Q. My dressage horse is now semiretired. When he was in intense training to compete at the upper levels, he received quite a bit of maintenance (joint injections, Equithrive, MSN, Osphos, etc.), including a daily dose of Equioxx (firocoxib) for his osteoarthritis. He is currently ridden very lightly three days a week, including one weekly jumping lesson that involves cantering over cross rails (nothing over 2 feet).

He is acting like he really loves the little bit of jumping and goes with his ears up and none of reluctance he had shown in his extended and collect gaits for dressage. He’s sound but stiff. My understanding is that Equioxx has a cumulative effect and needs to be given consistently to be effective. Would it be better to keep him on Equioxx daily or instead give him Bute (phenylbutazone) on an as-needed (once or twice a week) basis? Or, can I just give him Equioxx occasionally as needed? He has had gastric ulcers in the past, so that’s a concern as well.

—Via e-mail

A.Both phenylbutazone and Equioxx are commonly used and effective anti-inflammatory medications. Which drug to use and the frequency and duration of each medication is something all owners should discuss with their veterinarians. There is often a variety of factors that will be taken into consideration when making a drug choice.

In your question, you mention that your horse is stiff. This could be a sign that your horse is actually lame. A thorough lameness examination would be recommended prior to placing your horse on long-term medication.

A common misconception is that Equioxx does not cause gastric ulceration like phenylbutazone. But a recent publication demonstrates that both Bute and Equioxx can cause some degree of gastric ulceration. The gastric ulcerations seen were less severe in the Equioxx group. Because your horse has already had gastric ulcer issues, it would be recommended you place the horse on anti-ulcer medication or some other form of gastroprotectant in conjunction with any non-steroidal medication.

If your horse does need to be treated with non-steroidal medication, I would first see if Bute or Equioxx help the perceived stiffness you describe. Periodic administration of either is an acceptable choice, but which to choose depends on your horse. With your horse’s history of gastric ulcers I would likely try Equioxx first—treat him for 10 days and see how he responds. If there is a positive response then I would give it to him as needed. If Equioxx is not effective then you can give Bute as needed. I would not recommend that either medication be given long-term.

Routine exercise might be the best thing for the perceived stiffness. If he warms up and the stiffness resolves, I would not give him any medication.

Again, a thorough lameness examination might identify a source of lameness causing the perceived stiffness. Horses with osteoarthritis in the lower hock joints are often described by the owner as stiff. Medicating these joints may resolve the problem and is a more effective method of treatment than long-term non-steroidal anti-inflammatory medication.