A Veterinary Survey of cat ear mite Otodectes cynotis in the UK 2001: Incidence, Treatment and Treatment failure. C E Bennett & J Rudall

Correspondence to Dr. C.E. Bennett, Parasite Epidemiology Unit, School of Biological Sciences, University of Southampton. SO16 7PX, UK. E-mail: ceb@soton.ac.uk Tel: 0+44 23 80594407 Fax. +44 23 80594269



Otodectes cynotis is a mite of the family Psoroptidae and is estimated to be responsible for 50% of the canker cases worldwide (Sotiraka et. al. 2001).


Conduct a UK survey of incidence of Otodectes in cats by age in vet surgeries

Determine opinion of any local increase or decrease of the disease incidence

Determine the most frequently used treatment

Evaluate efficacy of currently available therapies.


Incidence in Great Britain. Otodectes incidence is 2.5 cases per surgery per month with the highest incidence in the North-West where 50% of surgeries see 11-20 cases / month.

Perceptions of increase in incidence between 2000 and 2001. In all districts the majority of vets believed that there was no change in incidence: p>0.05

Most frequent age
of infestation

Age range of infested cats 0-2 years 150 2-5 years 25 Over 5 years 5 There was a significant difference between the age ranges of infested cats p<0.01

Most frequently
used treatments

Canaural was the most frequently used treatment. This product contains antibiotics and an anti-fungal agent but no acaricide: specifically it contains: diethanolamine fusidate , framycetin sulfate, nystatin and prednisolone. The second most frequently used treatment was Stronhold (Shanks 2000) which was used most often as a secondary treatment on return. This product contains Selamectin a member of the avermectin class of compounds.

No. of  treatment failures / resistance


Evidence of resistance?


Kittens are most significantly at risk from infestation which may suggest that immunity arises with age. Where Otodectes infestations arise the majority of Vets use Canaural as their first line of attack even though it contain no acaracide. The avermectin product Stronghold is the most frequently used product where re-treatment after Canaural is found necessary. At present resistance to treatment compounds is at a low level with this infestation. 83 Surgeries have agreed to participate in a prospective survey which will investigate possible resistance to treatments in a project commencing August 2002.


Sotiraki ST; Koutinas AF; Leontides LS; Adamama-Moraitou KK; Himonas CA (2001) Factors affecting the frequency of ear canal and face infestation by Otodectes cynotis in the cat Veterinary Parasitology, 96, (4) 309-315.

Shanks. D.J,. et al. (2000) The efficacy of selamectin in the treatment of naturally acquired aural infestations of Otodectes cynotis on dogs and cats. Veterinary Parasitology. 91, 283-290.



This work is  pre-publication

information for participating veterinary surgeons