Red Spots on the stomach

Question
Hi Dr. Gotthelf,

We have a black and white 5 yo greyhound.  She has been getting dark red spots (blood red as opposed to the red of a a rash, though not bleeding) about the size of a dime or smaller in various places on her underside (stomach).  The spots come and go in about a day and a half.  Some are lighter colored in the middle.  

The spots don't hurt to the touch and no other behavior or health changes are noted.

Any idea what may be the cause of this?  It is spring in our area and  we have a lot of bugs but we used frontline a few weeks ago.

Thank you!

Answer
It is hard to diagnose on the internet. If these are large red spots, they can be from irritation, certain parasites, vasculitis, some blood clotting problems, or even infection.  You need to let your vet check the dog to see what the problem might be. Sometimes, it is necessary to do a skin biopsy of an active lesion to know exactly the disease.