Straight backed horse?

So, i'm new to this website. Found it while to do some research on horse's with straight backs. I put one of my horse's up for sale due to the fact I don't have time because i'm back to being a full time student and only have enough time for my other horse. The horse's past owner said he was green broke and she had ridden him, but he was in very bad shape when we got him. I have only lunged him around and walked him since I have had him. Anyways, recently I had an e-mail of someone interested in buying him, but after looking at pictures she wasn't interested because she said he cannot be ridden with his " straight back". I have never heard of that before in my life! He is a thoroughbred and in my oppinion that breed does have somewhat of a straight back. I guess I can see where she is coming from and now im going to have to get it checked out by a vet, but I was wondering what some other people thought. Let me know!

He doesn't look like he has straight back. He looks quite thin. I wouldn't ride him until he has more groceries.

I think what he needs is some weight & muscle development along his top line - then he will look a lot better.

I agree with everyone above ... he is just on the thin side and his backbone is showing... getting some weight on him and putting muscle on will help out a lot.. he looks like he would be a great and beautiful horse when he fills out... all he needs is some TLC

Yeah totally agree about the weight. I wouldn't even try to ride him until he gains weight and I have been trying to help him gain weight but I have only had him a couple months. I have just never heard that a horse has a back too straight and cannot be ridden. Well, he hasn't been ridden recently so, that might be one of the reasons why. I just wanted to see what some people thought. Thanks.

Certain back shapes can be harder to fit a saddle to. Maybe that is what the person meant. Other than that - I think it will look like a normal back once there is weight/muscle build up.

What are you feeding him to help with the weight?

He does have a straight and long back, which makes it a bit weak and hard to saddle fit, but with the right weight and muscle he should strengthen and make saddle fitting a bit easier.

Personally, I would not show potential buyers that photo. He is very thin there with no topline muscle. If you decide you really want to sell him, he needs to put on 100-150 lbs and do a lot of work in side reins to build his topline.

What are you feeding him? Diets high in sugar/starch (like grain or pelleted feeds) can actually cause a horse to lose weight, especially high energy breeds like TBs or other "hard keepers." I went through this cycle with my current ArabxTB and my last OTTB gelding...