Several regions throughout our County are currently experiencing drought conditions. These dry spells pose some unique healthcare and management challenges for horses.   Whether it is stress from heat and blowing dust, changing feeds or dwindling water supplies, the additive stresses from drought can cause potentially serious health problems for horses. Understanding and anticipating these problems will help maintain your horse’s health and welfare during this stressful time.

Horses that are stressed for any reason, including drought, benefit from good basic care. It is important to ensure that all horses are properly vaccinated and dewormed.  In addition, stressed horses require the other basics, like good shelter, nutrition, hoof care, and fresh water.

Horses that are normally maintained on dry-land pasture are affected most by drought, as their feed supply dwindles and their management requires change.  Any grass that is still present on pastures is usually severely drought-stressed.  Under environmental stress, grass undergoes periods of rapid growth followed by periods of dormancy, and this extreme growth pattern poses increased risk for laminitis and colic.  Horses that have been eating a dry hay diet do better if they are given time for their intestine to adjust to green grass again.  When we do get moisture again, be careful to moderate the amount of rapidly changing pasture your horses are exposed to.  Anticipate the dangers and make slow transitions in turnout time.

Weed toxicity is more likely under drought conditions, as desirable plant species are unavailable and sometimes the only green plants on the pasture are toxic weeds.  Feed horses an adequate amount of good quality hay to discourage them from eating toxic weeds under these conditions.

Horses on a productive pasture tend to exercise a great deal in a normal day as they forage. When green pasture is gone, they tend to exercise less, and instead wait around in the shade to be fed. These horses are more inclined to have problems with colic than those that are out foraging.  Feed a generous amount of a bland grass hay to give these horses something to eat and be occupied with during the day, rather than waiting around for a rich feeding.

Sand ingestion is more common in pastured horses under drought conditions, because horses graze grass down to short stubble, and tend to ingest more dirt or sand as they try to graze the last few short shoots and roots. Sand ingestion is a serious problem that can lead to colic and diarrhea.  Problems occur where soil particle size is large (true sand), and is not usually a problem in other soil types.  If you have a sandy soil type, prevention or reduction of sand ingestion is the most important management tool.  Feeding a psyllium product regularly may also be beneficial.

Rotate pastures to try to keep drought-stressed grasses alive by not overgrazing them.  This will preserve some ground cover, thus keeping the soil together and preventing wind and water erosion and soil loss.

Drought conditions drastically reduce the hay supply.  Horse owners accustomed to having a steady hay source may find that their supplier can no longer provide that. Hay prices become extremely high and horsemen often resort to buying small amounts from different sources. The greatest problem becomes maintaining hay consistency.  Radically changing feed types increases the risk for health problems like colic and laminitis.  Always try to maintain a consistent hay type, source and quality.  If this is not possible, mix the different hays to ease the transition between the types, and make the transitions as slowly as possible.  When purchasing hay from a new source, examine it carefully for mold, abnormal dust, weeds, blister beetles and sharp seed awns.

A pond or stream that is used by pastured horses as a water source may dwindle and ultimately become stagnant.  In some cases, this can allow bacterial and algae growth that may pose a health risk.  Be very careful to monitor water quality in these situations and always provide extra fresh water.

Wind causes stress for horses.  Blowing dust can cause eye irritation and respiratory problems, as well as just being a general nuisance.  Fly masks not only provide protection from insects, but certain types may also help protect from intense sunlight and dust.  Provide adequate shelter and clean feed and bedding to reduce dust problems.  Horses that develop coughs may need special treatment, which may include soaking hay before feeding.

Certain diseases such as Dryland Distemper (also known as "Pigeon Breast" or "Pigeon Fever"), and Vesicular Stomatitis can be more common in dry, hot and dusty conditions. Know the clinical signs of these diseases, be on the lookout for them, and immediately contact your veterinarian if you see these signs develop.  Good basic husbandry goes a long way in making horses more resistant to these and all diseases.

Drought has created severe wildfire risk for many areas, especially heavily wooded areas.  Horse owners that live in fire prone areas should be prepared for wildfire by having an evacuation plan.  All horse owners should have (or have easy access to) a serviceable truck and trailer that they can use quickly in an emergency.  All horses should be easily caught and should load, tie and trailer without difficulty.  If these basics are a problem, now is the time to resolve them yourself, or with help of a friend, neighbor, or trainer.  Don’t wait until you are faced with a dire emergency.

Originally printed in The Horse Magazine - AAEP Forum, June 2011