In Veterinary Medicine

Toxins produced by the Gram-positive bacteria Clostridium botulinum cause transient chemodenervation of mammalian muscle. The toxin binds to specific proteins within cholinergic presynaptic nerve terminals which regulate the release of acetylcholine in the synaptic space resulting is loss of muscle activation and function. Local injections with botulinum toxins are currently used in humans for the treatment of disorders that benefit from prolonged neuromuscular blockade such as strabismus, blepharospasm, focal dystonias, spastic ity, tremors, and anal fissures. Injections with botulinum toxin type A into the internal or external anal sphincter cause relaxation of the anal canal and allow healing of chronic anal fissures. Perineal lacerations in mares, which occur during foaling often dehisce after surgical repair due to the high pressure across the incision resulting from accumulation of feces in the rectum. We hypothesized local injections of Clostridium botulinum type B toxin into the external anal sphincter could cause a decrease in anal pressures, thus reducing the incidence of dehiscence if used before surgical repair of perineal laceratio