Muscle Weakness, Nutrition, and Cribbing

Shiloh

Shiloh developed a mysterious weakness in her hind end last April. No specific swelling, discomfort, or lameness. Lyme test negative. Bloodwork showed Vitamin E deficiency! (Muscle weakness is an early sign.) Happily, a couple months on a high quality natural E supplement resolved the problem. This was a reminder of how varied, individual, and changeable horses’ nutritional needs are; and that not all products provide the nutrition they claim to. Since horses get Vitamin E mainly from fresh grass, and even the best quality hay loses E quickly, any horse not on full pasture needs supplemental E. And we can't even be sure about that; comments on this facebook post report that even horses on full pasture are testing as deficient in E. Selenium, often associated with Vitamin E, is even more complicated. In some regions (like the northeastern US where I live) hay is deficient in selenium, so supplementing is advised. In other regions hay contains adequate selenium, and supplementing is dangerous because of toxicity. If you are unsure, consult your veterinarian. Vitamin E and selenium deficiencies can both cause a variety of symptoms, detailed in the reference articles. One new observation is a link between low selenium levels and cribbing. Could this make a significant difference for horses who crib? My facebook post of 8/17/23 includes reader experiences in the comments. For a discussion of how different feeds can impact a horse's behavior, see Can Food Make My Horse Behave Badly?
References:
The Consequences of Vitamin E Deficiency in Horses by Equine Disease Quarterly | Jan 16, 2021
https://thehorse.com/196536/the-consequences-of-vitamin-e-deficiency-in-horses/
How to Effectively Supplement Horses With Vitamin E by Clair Thunes, PhD | May 27, 2019
https://thehorse.com/172194/how-to-effectively-supplement-horses-with-vitamin-e/ Selenium and Cribbing: Is There a Relationship?
https://thehorse.com/136946/selenium-and-cribbing-is-there-a-relationship/
Could Selenium Deficiency be Affecting Your Horse? By Angie Beaudet | August 5, 2019
https://horsesport.com/magazine/nutrition/could-selenium-deficiency-be-affecting-your-horse/
Potential role for selenium in the pathophysiology of crib-biting behavior in horses By Arash Omidi, Reza Jafari, Saeed Nazifi, Matthew O. Parker
https://www.sciencedirect.com/science/article/abs/pii/S1558787817301776
Vitamin E and Selenium are Powerful Protectors by Dr. Eleanor Kellon
https://drkhorsesense.wordpress.com/2018/07/01/vitamin-e-and-selenium-are-powerful-protectors/