Dr. Thunes' pony started carrying extra body condition despite Arizona’s hot spring and summer weather. | Photo: Courtesy Dr. Clair Thunes

About six weeks ago, my daughter’s large pony moved out of his stall to live 24/7 in a sparse grass pasture. Now I know that grass being short doesn’t mean there is nothing there. Plus, being a pony, he’s pretty motivated to make the most of even the shortest blades of grass. Because this pasture offers more what I would call “mental health” grazing than nutrition, he has continued to receive his regular morning and evening hay meals.

About a month ago I stood back and thought I could see some extra condition on his body. I ran my hand over him, and he definitely had a layer of fat over his ribs—nothing major, but fat nonetheless. His crest, which I always watch closely, had gained a little softness but not much more than normal. For his conformation type I actually thought he looked good but acknowledged he didn’t need to gain any more weight.

I contemplated whether we needed to make dietary changes, but it was early May in Phoenix, and the weather was about to hit continuous triple digits. Our summers are a little like winters elsewhere in that horses here can lose weight in the summer the way horses lose weight during cold winters. It’s so hot that they might not be inclined to eat a lot of forage, and the weather can be stressful. Because this pony was new to us this past winter, I had no way of knowing how he would handle the heat. With a 10-day forecast predicting every day over 105^oF and several days over 110^oF, I decided to maintain the status quo, thinking he would lose weight due to the heat. If not, I would reassess