What are black particles in hair most likely to be?

• A. Fleas
• B. Lint
• C. Dust
• D. Seeds

Answer: (A)

Black particles in a dog's coat are most likely fleas, specifically flea dirt—the tiny specks of dried blood fleas leave behind as they feed. These specks cling to the hair and can look like pepper, which is why they’re easy to confuse with lint, dust, or seeds. The key clues are that they’re tied to parasite activity and itching, and you can test them by placing a few on a damp tissue; flea dirt usually reddens as it dissolves, revealing the blood content. Lint, dust, and seeds are inert debris and don’t come from parasites or cause itching, so fleas are the best explanation for dark particles seen in the coat.