Do not use in animals with known hypersensitivity to the active ingredient.

Use is contraindicated in animals suffering from cardiac, hepatic or renal disease, where there is the possibility of gastrointestinal ulceration or bleeding, or where there is evidence of a blood dyscrasia or hypersensitivity to the product.

Do not administer other NSAIDs or glucocorticoids concurrently or within 24 hours of each other.

The clinical effects of phenylbutazone can be evident for at least three days following cessation of therapy. This should be borne in mind when examining horses for soundness.

Some equestrian authorities regard phenylbutazone as a 'prohibited substance' within their rules.

Do not exceed the stated dose as the therapeutic index of phenylbutazone is low.

Use in any animal less than 6 weeks of age or in aged animals may involve additional risk. If such use cannot be avoided, animals may require careful clinical management.

Avoid use in any dehydrated, hypovolaemic or hypotensive animal as there is a potential risk of increased renal toxicity.

NSAIDs can cause inhibition of phagocytosis and hence in the treatment of inflammatory conditions associated with bacterial infections, appropriate concurrent antimicrobial therapy should be instigated.

Adverse reactions: In common with other NSAIDs that inhibit prostaglandin synthesis, there may be gastric and/or renal intolerance. This is usually associated with overdosage and such events are rare. Recovery is usual on cessation of treatment and following initiation of supportive symptomatic therapy, (see 'Overdose' section for further information).

Use during pregnancy and lactation: Pregnancy: Care should be exercised if administered to pregnant mares. Although no adverse effects of phenylbutazone on the foetus or maintenance of pregnancy have been reported during field use, no definitive safety studies have been carried out in the mare.

Foetotoxic effects of phenylbutazone have been recorded in experimental animal species at high dose levels. Avoid use around time of parturition.

Lactation: Phenylbutazone does not readily cross the blood milk barrier.

If the administration of phenylbutazone to pregnant or lactating mares is considered essential, the potential benefits should be weighed against the potential hazard to the mare and/or foal. Avoid use around time of parturition.

Interactions: Concurrent administration of potential nephrotoxic drugs should be avoided.

Phenylbutazone is extensively bound to plasma proteins. It may displace other drugs that are highly protein bound, e.g. some sulphonamides, warfarin, or it may itself be displaced to produce an increase in non-bound pharmacologically active concentration, which can lead to toxic effects.

Concurrent therapy with other therapeutic agents should be undertaken with caution due to the risk of metabolic interactions. Phenylbutazone may interfere with the metabolism of other drugs, e.g. warfarin, barbiturates, with resultant toxicity.

There is evidence to indicate that the pharmacokinetics of penicillin products may be affected by concurrent administration of products containing phenylbutazone, with a possible reduction of therapeutic efficacy, since tissue penetration may be reduced. The distribution of other drugs given concurrently may also be affected.

NSAIDs can cause inhibition of phagocytosis and hence in the treatment of inflammatory conditions associated with bacterial infections, appropriate concurrent antimicrobial therapy should be instigated.

Overdose: Overdosing may result in gastric and large intestinal ulceration and general enteropathy. Renal papillary damage may also occur with impaired renal function. Subcutaneous oedema, especially under the jaw, may become evident due to plasma protein loss. There is no specific antidote. If signs of possible overdosage occur, treat the animal symptomatically.

Incompatibilities: None known.

Operator warnings: Wash hands after use.

Avoid contact with the eyes. In case of accidental eye contact, irrigate eyes with plenty of clean water. If irritation persists seek medical advice.

Care should be taken to avoid inhaling or ingesting the powder. In the event of accidental inhalation or ingestion seek medical advice and show the product packaging.

General precautions: For animal treatment only.

Withdrawal period: Not to be used in horses intended for human consumption. Treated horses may never be slaughtered for human consumption. The horse must have been declared as not intended for human consumption under national horse passport legislation.