Crusty black particles in undercoat

[Boombud]

Boomer is an adopted older Cairn, my wife has had him about 3 years and he is definitely 'mama's baby'. We have just discovered that he has crusty black particles all through his undercoat. She brushed and shampooed him, but I don't know where this came from. I don't have a microscope but it was NOT fleas, and none of the particles were moving. They were small, irregular, and somewhat shiny...and I'd describe the color as black. This is a new situation, he's been bathed on other occasions and no evidence of this has been seen before. Any ideas? Boomer lives indoors, gets several walks daily around the condominium complex, and does not run free or roll around in dirt. He doesn't seem to have any discomfort from whatever this is (was? - not sure if the shampoo has eliminated this condition).

I've been busy getting logged in on this site, sorry I didn't take any pictures pre-shampoo.

[Sam I Am]

Having never experienced this, I did a google on fleas and flea dirt. Does this what your Cairns coat look like? If so contact your vet clinic for proper treatment. Pet shop type parasite treatments are not safe. 

 

[Hillscreek]

You often don't see the actual fleas on a dog but the dirt they leave shows as black specks on skin and through coat.

I wouldn't describe what I have seen on a dog as crusty though. Just tiny black specs. Can you explain this a bit more? Is it on skin or in coat or both? Is it actual patches or just scattered specks? Is Boomer scratching a lot?

Hope you can get this sorted soon. Poor Boomer.

[Boombud]

Verifying your input, 1 shampoo and much grooming later, searching through Boomer's undercoat, 1 live flea found and dispatched. Flea and tick treatment had been missed when it was due to be applied. We're being vigilant and will carry out thorough cleaning and regular inspection of his coat. 

[Lupinegirl]

My dog had blackheads like me, I think. Little oily black/gray crumbs that were attached to his pores but they pulled out/brushed out easily just like me removing a blackhead from a clogged pore on my face. Gross. They were especially concentrated on his back near the spot at the base of the tail that most dogs like having scratched. I kept checking for fleas and I used Frontline every month originally, and then K-P Advantix. I don’t know. I never did find out what caused that on him.