The White Stuff

It’s the go-to solution for aches, pains and high temperatures, but how does bute work and is it safe? Roger Lee​ MRCVS has the facts you need to know

- Roger Lee​

MOST of us are familiar with the little sachets of white powder sometimes sprinkled into a feed bowl. They contain bute, which is short for phenylbutazone, the chemical name of the active ingredient.

Different manufacturers try to give their product a distinctive trade name, but all versions contain the same basic drug. Bute is classed as a non-steroidal anti-inflammatory drug. Other drugs in the same chemical family include aspirin and ibuprofen.

Bute is versatile and powerful. It is used both in the short term, to reduce immediate pain and swelling after an injury, and also in the longer term, for example, to treat stiffness and discomfort caused by arthritis. Bute reduces localised infection, perhaps around a cut or an embedded thorn, which in turn helps the antibiotic to reach the site. The drug may also be given for a more generalised bacterial or viral infection, lowering the horse’s temperature and reducing the severity of symptoms.

Bute was first synthesised in 1949, and was originally used as a painkiller for people with arthritis. It proved to be effective, but unfortunately it also materialised that, in rare cases, it could cause potentially fatal changes to the patient’s blood cells and bone marrow. Its use was banned in human medicine, but it proved to be an equally good painkiller in animals without causing bone marrow suppression.