Yup. More vet bills. Guess Dawn felt she was being slighted on the veterinary front . . .
Last Monday, when I went to ride Dawn, she was very uncomfortable in the bridle - resisting contact and stopping to rub her face on her legs. We stopped riding, and I put her in her stall while we were untacking. It was clear she was having serious problems chewing - she was gaping her mouth, twisting her head from side to side and making exaggerated chewing motions with her head stuck out to the front. A lot of food was falling out of her mouth, and she was repeatedly spitting out chunks of hay that were partially chewed. Her posture and behavior were a lot like a horse with choke, but there was no coughing and she was still able to drink well, so it seemed we had some sort of (new) mouth injury.
Uh oh . . .
The dental surgery team had just been out the week before (a couple of months after her last molar extraction), and Dawn's extraction sites had fully healed, she looked good, and had been eating very well and gaining weight - in fact she'd gained so much weight (fat horse) that I'd cut her feed - a first for Dawn, who's always had trouble keeping weight on. I called them for advice. Since they weren't going to be down my way until Thursday (they're from one state over), they recommended having my regular vet out on an emergency call to rule out any foreign objects stuck in her mouth.
So vet call number one was that evening. The vet's truck didn't have a speculum on it (the clinic doesn't do a lot of dental work - they use other dental specialists to do it - so they only have one speculum and it was back at the clinic - a good speculum apparently costs around $10,000). But they sedated Dawn and were able to look around a bit in her mouth. No foreign objects, but they could just see that the right side of her tongue didn't look happy - hard to see more without a speculum. We started a course of Banamine for the pain and to prevent swelling.
Dawn improved a bit every day and by Thursday was able to chew soft hay (she refused hydration hay with grain mash) without spitting too much of it back out. The dental surgery vet came (that would be vet call number two), sedated her and was able to take a good look. It turns out she had a pretty nasty injury to the right side of her tongue - there was an area on the side, about four inches long by one inch wide, where she'd sheered off the edge of her tongue, removing the entire top layer and exposing the muscle. No wonder she was having trouble chewing! The vet said she was surprised that Dawn was chewing as well as she was with an injury like that.
I mentioned in passing that Dawn had previously had EPM and that when she did, in addition to some balance and soundness issues, her face was affected - drooping nostril, one eye blinking when the other didn't and lack of proper cranial nerve reflexes. The vet was very interested in that, and said that horses rarely bite their tongues and that a neurological condition can cause it, since the horse may either not have good control over where the tongue is in the mouth or not be able to completely feel it. In Dawn's case, since EPM symptoms in new infections (or inflammatory responses to such things a vaccinations) tend to often follow the same previously affected neural pathways, the dental vet said we should definitely check that out. Dawn is now on twice a day SMZ antibiotics and another course of Banamine.
I did a thorough neuro evaluation on Dawn on Friday morning (at the request of my third vet - the one who does our chiro and also handles endocrine and EPM related matters). She was quite abnormal in some of her responses - three legs were affected in the foot placement test - one hind was relatively normal. Her skin sensations were abnormally depressed all the way along her neck and back as far as the withers, and behind that were much more normal. Her turning tests weren't bad, but there were some subtle abnormalities - she wasn't stepping over as well, only to the midline, and one hind tended to drag on the outside. In backing, she was slow to move and dragged one hind toe. Her balance/strength also wasn't perfect - I was easily able to pull her off balance by the tail as she was led forward, although one side was more normal than the other (corresponding to the hind that was better). I didn't see any facial abnormalities other than a slight droop of her right nostril.
Since my EPM vet wouldn't be out until today, we started Dawn on the EPM medicine immediately - this wouldn't affect the EPM titers in the blood test, since those take several weeks to come down even if symptoms improve much more quickly. Also the Banamine might improve symptoms, but won't affect the titer levels. We also confirmed with the researcher who developed the treatment that the medication we're using for EPM (decoquinate) isn't interfered with by the SMZ's - it would have been interfered with by Uniprim so it's good we weren't using that.
Dawn is continuing to eat pretty well, and got her blood drawn for the EPM test this morning (vet call number three). I also did a quick recheck of her neuro symptoms and they were almost gone. The improvement could be due to the Banamine or to the EPM treatment - she's had three doses and improvement is often evident pretty quickly. I'll check her again after she's been off the Banamine for a few days.
Dawn and I will be riding in this side pull headstall - she goes very well in it and it may be our bridle going forward. I'm grateful to have such great vets on our team, but hope my horses decide not to require any more vet visits in the near future!