Surgical management of 43 cases of chronic otitis externa in the dog

: Over a seven-year period, chronic otitis externa was surgically managed in 43 dogs at the University Veterinary Hospital of University College Dublin. Lateral ear canal resection (LECR) was undertaken in nine of the 43 dogs: results were unsatisfactory, with a failure of the surgery in five of eight dogs and one dog lost to follow-up. Once end-stage otitis externa, with or without otitis media, is diagnosed, total ear canal ablation and lateral bulla osteotomy (TECA/LBO) is the best treatment option. In this series, 37 of 43 dogs underwent TECA/LBO and of the 29 dogs for which follow-up results were obtained 27 (93%) had an excellent or improved outcome to surgery. Complications following all procedures were most common in cases with a concurrent dermatopathy; therefore, definitive diagnosis and medical treatment for skin and ear disease is essential.     

Comparative assessment of genotypic and phenotypic correlates of Staphylococcus pseudintermedius strains isolated from dogs with otitis externa and healthy dogs

Staphylococcus pseudintermedius is considered a primary pathogen of canine skin and soft tissue infections, and the rapid emergence of methicillin-resistant S. pseudintermedius worldwide is a major issue. In the current study, genotypic and phenotypic correlates associated with S. pseudintermedius causing canine otitis externa were evaluated using 41 S. pseudintermedius strains isolated from dogs with otitis externa (n = 26) and healthy dogs (n = 15). The S. pseudintermedius strains were subjected to a comparative analysis of (i) genotypes (multilocus sequence typing, agr, and spa types), (ii) methicillin resistance and SCCmec types, (iii) multidrug resistance (MDR), (iv) biofilm formation, and (v) susceptibility to canine cathelicidin (K9CATH). A high degree of genetic diversity was observed in both groups of S. pseudintermedius strains, regardless of methicillin resistance. Almost all methicillin-resistant strains (>95%) harbored SCCmec V and displayed MDR. Although there was no difference in biofilm formation, S. pseudintermedius strains derived from otitis externa exhibited enhanced resistance to cationic antimicrobial peptide (K9CATH) compared with strains from healthy dogs. The high degree of heterogeneity in MLST, agr, and spa types prevented the identification of correlations between any specific genotype and virulence phenotype in otitis externa caused by S. pseudintermedius, These findings provide an important basis for monitoring and treating canine skin and soft tissue infections in Korea.     

狗髂外动脉的解剖观察

通过动脉灌注对6例不同品种，年龄，性别的狗尸体髂外动脉进行了观察。狗髂外动脉的主干依次为股动脉，Guo动脉，胫前动脉，跖背侧动脉，跖穿动脉和趾动脉，对隐动脉的分支，分布，股骨近端的一些关节支，关节囊支及闭孔支作了细致观察，此外，笔还对股深动脉，旋股内动脉，旋股外动脉和跖底动脉弓作了讨论。     

A semiquantitative cytological evaluation of normal and pathological samples from the external ear canal of dogs and cats

Abstract  Numbers of desquamated epithelial cells, yeast cells and bacterial organisms were counted in samples collected from the external ear canal of 37 normal dogs and 16 normal cats, and from 24 dogs and 22 cats with otitis externa. The aims of the study were to establish quantitative reference ranges and to correlate these data with the clinical status of the dogs and cats. Numbers of yeast cells and bacterial organisms were significantly increased in dogs ( P  = 0.05; P  = 0.0001) and cats ( P  = 0.0001; P  = 0.0001) with otitis externa, and in most cases high counts were correlated with clinical signs. Mean Malassezia counts per high-power dry field of ≥ 5 in the dog and ≥ 12 in the cat were considered abnormal. Mean bacterial counts per high-power dry field of ≥ 25 in the dog and ≥ 15 in the cat were considered abnormal. When used to differentiate normal from inflamed external ear canals, these figures provided a low sensitivity but a specificity of ≥ 95%.     

Bilateral Pinnal Squamous Cell Carcinoma in a Dog with Chronic Otitis Externa

Abstract— An aged dog with a chronic, bilateral, bacterial otitis externa developed bilateral squamous cell carcinomas of the pinna. The tumours were located where the pinna would cover the external auditory meatus and probably were induced by the chronic infection.
Résumé— Un chien agé souftrant d'otite externe bactérienne chronique bilatérale présenta un épithelioma spinocellulaire bilatéral des pavilions auriculaires. Les tumeurs étaient situées là où les pavilions auraient recourvert le méat auriculaire et furent sans doute provoqués par l'infection chronique.
Zusammenfassung— Ein alter Hund mit einer chronischen, bilateralen, bakteriell bedingten Otitis externa entwickelte Plattenepithelkarzinome en beiden Ohrmuscheln. Diese Tumore traten an der Pinna exakt an der Mündung des äußeren Gehörgangs auf, und sind möglicherweise durch die chronische Infektion induziert worden.
Resumen  Un perro de edad avanzada que presentaba una otitis externa bilateral bacteriana crónica desarrolló unos carcinomas de células escamosas bilaterales del pabellón auditivo. Los tumores estaban localizados en la entrada del meato auditivo y probablemente fueron inducidos por la infección crónica.     

Sterol composition in polyene antibiotic-sensitive and resistant strains ofMalassezia pachydermatis

The membrane sterol compositions of ten strains ofMalassezia pachydermatis were analysed by gas-liquid chromatography. Six of these were wild-type strains from clinical sources that were sensitive to polyene antibiotics, whereas the other four strains were resistant mutants that had arisen after treatment withN-methyl-N-nitrosoguanidine or UV radiation.The wild-type strains contained 838.8 to 1291.7 µg of sterol per gram of freeze-dried mycelium. The sterols were composed of 79% ergosterol, 19% fecosterol and 2% lichesterol. The mutant strains contained 277.1 to 348.8 µg/g of sterols composed of 76% ergosterol and 24% fecosterol.Abbreviations MIC minimum inhibitory concentration - UV ultraviolet     

Antimicrobial effect of combinations of EDTA-Tris and amikacin or neomycin on the microorganisms associated with otitis externa in dogs

Combinations of EDTA-Tris and two aminoglycoside antibiotics (amikacin and neomycin) were tested for synergistic activities against the microorganisms associated with otitis externa in dogs and for the solutions' stability over time. Synergistic activity was observed when EDTA-Tris plus amikacin and EDTA-Tris plus neomycin were tested againstStaphylococcus intermedius, Proteus mirabilis, Pseudomonas aeruginosa, andEscherichia coli, but not againstCandida albicans. Stability studies over a 3-month period indicated that the test solutions were stable at room temperature and that their antimicrobial activity was maintained.Abbreviations CFU colony-forming units - EDTA (ethylenedinitrilo)tetraacetic acid, disodium salt - FIC fractional inhibitory concentration - MBC minimal bactericidal concentration - MIC minimal inhibitory concentration - Tris tris(hydroxymethyl)aminomethane