Answered by, Alison Cornwall, DVM, Middlesex, Vermont
Question: What is the proper placement to measure the heart girth on a horse for weighing them? I see several different ways to do it and want to make sure that I am accurate.
Answer: Heart girth circumference, as a way to estimate weight of horses, has been used for many decades. It is inexpensive and easy but is not always accurate. What weight tapes are good at is monitoring change. A tape may say that your horse is 1000 lbs when he is actually 1100 lbs, but if he gains 50 lbs the tape is very likely to reflect that change accurately. Consistent placement and consistent pressure are the keys. Place the tape immediately behind the withers where the very last hairs of the mane emerge and immediately behind the elbow. Some tapes have a tension measuring device built in to the tape and these can help with consistent pressure between measurements.
Question: Is there a specific supplement to give a mare before foaling that would help prevent bone chips from occurring in the foal?
Answer: There is some data that shows that mares that consume a diet with 30 PPM of copper were less likely to have foals that then developed OCD. There is also some suggestion that low sugar diets may help. Mare and foal feeds are almost always very high in sugar (usually 25-30% Sugar + Starch) and therefore, I almost never recommend them. Solid nutrition with sugar and starch less than 15% seems to be the best.
Question: My mare is insulin resistant and has had three bouts of laminitis. She is on prascend and only gets grass hay that I soak first. I have had the hay tested and it is 13.99 % carbohydrate as dry matter and 11.99 % as received. Do you think I should continue to soak her hay and if yes, what supplements should I give her to make up for anything lost through the soaking? I do not feed her any grain. If you do recommend supplements, how do I find the best ones to use?
Answer: You have raised and excellent point that is often overlooked. When hay is soaked, sugars leach out of the hay as do vitamins and minerals. Proteins and fats do not. When I have horses on soaked hay for long periods of time, I typically advise owners to double the ration balancer during that time.
All horses should be on a balanced ration and for the huge preponderance of horses high quality hay, a low-volume ration balancer and water meet or exceed their needs. Examples of ration balancers include Triple Crown 30, Blue Seal’s Sunshine Plus, Purina’s Enrich Plus, Nutrena’s Empower Balance, California Trace Plus, and High Point. The idea is that you add 4 oz – 2.5 lbs of bagged feed per average-sized horse and this will provide all the vitamins, minerals and essential amino acids that your hay is likely to be deficient in.
Because of your concerns about insulin resistance, you want to choose a low-starch ration balancer. I would recommend 1 cup or so of alfalfa pellets as a carrier and then something like a double-dose of High Point Grass or California Trace Plus pending what region of the country your horse resides. This will ad negligible calories, but will help make up for what your mare is likely missing given her situation. If you get hay that does not need to be soaked, you can back down to a single daily dose of ration balancer.