Botulinum toxin type A treatment for a parotid gland injury in two adult horses

The most common disorder affecting the salivary glands in horses is trauma to the parotid gland or duct. Several management techniques have been described, each with their own set of complications. The objective of this case report was to describe the direct injection of botulinum toxin type A into the parotid gland and its outcome in two clinical cases involving damage to either the parotid salivary gland or its duct. Both cases involved iatrogenic damage to either the parotid salivary gland or its duct. Treatment for both cases involved the injection of 200 units of botulinum toxin type A into the parotid gland in order to reduce salivary production and to prevent the potential development of a chronic fistula. Follow-up assessment after the treatment was conducted via telephone consultation and photographs from the owners. In both clinical cases, a marked reduction in saliva production from the parotid gland was noted within 2 days after toxin injection and the wounds healed without complication. In the first case, the treatment was repeated after 3 weeks. No short- or long-term side effects after injection were reported by the owners. Limitations were the small number of cases and the lack of literature regarding the dose and treatment regime for botulinum toxin type A in horses. It was concluded that the administration of botulinum toxin type A appears to be a safe and effective therapeutic alternative or complementary procedure for the treatment and prevention of parotid gland or duct fistulas in horses.