Research News: 09/06

Shivers And EPSSM

The condition called ”shivers” causes the horse to have an elevated, twitching tail, twitching of the large muscles above the stifle joint, often with the leg lifted off the ground and shaking. It’s usually triggered by backing the horse or holding the leg off the ground, e.g. for shoeing. Shivers may be seen in any breed but is more common in drafts and those with draft blood lines (e.g. warmbloods).

Shivers is classified as a neuromuscular disease, but it’s not known if it is primarily a muscular problem or a neurological one. There may even be more than one cause for shivers in a horse.

The major cause of these symptoms to be differentiated from true shivers is pain. Pain anywhere from the lumbosacral area, back or lower down in the hind legs may cause the horse to exhibit these signs. Horses with claudication — insufficient blood flow to the hind legs caused by clotting in the major arteries — will also do it if they are worked too hard for the compromised blood supply to deliver enough blood to the muscles. Horses with tying-up may also sometimes shift weight behind and quiver in the legs.

It has been said that shivers is being seen more frequently, but there’s really no documentation of that. What is true is that shivers is being talked about more, since it was suggested that it could actually be a symptom of equine polysaccharide storage myopathy (EPSSM). However, simply because both conditions are most common in drafts doesn’t automatically mean they are connected, any more than some unique skin and hoof problems in drafts are tied to EPSSM.

A study performed at the University of Minnesota looked at 103 Belgian draft horses, including blood work for muscle enzymes and muscle biopsies. They found that 37 horses had EPSSM, 19 had shivers, but only 6 had both conditions at the same time — with 31 having EPSSM only and 13 had shivers only.

Furthermore, the rate of EPSSM in Belgians in general, 30%, is the same as the rate of EPSSM in Belgians that have shivers. Thus, while a horse could have both, shivers can exist without EPSSM, and they may be completely different conditions. Studies in the 1930s suggested shivers was linked to arthritis, which would make sense from a pain standpoint, but that has not been confirmed either.

There’s no effective treatment for shivers. Keeping the horse moving as much as possible, which is beneficial for both muscular problems and arthritis, is thought to help control symptoms. Vitamin E supplementation is usually recommended because of its beneficial effects for both muscle and nervous system tissue. Horses that also have EPSSM should be on an EPSSM diet, but this is not a specific treatment for shivers.Get Antibiotics To The Source Of Joint InfectionsGet Antibiotics To The


Source Of Joint Infections

Two separate reports, from the veterinary schools at Purdue and Ohio State, in the June issue of the Journal of the American Veterinary Medical Association, give a thumbs up for treatment of infected joints using a catheter and infusion-pump system to constantly deliver antibiotics directly to the horse’s infected joint. Success rates were high.

In the Purdue University study, the average treatment time was 6.1 days, with 93% of the infections being resolved. Of the animals available for long-term follow-up, 79% of them were in work for their intended purposes.

In the Ohio State study group, treatment times ranged from 6 to 16 days, and 81% of the horses available for long term follow-up were reported to be sound.

Joint infections in foals may occur following umbilical cord infections, or any bacterial infection that finds its way into the foal’s blood stream.

This is less common in adult horses but may happen if there is a deep-seated source of bacteria, such as a gutteral pouch infection or an abscess. Joint infections may also be caused by penetrating wounds or as a complication of a joint injection or surgery.

Prior treatments involved two or more flushings of infected joints with large volumes of sterile fluid, possible removal of the synovial membrane, antibiotic administration into the joint as well as intravenous or intramuscular antibiotics.

Similar success rates have been reported in adult horses treated this way, but each flushing of the joint requires general anesthesia, adding considerably to the risk and cost of treatment.

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