Picked up a TB off the track in October, wormed her 12/1 with Quest Plus and has been turned out. She cut her hind leg, which got infected. On Friday I cleaned it up, triple antibiotic wrap and started her on SMZ's. The wound was looking good, but on Monday night she came in with a small amount of swelling in her left front ankle & pastern, but sound. On Tuesday she had a little more swelling and seemed slightly off. She did not go out to graze over night with the other horses, but stayed in the run-in with hay.
Wednesday night she had swelling in both front legs from just below the knee down. Her temp, eating habits and poop were all normal, but again did not go out with the others.
This morning there is swelling in all 4 legs. Again temp, eating and poop normal, but not going out with the other horses. She cleaned up all the hay left for her. I stopped the SMZ's and gave her 2 grams of bute.
Has anyone ever had a horse react to SMZ's? I was giving 10 twice a day for a 1,000 horse. I used a weight tape for my estimate.
Red flag for me, simply because my Bonnie had a HORRIBLE reaction to what we're forced to assume was sulfa antibiotics as a weanling. She swelled up dramatically, all her joints were swollen, she was covered with hives which then scabbed up and half her skin fell off, leaving her nearly hairless! (this was January, too) Her urine was dark and she was one sick filly. Skin and bones, poor critter. She recovered beautifully but it was pretty darn scary and I'll never give her sulfa drugs again.
Obviously there are lots of other things it could be, but I'd for sure be super vigilant and be calling the vet.