All opinions and suggestions within our 'Veterinary Corner' are provided by K. Robinson MRCVS. The information is provided as additional support to our customers and spotlights veterinary matters throughout the year. If there is a particular subject you would like detailed in future articles please send us an e-mail and we will do our best to include it at a future date.*

Azoturia

Also known as tying up, exertional rhabdomyolysis or Monday morning disease, there are many factors which contribute to this:

• Over feeding of high energy ration without corresponding amount of hard work
• Highly strung mares/fillies more commonly affected than colts
• Heavily muscled horses more prone
• Cold weather (wind chill) may be a predisposing factor
• Electrolyte imbalance
• Vitamin E/ Selenium deficiencies
• Sudden adrenaline rushes

It is thought to be caused by an increase in lactose production in the muscle which will damage the muscle fibres.

Clinical signs range depending on the severity of the attack. It is usually the muscles of the hind limbs that are affected and the horse may just appear still or be completely unable to move. In extreme cases the horse may collapse. Profuse sweating is often seen with an elevation of heart rate, respiratory rate and temperature. The muscles over the bottom of the animal feel hard to the touch and if an attempt to lift the hind limbs is made they are very still and heavy. The urine becomes discoloured due to the release of myoglobin from the damaged muscle fibres. Occasionally a horse may show signs of colic – pawing the ground aid rolling and this is an important differential diagnosis.

Diagnosis
Can be made specifically by taking a blood sample and looking for a rise in two specific enzymes that are released from the damaged muscle fibres. These are AST and CK. CK is muscle specific and this rises immediately. AST is not so specific and the rise may take longer to be apparent.

Treatment
Stop exercise immediately and do not try to move the horse. Call the vet who will take blood, administer pain relief and in severe cases fluid therapy. The horse should be stabled after this until the following day and then turned out for 5-7 days with no ridden exercise. When exercise is re-introduced it should be done slowly and gradually.

Prevention
Horses should always be warmed up gradually prior to exercise. If the exercise level is altered the feed should be altered accordingly. Electrolyte supplements can be fed to the horses that have repeat attacks. Special oil-based high fibre diets can also be fed to horses that have repeat attacks.

*Disclaimer Please note that AmTrust Europe Limited can not take any responsibility for any veterinary opinions or advice provided. The articles we post onto our website are intended as helpful and educational information and are not meant to provide veterinary advice. Any concerns you have for your horse or pony's medical welfare should be directed to your own vet.