Personally, I would wait until the dog is at least 2 years. Testicular cancer is one that usually crops up later in life and can be generally dealt with by removing the testicals at that time. It is rare, but there is a higher incident rate in retained testicals according to some reports.
Neutering before the dog is fully mature can increase the incidents of other cancers with worse prognoses, like osteosarcoma, hemangiosarcoma, prostate cancer. And it can affect structural growth as well.
There is no hurry.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC