When I read your question my immediate thought was that your QH filly may have what my gelding has. When I watched the video, the similarities were almost identical. My horses suffers from a condition called 'Shivers' (or 'Shiver'). He has had it since he was a foal and it is often confused with wobblers symdrome.
A horse which suffers from 'Shivers' usually is affected in their hindlegs. When they move off from halt to walk one, or both back legs usually move forward fairly straight in an 'arc' to the outside before their foot steps under their body. This is different from a normal horse which will flex his joints and keep his leg directly under his body. My gelding does this, and so does your QH filly.
It can also be categorised by the hindleg getting 'stuck' and quivering before the horse puts it down (usually in the 'arc' shape), and the legs widening when asked to move backwards.
Background info of my gelding:
- Age- 13years
- Breed- Warmblood x TB x ID (good showjumping lines)
- Height- 17.1hh, wears a 'wide' fitting saddle.
- Intially trained as a Showjumper (competed affiliated tracks as a youngster)
- Given time off to mature between the ages of 5-10years old- this was due to his 'shiver' and he got cast quite badly in his stable. As a youngster he had difficulty walking down hills due to his shiver.
- Return to work- between the age of 10-11years. By this time his body had fully matured and becuse he had lived out full time, he was fairly strong and hardy.
- He has now been back in work nearly 3 years- we now compete Affiliated Showjumping 90cm (we jump up to 1.20m at home)- aiming for 1.15m this coming summer, Novice/Elementary dressage (including simple changes, lateral work, counter canter, medium and collection), we do some cross country (up to 1m) and lots of hacking. He is also lunged and long-reined.
- Regular work and schooling has definately helped his shiver. His shiver NEVER shows when he is ridden. It has not hindered his ability to perform in any way. He only shows his shiver when he moves off from a halt (and not every time). He is worse in his left hindleg than his right hindleg.
Feeding & Diet:
I have found through trial and error and reading around the subject (mainly online), that he is best having a low starch high fibre diet (so has been said for all horses with shovers). I weight his hay so I know that he gets the right amount for his body weight. I try to keep his weight as consistent as possible throughout the year.
- Low starch chaffs (such as molasses free, chaff suitable for laminitics, good doer etc)
- Low starch nuts/mixs- such as 'endurance type' feeds, slow release energy feeds etc
- Molasses free sugar beet- good source of roughage
- Selenium is super important to horses with shivers!- I took my gelding off his selenium suppliement for 5 months to see if there really was any effect- everyone who knew him commented that his shiver seemed so much worse- and it was! He has a selenium and lysine supplement.
- Joint supplements- I use 'Superflex' as this is for bone, cartilage, ligament and tendon
- Electrolytes when needed- very important for horses with shivers
- Apple Cider Vinegar- My physio recommended that I put him on this to help reduce the amount of fat in his muscle. She told me that horses who suffer from shivers do best when they do not hold too much body fat- as this can interfere with the nervous transmission within the muscle. It certainly hasn't made him worse and he has lost that extra bit of fat that I just couldnt shift (especially behind his shoulders).
I would not want to advise you on how or what to feed your filly (as I dont have any real knowledge on feeding youngsters)- I suggest you talk to your vet about that.
I have a very reputable physio who has showed me particular massages for his hindquarters. The aim is to help increase bloodflow, but to also increase the flexibility of the joints in this area. I have now been doing these exercises for a year (with regular 4 monthly visits from my physio) and I cant believe the difference they have made. I would suggest contacting a reputable physio in your area and having a chat with them. It may be helpful to your filly to start having some physio now- or they may recommend when it would be suitable (i.e once she has fully grown).
My horse has never been shod behind, nor has he ever been trimmed behind. I make sure he does enough road work for his feet to 'trim' themselves. His farrier thinks he has the best hind feet he has ever seen! Your little mare picks up her feet much better than my boy does- I cant 'hold' his back feet, through repetition, patience and persistence I have taught him that when i tap his leg he will lift it up just long enough for me to be able to pick on side of his hoof out. We just repeat the process until it is all done. He struggles with his left hindleg much more than the right and he has to stretch his head and neck really low to help balance himself. He is worse when other people try to do it, he panics and snatches his leg up and it quivers and almost gets 'stuck'. I'm the only one who picks up his back left now. He is fine with his front legs, and has them shod as normal.
I would suggest reading whats on the internet about this subject and then speaking to your vet about it. It is definately recognised here in the UK and I am pretty sure in the US too.
I hope this has been helpful, as I said before I am not a vet so I can only go on the similarities that I see between your QH filly and my gelding. She may suffer from wobblers, but I hope that if she suffers from anything the it is a 'shiver'. If my boy is anything to go by, with patience and slow but correct training she will be able to have a good quality of life and will be able to perform and be ridden. My boy loves his work, he drags me onto the trailer to go to a show and I worry what will happen to his mental state when his body finally does get the better of him.
"My horse's feet are as swift as rolling thunder, he carries me away from all my fears, and when the world threatens to fall asunder, his mane is there to wipe away my tears" (Bonnie Lewis)