It is tempting to classify ponies as small horses and treat them the same. They are the same species, Equus ferus caballus, but the smallest equines in our care have some unique characteristics that require particular attention for optimum health.
Ponies are especially good at using their groceries to put on weight, making obesity a common issue. While some ponies work hard as driving animals and show ponies, generally they are less likely to participate in high performance activities, such as racing.
So the combination of healthy appetite, efficient use of what they eat and lack of activity creates a propensity to be overweight.
Aging is also associated with increased obesity in ponies. If your pony is wider than it is tall, that is a good indication of a problem.
More specifically, a body condition score is a good starting point. This five-point scale assesses fat deposits over the neck, ribs, along the back and the tail head. If facilities permit, actually weighing the pony to monitor weight is also helpful but most people don’t have these types of scales. Finally, you can measure the circumference around the girth.
Careful attention to feed and avoiding unnecessary grain supplementation is an important starting point.
Grazing muzzles reduce how much grass or hay a pony can eat. There have been other great improvements on this technology — there are now a large number of nifty feeding products to help stretch out meals by slowing down how quickly the pony can consume food.
This not only slows down meal consumption if a pony is on a diet, but it also is a form of behaviour enrichment, similar to what they use in zoos to provide mental stimulation for their animals. These include slow-feed hay nets that have small holes and a variety of food toys that have to be moved to get to the hay.
On the other side of the feeding spectrum, ponies can be bullied away from the things they need. We revere ponies for their feisty personalities, but they are not always top of the herd pecking order, making it important to ensure that they have adequate access to food, water and shelter resources if housed with full-sized horses.
Unfortunately, obesity in ponies is linked to a number of other diseases. For example, obese ponies can develop abnormalities in how they use and store fat, leading to a condition known as hyperlipidemia. Affected ponies have high triglycerides in their blood and also deposit fat in their livers.
In fact, the fat may be visible in a blood sample. Often episodes of hyperlipidemia are triggered by a change of circumstances such as pregnancy, sudden withdrawal of feed, severe illness or stress.
Another major disease of concern in ponies is founder, also known as laminitis. This is a painful condition where the delicate inner hoof tissues become inflamed and separate. Overweight ponies are more prone to this condition, but it can also occur in ponies that are normal weight.
Bouts of laminitis can be brought on by sudden diet change. A common example is when they are turned out onto lush pasture or they accidentally get into a grain bin and gorge themselves.
Ponies in their late teens and 20s are at risk of developing diseases of the endocrine system.
Most common is equine cushings, also known as pituitary pars intermedia dysfunction (PPID). A growth in the pituitary gland of the brain leads to hormone abnormalities that trigger muscle loss, abnormal fat deposition, laminitis, and abnormal hair shedding. This condition can be managed with medication and attention to diet and supportive care.
The second common endocrine disease of ponies is metabolic syndrome where ponies have insulin-resistance, usually in association with overweight body condition. Ponies with metabolic syndrome are also prone to laminitis.
Both PPID and metabolic syndrome can occur in the same individual as well.
Managing ponies to maintain a healthy body weight is one of the most impactful health interventions an owner can undertake.
Dr. Jamie Rothenburger, DVM, MVetSc, PhD, DACVP, is a veterinarian who practices pathology and is an assistant professor at the University of Calgary’s Faculty of Veterinary Medicine. Twitter: @JRothenburger