Regarding the cryptorchidism, you may want to seriously consider neutering him.
The body temperature is too high for the testicles to be internal. Sometimes a tumor/cancer can develop a few years down the road, or not. Discuss with your vet. A late in life neuter is even harder on them.
Cryptorchidism is a hereditary condition and it is recommended not to breed these dogs.
I have heard giardia can be stubborn and take a long time to resolve. I also have heard that it can take two or three courses of treatment to get rid of it.
Ask your vet if he will always test positive for giardia? Even when asymptomatic? Can he give it to other dogs via urine and feces exposure?
