Thiabendazole (Tresaderm®) for Dogs and Cats

Overview of Thiabendazole for Dogs and Cats

Thiabendazole, also known by the brand name Tresaderm®, is a drug used for the treatment of infections caused by parasites (mites and worms) and fungi (molds and yeasts) in dogs and cats.
Though most often used as a de-wormer in large animals, when combined with other drugs, thiabendazole is an effective treatment for certain ear conditions in dogs and cats. The drug kills ear mites and controls ear infections caused by the yeast Malassezia.
The product Tresaderm® contains thiabendazole combined with the antibiotic, neomycin and the steroid, dexamethasone. Neomycin is effective against a variety of bacteria (including Pseudomonas, Proteus and Staphylococcus), while dexamethasone offers relief from itching and reduces inflammation.
Thiabendazole is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

This drug is registered for use in humans and animals.
Human formulations: Mintezol® (Merck)
Veterinary formulations: Tresaderm® (MSD Agvet)
Oral forms of thiabendazole are becoming less available due to reduced manufacturing and distribution.

Thiabendazole is prescribed to treat or control infections caused by susceptible parasites, fungi and bacteria.
Tresaderm®, which contains thiabendazole is indicated for the treatment of acute and chronic otitis externa (ear infection/infection) caused by bacteria or ear mites.
Thiabendazole is also used in the treatment of dermatomycoses (fungus infection of the skin) caused by the molds Microsporum and Tricophyton in dogs and cats.
Thiabendazole is not effective against infections caused by viruses or by certain mites or fungi. Identification of the offending fungus, parasite or bacterium should be obtained before using this product.
Thiabendazole is also effective in killing a variety of gastrointestinal parasites; however, internal use of this product carries the risk of side effects and there are safer products to use for this purpose. Previously, this drug was used to treat nasal cavity infections caused by some molds; however, side effects also limit this use.

While generally safe and effective when prescribed by a veterinarian, thiabendazole can cause side effects in some animals.
Thiabendazole should not be used in animals with known hypersensitivity or allergy to the drug.
Thiabendazole should be avoided in pregnant animals.
The combination of thiabendazole, dexamethasone and neomycin in Tresaderm® is generally safe for topical (skin, ear) use in dogs and cats.
Do not use this drug in the eyes!
Thiabendazole may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with thiabendazole. Such drugs include theophylline and aminophylline.
It is possible that the steroid component of Tresaderm®, dexamethasone, can be absorbed into the circulation. Chronic use can suppress the function of the adrenal glands.

Thiabendazole, combined with neomycin and dexamethasone is available in 7.5 ml and 15 ml dropper bottles.

Medication should never be administered without first consulting your veterinarian.
The typical dose of Tresaderm® ranges from five to 15 drops in the ear canal for seven days.
For skin conditions apply two to four drops per square inch of the area to be treated twice a day for seven days.
The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.