Chronic Demodex Mange

by Gop
(Thailand)

Reader Question: Does Demodex Improve After Progestanin Administration?

The dog began to show obvious symptoms of Demodex mange at approx 4 months of age. Oral Ivermectin was trialed for 4 weeks with once a week dosage. She responded positively, but mange returned after another 6 weeks.

At this stage she began weekly subcutaneous injection of Ivermectin 600 micrograms per kg body weight, because this is a considerably less expensive treatment than oral equivalents and she isn't disturbed by the injections at all. Her hair loss disappeared and was held in check with this regime. She became pregnant and her Demodex became more noticeable. After she delivered her puppies the Demodex became extremely noticeable. The dosage was increased to twice weekly and this was effective. Her overall hair density was reduced but seemed to be stable. Any missed doses quickly resulted in obvious hair loss and darkening skin.

At 20 weeks post partum she was given 50 mg Methoxprogestanone IM, for contraception. Within 10 days her hair replacement was noticeable and continued to thicken. Within three weeks the Demodex was un-noticeable and the Ivermectin halted. It is now 5 weeks post the MPA and all seems well. None of her puppies are showing symptoms of Demodex mange they are however receiving Ivermectin sc. every 2 months as Heartworm prophylaxis

This is anecdotal I know but I wonder if there has been any other observation of Demodex improving after progestanin administration?

Gop

Veterinarian Answers Reader Question Regarding Improvement Of Demodex After Progestanin Administration

Hi,

Interesting case. One note, the dose of ivermectin typically used for heartworm prophylaxis is extremely low and would not affect whether or not your puppies develop demodicosis. Their greatest risk is genetic and based on inheriting problematic genes from their mother and/or father. I would not recommend breeding this individual again. Demodicosis is not a contagious disease for anyone who is wondering.

As for the improvement in your dog’s symptoms after progesterone therapy, yes, there is evidence that progesterone helps some pets with skin problems, but the hormone is not typically recommended because the side effects can be quite severe. Some dogs with generalized demodicosis require life-long treatment with parasiticides because their immune systems are just not able to keep mite numbers in check without help.

Good luck,

Jennifer Coates, DVM