Recent research comparing biomarkers in horses' blood with X rays showed these tests might be useful for predicting whether an animal is at risk of developing a bone or joint disorder, such as arthritis, said the study authors.

"If so, blood screening, which is easier than radiographic evaluation of large crowds of animals, would permit preselection," said Denis Verwilghen, DVM, MSc, DES, of the University of Liege in Belgium.

Because arthritis is a joint problem that mostly involves cartilage, X rays are not the best diagnostic tools–they can give indications about the condition of the cartilage, but by the time signs of bone changes are visible on an X ray, a lot of joint damage is already done.

"The best assessment of the joint surface can be obtained by examining it by arthroscopy (i.e. look with a camera into the joint)," he said, but the procedure is fairly invasive and not feasible on all horses. Ultrasonography can also aid in the evaluation of joint surfaces, but not all areas are accessible, and not all veterinarians perform ultrasounds