Azoturia in horses (sometimes referred to as tying-up syndrome), is an inflammation that can lead to damage of the horse's skeletal muscles. In years past, this disorder was called Monday morning sickness because it frequently affected horses that were fed the same each day but were given the weekends to rest and then worked hard again on Monday. Azoturia can also affect horses that are out of shape or overweight and fed more than their bodies require then abruptly are required to work. Tying-up has the same symptoms but is generally the term used when the symptoms are mild.
Signs
This disease is more often seen in young horses and those of muscular builds such as drafts and even Quarter Horses. The signs generally appear following a hard workout or endurance ride. The horse can experience moderate to severe pain which is often misdiagnosed as colic. It is important that if you are unsure of your horse's condition, you should not walk your horse until a veterinarian has confirmed the illness. Walking a horse with muscular problems can cause permanent damage.
As the pain sets in, a horse may begin to become sluggish during their work and may even refuse to move. The horse may sweat even when resting and the heart and pulse rate will elevate. The hindquarters will appear stiff as the horse moves. The rear muscles are often firm to the touch and the horse may show discomfort when touched in that area. In some cases, the muscles may spasm or tremor.
Horses experiencing this illness have been known to go to the ground and be unable to get back up. In extreme cases of azoturia, the horse's urine may be discolored from a brown color to dark red. There have been cases where the urine was almost black in color. The discoloration is caused by the damaged muscle tissue breaking down waste which is then expelled through the urine. In rare cases, this process has led to kidney damage and occasionally death. In mild cases of tying-up, these symptoms will not be as debilitating and the urine will not be discolored.
Treatments
During treatment, the horse should not be fed any grain and allowed only limited amounts of hay and plenty of fresh water. Depending upon the severity of the symptoms, a horse can recover with simple rest and nursing care which can take a few days to several weeks. The feed can slowly be introduced and increased as the horse begins to show signs of recovery. When the horse has shown a dramatic sign of improvement, hand-walking can be initiated and eventually training can resume at a slow pace.
In severe cases where a horse has gone down from their condition, soft bedding should be provided in the stall. The horse will also need turned frequently to avoid circulation problems and sores. It has been taught that a horse should never be left down but with this type of muscular disorder, forcing a horse to rise and stand too early can cause permanent damage to the muscles. Caring for a horse that is down requires vigilant nursing care to prevent other disorders caused when a horse cannot get on their feet.
A veterinarian can also administer drugs to help ease the discomfort and speed-up recovery time. Vitamin E and selenium is a treatment of choice as it can bring immediate relief to the horse. Anti-inflammatory drugs may also be recommended by a vet. IV fluids may be required to help flush the kidneys and keep the horse hydrated. In the most severe cases where a horse may not be able to rise for an extended period of time, a vet may need to insert a stomach tube and provide a laxative to keep the intestines working properly.
For mild cases of tying-up, the horse will only need watchful nursing care and perhaps some mild medications to help ease discomfort. A horse diagnosed with tying-up will be able to stand and will improve with slow walking to help loosen the muscles.
Prevention
Most cases of azoturia or tying-up are preventable. A horse that is fed large amounts of feed (especially grains), need the amount decreased on days of rest. Horses that have had bouts of this illness may need their rations decreased prior to any high endurance workouts. Food rations should be balanced according to the horse's daily activities and a horse should not be overweight. Adjust feed amounts according to the day's activities.
For animals that are only ridden occasionally, adjusting the rations can be difficult. Horses that are generally kept out to pasture and ridden for pleasure on occasion should be watched closely during the ride. At the first signs of discomfort, do not force the horse to walk, stop immediately, and allow the animal to rest.
The prognosis of most animals that experience azoturia or tying-up is generally positive. With proper treatment, the horse usually makes a full recovery. However, horses that have one episode of the disorder have a higher chance of reoccurrences. This may require the horse needing vitamin injections on a regular basis or adding two to four ounces of baking soda to their rations. Access to salt and fresh water at all times can also help decrease the chances of the disorder or minimize the symptoms. For cases of azoturia, it is important that owners seek veterinarian care for their animal. Together, a decision can be made on the best treatment options for the horse.
References:
HOW TO BE YOUR OWN VETERINARIAN (SOMETIMES), by Ruth B. James, DVM, copyright 1990.
COMPLETE HORSE CARE MANUAL, by Colin Vogel,BVM, copyright 1995.