Which of the following characteristics are true of fur mites?

• A. They can lead to excessive scratching and hair loss.
• B. They do not penetrate the skin.
• C. They are the most common ectoparasites found in rodent colonies.
• D. All of the above

Answer: (D)

Fur mites are external parasites that live on the fur and skin surface of rodents. They cause irritation, so the animal may scratch or rub, leading to hair loss or thinning of fur. Because they stay on the surface and do not invade deeper layers, they do not penetrate the skin. In many rodent colonies, fur mites are a very common ectoparasite finding, which is why the statement that they are the most common ectoparasites in laboratory rodents is true. Detection is usually through observation of clinical signs like itching and hair loss, and can be confirmed with skin/coat examinations or tape tests. Management focuses on treating the affected animals with approved ectoparasiticides, improving environmental cleanliness and cage hygiene, and quarantining new animals to prevent introduction and spread.