I would definitely ask the vet, but I would also have him seen by a chiro. We have one locally who is great, and she always has some exercises that can help build muscle. While it may not eliminate it, of indeed he IS swayback, it won;t hurt, and very well may help. I recall one being a belly scratch. There is a spot under the horses belly near the umbilicus, that, if you "scratch it" hard enough you can see then raise their back. You scratch and hold several times a day to help build the muscle. I think there were a couple more, but I do not remember them......anyway-that would be my suggestion. At the very least you feel like you are doing something while he grows, and will hopefully grow out of it!
He's got lordosis. Not too bad but enough that you will have to work at saddle fit.
Working him long stride with lower headset will develop the muscles. He's not going to grow out it. It is genetic and it causes some of the vertabrae to be triangular not squared which caused the drop in the back. If you have concerns as to the strength, the vet can xray to confirm he's good to go.
I had a much worse saddlebred that with careful conditioning and saddle fit, was actually one of my better show horses.
Actually saddle horse people call it a soft back....
I have not read all of this thread, so I don't know if someone has already brought this up or not. Although sway back can be genetic, is it also nutritional. If he did not get the right nutrition when he was little little, it will cause a sway back. I used to work with a rescue that actually started actively picking up horses who had this kind of sway back and breaking them to harness so they could have a productive life - but some of those colts were 20 times worse than your boy.
I also knew a person (not goign to call her a friend) who didn't think anything of poor nutrition for her mare in foal, of poor nutrition for the foal, or startign the filly under saddle at 18 months old. Needless to say this filly had severe sway. Eventually I convinced her to part with the filly at about seven or eight years of age. By this time, constant malnutrition had dropped her back almost a foot - and she rode that horse hard too.
I worked with the people who got the mare on techniques for stregthing her back. The first step was better nutrition and putting 300 pounds of weight on her. That whole time, they did TTouch exercises to get the mare to lift and round her back. You do this my digging your fingernails into the centerline of the belly. It is not a good sensation and the horse moves away from it, lifting and rounding thier back. Please do a search to find out exactly how to to this, as I have only done it a couple of times.
Anyway, it took about a year and a half but they brought that mare's back almost streight! For the first time she could wear a western saddle. It is possible to do a lot towards 'fixing' a sway - though his back may never be as stong as it should have been.
I hope this helps. He is beautiful and very lucky that he found you. Pleaes give him a hug for me!
Most of the horses I've seen like this have been SE, but not always.
I know a few boys like this that are making endurance and great riding mounts.
As he matures he may round out and fill in there some. Three is still an awkward age for Arabians with the amount of maturing they have yet to do.
Don't give up on your guy yet! :)
You have some great sugestions here, I can't help but mention, "hill therapy" has been used for many years by all sorts of people to strenthen the hind end and back. Just now parelli has magicaly 'discovered' it. Urg. Any how, we had a paint filly that was similar looking, was geneticly caused, but the vet said she was strong and as long as the saddle fits properly she could be started and ridden like any other horse.
Yea a guess for the same reasons as the hill therapy I would take your boy out on some hikes. We had a sway back gelding that we trail rode over the summer, we constantly had to climb steep hills to get up the mountain by the end of the summer we no longer needed the correctional pad.
I agree with what several others have said - it appears to be the genetic form of lordosis. I have a thoroughbred gelding with the same condition, and I researched it extensively when I got him. He raced and then showed in the A circuit hunters for a number of years before I retired him last year at 14 (due to sesamoiditis from racing injuries, not because of his back). He had zero health problems related to his back. Saddle fit was a challenge but other than that he was perfectly fine. You can help develop his topline with the exercises mentioned earlier in the thread like you would do with any horse, and this will make the dip less prominent as muscle develops. It looks a little odd but that's it. I would encourage you to introduce him to different disciplines just as you would any 3 year old, and see what suits him best. Along the way you'll encounter knowitalls who will insist that he is an invalid and you are being a meanie to make him work, but it's nonsense. I had multiple very good vets examine my horse over the years for this and that, and his back was a total non-issue. They just note it in the file and say it's cosmetic. His dip is more pronounced now that he is not working and has lost topline muscle, but the picture below shows him in show condition.
Best of luck with yours! Good for you for taking him on