Be careful with joint injections [H&H VIP]

  • Do joint injections show up on dope tests? Peter Green MRCVS finds out

    The injection of very small doses of medication straight into a joint can achieve the same — or even better — results as giving the horse a larger dose by standard injection into a vein or muscle.

    The theory is that joint injections target the medication at the precise place where the problem is. Joint injections are commonly used for arthritis or degenerative joint disease in performance horses. Not only does the joint injection get the medication straight to the problem, logic suggests that it also keeps the medication enclosed in the joint capsule. This means the drug is less easy to detect in samples.

    Steroids are banned in racing and most serious competitions. But tiny steroid injections straight into a joint are considered less risky and harder to detect — or so some vets believed.

    Italian researchers recently published the results of an experiment in which they injected very small therapeutic doses of steroid into 1 hock joint of standardbred trotters. They then measured the adrenal function of the horses.

    The horses’ natural steroid, cortisol, was suppressed within 12hr of injecting the joint. This showed that the artificial steroid had leaked sufficiently from the joint to feed back and reduce production of the natural hormone. Moreover, the injected steroid was detectable in urine for up to 48hr.

    This shows that joint injections have effects on the whole horse — and could cause a horse to fail a dope test.