Bute: long-term use

05th April 2019

If you are lucky enough to have a horse that makes it to their twilight years you will be well aware of their tendency to slow down and stiffen up. For some horses, this happens in their mid to late teens and some soldier on into their twenties before their joints start to creak. There are many, many factors that influence arthritic changes: discipline, individual biology, past injuries and ‘mileage’ to name but a few, but while a horse that has developed arthritis will need to managed slightly differently, it certainly does not mean they need to be retired!


It is important to point out that what works for one horse may well not work for others. It depends on the severity of changes, location of changes and temperament of your horse among other things. There are tiers of invasiveness involved in treating arthritis and, here, I am going to touch on the more invasive procedures, but focus on long-term bute use as this is the most common treatment.


Arthrodesis is a procedure in which joints are fused permanently. This can be done by a few methods, but requires a general anaesthetic, a period of box-rest followed by a controlled-exercise programme. Joints that can be arthrodesed are the small hock joints and the pastern joint (joints with naturally limited movement). The decision to arthrodese joints is usually taken when there is so much damage that any other treatment would not alleviate pain to a satisfactory degree. Following arthrodesis, the horse may or may not be able to return to work and decided on a case by case basis. On rare occasions, the fetlock joint can be arthrodesed, but this is usually following a severe, traumatic injury and is considered a salvage procedure.


Joint medication: for every joint in the horse, there is a given approach which allows a vet to insert a needle and either remove joint fluid for testing or inject medications. Commonly treated joints are medicated with steroids and/or hyaluronic acid, which targets inflammation and improves joint lubrication, respectively. Medicating joints in some disciplines is common place and keeps the horse competing at the top of their game. However, the risks may outweigh the benefits for a horse in light work only. Joint medication lasts a varying length of time depending on the horse, the severity of joint disease, and drugs used.


Phenylbutazone, or ‘bute’ in layman's terms, sold as Equipalazone, is the choice of most horse owners for reducing stiffness and pain associated with arthritic changes. After a discussion with your vet, your horse may be put on a trial period of ‘bute' for two or three weeks and, if you find that your horse has a spring in his step that you haven’t seen for a while, regular ‘bute’ may well be the way forward for you. Of all the drugs we use in equine medicine, ‘bute' in low doses is considered to be pretty safe, but no drug is used completely without risk. Phenylbutazone is part of a group of drugs called non-steroidal anti-inflammatories (NSAIDs), which essentially do what it says on the tin. They work in the same biological pathway as steroids, modifying the body’s inflammatory response, but lower down the pathway and, therefore, have less side-effects. Side-effects that we see include gastric ulceration, kidney and liver damage and occasionally colitis, although this usually requires much higher doses than is commonly used for daily medication.



‘Bute’ comes in three forms: a powder added to feed; a paste; and an injectable preparation. Injectable ‘bute’ can only be administered by a vet and ‘bute’ in paste form is considerably more costly than powdered ‘bute’, handy for short-term treatment, but unrealistic for long-term medication. If you struggle to get your horse to eat ‘bute’ in feed, there is a drug available called suxibuzone, a pro-drug, which means that it is converted to phenylbutazone by the liver. It is marketed as Danilon and some owners find that their horses eat it more willingly. There is also some suggestion that Danilon is less likely to cause ulcers than ‘bute’.


In the initial stages of medicating your horse with ‘bute’, it is well worth spending time working out exactly how much is effective for your horse. It seems like common sense, but the lower the dose of ‘bute’ you use, the less likely you are to see side-effects and also the added bonus of more pennies in your pocket! It may be the case that your horse only needs ‘bute’ in certain circumstances, such as in winter when it’s cold or if they do more work than normal as a one-off for example, a long hack on a Saturday may mean you give a sachet of ‘bute’ when you get home to prevent stiffness the following day. As the years go by, you may find that where half a sachet of ‘bute’ used to cut the mustard, it no longer does. This is to be expected, but have a chat with your vet before altering the dose.


If your horse is on regular ‘bute’ treatment, you may buy a box at a time either direct from your vet or using a prescription from an online pharmacy. To do either of these, it is the law that your horse must be seen by a vet at least once a year. Annual vaccination time is the perfect opportunity for this. On the topic of law, a horse being treated with ‘bute’ or Danilon at any stage of its life must have been signed out of the food chain in its passport. Once the relevant page in your horse’s passport has been signed by both yourself and your vet, it can never be sent for human consumption either by you or by anyone you may sell your horse to.


Some owners find long-term drug use concerning, regardless of the risk and side-effects, so it is important to mention here that as an adjunct, there are lots of options for supplementing the diet and modifying exercise regime to help with joint health. It is worth asking your vet about efficacy of supplements before investing in large tubs of them as some are more effective than others and similarly, ask your vet to help you put together a tailored exercise program because what works for one horse may not suit another.


Finally, as with any medications for your horse, you must consider competing rules. Dependent of the competing body, there will be slightly different regulations, but any performance-enhancing drug will have a withdrawal and detection period to be observed. Mention during your veterinary consultation if you have any competitions coming up to ensure you are complying with regulations.