By Sharon Vanderlip, DVM
Mites are miniscule arthropods, also known as acarines. They vaguely resemble their relative, the spider, and have transparent or semitransparent bodies. There are numerous species of mites, but only two of them parasitize ferrets. Ear mite infestations in ferrets are caused by Otodectes cynotis. Skin infestations are caused by Sarcoptes scabiei.
Ear mite infestation, also known as “ear mange,” is very common in ferrets. It is also common in cats and dogs. Otodectes cynotis ear mites live their entire lives inside animals’ ears. Ear mites are contagious and spread by direct contact among ferrets, cats, dogs and other animals. In other words, cats and dogs can transmit ear mites to each other and to ferrets, and ferrets can spread ear mites to cats, dogs and other ferrets.
O. cynotis often passes unnoticed in ferrets for several reasons. One reason is that the mites are too minute to observe without the aid of a microscope. Another reason is that ferrets, unlike cats and dogs, rarely show signs of ear scratching and head shaking when they have an ear mite infestation. Finally, although a thick, reddish brown to black, waxy discharge is commonly observed in ferrets suffering from ear mite infestation, it is also normal for ferrets to have a brown ear wax. A definitive diagnosis of ear mite infestation cannot be made by observing the color of ear wax. The diagnosis must be confirmed by examining the waxy discharge under a microscope to confirm the presence of Otodectes mites and eggs.
Ferret owners must be vigilant and observe their pets every day. Close observation of an affected ferret’s ear (pinna) and ear canal usually reveals a dark brown to black colored waxy substance. This substance is composed of microscopic mite parasites, mite eggs, and sebum (sebaceous gland secretions, combined with fat and cellular debris) and is characteristic of ear mite infestation.
A veterinarian should be consulted immediately if:
- The ferret’s ear has a foul odor
- The color of the ferret’s ear wax darkens or changes
- The thickness or quantity of ferret’s ear discharge increases
- The ferret appears to be in pain
- The ferret has any behavioral changes or is lethargic
- The ferret has a poor appetite or is depressed
- The ferret scratches its ears or shakes its head
- The ferret shows loss of coordination, loss of balance or circling
- Other pets in the household have signs of ear mites or have been diagnosed with ear mites
Ear mite infestation is quick, easy and non-invasive for a veterinarian to diagnose. A sample of the waxy discharge is taken directly from the ear using a cotton swab or other gentle method and then examined under the microscope. Early diagnosis and treatment is important to bring the ferret relief and to prevent complications such as middle ear and inner ear infections, ataxia, loss of hearing or secondary fungal ear infections. Ear infections require treatment with antibiotics. (Mucormycosis is an infection caused by the fungus Absidia corymbifera and has been known to occur with ear mite infestation).
An ear examination and microscopic evaluation of ear wax should be a part of every ferret’s routine physical examination. Ferrets should have a health check and veterinary examination once every six months. At every exam, ears should be checked for ear mites because ear mites are not readily apparent and can be acquired from other animals at any time.
Several products are available to treat ear mites in ferrets, including pyrethrin, rotenone and thiabendazole. Medications that are instilled directly into the ear canal might have less of a chance of succeeding because ferrets have tiny ear canals and it is difficult to administer the full amount of medication into the ears. In addition, ferrets dislike having liquid dropped into their ears and may struggle and resist treatment.
Ivermectin is another effective anti-parasitic product that can be used in ferrets to kill ear mites. Ivermectin also kills parasitic intestinal roundworms (nematodes) and prevents heartworms (Dirofilaria). Owners who give their ferrets ivermectin tablets for the prevention of heartworm disease may find that this monthly preventive helps keep their ferrets free of ear mites as well.
Ivermectin can be massaged directly onto the ears or given by injection. The first treatment is usually followed up by a second treatment two weeks later. The required ivermectin dose must be determined by the prescribing veterinarian, on a case by case basis. Ferret owners should advise their veterinarians if their jills are pregnant before ivermectin is given, so that the dose can be adjusted accordingly.
Successful treatment and elimination of O. cynotis depends on several factors
- Using the appropriate product
- Giving the correct dose
- Administering all of the product at the correct time intervals
- Treating all affected animals in the house at the same time
- Isolating affected animals from non-affected animals
- Veterinary examination of all new animals immediately upon arrival
Sarcoptes scabiei in ferrets is rare, but symptoms of this parasitic disease, known as scabies, can be serious. In addition, Sarcoptes is contagious to dogs, cats, other family pets and humans. Transmission is by direct contact or by contact with contaminated materials, such as animal bedding.
Ferrets parasitized by S. scabiei may show one of two forms of scabies. One form of scabies affects the skin and causes intense skin itching (pruritus) and hair loss (alopecia). The other form, known as “foot rot,” affects the ferret’s feet, causing pain, swelling, inflammation, scabbing and eventual loss of claws. Both forms of scabies require immediate veterinary care and treatment. Without treatment, the condition can quickly worsen and the ferret’s health can deteriorate.
Ferrets suffering from the “foot rot” form of scabies need multiple foot soaks and cleaning of scabbed areas. Treatment must be initiated immediately to prevent loss of claws. In addition to anti-parasitic medication to kill the Sarcoptes mites, antibiotics and pain medication may be recommended for ferrets suffering from “foot rot.”
To accurately diagnose scabies, the veterinarian scrapes the animal’s skin with a thin blade and transfers the material onto a slide to examine under the microscope. Sarcoptes mites can be difficult to detect, so often several skin scrapings, taken from different parts of the body, must be done before the Sarcoptes mites can be found and a definitive diagnosis can be made.
There are several types of treatments available, including ivermectin, sulfa dips and carbaryl shampoo. In many cases, ivermectin is the treatment of choice, combined with daily baths for four consecutive days. The best and safest treatment should be decided by the examining veterinarian, based on the ferret’s size, age and health.
After infestation, cages must be disinfected and all bedding material discarded. Affected animals must be isolated from healthy animals and all animals in the family should be checked for scabies by a veterinarian. Owners with itchy spots or lesions are advised to contact their physicians immediately.
Sharon Vanderlip, DVM, has provided veterinary care to exotic and domestic animals for 29 years. She has authored numerous scientific articles and 18 books on pet care and she has received awards for her writing and dedication to animal health. Dr. Vanderlip may be contacted for seminars, consultations and speaking engagements at her website. Click here.