Tetanus in the horse: a review of 20 cases (1970 to 1990).

The research focuses on studying the occurrence and impact of tetanus in horses, compiled from case records at the Ontario Veterinary College-Veterinary Teaching Hospital over 20 years (1970-1990). The study highlights a high fatality rate and a strong correlation between vaccination and survival.

Study Sample

• The researchers examined a sample of 20 horses that were referred to the Ontario Veterinary College-Veterinary Teaching Hospital with tetanus between 1970 and 1990.

Fatality Rate

• The study reports a high mortality rate, with a staggering 75% of the studied horses succumbing to tetanus.

Association with Vaccination

• One of the significant findings is the strong correlation between previous vaccination and survival. The researchers found that a horse’s chances of surviving were increased dramatically if it had been vaccinated against tetanus before contracting the disease.

Development of Clinical Signs

• Most of the studied horses had been injured around 9 days (ranging from 2 to 21 days) before they began showing clinical signs of tetanus.
• The most common symptoms were hyperesthesia (excessive sensitivity in any of the senses) and prolapse of the third eyelid.

Treatment Approaches

• The treatment regimens provided in the hospital varied between horses. However, all received parenteral penicillin, tranquilizers, tetanus toxoid, and antitoxin.
• Five of the non-surviving horses received intrathecal tetanus antitoxin, with one experiencing seizures as a complication of this invasive treatment.

Prognostic Indicators

• The study suggests that the prognosis was best for horses that had received a vaccination before being injured, responded to phenothiazine tranquilizers, and didn’t rapidly become recumbent or laid down (within 24 to 48 hours).

Recommendation of Vaccination

• Based on the observed species susceptibility, the potential for wounds becoming contaminated, and the increased survival rate of vaccinated horses, the study strongly recommends yearly vaccination against tetanus for horses.