In addition to Pangea's neverending hoof issues, hock arthritis, old stifle trauma, probable sidebone and ringbone, and skin issues, we can now add one more problem to the list: the possible onset of shivers.
If you are unfamiliar with shivers, there is a good writeup here on what it is exactly, but in short shivers is basically a neuromuscular condition that is characterized by trembling of the tail while held erect, trembling of the thigh muscles and a flexed and trembling hind limb. It can happen to one or both legs (usually both), and the degree to which the tail is involved (and legs, actually) varies from horse to horse, and from day to day. It shows up most often when picking up the hind legs, turning in tight circles, or backing - the horse may appear to get "stuck" with one hind leg jerked very high and trembling. The onset is usually gradual, and most often is progressive. The cause of the disease is unknown, and there is no treatment. Some horses get along with it just fine for years and years, some deteriorate to the point of euthanasia rapidly. Nobody can predict what is going to happen in the individual.
In P's case, as in many early-onset cases, she has been gradually having a harder and harder time picking up her hind legs for me. Trimming her hind feet used to be easy - she was dramatic at first about picking them up, but would relax into it quickly and I could trim away. I thought that was just her particular flair. Now, she is finding it increasingly difficult to pick her hind legs up, equally on both sides, and jerks them as high as she can into the air whenever I touch them to pick them up - if she can pick them up at all. Sometimes, she'll completely lose her balance and have to snatch the foot back to keep from falling. She also has started to have an increasingly hard time backing up. Somedays, she can't do it at all. Other days, like today, she showed no symptoms or problems when in reverse. She also occasionally lifts a hind leg high into the air and holds it there... I had thought it was a sign of discomfort in her hind end from being creaky and stiff. Now, I'm pretty sure she really is showing the early signs for shivers.
It came to a head yesterday when I went to medicate the scratches on one of her hind legs. I had thought at first that she was being dramatic about her treatment - always jerking her legs up high whenever I'd clean them and apply ointment - but now that they are almost gone, I would expect her reaction to be far less. Yesterday, she caught me completely by surprise with how fast and how high she jerked her leg upwards and outward, and I just didn't get out of her way fast enough. She caught me directly in the cheekbone and eye with her hoof, and HARD. If you'd never been struck directly in the face with a hoof, there is no possible way to describe that sort of pain... and I didn't even get seriously hurt!
Once the room stopped spinning and I could open my eye again, the gears in my head started spinning. She didn't kick me in the face on purpose.... so what the heck happened? I started thinking back to all the times she has been dramatic recently with her hind end, and at some point it hit me that she is showing all the classic early signs for shivers. Great... add that to her laundry list of problems!
I am pretty sick today, due to the fact that I've been doing an awful lot of standing around in the cold rain, but I managed to get a very poor-quality video of some of her symptoms today. She wasn't showing much at all today - I think that she is much more relaxed in her body the day after she goes to the AquaTread, so it makes sense that she would be loser in her hind end today. Most of what you can see is on her right hind, where you'll notice her lose her balance and have to grab the leg back from me to keep from falling. Note that I am NOT holding that leg up there - I am merely asking for the hind leg and touching it while she holds it up that high herself. She didn't show many symptoms on the left hind, but she usually shows them equally. She backed with no issues today - backing often causes her to get stuck and frustrated - but you can see some dramatic steps when she turns in tight circles. She is crossing over properly for the most part on the tight circles (inability to cross hind legs while turning tightly can be indicative of other neuro problems, so thankfully she passes that test with no issues!). Her symptoms were very, very mild today, but you can get a vague idea of what is going on.
I'm going to schedule a vet appointment for next week to see if I can get a better idea of what is going on. She is already on a very low-carb low-sugar diet with lots of added fat, which can be helpful for these kinds of cases, but I am also looking in to adding Vitamin E to her diet, something which anecdotally is said to usually help shivers horses.
It's just one thing after another, isn't it?