Only further diagnostic testing will allow the veterinarian to arrive at a diagnosis. He has had abnormal lab work, so something is wrong.
An increased white cell count usually makes veterinarians worried about either infection or cancer.
Additional diagnostic tests are needed to rule out infection. X-rays, ultrasounds especially of the stomach and lungs, kidneys (whatever the examining vet advises) to check for tumors.
I don’t want to scare you, but German Shepherds are vulnerable to certain types of cancer (genetic).
The sooner you get a diagnosis the sooner you can evaluate treatment options, he’s a young dog. Good luck
Ps: waterchestnuts are not toxic to dogs, however they may have upset his stomach.
But I would think if that was the case he’d be over it by now. Make sure he’s drinking water, if not, or he doesn’t eat times 3 days get him right back to the vet.
Consider the nearest 24/7 emergency veterinary clinic if he takes a turn for the worse and your vet isn’t available.
