altAuthor - Dr. Katharina Lohmann

Dr. Katharina Lohmann graduated from Freie Universität Berlin, Germany Veterinary School in 1995 and is certified as Diplomate of the American College of Veterinary Internal Medicine (ACVIM). She obtained her PhD from the University of Georgia, working under Dr. James N. Moore. Since 2004 Dr. Lohmann has held the position of Associate Professor Large Animal Medicine at the Western College of Veterinary Medicine in Saskatoon.


Care and management of geriatric horses is becoming an issue of increasing importance to horse owners, and the number of geriatric horses presented for veterinary care appears to be increasing. There is no universally accepted definition of a “geriatric” horse; however, the term is mostly applied to horses that are older than 20 years of age and/or are showing physical signs of old age. To date, few conditions are recognized as affecting geriatric horses exclusively, but management issues of common conditions in aged horses may present particular challenges.

Weight Loss and Feeding
Weight loss is a common problem in geriatric horses and may be caused by underfeeding, inability to utilize roughage, severe dental disease, and underlying diseases resulting in nutrient loss or increased nutrient requirement. Rank order within groups and chronic pain should also be considered. Body condition scoring is an important measure to monitor weight maintenance in aged horses. Regular dental examination and correction are indispensable in aged horses; however, limited ability to correct dental abnormalities such as wavemouth formation often necessitates the use of special diets. Complete pelleted feeds, especially “Senior diets”, are very useful as they provide a balanced diet and cover roughage requirements, are palatable, easy to chew and highly digestible. Water intake may be reduced in aged horses, and easily accessible sources of clean, good-quality water are imperative.

Dental Care
Regular dental examination (once or twice a year) is an important component of any preventative medicine program in aged horses. Proper dental care throughout life may also prevent development of abnormalities with age, and reduce the need for extensive dental correction in aged horses. Horses teeth “lengthen” throughout life, and teeth are gradually pushed out of their socket in later years. Dental correction in aged horses therefore has inherent limitations, and maintenance of appropriate tooth function should always supersede cosmetic concerns.  Along with mechanical failure to chew feed, tooth loss and pain associated with gum disease or temporo-mandibular joint disease are major reasons for poor eating capacity in aged horses. Sinusitis may occur with tooth root infections.

Exercise
Regular exercise may help to maintain mobility and prevent decline of heart, lung and muscle function with age. There is no reason to avoid exercise in healthy, aged horses; however, owners should be sensitive to conditions associated with chronic pain (e.g. arthritis) and should adjust exercise regimens to avoid exhaustion. Tack may also need to be adjusted if physical changes such as development of swayback lead to discomfort.  Joint supplements, especially those containing glucosamine and/or hyaluronic acid, may be useful in some horses, and judicious use of anti-inflammatories should be discussed with the attending veterinarian in individual cases. Complementary therapies such as acupuncture can further be considered.

Vaccination and Deworming
Preventative care programs should be discussed with the attending veterinarian and should be tailored to the individual horse and barn situation. Vaccination programs generally need little adjustment in aged horses; however, immune response to vaccination may decline with age and may be impacted by concurrent conditions such as chronic parasitism. Aged horses remain susceptible to many infectious diseases, and proper vaccination programs should be maintained to ensure animal welfare. Parasite control programs should be reviewed in horses losing weight, and in those with concurrent conditions such as pituitary dysfunction that may impair the immune system.

Diseases in Geriatric Horses
Aged horses suffer from common diseases and are more susceptible to certain conditions including pituitary pars intermedia dysfunction (“Equine Cushing’s Disease”), strangulating lipomas and recurrent airway obstruction (“heaves”). Certain neoplasias such as melanoma are also more common in aged horses.

 

Colic remains a number one problem in geriatric horses, and colon impactions may in some cases be attributable to improper feeding, reduced water intake and dental disease. Necessity for colic surgery often presents a challenging decision to owners, but while anesthetic risk may increase somewhat with age, a consistent correlation between patient age and outcome of colic surgery has not been reported.

Chronic respiratory diseases such as heaves may be attributable to chronic allergen exposure throughout life, and permanent damage to lungs may result in less than ideal treatment response in aged horses. While data specific to horses are lacking, proper management to minimize allergen exposure may prevent development of allergic respiratory disease with age. Some owners may be reluctant to commit to life-long management changes and/or medical therapy in geriatric horses with heaves; however, the effect of chronic disease on weight maintenance and other aspects of overall health must be considered.

Endocrine diseases have received much attention in aged horses. Equine Cushing’s disease appears to be common; clinical signs include hirsutism (delayed shedding and a curly haircoat), weight loss and poor body condition, increased drinking and urination, and lethargy. Laminitis (“founder”) and recurrent infection are common complications in horses with pituitary disease. Signs previously attributed to thyroid dysfunction, such as cresty neck and obesity, are now more commonly associated with a “metabolic syndrome” similar to type II diabetes in humans. Diagnostic testing and appropriate treatment regimens should be discussed with the attending veterinarian.