Thoroughbred filly beats odds on surviving tetanus

Tenacious Candy, a 2-year-old Thoroughbred filly, who was hospitalized at UC Davis that overcame tetanus and injury (Image courtesy of UC Davis College of Veterinary Medicine)

Tenacious Candy, a 2-year-old Thoroughbred filly, was brought to UC Davis veterinary hospital after a cut on her leg exposed her to the bacterium that causes tetanus. Tenacious Candy, once she was cut, went down in an exerciser and it took 3 men and a tractor to get her up. At first, she was able to eat and drink but over a couple of hours she stiffened. By the time Tenacious Candy arrived at UC Davis veterinary hospital, she had a prolapsed third eyelid, a rigid mouth, and stiff body and tail, all classic signs of tetanus.¹

Tetanus is a potentially fatal diseases that is characterized by muscular spasms caused by a neurotoxin created by Clostridium tetani. These organisms and their spores are located within the intestinal tract of horses, other species, and are abundant in soil, surviving for many years. The spores of tetanus can enter the body through open wounds, particularly puncture wounds, and they go on to proliferate under the right conditions.² The disease is typically treated with antibiotics typically penicillin, tetanus antitoxin injections, and other medications, but for severe cases a sling might be required. The infected horses are usually kept in dark and quiet stalls with deep bedding since they are sensitive to stimuli. Occasionally the stalls include padded walls to minimize further injury.

The team at UC Davis gave Tenacious Candy a tetanus antitoxin medication and supportive care of fluid therapy, muscle relaxants, and a quiet environment with low light, noise, and activity. After a week of hospitalization, she showed signs of improvement with her ability to eat and a reduction of stiffness. She was then transferred to the Center for Equine Health at UC Davis for rehabilitation.

“It is not a recovery that can happen overnight,” said Emily Berryhill, DVM, DACVIM, assistant professor of equine medicine, in the release.¹ “Horses recovering from tetanus routinely go through an extensive rehabilitation process. The toxins can be out of their system after being bound with antitoxin, but the damaged neuromuscular junctions need several weeks to regenerate.”

Although doing well, Tenacious Candy sustained significant muscle weakness due to the disease and tore a muscle in her hind leg during a rehabilitation session. She was brought back to the hospital and placed in a ling to stabilize Tenacious Candy and prevent any further injury. She was discharged after a month once she was able to lay down and get up repeatedly on her own.

Tetanus is preventable with vaccination and it is recommended that horses have a primary vaccination series of 2 doses at 4-6 week interval as a foal. This is then later on followed by repeat vaccinations at 1-years-old and annually after that. In Tenacious Candy’s case, she was vaccinated on schedule, but the team believes she did not generate the full immunity she needed to as a foal which in result increased her risk of developing the disease. According to the release,¹ the vaccinations she received did provide her a partial immunity, which helped her survive even though she was not fully protected from the disease.

“Candy’s survival was touch and go that first week,” said owner Mary Ellen Conway.¹ “She is alive today because of the unflagging, over-the-top care given by Berryhill and the entire UC Davis team. I am beyond grateful they pulled her though.”

References

1. Equine Medicine Specialists Help Thoroughbred Filly Beat the Odds to Survive Tetanus. News release. UC Davis College of Veterinary Medicine. Published July 22, 2024. Accessed August 6, 2024. https://www.vetmed.ucdavis.edu/news/equine-medicine-specialists-help-thoroughbred-filly-beat-odds-survive-tetanus
2. Young A. Tetanus. UC Davis School of Veterinary Medicine. Published March 29, 2021. Accessed August 6, 2024. https://ceh.vetmed.ucdavis.edu/health-topics/tetanus