Black scabby places on 4 y/o German shepherd

I I have a 4 year old full blooded German shepherd and about a month ago I noticed a black scabby looking place in his groin area. After looking I found 3 more. I thought they were his nipples but they feel like a scab and they’re in the same spot on both sides of his groin, that’s why I thought they were his nipples. He won’t hardly let me look at him and the last time I took him to the vet it was only a tech visit and he wouldn’t cooperate for them to look at him. I’m worried it may be something else, has anyone else had anything like this on their dogs? I plan on making another appointment to see the vet

Hello and thank you for this interesting question.  These could be the normal colour for your dogs' nipples.  However, it is somewhat important to know that they are not for example melanomas or lymphoma so another vet visit may be a good idea; it is a good idea to take the photos along with you and perhaps to warn your vet in advance that he is a difficult patient to examine; they might work with you to devise devious examination methods eg posing as a stranger out for a walk in the carpark rather than carrying out examinations in the waiting room.  As a rule of thumb, the colour of nipples should reflect the colour of the skin around them.  Some dogs nipples change with hormones (eg heat in females) or skin with yeast infection.  Your vet will consider the bigger picture and if not completely happy that things are normal, may ask to sedate or anaesthetise the patient for samples.