What is a sarcoptic mite in a dog? - briefly
The sarcoptic mite (Sarcoptes scabiei var. canis) is a microscopic ectoparasite that burrows into a dog’s epidermis, causing intense pruritus, crusted lesions, and hair loss. It spreads readily between animals and humans and requires prompt veterinary diagnosis and acaricidal therapy.
What is a sarcoptic mite in a dog? - in detail
The sarcoptic mite, Sarcoptes scabiei var. canis, is a microscopic ectoparasite that burrows into the epidermis of canines. Adult females create tunnels 0.2–0.5 mm deep, laying 2–5 eggs per day. Eggs hatch in 3–4 days, releasing larvae that mature into nymphs within 5 days and then into reproducing adults after an additional 5–7 days. The complete life cycle lasts approximately 2 weeks under optimal temperature and humidity.
Clinical signs result from the mite’s mechanical damage and the host’s hypersensitivity reaction. Primary manifestations include:
- Intense pruritus, often worsening at night
- Erythema and papular lesions on the ears, elbows, hocks, abdomen, and interdigital spaces
- Crusty, alopecic patches where mites have burrowed
- Secondary bacterial infection secondary to self‑trauma
Diagnosis relies on direct identification of mites, eggs, or fecal pellets in skin scrapings. A superficial scraping from an active lesion, examined under a light microscope at 100–400× magnification, typically reveals the characteristic oval-shaped mite with short legs. In ambiguous cases, adhesive tape impression or dermoscopy can supplement findings.
Effective treatment requires acaricidal therapy combined with measures to prevent reinfestation. Recommended options include:
- Topical agents – selamectin, imidacloprid + moxidectin, or amitraz applied according to label intervals.
- Systemic medications – oral ivermectin (0.2–0.4 mg/kg) or milbemycin oxime, administered weekly for three doses.
- Environmental control – washing bedding at ≥60 °C, vacuuming carpets, and treating the household with appropriate insecticides if necessary.
Supportive care involves antihistamines or glucocorticoids to reduce inflammation and analgesics for pain management. Monitoring should continue for at least four weeks after the final dose to confirm eradication, as residual pruritus may persist due to hypersensitivity.
Prevention focuses on limiting exposure to infested animals, maintaining regular veterinary check‑ups, and applying preventive acaricides in high‑risk environments such as kennels or shelters.