Steroids can help speedy recovery of the horses suffering from illness, injury or extreme stress by maximizing protein synthesis. They can boost up the appetites of the equidae. However, steroid abuse on horses may have serious side effects. The steroid abuse on horses may cause exaggerated or even dangerous male sexual behavior and troublesome reproductive woes in horses.

In late 1980, the Colorado State University conducted a study on horses to ascertain the effects of steroid abuse on the animals. The study included 48 yearling fillies and categorized them into three groups. The researchers administered different brands of anabolic steroids to each group of fillies, every three weeks, but they administered four times the proper doses (steroid abuse) to one group. The researchers found out that over the course of a year, none of the fillies on steroids showed a single normal four day heat; all had fewer ovulations and heats than the control group, and one group never ovulated at all.

The scientists revealed that fillies became aggressive toward other horses and behaved typically like stallions. The fillies were also observed teasing and mounting herd mates. The most of these fillies developed ovaries and had their clitorises protruding outside their vaginas. When researchers attempted to breed them, these fillies took two months to become pregnant, and after pregnancy, they had extremely high 21 % of early embryo deaths, compared to the normal fillies.

The Colorado State University in 1982 conducted a similar study to reveal the negative effects of on stallions. The study revealed that the stallions on anabolic steroids had shriveling of the testicles, and diminished sperm production and poor semen quality.

The findings of the study have made many sport bodies, including the AQHA and a number of paramutual racing committees, to outlaw anabolic steroids and institute horse testing procedures. The true fact of the study is that steroid abuses on horses doesn't not help enhancing performances.

According to veterinarians, anabolic steroids should nether be given neither to mares nor to horses. The young horses that are often put on anabolic steroids for enhancing their power, performance, and speed, never develop to full size and lose their fertility.

?I am very strongly opposed to the use of anabolic steroids in a young horse,? says Martin Simensen, DVM, the official veterinarian of the United States Equestrian Team.