Red flat skin pattern

by Gina
(Southern Illinois)

My Jack Russell has developed flat round skin pigmentation around his groin area. He is about 7 months old.

The other day he was laying in the grass. He was on his back. I noticed that he had about 5 round red patches on his groin. They almost looked as if they were bleeding, but the weren't. Later they disappeared not to return until last night when he had just one. He has black spots on his groin as well.

Do you know if this is some allergy? He is not scratching, has no indicatino of hairloss or appetite loss. Any help before going to a vet will be most helpful.

Thanks,

Gina