Your horse will perform better for you if you keep him healthy, he will look better, and he will be happier. You will reap the rewards if you invest some time and money into your horse's health and condition.
Your horse needs adequate food: hay or grass, and he needs a constant supply of clean water.
Horses spend about 80% of their time eating when they're out at grass, and they get bored if there is nothing available for them to munch on.
Rescued horse Kate Moss, before and after
Horses need to be wormed every six weeks. There are different wormers that kill different parasites, so you should use a different one each time to make sure you kill all the different types.
He needs to have his feet trimmed every six weeks also, even if he has no shoes. If he is doing lots of road work he needs shoes, and his hooves need to be seen by a farrier every six weeks.
You should never canter or gallop on concrete as you will damage your horse's bones. Trot only on the roads and have a canter on the grass. Otherwise your horse will be lame, he will be out of action and he will be suffering with pain.
Never leave your horse tied up where he cannot get grass and water, this will make him sick. Never leave your horse on his own where he cannot see and hear another horse. They get very lonely and depressed if they are not with other horses, as they are herd animals.
You will need to get your horse's teeth checked every year by a horse dentist. Horses have hook teeth that keep growing and they need to be rasped so that they don't grow into the gum - this is very painful if it is allowed to happen. If his teeth are sore he will not work nicely for you as he will hate having the bit in his mouth.
If you start by following these simple guidelines you will have a horse that is a credit to you, and that you can be proud of!