BUTE AND ISOXSUPRINE
Treating Navicular Disease With Drugs
These types of treatments are only intended to reduce the pain caused by navicular disease. They do not address the fundamental causes.
Two drugs are commonly prescribed, Bute and isoxsuprine. I will address each seperately below.
What is bute and how does it work?
Bute for horses, or phenylbutazone, is an analgesic and is possibly the most prescribed drug for navicular disease and other forms of lameness in horses. It is effective in treating inflamation and pain. It cam be applied by injection, tablet or most commonly for horses as a paste or powder.
Bute can be effective if applied soon after the onset of navicular disease.
Bute works by inhibiting an enzyme called cox. However, cox is important for liver function and also protecting the lining of the horses intestines. Horses who experience prolonged treatment of bute or are prescribed high doses run the risk of developing ulcers in the stomach or digestive tract. Note: Question your prescription if it is more than 4mg per day. There is also some risk of kidney damage. There are also other possible side effects but these are less common.
Please take care when working with bute as it is known to adversely affect the health of humans. Be careful not to inhale the powder and always wash your hands immediately after handling.
What is Isoxsuprine and how does it work?
Isoxsuprine is thought to increase circulation to bone of the horses feet and therefore act agoinst the causes of Navicular disease.
There is some considerable debate over whether isoxsuprine actually works. Some believe that it is totally ineffective while others believe it is only effective when combined with other treatments.
In some cases it may increase the horses heart rate or cause changes to blood pressure. If you are already treating blood pressure related conditions, please consult your vet. It should also not be used in horses with bleeding.
There is also the possibility that there will be some irritation of the gastrointestinal tract.
Isoxsuprine is a prohibited class B drug and is banned in some equine competitions. If you are planning to enter your horse into a competition, it might be wise to check the relevant rules before administering this medication.
A final word
Please consult your vet when administering Bute to your horse.