Postmortem evaluation of homotypic variation in shoe characteristics of 201 thoroughbred racehorses.

This research article explores the development of a standard technique for the evaluation of racehorse shoes and attempts to assess variation between horses’ shoe characteristics in relation to age and sex by studying 201 thoroughbred racehorses in California. The aim is to understand if one hoof’s shoe can indicate the type of shoe on its counterpart or on all four limbs.

Research Methodology

• The researchers conducted a cross-sectional study involving 201 Thoroughbred racehorses that died or had been euthanized at California racetracks between August 1992 and July 1994.
• They measured the shoe characteristics on the deceased horses and applied a comparison between limbs (homotypic variation) using the percentage of agreement.
• Chi square analysis was employed to compare shoe characteristics between horses grouped by age and sex.

Findings of the Research

• The research found that 90.5% of the horses had toe grabs, and 15.9% had rim shoes. Heel traction devices were less common on front hooves (2.5%) compared to rear hooves (6%).
• Pads were present on 24.9% of horses, with bonded rim pads being the most common. Special types of shoes were detected on 5% of horses.
• There was a high percentage of agreement between the left and right front hooves and between the left and right rear hooves (equated to 20 out of 25 variables with an agreement of 99% or higher).
• The percentage of agreement significantly dropped when comparing between left front and left rear hooves and between right front and right rear hooves (2 out of 25 variables with an agreement of 99% or higher).
• A significant association (P < 0.05) was found between the presence of a pad and age. Additionally, the characteristics of several shoe variables like size, presence of a special shoe, and overall wear matched were significantly associated with sex (P < 0.05).

Conclusions Drawn

• With the exception of variables related to special shoes, wear, and weight, one shoe for the respective front or hind limbs could be used as an indicator for the contralateral shoe worn by Thoroughbred racehorses without considerable loss of information.
• However, one shoe could not act as an indicator for the characteristics of all four limbs’ shoes.
• The study concludes that certain shoe characteristics are associated with the horse’s age and sex. These variables should be considered as possible confounders in studies of shoe characteristics.