Help with horse who is dropping his head

Within the last couple months of riding a horse I lease I have noticed a tendency of him to start dropping his head very low at trot. He drops it so low that it nearly pulls me from my seat. I don't want to fight with him, but I also don't think this is right at all. It is also a problem with the few times I have cantered him lately. I feel like I have no control at all and his canter is more like an outta control freefrawl with him leaning in and running his head low. I am not an advanced rider at all and have only taken lessons for a year now. The horse I lease is mostly only ridden by myself a couple times a week. The owner is pregnant and cannot ride him. I feel like he is trying to avoid the bit by dropping his head so far and it has actually scared me a couple times that me he may be trying to pull a runaway with me! I read in a couple places that this may be him leaning on me? Or it is just an issue that he cannot support himself yet and needs lunge work to develop his collection. I have been practicing spiral work at the walk and trot to hopefully develop more support and collection. But is the head dropping an indicator of something else?

Whenever your horse drops his head, squeeze with your legs and get him to raise his head again. Just like with a horse that is learning a headset, make it uncomfortable for him to have his head too low - keep bugging him with your legs until he raises his head to the correct position, then let him be... as soon as he drops his head, bug him again.
The key here is consistancy - whenever he is not in the right position, be after him about it. This is especially important when you're just starting to correct this bad habit; you want to make sure you catch it every time.

I will have to try that. But will the extra leg also encourage him to move even faster?

That's where your seat comes in - make him stay at a nice pace. Remember, leg does not always mean "go faster" - more times than not it doesn't actually ... your legs should:
- make them move forwards
- influence the headset
- steer
- influence gait tempo
- tell the horse when to yield to them, ie. With lateral movements

..so it's not all about speed ;)

Thanks for your input! I will do this next time I ride!

I was riding a friends TB one day. He was a bit of a lost case and needed lost of re education. He would always fight who ever rode him. It was almost always him who won.

Hew would always ride with his head low and long. He would take the bit and run with it too. He was really weird with his mouth at times too. You couldn’t have any contact with him. He hated it. But when you tried to pull him up he would be very hard mouthed also

Anyway one day we decided put a bitless bridal on him. He was doing great for the first 15mins.Normally he was hard to get into and out of canters. All of his transitions were horrible. But this time he was easy to stop and to get moving. He didn’t have his head so low either.

I 'thought' I had a lot more control over him. It felt like he was working with me instead of against me like he normally did. I think it had to do with the mechanics of a bitless bridal. It works by pressure?

On my second or third canter he bucked twice. He stuck his head right down and bucked. He was too strong for me to pull his head back up, and gosh did I try! The bucks came out of nowhere! We went trot, trot, corner sitting trot, canter, canter buck buck... and plonk I fell off and fractured a small bone in my foot.

So moral of my story… hmm not too sure if it even fits your problem! Haha …. Be very aware of a horse who has his head down!

Maybe get your horses back checked out. He might have done something to it.

Also when a horse has his head down like that they have all the control. Its easier for them to buck or take off. I would get some advice from friends who ride and / or an instructor who has seen this horse being ridden by yourself. Maybe ask the owner to watch you ride one day, and ask for their opinion.

Heres a pic of the bucking TB - he is the chestnit.

Sounds like a horse we have. This horse was ridden in draw reins, ridden with his nose to his knees. He's a very downhill built horse, which means his front end is lower than his hind. When he first came for training, my trainer was too freaked out by his way of going that she didnt even put him into trot. He just felt like he was running down a hill faster and faster and barreling out of control. Lol.
Your horse sounds similiar, in that he puts his head down because he hasnt learned how to carry himself. I wouldnt call it a back problem, I'd call it a "downhill leaner" problem. :)
For you, what I would do is when you are riding him, keep him slow. The faster he goes the harder it will be for him to pick himself up. At the walk, give him the feel in your body that you want him to slow even more, and take gently on the reins,(perhaps even a little it of an upwards pressure, rater than back towards your hip) then a slight tug, then an immediate, urgent release. Like, throw your hands forward like he'll do something really really bad if you don't do it fast enough. ;)
What that does, is gives him the aid to steady with the gentle take on the reins. Most likely, that'll be ignored, and the quick tug and then release sets him back and since you arent still pulling, he's got nothing to lean on. The quick tug in the middle is just in a moment, it's not a jerk. You shouldnt feel like you release the reins after the gentle take on the reins, its should all flow together.
Do this every time he feels like he's falling down on his head. If he reacts positively, ten immediately back it up with some leg so send him forwad after he's steadied himself.
This will teach him to carry himself without you having to feel like you have to hold him up. If you can get the owner out one day and tell her the stuff you're learning maybe she can help. :)
Just keep in mind a horse like that will sucker you into pulling on him, but try your very hardest not to hold him up. You can teach him to do it himself.

Thanks for all your insight! I still haven't had an opportunity to ride because the poor guy lost his shoe and I didn't want to risk hurting him with my riding. But one of the posts mentioned that he might suffer from a sore back. And that is something I have considered lately. While I groom him, he gets very rigid and tense when I start to brush his right back side. So it may very well be contributing factor. I also feel that he is unable to support himself and this is a way of escaping it. I have been working on it with walking and trotting, but his canter has always been a little outta control! I don't think he was ever worked with long enough to properly develop his canter. He is an ex-racehorse with a lot of energy when it comes to cantering! I spoke with another woman who said that a lot of the old racing habits he has will be tough to break. As in taking in more rein, just means go faster with him. He still equates that with an upward transition. So I am working with him to try to re-educate him on that too! But it is all an education for me as well! But thanks again for all your help. I hopefully will see him in the next couple days and I can try out your recommendations.