With the advent of ivermectin-based dewormers in the late seventies, a new lease on life was given to the older horse population. Horse owners could now control the large strongyle. Migration of this extremely destructive strongyle's larvae up the mesenteric arteries and the ensuing damage was largely responsible for limiting a horse's life to around the 20-year mark. This limit on a horse's life meant we rarely had to deal with geriatric diseases of horses.

With good health care, horses are now be expected to live into their 30s. With increasing age we are seeing more problems that result in weight loss despite continuing a good diet. Most common is Equine Cushing's (EC) disease better described as pituitary pars-intermedia dysfunction (PPID). This article discusses the diagnosis of common problems that cause weight loss, treatment options, and provides links to articles with more detailed information.

A horse greater than 20 years of age should be considered geriatric. Problems can often be identified by history so detailed information on these topics should be taken. Several help identify PPID early:

• feed amount and quality
• pasture and housing conditions
• past disease problems
• deworming practices
• changes can be very important:
  • shedding patterns in the spring
  • in the environment
  • pasture companions
  • feed and water consumption
  • urination frequency

Many geriatric patients can be safely fed a maintenance ration designed for all horses without modification. In cases where the horse has loss of body condition and no other existing disease, the horse should be fed a very palatable, easily masticated, easily digested, dust-free diet that has a higher protein content (12-16%), maintenance levels of calcium (1%), and slightly elevated P content (0.4 - 0.65%), maintaining a Ca:P ratio of close to 1.5:1.

Older horses may be more sensitive to cold and adverse conditions. Be sure the horse always has shelter to escape the wind and rain when cold. They may also not compete as aggressively for food, so they should be fed separately from their pasture mates. Older horses may not adapt rapidly to change, particularly when moving into a new situation. Changes should be made slowly with the horse carefully monitored for successfully coping with the new situation.