Equine Reproduction and Stud Medicine Q&A 21

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A 4-month-old foal sustained a wound to its right stifle one week ago. Over the last 48 hours the foal has developed a stilted gait and seemed unwilling to feed from the ground as usual. It has a high tail carriage and, when menaced, the response shown is initiated:

Question	Answer		Article
What is your clinical diagnosis and what prognosis would you give the foal?	Tetanus. With a slow onset of clinical signs, appropriate aggressive therapy and no rapid deterioration, the foal has about a 50% chance of survival.		[[|Link to Article]]
What factors may have led to the foal being susceptible to this disease?	(1) Inadequate vaccination of dam with failure to give a tetanus toxoid ‘booster’ 1–3 months prior to parturition. (2) Failure to recognise the above and hence administer tetanus antitoxin at birth and 3–6 weeks later would lead to inadequate passive immunity. (3) Failure of passive transfer at birth without checking the tetanus status of a colostrum or plasma donor. (4) Waning of passively derived tetanus antibodies prior to initial vaccination.		[[|Link to Article]]
What treatment should you institute?	(1) Penicillin therapy; initially sodium benzyl penicillin IV four times over the first day of treatment followed by procaine penicillin IM twice daily. (2) Tetanus antitoxin 20,000 IU IM for 3–5 days to neutralise unbound toxin. (3) Acetylpromazine or a combination of diazepam and xylazine to relieve muscle spasms and provide sedation. (4) Provision of a quiet, dark environment with soft but firm bedding, e.g. peat. (5) IV fluid therapy and nutritional. (6) Recognition of when prognosis becomes hopeless to allow speedy euthanasia.		[[|Link to Article]]
What would you recommend as routine stud farm management for the prevention of this disease?	Ensure mares are fully vaccinated and receive annual boosters 1–3 months prior to foaling. If in doubt, administer tetanus antitoxin to the foal at birth and repeat 4 weeks later. Administer tetanus toxoid at 3–4 months of age, again 4 weeks later and repeat annually.		[[|Link to Article]]