid dogs in the suburbs of Harare. Farmers have also noted an apparent increase of jackals in the rural areas. Both sets of observations are ominous as rabies tends to be the consequence of a population increase of these two key groups of vectors of rabies. Rabid dogs and jackals are not always easy to recognise. Typically the animal appears abnormally fearless in strange company. Jackals may appear tame and tameness may change to severe aggression. Animals may vocalise with deep growls and of course salivation is commonly observed. The so called 'dumb' rabies is particularly difficult to recognise as the animals may appear depressed, quiet and may stand with the head pressing into a tree or fence. Some cases appear as if there is an obstruction in the throat as the mouth is slightly open with intense salivation. Perhaps the most dangerous situations arise when a rabid dog moves unrecognised through a community of people and the dog may be approached by children who may fondle the dog , the child is bitten and the dog moves on leaving the victim with a mere scratch or a deep penetrating bite wound. Rabies virus is transmitted through any damage to the skin surface and a mere scratch may be fatal. Warn your children against playing or touching strange dogs. Take notice of children or adults reporting an encounter with an aggressive dog. Many children die every year especially in rural communities from unreported bites by rabid dogs.

I recently attended the South African Veterinary Congress in Port Elizabeth where the list of human fatalities from rabies included a child dying from rabies after the child reported being bitten by a dog but the teacher dismissed the complaint as the bite was considered too small to be dangerous. An Irish tourist visiting Kruger National Park received a small bite wound while separating two fighting dogs at the park entrance. The unfortunate lady died in Ireland 2 years later from rabies.

Rabid dogs and jackals can be major transmitters of rabies in cattle. I have recently had a few calls from farmers who describe typical rabies symptoms in their cattle. Cattle usually showed some form of hind leg weakness causing stumbling and knuckling over at the fetlock joints. Sometimes the front legs are affected. The cattle may become very aggressive which may accompany intense deep vocalisation with salivation. The rabid animal may charge both humans and other animals. Rabid cattle die within a few days of showing symptoms.

What is unpredictable with rabies in cattle is the outcome of a rabid dog/s moving through a herd of cattle biting cattle randomly. Some farmers have lost 7 cattle in a week and others report loses varying from 2 to 5. Cattle in feedlots and dairy cows in confined in small pens are the most susceptible to multiple deaths from rabies. Vaccination against rabies is the main method of protecting cattle in addition to ensuring all dogs in the area have been vaccinated against rabies. Rabid dogs can move over great distances and 100% vaccination of dogs is unlikely to be achieved.

Fivet has the necessary rabies vaccine for all types of livestock (Defensor 3) . A single intramuscular injection of 2mls of the inactivated vaccine will protect the animal for 12 months. The vaccine is very effective and available on prescription.