I have a 29 yr old arab mare with dramatic weight loss. Here is a brief history:
* She is on very, very nice hay (nicest hay I have ever seen) diet with Healthy Glow (20+% fat) feed. She has never been a picky eater.
* She is old, but has been in good health until recently. Until ~1.5 months ago was still doing light ride once/week and seemed to enjoy it.
* She had colic surgery at 19, 28' small intestine lost. No major colic issues since, just a few minor impaction colics (but nothing in past 4 years).
* Her teeth are in good condition for her age. Have been checked by vet 3 times in last 4 months. She has seen an equine dentist annually for many years. She is missing one tooth for ~5 years.
* she was sore/lame last fall, vet thinks due to farrier cutting off too much sole (she had almost non on x-ray). Farrier was very aggressive with hoof knife (horse was barefoot). Changed farrier, did easy boots/rest, and she has not shown any lameness since. No heat in feet during this or evidence of founder. But could have been sign of cushings (see below).
* No history of ulcers.
* Started losing a little bit of weight end of winter. Live in Wyoming, so not uncommon for horses to drop a little weight in winter, but still concerned. Horse was blanketed and has shelter. Started upping her fat supplement to compensate. Was eating hay well. Supplement did not seem to help much.
* Got vet out to look at her ~late March. Low body temp. Skinny. Teeth good. Was wormy (obvious worms on rectal), despite being on a worming schedule (sign of being immune-compromised?). Wormed her. Was chewing well, so recommended increasing hay and fat. Went to getting enough hay that was basically free choice. Blood work normal. Noticed lump in thyroid area, vet was not too concerned as blood work normal.
* Vet check in April. Still skinny, but about the same as before (although was hoping for weight gain with better weather). Good teeth, vaccinated, no worms/eggs on fecal. Low body temp. Horse bright and alert.
* Weight slowly coming off. Increased fat again. Did not shed out well. Seems to enjoy light riding. Good appetite and good attitude.
* Late June/early July - weight dropping extremely fast. Horse is now scary skinny. Get vet back out again and again. Low body temp, seems very thirsty. Vet suspects cushings. Checked lump/growth in thyroid area for cancer cells, nothing looks cancerous. Blood work normal.
* Last 2-3 weeks. Pull out from other horse. Notice that while she seems to be eating hay, is just spitting it out. Think it could just be simple lack of food (duh!) and feel horrible. Change to pellets (timothy, avoiding sugar due to cushings and alfalfa due to possible compromised kidney function). Keep doing fat as well. Start with soaked pellets and she eats them fine. She is excited about fat supplement. Still plays with hay and tries to eat. Dropping >> food, even pellets. Seems to not be able to hold food in mouth. Cushing meds are back ordered from multiple sources, vet scrambles to find some. Finally get in ~week ago and start on medication. Notice that one side of her face is swollen and wonder about infected tooth (only felt on petting her head and asymetrical, could have been that way for a while). Start on antibiotics.
* Last few days. Went from mash being O.K. To refusing mash. Would still eat dry pellets. Worried about feeding dry, but need her to eat so just did it. Weight dropping like mad (now probably body score of 2 - just scary thin). Got vet out again. Looked at teeth again, nothing appears infected. However, tongue is huge (barely any space around tongue). Cheek on swollen side is large, but tissue is healthy. No mouth ulcers or bit marks. Tried putting her on tri-hist/banamine to reduce swelling. Later in day only eating the fat pellets and few of the hay pellets. Now just picking at food and not eating much at all. Did eat soft, short grass and appear to get it down. Not interested in hay at all.
* Scoped today - looks normal (not able to get into stomach, scope not long enough), tongue still same. Belly tap normal. Body temp now normal, not low. "Burping" (yes, horses can burp, no she is not sucking air) and STINKS. Took off tri-hist as highly doubt any allergic reaction/bug bite is at play. No interest in food when put up, not even the fat suppliment (which she normally chows down and begs for). This mare is NEVER off her food (even after colic surgery). She has not gone off food on drugs before, so think this is disease progression and not related to medication. Side of face still swollen/same. Think may be lymph system drainage.
At a loss. Vet is stumped. Thinking it may be time to let her go, but don't want to do that if there is something treatable (non-invasively) going on.
Anyone have any insight?