black dots burrowed in my dogs skin

Question
Thank you for donating your time.
For the past few days I noticed small black dots embedded inside my dog's
skin, near his genital area and lower abdominal area where there is no hair.
Today I noticed a few seem to get bigger and I tried pulling one out with a
tweezer. It came out looking like an extremely small flea but I wasn't sure. It
resembles a black head of a pimple but I thought I saw small legs. Could this
be a flea pupae burrowed in my dog's skin or even mites?

I recently had a moderate flea problem with my dog. There's a nest in my
yard and about 1-2 would latch on to him every few days. My sister and I have
caught most of them, in addition to treating him with frontline and spraying
my house and yard but after 3 weeks fleas started reappearing. Could those
dots be flea eggs or even mites? Thanks again for your help.

Answer
What you are probably seeing are truly blackhead or comedones.  These are very commonly found on dogs' skin when there is a skin allergy.  Neither fleas or their larvae burrow into the skin. Try wiping these with isopropyl rubbing alcohol to see if you can loosen them to make them easier to remove. Some dogs with low thyroid hormone levels are prone to these, too.