In this final installment of a three-part podcast on equine weight loss, we talk to Drs. Pat Harris and Nicky Jarvis. This third episode focuses on health and management issues for equine weight loss.

Harris is a past president of the British Equine Veterinary Association and is a European specialist in veterinary and comparative nutrition. She is the Nutrition and Science Advisor to Mars Horsecare and the WALTHAM™ Equine Studies Group. Harris has spent much of the last 30 years working to help improve the care and nutrition of older horses. She also is passionate about seniors because of her dedication to her own older horses. Harris has advised on the care of many other seniors and has authored numerous articles on their care. Her involvement in several global senior research teams gives her special insight into some of these studies. Harris is also on the Executive Advisory Council for My Senior Horse.

Jarvis is head of Veterinary and Care at Redwings Horse Sanctuary in Norfolk, England. She qualified from the Royal Veterinary College, London, in 1990 and worked in mixed practice for two years before moving to Newmarket, where she completed a two-year internship at Rossdales Equine Hospital. Jarvis then joined Redwings Horse Sanctuary in Norfolk in 1996. She is now head of Veterinary and Care there, working with what she calls an “incredible” team of veterinary surgeons and nurses to care for more than 1,500 resident horses, donkeys, and mules. Jarvis attained her RCVS Certificate of Advanced Veterinary Practice in Equine Medicine in 2012 and her CertAVP in Equine Surgery Soft Tissue in 2013. Her specialist interests include equine nutrition, geriatric medicine, internal medicine, and colic.

(Editor’s note: The content of this podcast is the expert’s approach to the topic. Please consult with your practitioner if you have questions.)

Differences in Equids

Jarvis said there are many things that are the same between horses, ponies, donkeys, and mules. That includes dentition issues. Having the appropriate diet in the right amounts is important. Dealing with parasites is critical. Clinical conditions such as osteoarthritis can occur in all older equids.

“I was trying to think what the critical differences would be, and the key thing to me is how stoic donkeys, mules, and little aged ponies are,” she said. “I think that makes it much more of a challenge as an owner to see those early signs of disease and that animal being unwell.”

She said while she appreciates that horses are individuals and have their own characteristics. “But if a horse is colicking, you will get an Oscar-winning performance,” she said. “But your donkey might literally be a little bit quiet and actually have a serious problem.”

She said body condition scoring might be your first indication of chronic disease in donkeys and smaller ponies.

That other differentiator in equids is a difference in lifespan. “When you talk about a Thoroughbred, they are aged when they are 15 and might only live into their 20s,” Jarvis said. “When you talk about a small Welsh pony, very often they are chugging along nicely into their 30s. As for the donkeys, some of them can reach 50!”

She said maybe the smaller ponies and donkeys don’t have the same wear-and-tear as horses that were in ridden work and competition.

Harris reminded the audience that donkeys and ponies are not small horses. She noted that these small ponies will be great for 20 years, then at some point there is a ‘switch.’ “Don’t have the assumption because they have always been a good doer that they always will be. You have to be aware that things do change and can change quickly,” she added.

Hyperlipidemia

Jarvis said the other thing that she wanted to mention was hyperlipidemia. “This is a condition where if there is a negative energy balance—for some reason that equine hasn’t been provided enough food or is feeling unwell and isn’t taking in enough food—the body uses lipids and triglycerides from the fat stores. In small amounts that’s okay because that’s what they do to provide extra energy. But, in large amounts it can build up in the blood and settle out into the liver. When they go into full-blown hyperlipidemia they are not only exceptionally ill, but has a very high mortality rate.”

She said hyperlipidemia can happen in horses, but it much less common than in small ponies and donkeys. “It’s something to be aware of when you are looking into the underweight equine,” she noted.

Donkey Weight

Jarvis reminded that there are huge differences between donkeys and horses, especially from a dietary point of view. “I know we are talking about the underweight equine, but how quickly donkeys can gain weight if we try to feed them like we do a horse,” she said.

Feeding donkeys on the same rich grazing and with high-quality (calorie-rich) hays can lead to obesity. “If they have good dentition, donkeys tend to like a bit of straw in their diets,” Jarvis said.

She said owners often are on the edge of having their donkeys on the overweight side of the scale.

Other Weight Thoughts

The feed format as well as the feed can be limiting to senior horses. Harris noted that as horses age, sometimes you need to go from feeding long-stemmed fiber to  providing shorter fiber pieces such as chaff. But if a horse has diastema (spaces between the teeth), those  shorter bits of forage can get stuck between the teeth and you need to consider mashes.

Harris said some people say they can feed the same feeds to older horses as they did when the horses were younger. And Harris agrees to a point. “We need to be cautious that we don’t want to overload them with non-structural carbohydrate,” noted Harris. “Older horses tend to develop more insulin dysregulation.”

She also said that often we need to  make sure we are giving them smaller meals (for example to reduce the amount of starch and sugar in each meal). “This comes back to working with owners,” stated Harris. “It’s great saying we will divide it into this number of meals, but it may not be possible. But is there a way to work with a friend so that you feed in the morning and evening and they feed at lunchtime so the horse is getting three meals a day not two meals a day?”

She said you are feeding the same amount in a 24-hour period, but the horse gets less feed and therefore less starch and sugar in each meal.

Feed Types

Harris said she has found that some horses don’t fare as well when using certain feed types. “Some horses can’t cope with as much cereal,” she said. “This has nothing to do with insulin dysregulation and glucose, per se. I don’t know if it is gastric health. But some of them don’t tolerate very much cereal, even if not ID and if fed too much for them they may show signs of colic soon after eating.”

She said that is important when dealing with a weight loss animal. “If you have a weight loss animal and you are trying to put weight on, you can start by feeding  more,” Harris noted. “That’s fine if their teeth are good. If not, then we need to think about complimentary feed. And because they are older, we might not want to give them as many cereals.

“We might think about a low-starch complimentary feed,” she continued. “High in highly digestible fibres. Then we need to think about oil.”

Harris said some older horses tolerate oil really well, and others either find it unpalatable. If they won’t eat an oil diet, you need to use a highly digestible, high-forage diet. That could include mashes.

Harris reminded owners therefore that it’s not just the amount of feed, but the format that can be important. “This is where working with an experienced nutritionist can be really good,” she advised. “Talk to your vet so you know what the issues are. Then work with a nutritionist to work around your individual animal decide together on the right feed.”

Editor’s note: Make sure to use the links below to hear the first two parts of this podcast with accompanying articles on horse weight loss.

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