Tetanus in horses: an overview of 70 cases

Abstract

Tetanus is characterized by high case fatality rates in horses. Comprehensive case series studies involving equine tetanus from different geographic areas enable the evaluation of prognosis, efficacy of treatment, and control measures. We retrospectively investigated some selected epidemiological data (breed, age, gender, use of the horses, history of vaccination, seasonality, presence of wound/history of surgical procedures, clinical outcomes) and main clinical aspects (clinical signs, incubation period, length of hospitalization, and period between onset signs and hospitalization) in 70 cases of equine tetanus over 1990-2015, with emphasis in the association between these data and the clinical outcomes. High mortality rate (72.9%) was observed in this study. Forty (57.1%) horses presented history of wounds or surgical procedures related with tetanus, represented mainly by lesions in the hind limbs (42.5%), front limbs (15.0%), umbilical infections (7.1%), castration (4.3%), and face wounds (4.3%). Hyperesthesia, limb spasticity, cervical stiffness, tetanic spasms, and restriction of jaw movement were the main consistent clinical signs. Besides no statistical association, all the horses with umbilical infections, wounds in face, prolonged recumbency, sweating, dysphagia/aphagia died, and together with delay between onset of first clinical signs and prompt veterinary assistance (< 5 days) were considered indicative of poor prognosis; whereas there was a significant association (p=0.001) between survival and length of hospitalization > 7 days, seemed as an evidence of good prognosis. The high mortality rate of tetanus, even in horses under specific treatment, highlight the need for early diagnosis, prompt veterinary assistance, and establishment of prophylatic measures in equine farms.

Clostridial Diseases of Horses: A Review

“…Epidemiology. While uncommon, neurologic disease as a result of TeNT intoxication is often severe with high mortality in affected animals [91,92]. Susceptibility to TeNT varies between animal species and unvaccinated horses are particularly susceptible to this neurotoxin [89].…”

“…Gross pathology. Postmortem findings in animals affected by tetanus are often nonspecific [92]. Lesions such as ulceration secondary to prolonged recumbency may be appreciated.…”

Vaccine Production to Protect Animals Against Pathogenic Clostridia

“…The mortality rate of tetanus cases in both humans and animals is high [4,87,88]. Nevertheless, tetanus can be effectively prevented by vaccination.…”

“…For example, World War II saw substantially less tetanus-related deaths compared to World War I, when the vaccine was not yet accessible [90]. The incidence of tetanus in animals has also decreased due to consistent immunization programs [88].…”

A survey of veterinarians' practices, recommendations and perceptions associated with the prevention of tetanus in horses in Australia

“…9,11 Prognosis for equids diagnosed with tetanus is generally poor, with or without intensive treatment, while vaccination prior to challenge has been associated with prevention, reduced severity of signs, as well as improved prognosis. 3,[5][6][7][8]10,12,13 Prevention of tetanus in equids relies primarily on active immunisation, which is achieved by administration of commercial, adjuvanted toxoids produced from formalinised toxin of Clostridium tetani. 9,14 Generally, priming courses involve 2-3 doses of tetanus toxoid at 4 week intervals, followed by a booster dose 12 months later.…”