I did equine science degree but sure most the books cover both!
I used Equine Exercise Physiology (Marlin and Nankervis) a bit.
Also Veterinary Notes for Horse Owners (Hayes)- some of it is a bit basic and sometimes dated but has profiles of every disease/disorder so good for Injury/Disease modules!
If you do complex nutrition. Nutrition and Feeding (Frape) is good but quite complicated.
Otherwise Pubmed is good to search for research articles.
Or search under equine anatomy/diseases/physiology/biomechanics/nutrition on amazon. Quite a lot of deals if you buy 2 books!
def agree with all of above and look at loads of EVJs as they are really useful although i never really looked at them till my last term of my HND! should have sooner