What should I use for arthritis in a horse's hock? My vet said to use a product with glucosamine, MSM and chondroitin in it. What should I use?
Horse Journal Response
With a hock, what works best often depends to a great extent on the stage of the disease. The joint supplements like glucosamine and chondroitin will be most useful in early cases and problems that don't involve the lower joint of the hock.
Once it's to the stage that there is a considerable amount of extra bone (osteophytes) forming along the lower hock joint, the joint is trying to fuse. Joint supplements, anti-inflammatory drugs and hyaluronic acid injections may make the horse more comfortable but could also slow the fusion process.
The most promising treatment on the horizon for those cases is injection of 70% ethanol into the joint to speed up the fusion, as this may be considerably less painful for the horse than older methods. Otherwise, keeping the horse in gentle work to avoid stiffness and help the fusion along is recommended. The addition of neoprene boots overnight may also help, as they can be warming to the joint. In fact, neoprene is so warming that we don't recommend leaving them on the joint for more than 24 hours without a break.
Check our website at www.horse-journal.com for articles on nutraceuticals and arthritis. In addition, we have a current field trial of nutraceuticals underway that we expect to have completed by late fall.
OSSIFYING MYOSITIS
My 24-year-old Arab gelding has just been diagnosed with ossifying myositis in his left hind leg. He had periodic stifle problems in the past, and I thought this was a recurrence. His hamstring muscle is hard as a rock. We have had a lot of snow and ice here in Minnesota, and he likely slipped or strained his stifle going through the deep snow. I've never heard of this before. My vet hasn't seen a case in 15 years. Do you have any information?
Horse Journal Response
Ossifying or fibrotic myopathy is replacement of part of a muscle belly by scar tissue (fibrotic) or calcified scar tissue (ossifying).
It usually occurs in the semimembranosus or semitendinosus muscle, two long strap-like muscles that start high on the horse's hindquarters and attach to the tibia close to the stifle. The scarring interferes with the horse's normal muscle movement.
There's a characteristic gait with this problem. As the horse is bringing the leg forward, the movement will abruptly stop and foot be slapped down forcefully. If you're not seeing that type of gait, it would be a good idea to have an ultrasound examination of the muscle to be sure you're not feeling a muscle spasm secondary to pain from something else.
If it is fibrotic myopathy, there are currently two surgical procedures in use. One involves making an incision through the scarred area of muscle (myotomy), and was presented at the 1998 AAEP convention. It's a relatively simple procedure with a high success rate that can be done with the horse standing and sedated using local anesthesia.
The second option is tenotomy (cutting) of the tendon where it inserts on the tibia. Results with the two types of procedure are reported to be approximately the same in terms of improving the gait (75 to 100% improvement, high owner satisfaction) and returning the horse to use. It's important to make sure other muscles are not involved and in this case, because of the past history of stifle problems, it would also be wise to have the stifle joint examined by ultrasound before deciding on any surgery.
