Hives in horses
3 of 12 horses on property have developed chronic hives in last 3 mos and it has not significantly improved since end of insect season.All horses on property are fed the same locally grown Timothy mix which has no apparent mold. These three are out on pasture more than others on property. 1 of the 3 horses wears a blanket. We did find black 1 1/2”-2” diameter “puff balls” actively growing in field- a fungus? Possibly cause of allergic reaction?
Deschutes County Oregon
Utricaria or hives in horses can be caused by a wide variety of substances. Those substances can be inhaled (pollens, dander, mold spores, smoke, dust , chemicals), ingested (drugs, various food tems), infections (bacteria, fungi, parasites), contacts (plant materials, plastic, chemicals), and the list goes on. I would try figure out the cause by progressive elimination beginning with changin the (possible to alfalfa), if that does not help elinimate turnout, and so on. You veterinarian can prescribe antihistamines or steroids to treat teh lesions.