How to treat ringworm cats if lime sulfur products aren’t available

A black kitten lies on the couch. Selective focus. Horizontal.What’s going on with lime sulfur availability, and how can we treat ringworm cats if we can’t get it? That’s the topic of recent guidance from the Association of Shelter Veterinarians as concerns about recently discontinued products grow.

It is true that some companies — Dechra  and Vetoquinol — have discontinued their lime sulfur products. Dechra reps are being told to recommend Dechra’s Malaseb® 2% Miconazole/2% Chlorhexidine shampoo.

Additionally, the ASV wrote that “Revival Animal Health, the company behind the Vet Basics line, said that they were planning to continue making their product, had no
difficulties getting the base chemicals, no shortages, and no anticipated issues filling orders. Davis Manufacturing also reports they are still making their lime sulfur products and have plenty in stock. PetMD, which is only distributed through Chewy, is also continuing to manufacture lime sulfur and has plenty in stock.

From the ASV guidance on alternatives to lime sufur:

2% Miconazole/2% Chlorhexidine shampoo is effective as an adjunctive treatment for dermatophytosis along with an appropriate oral antifungal when diluted 1:1 and used twice weekly. The time to cure is longer than for appropriately concentrated Lime Sulfur or Enilconazole (if you live in a place where you can get it) on the order of a couple weeks, and some study cats required rescue treatment with lime sulfur. Products containing just miconazole or just chlorhexidine are not equivalent.

Accelerated Hydrogen Peroxide products such as Ogena’s Pure Oxygen/Peroxiwash shampoo has not stood up well in preliminary side-by-side tests likely because it has no residual antifungal activity. We do not know the optimum concentration or frequency of bathing. There are as yet no published studies about in vivo use of this product against dermatophytosis, though some may be in the works.

Topical sprays (and mousses) such as 1% clotrimazole, 1% terbinafine, or 2% miconazole/2% chlorhexidine might help provide residual activity if used after shampooing with one of the above products. These have only been tested in vitro. We don’t know whether you need to spray just the lesions you see or the whole cat. Some of these are pricey.

They also caution that alternative treatments that don’t have residual activity may change how your cultures grow.

Download the complete ASV Guidance document here.