Puppies urine smells of ammonia?

Hey everyone.....got a new puppy, he's about 3 1/2 months old....he's still going thru the potty training and does pretty well, but does have his accidents. I've got other pups, but, with him he does have accidents and when he does, his urine has a very strong ammonia smell...almost eye burning!! He's 1/2 Lab, 1/2 Chow and seems to eat and do his poops fine. I'm going to call the vet Monday morning as I'm concerned he may have a kidney infection, and was concerned on whether or not the pups have different levels of urine smell..I've never encountered this strong of a smell....He drinks a ton of water, as soon as I put a bowl of water down, he'll drink the whole bowl and then it comes back out. Other than the strong odor of pee, he acts like your typical puppy and semms to do fine. Any advice would be helpful!!!