The Senior Horse

is not limited to the horse or pony that eats an overabundance of rich grass often when given unrestricted access to rich spring pastures. It can develop from eating poisonous plants overconsumption of grain retaining the placenta after foaling a disease that spikes a prolonged high temperature the metabolic changes associated with equine metabolic syndrome EMS or trauma from repeated concussive forces road founder.
Laminitis can occur in any breed at any age however overweight horses and those with metabolic syndromes more frequent in older horses do have a higher risk of laminitis. Laminitis is also a common sign of pituitary pars intermedia dysfunction PPID in the older horse. The best defence against laminitis is to prevent the aforementioned causes from occurring. 
Horses suffering laminitis will usually be reluctant to move and often stand with their front feet well out in front of them rocking back on their heels seeking relief from the pain. They can appear as if they are walking on eggshells. The hoof will be hot to touch. In severe cases the laminae weakens to the point where the coffin bone may rotate andor sink.
Horses and ponies with PPID suffer an increase in cortisol levels. Excess cortisol is produced by the adrenal gland because the part of the brain that controls the adrenal gland the pituitary gland is not functioning properly. High cortisol levels increase blood sugar glucose levels and suppress the immune system. This hormonal disease often goes unnoticed as signs are slow to develop and are often mistaken as normal in the aging process. The disease typically occurs in older equids but has been diagnosed in horses and ponies as young as ten. While all ages genders and breeds are susceptible to developing PPID ponies and some breeds of horses specifically Latinblooded horses such as Paso Finos Peruvian Pasos Spanish Mustangs Arabs and Morgans seem to develop PPID more frequently.
Horses and ponies with PPID will often develop a potbelly appearance. You may notice other changes in body conformation. Common signs of PPID include formation of fat pads on top of the neck tail head and above and around the eyes. Horses with PPID also tend to lose muscle.
Look for abnormal hair coat including patches of long hair on the legs wavy hair on the neck changes in coat colour or shedding patterns and unusual whisker growth.
Up to 70 percent of horses seen for laminitis have been
found to have PPID. It is often treated without identifying the underlying cause.
More early warning signs for PPID include decreased athletic performance change in attitudelethargy and delayed shedding of hair coat.
In more advanced stages of PPID the signs can include lethargy depression generalized hypertrichosis long shaggy hair coat loss of seasonal coat shedding skeletal muscle loss rounded abdomen abnormal sweating increased or decreased excessive thirst excessive passage of urine chronic or recurrent infections i e. sole abscess ulcers etc. laminitis absent reproductive cycleinfertility and hyperglycemia high glucose levels in the blood.
Early diagnosis is important. Contact your veterinarian if you notice any of the above signs in your older horse. After a complete examination if your veterinarian suspects PPID he or she may recommend following up with some blood tests to check for the disease. The most common tests to diagnose equine PPID include measuring resting basal ACTH adrenocorticotrophic hormone and fasting insulin level. Studies have indicated success managing the clinical signs of PPID with the drug pergolide mesylate. It acts on the pituitary to ultimately decrease circulating ACTH and other hormone levels. Daily treatment is needed to improve the horses quality of life by reducing disease signs and the risk of other illnesses. Your veterinarian will be able to advise if pergolide mesylate is a treatment option for your horse.