Question
I own a Friesian mare in moderate body condition (1,000 lb or 450 kg). She is turned out 24/7 with unlimited access to a round bale (mostly timothy) and a mineral block with added selenium. She is also fed a small amount of textured feed (1 lb or 0.45 kg) to which I add digestive and magnesium supplements. I exercise her three or four days a week, mixing up the work between trail-riding, low-level dressage, and groundwork. She suffers from high anxiety that has not improved with any amount of training. I have tried multiple ulcer, calming, and hormonal supplements. Magnesium has helped some mild muscle spasms she experiences, but those spasms still occur when she is stressed. Could you verify nothing in her diet is likely spurring on this unrelenting anxiety?
Answer
Free-choice mineral products work well in some management situations, but it is difficult to achieve appropriate and consistent intake. I suggest adding a high-quality vitamin and mineral supplement to the textured feed or switching to a ration balancer. These changes will ensure optimal nutrient intake on a daily basis to support long-term health.
The types of energy sources the diet provides can have an effect on behavior. Studies have shown, for example, that feeding higher levels of fat may confer calming tendencies. Reducing the amount of starch and sugar consumed can also help some horses. Although your mare’s current diet appears to be low in starch and sugar, some grass hay can have enough sugar to affect sensitive horses, particularly when combined with high intake. If your hay supply is consistent, it would be valuable to send off a representative sample for analysis to know the nutritional value.
Supplemental natural-source vitamin E can be beneficial for horses with limited access to fresh, green forage to support adequate antioxidant defenses. Chronic anxiety can lead to oxidative stress and damage that may require elevated intakes of antioxidants such as vitamin E. Nano-E delivers a highly available source of vitamin E to rapidly increase vitamin E status.
Even though you’ve tried some calming supplements in the past, including magnesium, you may consider thiamine alone or in combination with magnesium. Research has indicated that adding thiamine and organic magnesium to the diet can reduce anxiety by maintaining optimal nerve function.
Chronic anxiety and behavior issues can be related to pain or discomfort requiring veterinary evaluation and treatment. Other considerations include social dynamics (herd hierarchy, herd-bound issues, human attachments), environmental conditions, and management practices.
