hi can anyone reccomend any good books on dog health

If you want natural remedy type ones then these are both quite good.

"The Encyclopaedia of Natural Pet Care" (by C.J. Puotinen)

"Dr. Pitcairn's complete guide to Naural Health for Dogs and Cats" (Richard H. Pitacairn and Susan Hubble Pitcairn) 

thanks ,it just got me thinking when brock came ill yesterday that i dont know the first thing about dog health it really scared me thanks

The one I have is 'Veterinary Notes for Dog owners' by Trevor Turner.
It is helpfull to have but your Vet is the best one to make a diagnosis. :D