Preventive efficacy of a topical combination of fipronil--(S)-methoprene--eprinomectin--praziquantel against ear mite (Otodectes cynotis) infestation of cats through a natural infestation model

Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against ear mite (Otodectes cynotis) infestations in cats

Esafoxolaner, a purified enantiomer of afoxolaner with insecticidal and acaricidal properties, is combined with eprinomectin and praziquantel, nematodicidal and cestodicidal compounds, in NexGard® Combo, a novel topical endectoparasiticide formulation for cats. The efficacy of this formulation was assessed against Otodectes cynotis in two laboratory studies conducted in South Africa and in the USA with local isolates, and in one field trial conducted in Europe. In each study, cats were randomly allocated to a placebo-treated control group and a novel formulation-treated group. In the laboratory studies, cats were treated at the minimum recommended dose; in the field trial, cats were treated at label dose. All included cats were diagnosed positive for O. cynotis prior to treatment by otoscopy. The main variable of efficacy was a comparison of the number of live O. cynotis collected in both ear canals of all cats in the treated and control groups, one month after treatment. Efficacy of the novel topical formulation exceeded 97% in the three studies. These studies demonstrated the high effectiveness of NexGard® Combo in cats for the treatment of O. cynotis infestations. No health abnormalities were attributed to the treatment in any of the studies.

Otoscopy and aural cytological findings in a population of rescue cats and cases in a referral small animal hospital in England and Wales

OBJECTIVES

Otitis externa is seen clinically in cats, although studies investigating this condition within the UK are lacking. The objective of this study was to investigate the prevalence of Otodectes cynotis mites and microbial infection in the ear canals of cats in various rescue centres and a referral hospital.

METHODS

Otoscopy was performed in 332 cats. Otoscopic findings were noted, including the gross visualisation of Otodectes species. A sample of cerumen was collected for cytological evaluation and a cerumen smear for detection of Otodectes mites if there was a large amount of aural exudate present.

RESULTS

O cynotis infestation was noted in 3/341 cats (0.9%, 95% confidence interval [CI] 0.3-2.6). A total of 129/341 (37.8%; 95% CI 32.7-43.0) cats were found to have Malassezia species within one or both ears. Bacteria were found unilaterally in 9/341 (2.6%; 95% CI 1.4-4.9) cats. Analysis of the cytological findings showed an increased likelihood for Malassezia species to be present as age increased (n = 293; Pearson r = 0.204, P <0.001). There was also an increased likelihood of finding Malassezia species in both ears if found within one ear (n = 327; r = 0.499, P <0.001). There was a positive correlation between the number of Malassezia organisms and the quantity of aural exudate (n = 338; r = 0.778, P <0.001). Cats in which Otodectes species infestation were noted (n = 3) had moderate or large quantities of cerumen.

CONCLUSIONS AND RELEVANCE

This study shows that there was a low prevalence of O cynotis in this cohort of cats. In normal cats it was not unusual to find Malassezia microorganisms upon aural cytology, bacteria were noted far less frequently and in two cats this was associated with underlying anatomical pathology.

Efficacy of fluralaner spot-on solution for the treatment of Ctenocephalides felis and Otodectes cynotis mixed infestation in naturally infested cats

BACKGROUND

Cats can be infested with several ectoparasite species, especially Ctenocephalides felis and Otodectes cynotis. The aim of this study was to evaluate the efficacy of a single topical application of fluralaner against C. felis and O. cynotis natural infestation in stray (study 1) and owned (study 2) cats in central and southern Italy.

RESULTS

The number of live fleas found on each cat on Day 0 ranged from 1 to more than 30 (arithmetic mean live flea count = 11.9 in study 1; 14.6 in study 2) while no live fleas were found on days 7 and 84 post topical application of fluralaner. The number of live mites found on each cat on Day 0 ranged from 1 to 42 (arithmetic mean live mite count = 6.4 in study 1; 8.9 in study 2) while no live mites were found on days 7 and 84 post topical application of fluralaner.

CONCLUSIONS

Topical fluralaner completely eliminated fleas and ear mites from infested cats and was 100% effective against both parasites up to 84 days after treatment.