The susceptibility of Pseudomonas spp. isolated from dogs with otitis to topical ear cleaners.
OBJECTIVE
To investigate the in vitro efficacy of commercially available topical otic preparations ("ear cleaners") against Pseudomonas spp. isolated from canine ear infections.


METHODS
Between January and May 2011, 50 isolates that were morphologically and phenotypically confirmed as Pseudomonas spp. were isolated from 48 dogs that had been identified with clinical signs of otitis externa and media at a referral dermatology clinic in the north west of the UK. The in vitro efficacy of eight different topical preparations against these isolates was investigated using an in-agar inhibition test.


RESULTS
Of the eight preparations tested, three showed consistently good in vitro activity against Pseudomonas spp., while a further three were consistently ineffective. For the remaining two -preparations, in vitro efficacy was variable and inconsistent.


CONCLUSIONS
Topical treatment with ear cleaners is considered to be a valuable adjunct in the treatment of canine otitis that involves multi-antimicrobial-resistant organisms such as Pseudomonas spp. Where treatment with antimicrobials is not an option, the use of these preparations, as a sole form of therapy, may be effective in some cases. As a comparison with other similar studies looking at the activity of ear cleaners against bacterial isolates from otitis, this study uses isolates from 50 ears from 48 dogs providing a significant number of isolates for analysis.
Abbey Veterinary Services, Newton Abbot Devon, United Kingdom.
S I
SI
Steen
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S
Paterson
D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D008826:Microbial Sensitivity Tests / Q000662:veterinary*; D010031:Otitis / Q000188:drug therapy / Q000662:veterinary*; D011549:Pseudomonas / Q000187:drug effects* / Q000254:growth & development; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents