I own a 13 year old Welch/Quarter horse cross mare named Dawn. When I first bought her three years ago, unknown to us, she had ulcers causing her to lose weight rapidly in the winter and go off feed when given bute for a sore back. She underwent ulcer treatment with UlcerGuard, alfalfa, Red Cell (she was anemic from the ulcers), and aloe vera juice. We also changed her feed from EquiLene to Nutrena SafeChoice Perform upon recommendations from a nutritionist. Within a month, she was happy and healthy and gaining weight rapidly. Since then she’s been overall very healthy, maintained weight, etc.
In August, she was put on stall rest (from being out on pasture 24/7) due to a lateral branch suspensory sprain in her left hind leg. In November, she was allowed out in a small pen in the paddock with other horses and mid-December she was finally turned out with no issues. During stall rest she received 10-15 lbs high quality grass hay, reduced grain amounts, and free choice salt.
Ever since coming off of stall rest, she’s been more spooky, standoffish, and unfriendly to the point of being aggressive to the other horses she’s turned out with. She used to be low-man on the totem pole, quiet/not spooky, and friendly (although she is more of a one-person horse rather than the buddy-gelding type). She no longer greets me happily although she’s been completely cleared by two veterinarians. I’m starting to wonder if it’s because of her diet and possibly a thiamine (B1) deficiency.
She is currently in mild-moderate work to get her back in shape and conditioner her while being very careful of her suspensory/soft tissue.
Her current ration is:
Turn out 24/7 except for grain meal on a bermuda/rye grass pasture that’s rather poor because of the weather
1 pound Nutrena SafeChoice Perform
1 pound Nutrena Empower Balance Grass Formulation
1 oz. Dumor Electrolytes (she doesn’t use a salt block hardly at all)
1 scoop (3.78 g) of Mare Magic (started in mid-October because of stall-induced anxiety)
2-4 pounds of good quality grass hay (coastal mix, I believe)
I recently evaluated her diet with FeedXL which only showed that her Vitamin B1 levels were pretty low.
Any suggestions on what to address? What could cause such a drastic change in behavior? How can I fix these issues?