Repetitive Stimulation of the Common Peroneal Nerve as a Diagnostic Aid for Botulism in Foals

Mechanical ventilation and management of an adult horse with presumptive botulism

OBJECTIVE

To describe the clinical course, management, and outcome of a horse with a presumptive diagnosis of botulism treated with long-term mechanical ventilation.

CASE SUMMARY

A 6-year-old Quarter Horse gelding with a history of esophageal obstruction was evaluated for progressive tetraparesis. Generalized and progressive skeletal muscle weakness characterized by recumbency, decreased tongue, tail, eyelid, and anal tone, and respiratory failure was observed. Anticholinergic signs including decreased salivation, xerophthalmia, and ileus were also noted. A presumptive diagnosis of botulism was made, although mouse inoculation and spore identification testing were negative. Pentavalent botulism antitoxin was administered on Day 3. The horse was maintained on a water mattress and was managed with mechanical ventilation for 2 weeks. Complications encountered included necrotic rhinitis, intertrigo, decubital ulceration, jugular and cephalic vein thrombophlebitis, corneal ulceration, and transient ventricular tachycardia. The horse showed marked improvement in skeletal muscle strength and parasympathetic nervous system function, allowing it to be successfully weaned from the ventilator but suffered large colon volvulus on Day 21 and was euthanized.

NEW OR UNIQUE INFORMATION PROVIDED

To the authors' knowledge, this is the first report of successful weaning from long-term mechanical ventilation and management of recumbency using a water mattress in an adult horse with presumptive botulism.

Management of animal botulism outbreaks: from clinical suspicion to practical countermeasures to prevent or minimize outbreaks

Botulism is a severe neuroparalytic disease that affects humans, all warm-blooded animals, and some fishes. The disease is caused by exposure to toxins produced by Clostridium botulinum and other botulinum toxin-producing clostridia. Botulism in animals represents a severe environmental and economic concern because of its high mortality rate. Moreover, meat or other products from affected animals entering the food chain may result in a public health problem. To this end, early diagnosis is crucial to define and apply appropriate veterinary public health measures. Clinical diagnosis is based on clinical findings eliminating other causes of neuromuscular disorders and on the absence of internal lesions observed during postmortem examination. Since clinical signs alone are often insufficient to make a definitive diagnosis, laboratory confirmation is required. Botulinum antitoxin administration and supportive therapies are used to treat sick animals. Once the diagnosis has been made, euthanasia is frequently advisable. Vaccine administration is subject to health authorities' permission, and it is restricted to a small number of animal species. Several measures can be adopted to prevent or minimize outbreaks. In this article we outline all phases of management of animal botulism outbreaks occurring in wet wild birds, poultry, cattle, horses, and fur farm animals.

Suspected tick paralysis (Ixodes holocyclus) in a Miniature Horse

A 9-year-old Miniature Horse gelding infested with ticks (Ixodes holocyclus) was presented with flaccid motor paralysis causing recumbency. Neurological examination and other diagnostic tests did not identify an alternative aetiology, leading to a presumptive diagnosis of tick paralysis. The gelding was treated with tick antiserum and intensive supportive care. He made a gradual recovery over the 48 h following presentation and was discharged without further complications. This case report describes in detail the clinical signs and successful treatment of a Miniature Horse with flaccid paralysis caused by suspected envenomation by Ixodes holocyclus.

Miscellaneous neurologic or neuromuscular disorders in horses

NMD is an important cause of morbidity in horses. Signs of dysfunction could be variable depending on the specific area affected. NM disease can go unrecognized if a thorough evaluation is not performed in diseased horses. Electrodiagnostic testing is an area that has the potential to document and improve our understanding of NM disease yet is uncommonly performed. Keeping an open and observant mind will enhance our ability to search and find answers.