by: Marcia King

Click this link for the original article in its entirety: TheHorse.com

 

Whether you consider a horse to be old at 18 or 25, at some point, senior horses are going to start showing clinical signs of aging–moving more slowly or stiffly, becoming unthrifty, developing a dull coat, or displaying subtle or obvious signs of a disease process. Here are some of the common problems you could encounter in your aged friend and what you should know about those topics to help him through those golden years.

In today’s Part 2 we will cover the following topics:

– Cushing’s Disease

– Degenerative Joint Disease

– Dental Disease

– Chronic Diarrhea

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Cushing’s Disease

Equine Cushing’s disease (ECD, or pituitary pars intermedia dysfunction) is commonly diagnosed in aged horses, says Rachel Jahnke, BSc, DVM, of Wisconsin Equine Clinic & Hospital in Oconomowoc, Wis. Due to a tumor that forms in the pars intermedia of the pituitary gland, Cushing’s results in excess production of cortisol hormone, which in turn leads to hirsutism (a long, often curly hair coat that does not shed out well), laminitis, lethargy, excessive drinking and urinating, muscle wasting (especially over the topline), increased appetite, and recurrent infections.

Management is multifaceted and includes good-quality feed, deworming, regular dental care, routine farrier work, good grooming, and, if needed, antibiotics and drug therapy.

“Horses with ECD are prone to laminitis,” Jahnke explains, “so diet is very important; feeding lots of high-energy hay/grain may complicate laminitis. Make sure fresh water is always available as horses with ECD drink more.”

Because ECD horses do not shed out well, prevent over-heating by clipping the hair coat in spring and several times throughout the summer, and by providing adequate ventilation such as a fan to keep the horse cool.

“Avoid making the horse sweaty, as this will promote skin infections,” says Jahnke. “The owner may want to body clip the horse, then blanket in winter.”

Drug therapy includes antibiotics to manage recurrent infections or pergolide, bromocriptine, and cyproheptadine to treat clinical signs of ECD. Jahnke notes that acupuncture combined with Chinese herbs has also yielded beneficial results for some horses.

Prognosis varies. “If managed well, these horses can live several years as very functional, happy horses,” Jahnke says. “For some horses, the clinical signs–especially laminitis–become difficult to control and the horse might need to be euthanatized. Occasionally the pituitary tumor becomes large enough that neurological signs are observed and euthanasia might be indicated.”

Degenerative Joint Disease

Degenerative joint disease (DJD) refers to destruction of joint cartilage. Often accompanied by inflammation, the disease is progressive and commonly occurs with aging.

“In feral horses, there is a pattern of DJD which is age-related,” notes Antonio Cruz, DVM, MVM, MSc, DrMedVet, Dipl. ACVS, ECVS, assistant professor of large animal surgery at the Comparative Orthopaedic Research Laboratory, Ontario Veterinary College, University of Guelph. “However, the way we use horses–strenuous exercise, working on hard surfaces, insufficient rest following strains or injuries–can accelerate degeneration.”

Typically, DJD presents as lameness, stiffness, joint swelling, and moving slowly or reluctantly.

“Once the degenerative process begins, there is no return,” Cruz states. “Joint cartilage does not regenerate. We can only try to slow it down and to make horses usable and comfortable.”

Management techniques include using analgesics on a short-term basis (long-term use might be associated with adverse side effects such as gastric ulcers), anti-inflammatories, joint medications such as hyaluronic acid or glycosaminoglycans, providing a cushiony bed (deeply bedded stall or run-in shed) to minimize pressure on painful joints, good footing for exercise (avoid surfaces that are slippery, deep, or really hard), and proper management of the feet (improper balance places additional strain on the joints). Maintain some degree of activity to prevent stiffness, Cruz advises. Some horses can still be ridden lightly, while others do best with just turnout or hand walking. Soreness after exercise suggests over-use or an ongoing problem that needs to be investigated.

The rate of joint degeneration varies. Good management can keep many horses comfortable for the remainder of their days; other horses reach a point where uncontrollable pain is too overwhelming and there is no quality of life. In those situations, Cruz recommends euthanasia.

Dental Disease

Many horses develop periodontal disease or lose teeth prematurely, not as a condition of aging, but from years of neglect. “This is a major issue in older horses,” says David O. Klugh, DVM, Fellow in the Academy of Veterinary Dentistry and owner/practitioner of Equine Dental Associates, a referral practice in Newberg, Ore. “It’s a common misconception that it’s normal for a horse to have its teeth run out. Although the rate of tooth eruption in older horses slows down considerably, it doesn’t quite stop completely. Horses should have all their teeth for all of their lives, regardless of how old they get.”

With periodontal disease, the health of the gum deteriorates, so inflammation starts to occur between the teeth, leading to infection and loosening. When teeth become too loose, tooth extraction is usually the only viable option.

Signs of dental problems include dropping feed out of the mouth, bad mouth odor, difficulty chewing, swelling on the side of the face, and bitting problems. Gradual depression, an increased quietness or sedentary behavior, or other behavioral changes can also be associated with dental disorders.

“Frequently, by the time you see clinical evidence of a dental problem, the dental problem is pretty severe and may be beyond help, other than extraction,” Klugh says. To prevent these problems from occurring, older horses should have their teeth examined at least once a year during a physical exam, but the more frequent the exam, the more likely a problem will be caught before it gets too severe.

Horses that lose so many teeth that they can’t effectively grind their feed should be given complete feeds (pellets or grain) softened by water, Klugh suggests. A high-energy equine senior feed is helpful for horses that have difficulties masticating feed such as grass hay.

Chronic Diarrhea

The bowels of older horses often experience age-related changes that result in chronic diarrhea. Diarrhea can be caused from any number of maladies, including various infections and disease processes; therefore, it’s important to differentiate between chronic “old age” diarrhea and disorders due to underlying causes. Hope says that generally age-related chronic diarrhea presents where the horse is basically happy and in good weight, but with loose stools. Diarrhea accompanied by serious weight loss and stools that are watery or bloody suggests an underlying disease.

One major assist to these horses is to provide a more digestible diet. “A pelleted or complete feed can help,” says Hope. “Avoid rich hay; grass hay is a little easier to digest. During bouts of diarrhea, give the horse Kaopectate or something similar to coat the digestive tract, and probiotics, acidophilus, or yogurt to restore normal or ‘good’ bacteria back into the digestive tract.”

Next we will cover the following topics:

-Eye Problems

-Hoof Changes

-Reproductive Function

-Respiratory Factors

-Weight Loss