Mite-y Itchy
A demodex mite seen through a microscope
History
Scooby is a 14 month old, male, Smooth Collie. He was seen because he had redness and hair loss on his neck, chest, and right front leg. He was also scratching and sore on his right front leg.
When he was younger, he was diagnosed with Demodex mites on his face, which were treated with medicated shampoo and ointment as well as immune and skin support supplements.
His owners wanted to have Scooby neutered, but there was some concern the procedure may cause the Demodex to get worse due to stress and related immune suppression. Pre-operative bloodwork did not point to any immuno-suppression, and neuter was performed at approximately 13 months of age.
Physical Examination
On physical examination, Scooby had a number of spots on his skin about 3 to 5 centimetres in diameter. The spots were red and crusty. Otherwise, his physical examination was normal.
Rule-Outs
Based on his physical exam, possible rule-outs for Scooby included:
- Recurrence of the mites
- Allergic reaction
- Skin infection
Diagnosis
Since he had previously had mites, a skin scrapings were done on 8 sites to check for recurrence. Bloodwork was also done to check for any immuno-suppression or other diseases.
The bloodwork was normal. The skin scrapings were examined under the microscope and showed mites at 6 of the 8 sites, indicating that the Demodex mites had returned.
Treatment
A prescription anti-parasitic medication was prescribed. It was given topically (between the shoulder blades) every 2 weeks for 3 doses. As well, vitamins pills to support the immune system were prescribed twice daily, to be continued indefinitely. Omega fatty acid supplements were also given along with the vitamins to support the skin. Finally, an antibacterial ointment was applied to the affected areas twice a day until they healed.
The anti-parasitic medication was continued afterwards on a monthly basis as a heartworm, flea and intestinal parasite preventative as well (as it is very effective for these parasites as well).
Outcome
Scooby's owners monitored his skin at home, and it cleared up following the treatments, and fur started to regrow over the spots.
Discussion
What are Demodex mites?
Demodex are microscopic parasites that are often found on the skin of normal animals. Usually, their numbers are low, kept in check by the immune system.
Demodicosis
Demodicosis is an infection with an abnormal number of Demodex mites. This happens when a pet's immune system is unable to keep the Demodex mites under control. This is largely determined by genetics, but is exacerbated by stress and other illnesses. Demodicosis typically presents, as it did here, with red, crusty, hairless and sometimes itchy spots on the skin.
Progression
Demodicosis is often seen in puppies, localized to the face. This is usually cured quite readily with conservative treatment, as it was with Scooby. If it found elsewhere on the body, or it doesn't respond to conservative treatment, anti-parasitic medication is called for. In the past, this treatment used to consist of repeatedly "dipping" dogs in a powerful (and smelly) liquid. Fortunately, topical medications
If you are worried about mites in your pet, please contact us.
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