Question

My horse just turned 17 years old. He is used as a show hunter and kept in good physical condition. He has always been an easy keeper, consuming hay three or four times a day as well as 3 lb (1.4 kg) of a senior feed. He is on a regular worming plan. About two to three months ago, he began to lose weight for no apparent reason. We upped his grain, first by 1 lb (0.45 kg), then 2 lb (0.9 kg), and finally to 3 lb (1.4 kg) more, for a total of 6 lb (2.8 kg) per day. He has not gained the weight back. I started him on a weight-gain supplement and wormed him an extra time. I estimate he lost about 200 lb (90 kg) and has only recently started to put some back on. His teeth are regularly checked (every 6 months) and floated when necessary. I am concerned that at his age maybe he is lacking something he needs, hence the weight loss.

Answer

I reviewed the initial ration with 3 lb (1.4 kg) of the senior feed and the current ration with 6 lb (2.8 kg) of feed per day. The lower intake level was not meeting the full nutrient and energy requirements for your gelding’s activity level and size; however, all of these are now being met with 6 lb (2.8) of feed per day.

I used nutritional composition estimates for grass hay as the forage source, but the type and quality of hay can have a significant impact on its caloric value. Additionally, if the hay is being fed by flake rather than weight, flake sizes can differ between bales, thus changing the amount of hay the horse is given each day. During the weight-loss period, was there a change in hay source or a noticeable decrease in the amount of hay your gelding was consuming each day?

Certain horses with inexplicable weight loss have problems with hindgut acidosis, a condition caused by elevated pH of the hindgut (cecum and colon). If severe enough, hindgut acidosis can cause colic, sometimes recurrent in nature. Once the pH of the hindgut is stabilized, affected horses often have greater feed efficiency and nutrient absorption, which allows them to gain weight. To combat hindgut acidosis, we suggest EquiShure, a time-released hindgut buffer.

Additionally, we recommend performing a fecal egg count to check for parasite load in combination with an appropriate deworming schedule.