Auricular mange or otacariosis is a pathology related to the presence of an acarienOtodectes cynotis in the auditory ducts of an animal.
It is very common in our domestic carnivores (dog, cat but also ferret).
Who is responsible?
The parasite responsible for auricular mange is a microscopic mite (less than 0.5 mm) that spends all its life on the animal that it parasites:
It lives on the surface of the auditory canal where it feeds on debris of epidermis and cerumen and where it reproduces. Eggs, larvae and adults are therefore present in the ears of the parasitized animal (these mites are only able to survive a few days in the external environment).
The complete life cycle of the parasite (passage from egg to adult) takes place in 3 weeks.
Mites may occasionally come to localize in the periauricular zones or under the chin in the cat.
Contamination
Transmission of the parasite is by direct contact between an animal and an infested animal. It can take place within the same species but an interspecific contamination (from cat to dog, from ferret to cat ...) is also possible.
It is a highly contagious parasite, particularly in young animals and large numbers, communities (livestock, refuge, pet shop, cattery, kennel ...)
SYMPTOMS
Some animals, especially in ferrets, may be asymptomatic carriers of the parasite but in most cases symptoms are present:
¤ The presence of Otodectes cynotis in the ear canal of an animal is accompanied by severe itching and pain.
The animal, very embarrassed, frequently shakes his head.
Any attempt to examine the ear is accompanied by an auditopodal reflex (the dog or cat scratching frantically with the hind leg as soon as one touches the ear)
- This very marked scratching can be accompanied by skin lesions sometimes very impressive on the head and especially on the circumference of the ears.
It can also cause an otomatoma (a vessel ruptures and begins to bleed forming a pocket of blood between the skin and the cartilage of the ear)
¤ Otodectes cynotis is also responsible for an increase in the secretion of cerumen in the ear canal.
- A cerumen, first blackish and dry, and then more pasty in the more advanced mange, can very often be noticed in the affected ear.
- This cerumen promotes the appearance, especially in the dog, of superinfected otitis. Yeasts and bacteria then develop in the ear canal and the dark cerumen leaves room for purulent flows.
¤ In the most advanced stages:
- Otitis externa may be complicated with otitis media if accompanied by an alteration of the eardrum.
- The discomfort occasioned may be such that the animal keeps the head leaning constantly and may suffer from loss of balance.
Diagnostic
The diagnosis of ear mites is made by highlighting by the veterinarian either:
- or of the adult parasite directly in the ear canal by means of an otoscope
- either adults, larvae or eggs of the parasite under a microscope on a secretion sample
Adults and eggs of Otodectes cynotis examined under a microscope
When the amount of parasites in the ears is large, the diagnosis is easy.
On the other hand, some animals have a certain "hypersensitivity" to Otodectes cynotis. A very small number of mites can be responsible for very marked itching and the allergic animal will self-mutilate, resulting in sometimes impressive skin lesions.
The detection of the parasite will then be much more difficult because:
It is present only in very small quantities and therefore difficult to detect
And that the symptoms can mimic any allergic pathology (allergy to pollens, mites, food allergy ...)
Treatment
The treatment consists in killing the parasites:
- Atrial ointments active against otodectes are used
- A cleaning of the ears 2 to 3 times a week with a suitable cleanser must be associated with this treatment.
It will make it possible to detach the cerumen present in the auditory ducts, thus ensuring a mechanical elimination of a large quantity of parasites as well as a better action of the acaricide (this one will then be directly in contact with the surface of the auditory canal And not "drowned" in the dirt)
- Some spot-on treatments are also active against ear mite mites.
These are products containing selamectin or moxidectin.
These products will be applied at least twice to 15 days apart
- Knowing that the parasite is very contagious and that asymptomatic carriers can exist, treatment of all the individuals of the home is necessary (dogs, cats, ferrets, even in the absence of clinical sign)
As mentioned earlier, the mites survive only a few days in the external environment.
- In households, frequent passage of the vacuum cleaner on the surfaces in contact with the infested animal will often make it possible to clean the environment.
- In larger numbers, in view of the high infectivity of the parasite, products capable of killing mites should be used for cleaning all surfaces in contact with animals.
The introduction of a new animal into a home must be systematically preceded by careful examination of its auditory ducts to ensure that it is not carrying mites responsible for ear mites.
The application of a spot-on treatment against these mites (ask your veterinarian for advice) may also be carried out before the newcomer is put in contact with the other animals of his / her host family , All the more so if it is an animal that comes from a community or has lived outside.
