Dangers of Bute in Horses

Bute is one of the most common medications administered to horses. However, horse owners should be well aware of the health risks associated with this medication.

High-Risk Horses

Both very young and very old horses are at higher risk for side effects from phenylbutazone. As with any drug, caution should also be used in horses that are ill or under stress. Bute should not be combined with other anti-inflammatory medications, such as aspirin or Banamine, or used at the same time as herbs that can influence clotting time, such as hawthorn, salvia, angelica, ginkgo, feverfew and ginger. Use bute with extreme caution in a horse with a history of kidney or intestinal tract problems, and with drugs that may have negative effects on the kidneys, such as the antibiotic gentamicin.

Bute, short for phenylbutazone, is probably the most widely used drug in horses. Bute is an inexpensive, highly effective treatment for inflammation and pain that can be injected intravenously or given orally to horses as a powder or paste. Bute works by inhibiting a class of enzymes called cyclo-oxygenases, COX for short. Activation of this system is a necessary step in the complex chain of events that results in inflammation.

So far, so good, but it turns out that horses also need COX enzymes for normal kidney function, for secretion of the protective lining that shields the intestines from damage and for production of blood cells. Low-level activation of the “bad,” inflammatory COX enzymes is essential for normal healing of tissues after injury or just plain routine wear-and-tear repairs.

Horses treated with bute, especially at high doses or for long periods of time, can develop ulcers in their stomachs or colon, kidney damage and, in some cases, bone marrow suppression, although bone marrow problems are less common. More recent research has found that bute can slow the production of joint cartilage and delay bone healing. Bute also interferes with thyroid function.

This doesn’t mean that you should never use phenylbutazone. It does mean it should be used properly and only when necessary. Anti-inflammatory drugs are meant to be used for a relatively short period of time (days) for acute/new problems or flareups of active problems, for example, when a horse pulls a tendon, has acute laminitis or is worked too hard and an old joint problem becomes obviously worse. Three to seven days is the usual treatment course.

Fortunately, you have some effective alternatives to dealing with inflammation and acute or chronic pain. Use phenylbutazone for short courses when really indicated, but otherwise try one or more of the following.

Cold is an extremely effective way to block inflammatory reactions in their tracks and also provides pain relief. The feet and lower legs of horses are very tolerant of cold. It can also be used for wounds, stings, bites, etc. on the body.

For the feet and lower legs, stand the horse in cold running water, a bath of ice water or use ice wraps. To avoid the mess if you don’t have ice wraps, place several cotton leg wraps soaked with rubbing alcohol or witch hazel in the freezer and use these after they have super-cooled for an hour or more. (You should change them every 15 to 20 minutes for best effect.) Sore, hot feet can be packed with a poultice that has been chilled in the freezer when you’ve finished icing.

Ice/cool as often as possible and as long as possible for best results. Horses’ lower legs have been kept in ice-water baths for one to two days with no ill effects.

Have you ever left an emergency room or your doctor’s office with a sprain or swollen joint and not had it wrapped? Bandaging helps stabilize the area to prevent extremes of movement, provides mild support and controls swelling. The result is usually an immediate improvement in comfort.

Problem tendons, ligaments and fetlock joints can be wrapped with regular standing wraps. Knees and hocks can receive some support by using a human elastic or lightweight synthetic knee brace. Adjust the brace so that the hole is positioned over the bony prominence at the point of the hock or in the back of the knee.

Caution: Do not wrap hot, swollen legs if you are not expert at applying bandages. Uneven pressure can cause serious problems. Always wrap after thoroughly cooling out the area. Braces on knees and hocks should be just snug enough to stay in place and should never leave an indentation on the skin. Wrapped areas should be checked several times a day to make sure the wrap or brace has stayed in place and that there is no swelling of the skin above or below the wrap. If there is a mark on the skin at the edge of the wrap, it’s too tight. You should be able to easily insert a fingertip between wrap/brace and skin. If you are unsure, don’t use wraps or braces.

Herbal Alternatives
A variety of herbs have been used as substitutes for phenylbutazone, aspirin and other anti-inflammatory drugs. For rapid control in acute situations, your best bet is a product with an effective dose of Devil’s Claw, such as the liquid B-L Solution, www.equineamerica.com, or the powdered products DC-Y, www.medvetpharm.com, or Devil’s Claw Plus from www.uckele.com.

For long-term control of pain and low-grade inflammation in chronic conditions, try products based on Boswellia, curcumin and ginger like Phyto-Quench, www.uckele.com, or Pain Management, www.platinumperformance.com. These latter products may take longer to reach full effect.

Use caution with most liniments and rubs because the initial icy feeling quickly gives way to warmth as an irritant effect occurs, which leads to more blood flow and possibly more swelling. When there is evidence of worsening pain and any suspicion of reactivated inflammation, your safest and most effective choice is Sore No More, an Arnica-based liniment in a nondrying, witch hazel base, from www.equilite.com.

For topical pain/stiffness relief after acute inflammation is controlled, in place of bute try a topical capsaicin cream like Equi-Block, www.donalex.com. Capsaicin works by depleting one of the chemical messengers that cause the sensation of pain. For best results, it should be applied several times daily the first few days.

Caution: Capsaicin itself causes an unpleasant sensation when first applied, should not be used under wraps and should not be used in acutely inflamed areas.

For more information on bute, check out www.drugs.com/cons/Phenylbutazone.html

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