Factors associated with the risk of developing sarcoid tumours in horses.

This research investigates the risk factors that are associated with the development of skin tumors, known as sarcoids, in horses. The study finds that certain breeds, gender, and age affect the likelihood of a horse developing these tumors.

Methodology

• The researchers conducted a retrospective case-control study, where they went through past records to identify patterns or correlations. This approach was used because sarcoids occur over a long period and you can’t start a study today and simply wait for sarcoids to develop.
• The study included 503 horses that were diagnosed with sarcoids between January 1980 and December 1989 at the New York State College of Veterinary Medicine.
• The control group was of similar size and comprised horses that did not have sarcoids during the same period.
• Data on the age, breed, and sex of the horses were obtained from computerized records.
• This information was analyzed using multiple logistic regression, a statistical method that helps understand how different characteristics (age, breed, sex) influence a certain outcome (in this case, the development of sarcoids).

Results

• The study found that certain breeds including the Appaloosa, Arabian, and Quarter horses were more likely to develop sarcoids than Thoroughbred horses.
• Standardbred horses, on the other hand, had a lower risk of developing these skin tumors.
• The researchers also found that geldings (neutered male horses) had a higher risk of developing sarcoids compared to stallions (intact male horses).
• However, they found no significant difference in risk between stallions and mares (female horses).
• The risk of developing sarcoids increased with age, becoming most likely up until 15 years, and then declining afterwards.

Proportional morbidity rate

• The researchers also obtained data from the Veterinary Medical Data Program, which had incidence rates of sarcoids in different veterinary colleges across North America.
• This provided them with a snapshot of how common these tumors were across the wider horse population.
• They found that the proportional morbidity rate — essentially the percentage of horses with sarcoids among all horses seen by the colleges — ranged from 0 to 14 per 1,000 cases, with an average rate of 6 per 1,000.