Choosing the Right Approach for Demodectic Mange: Evaluating Sulfur, Ivermectin, and Selamectin

Evaluating Treatment Options for Demodex Mange in Dogs

“My 2 Frenchies decided they were going to let their Demodicosis get out of whack a couple of weeks ago. I was applying triamcinolone acetonide 0.1% cream to their folds when appeared to be inflamed (either by not drying fully after baths or for whatever reason). I totally didn’t think of weakening their immune systems. In addition, I was feeding them a fresh diet only to find out they were both allergic to chicken. I know—double whammy!

So I ended up changing their diets and giving them both sulfur dips once a week. They’ve had two so far. The first dip cleared up the little red bump rash almost immediately. I was impressed. The second bath gave my big guy time to grow some hair back. He had about three little patches of hair loss, nothing really major. I continue to brush their hair daily, which appears to help remove any old gunk (dry flakes, dried skin, etc.). I put them both on selamectin only to read somewhere that it wasn’t the best for Demodicosis. Then I found Ask a Vet and read through some of your articles. I ordered the sheep drench 0.8 and have given them both their first doses today—0.1cc and 0.3cc.

My understanding is to continue with the sheep drench for three months, correct? Do I continue with the selamectin drops behind the neck too? And should I continue with the NexGard the vet gave me months ago to help with all the other nasty bugs? Do you recommend anything else? I just want to make sure that I prevent them from getting any other parasites in the future.

Do you think that I should give them the sulfur dips (aka rotten egg baths) monthly? Should I give them probiotics? Any information would be so helpful.” —Marie

Demodex Mites Present Treatment Challenges

Treating demodectic mange often yields mixed results, as you have experienced. Numerous therapies are available that can be effective, but certain factors can cause a dog's skin condition to flare up again even after apparent resolution.

Underlying Food Allergies May Hinder Recovery

Food allergies are a common complicating factor. If you identified your dogs' allergies through an elimination diet, that's a good start. However, if skin issues related to food persist, Demodex may not resolve even with appropriate treatment.

Steroid Use Can Aggravate Lesions

Topical steroids such as triamcinolone cream are not advisable for dogs with demodex, as they can worsen skin lesions. (1) While steroids may alleviate skin problems caused by food allergies, they should be avoided when Demodex is also present.

Role of Sulfur Dips in Managing Demodectic Mange

Lime-sulfur shampoo and dip remain a primary treatment for demodex, often used alongside amitraz, another first-line option. However, sulfur does not always work, which explains the existence of many alternatives.

Sulfur can improve overall skin quality, but if ivermectin is being used, it may not be needed.

Can Probiotics Aid in Fighting Demodex Mites?

Research indicates that certain bacteria in the microbiome can enhance skin health. (2) A Purina probiotic might be beneficial, but if you prefer not to use it, select a probiotic with comparable bacterial strains.

Although no studies have specifically examined probiotics for skin improvement in Demodex cases, they may offer immunological benefits even if clinical signs persist. Given your dogs' other skin issues, this could be a worthwhile addition.

Duration of Ivermectin Therapy for Demodecosis

Three months of ivermectin typically resolves most demodicosis cases, though it's not guaranteed. At the correct dose, the median time to cure was 10 weeks (range 6 weeks to 5 months), and if a dog did not respond within that period, a second round of ivermectin often led to resolution. (3)

Skin Scraping at the End of Treatment

It's best to have your vet perform a skin scraping after therapy to check for Demodex under the microscope. If none are found, the mites are gone, but your dogs might need a bit more treatment.

Combining Selamectin with Ivermectin: Is It Beneficial?

To my knowledge, no studies have evaluated the combination of selamectin and ivermectin.

Selamectin might be effective in some cases where ivermectin failed, or it might not. Drawbacks include its relatively high cost and the difficulty of administering it to some dogs due to its unpleasant taste. A few dogs in studies experienced neurological issues, but these resolved with treatment. (4)

There is no advantage to using ivermectin and selamectin simultaneously. If ivermectin fails, you might consider trying selamectin later.

Alternative Options When Ivermectin Fails

Most dogs, though not all, respond to the ivermectin regimen. If not, selamectin is an option.

The NexGard you already have may resolve the Demodex infection on its own. (5) As far as we know, there are no contraindications to using ivermectin and NexGard together. A newer medication, Sarolaner (brand name Simparica), may also be effective. It controls fleas and ear mites and kills Demodex mites. (6)

Fluralaner (Bravecto) is another option that has been shown to eliminate 100% of Demodex mites over time. (7) With Simparica and Bravecto, you can administer the flea-control dose, which also treats Demodex, making costs lower than some other regimens.

Sources

(1) Miller WH, Griffin CE, Campbell K. Muller and Kirk’s Small Animal Dermatology. 7th ed. Philadelphia, Pennsylvania: Elsevier; 2012.

(2) Marsella R. Evaluation of Lactobacillus rhamnosus strain GG for the prevention of atopic dermatitis in dogs. Am J Vet Res 2009; 70(6): 735-40. i.nlm.nih.gov/19496662/

(3) Ristic Z, Medleau L, Paradis M, White-Weithers NE. Ivermectin for treatment of generalized demodicosis in dogs. J Am Vet Med Assoc. 1995 Nov 15;207(10):1308-10. PMID: 7591924. i.nlm.nih.gov/7591924/

(4) Schnabl B, Bettenay S, Glos N, Linek M, Loewenstein C, Mueller RS. Oral selamectin in the treatment of canine generalised demodicosis. Vet Rec. 2010 Jun 5;166(23):710-4. doi: 10.1136/vr.4850. PMID: 20525946. i.nlm.nih.gov/20525946/

(5) Beugnet F, Halos L, Larsen D, de Vos C. Efficacy of oral afoxolaner for the treatment of canine generalised demodicosis. Parasite. 2016;23:14. doi: 10.1051/parasite/2016014. Epub 2016 Mar 24. PMID: 27012161; PMCID: PMC4807374. i.nlm.nih.gov/pmc/articles/PMC4807374/

(6) Six RH, Becskei C, Mazaleski MM, Fourie JJ, Mahabir SP, Myers MR, Slootmans N. Efficacy of sarolaner, a novel oral isoxazoline, against two common mite infestations in dogs: Demodex spp. and Otodectes cynotis. Vet Parasitol. 2016 May 30;222:62-6. doi: 10.1016/j.vetpar.2016.02.027. Epub 2016 Mar 4. PMID: 26971196. i.nlm.nih.gov/26971196/

(7) Fourie JJ, Liebenberg JE, Horak IG, Taenzler J, Heckeroth AR, Frénais R. Efficacy of orally administered fluralaner (Bravecto™) or topically applied imidacloprid/moxidectin (Advocate®) against generalized demodicosis in dogs. Parasit Vectors. 2015 Mar 28;8:187. doi: 10.1186/s13071-015-0775-8. PMID: 25881320; PMCID: PMC4394402. i.nlm.nih.gov/pmc/articles/PMC4394402/

This article is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from your veterinarian. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2023 Mark dos Anjos, DVM