BOTULISM VACCINATIONS AND DISEASE INFORMATION

BOTULISM

This disease originally was regarded as a food poisoning type disease until the early 1980's, when it was found to be able to be contracted by contamination of various types of wounds, both internal and external, with botulism organisms. For example, the organism has been isolated from stomach ulcers in foals, from the navel cord and from many types of skin wounds. It is also possible that the organism lives better in some areas than others i.e. different soil types. I believe the disease is more prevalent in areas that also have a higher incidence of Tetanus and Blackleg.

CAUSES OF BOTULISM

The disease is caused by the organism producing toxin either in spoiled feed, in spoiled water or by the organism contamination feed, being eaten and then infecting ulcers etc. inside the horses. The organism may also contaminate wounds by contact with contaminated soil, it them produces toxin in the wound which may be absorbed from the wound directly or in some cases be ingested by the horse biting at the wound.

SYMPTOMS OF BOTULISM

The symptoms are associated with a flaccid paralysis which is usually first seen as a tongue paralysis and an inability of the horse to swallow. The affected horse may appear to eat and drink, but does not actually swallow and consequently often has food jammed up in the back of the mouth. They also appear to drink for long periods, but, if given water in a bucket, so as to be able to measure what they drink, you will find they have not actually drunk any at all.

As the amount of toxin increases, so do the rapidity of symptoms. General muscle trembles soon appear, the tongue can be drawn out of the mouth and the horse cannot pull it back and it may at some stages of the disease show fine trembling of the tongue muscles.

As the condition deteriorates, the horse's chest and breathing muscles are affected and they endeavour to use their abdominal muscles and so develop a "heaving" type breathing. Acute cases go down fairly rapidly and can be down, unable to get up, within four (4) to twelve (12) hours of first symptoms.

This is all related to the amount of toxin present. More toxins produce rapidly changing symptoms and death. Low doses may just cause weakness and tongue paralysis and some of these horses can recover over ten (10) to fourteen (14) days with supportive treatment.

Foals are first found by the fact the mare has not been sucked. They display the tongue paralysis and a stiff stilted walk and usually then collapse suddenly onto the ground. They may well appear to be fairly normal if left undisturbed on the ground. This deteriorates to where the foal cannot get up. Additional symptoms are paralysis of the bowel, inability to pass manure, dehydration and general muscle trembling and weakness.

All horses, which are not destroyed, die of respiratory paralysis.