Equine Health Update EHU Vol 21 Issue 01 | Page 39

CPD Article | EQUINE adverse effects are uncertain 11 . Currently intravenous administration of 50 000 IU in early cases is used 4 and can be repeatedly injected daily, while clinical signs are present with no adverse effects such as Theiler’s Disease noted 9 . The poor availability of TAT limits its’ widespread use 9,4 and not all studies 4 indicate that it may positively influence treatment outcome. In an unvaccinated horse with a contaminated wound, TAT can be used prophylactically at the initial examination 6 as passive immunity is present within 24 hours of administration and remains active for 3 weeks thereafter 7 . Prevention The current vaccines are formalin-inactivated, adjuvanted toxoids 1 , as the tetanus toxoid is a potent antigen that rapidly induces a strong serological response. Therefore vaccination is most often prophylactic 4 . In an adult horse the recommended vaccination schedule is as follows: an intramuscular vaccination with two doses of the tetanus toxoid administered 3-4 weeks apart and thereafter the horse is revaccinated annually. Should the horse sustain a wound, a booster vaccination should be administered immediately especially if the horse has not been vaccinated within the last 6 months. All pregnant mares should be vaccinated 4-6 weeks before parturition 5 . As clinical disease does not result in a sufficient immune response, recovered horses must be vaccinated 5 once fully recovered. Serological data indicates an initial 3-dose primary vaccination series produces a more consistent response in all foals and therefore foals should be vaccinated from 4-6 months old with a 4-6 week interval between the first and second dose with the final dose administered when foal is 10-12 months old 1 . All in-field surgical procedures should be conducted with the best possible aseptic technique and thereafter animals should be turned out onto green pastures or at least clean ground 12 . Should a horse obtain a wound, the wound should be treated appropriately as quickly and as effectively as possible. REFERENCES 1. AAEP Tetanus Available online https://aaep.org/guidelines/ vaccination-guideline/core-vaccination-guidelines/tetanus [ac- cessed on 12 October 2018] 2. Green, S.L. et al (1994) Tetanus in the Horse: A review of 20 cases (1970 -1990) J. of Vet. Int. Med. 8 (2) pp. 128 – 132 Available online http://onlinelibary.wiley.com.ezproxy.liv.ac.uk [accessed 3 April 2018] 3. Kabura, L. (2006) Intrathecal vs intramuscular administration of human anti-tetanus immunoglobulin or equine tetanus antitoxin in the treatment of tetanus: a meta- analysis Tropical Med. & Int. Health 11(7) pp. 1075 – 1081 Available online http://www. sciencedirect.com [accessed 3 April 2018] 4. Kay, G. & Knottenbelt, D.C. (2007) Tetanus in Equids: A report of 56 cases Eq. Vet. Ed. 19 (2) pp.107 – 112 Available online http://onlinelibary.wiley.com.ezproxy.liv.ac.uk [accessed 3 April 2018] 5. Lavoive,J.P. & Hinchcliff,K.W. (2008) Blackwell’s Five minute Veterinary Consult: Equine 2nd Edition, Wiley-Blackwell publishing 6. Liefman, C.E. (1981) Active Immunisation of Horses against tetanus including the booster dose and its application. Aus. Vet. Jour. 57 (2) 57 – 60 Available online http://onlinelibary.wiley. com.ezproxy.liv.ac.uk [accessed 3 April 2018] 7. O ‘Brien, M.A. (1993) Equine vaccines in the United Kingdom: Application and efficacy Eq. Vet Ed. 5 (1) pp. 47 – 51 Available online http://onlinelibary.wiley.com.ezproxy.liv.ac.uk [accessed 3 April 2018] 8. Reed, S. Bayly, W., & Sellon, D. Equine internal medicine 3rd Edition 2010Saunders Elsevier 9. Reichmann, P., Lisboa, J.A.N. & Araujo, R.G. (2008) Tetanus in Equids: A review of 76 cases J.of Eq. Vet.Sci. 28 (9) pp. 518 – 523 Available online http://www.sciencedirect.com [accessed on 3 April 2018] 10. Rings, D.M. (2004) Clostridial disease associated with neuro- logical signs: Tetanus, Botulism and enterotoxamia Vet. Clin. N.Am: Food An. Prac. 20 (2) pp. 379 – 391 Available online http://www.sciencedirect.com [accessed on 3 April 2018] 11. Stampfli, HR “Tetanus – lockjaw” Available online https://www. msdvetmanual.com/generalised-conditions/clostridail-diseases/ tetanus [accessed 11 October 2018] 12. Steinman A. et al (2000) Intrathecal administration of Tetanus anti-toxin to 3 cases of tetanus in horses Eq. Vet. Ed. 12 (5) pp. 237 – 240 Available online http://onlinelibary.wiley.com. ezproxy.liv.ac.uk [accessed 3 April 2018] • Volume 21 Issue 1 | March 2019 • 39