Azithromycin concentration in severely inflamed canine external ear canals - a case series

OBJECTIVE

To determine azithromycin concentration in severely inflamed canine external ear canals.

MATERIAL AND METHODS

Five dogs of various breeds and ages with severe and chronic otitis externa underwent ear canal reconstruction surgery. A single oral dose of azithromycin at 10 mg/kg was administered 12 to 24 hours prior to surgery. Tissue samples were collected from the excised external ear canals and azithromycin concentration was determined using a liquid chromatography-tandem mass spectrometry method.

RESULTS

Azithromycin concentrations ranging from 11.4 to 107.0 μg/g (mean 59.2 ± 44.6 μg/g, median 50.9 μg/g) were detected in the chronically infected external ear canal tissue 12 to 24 hours after administration.

CLINICAL SIGNIFICANCE

Little information exists on antibiotic concentrations in pathological tissues of dogs. Macrolides are known to concentrate in skin tissue. In light of the present results, investigation of clinical efficacy of azithromycin in chronic canine otitis externa is warranted.

Perivulvar dermatitis in a cat treated by episioplasty

Perivulvar dermatitis is common in obese, older female dogs that have infantile vulvae. Removing the excessive perivulvar skin folds by episioplasty has been recommended as the treatment of choice for perivulvar dermatitis in bitches. This report describes a case of perivulvar dermatitis in a cat that was treated by episioplasty. Ten days after surgery a substantial improvement was noticed, and 67 days later the skin in the perineal/perivulvar area appeared to be normal. The cat had not been given any medication. As in bitches, episioplasty in cats can be successful in reducing perivulvar dermatitis.

Zinc-responsive dermatosis in dogs: 41 cases and literature review

Forty-one cases of zinc-responsive dermatosis in the dog are described. The Siberian husky was the predominant breed affected. Periocular crusts were the most common clinical sign and parakeratosis was noted in the skin biopsy specimens of all dogs. Treatment with oral zinc ameliorated the clinical signs in most dogs, but cases necessitating other treatments such as parenteral zinc or retinoids are reported. The authors recommend a starting dose of 2-3 mg kg-1 elemental zinc per day in the treatment of this disorder.

Development of a polymerase chain reaction-based assay for the detection of Alternaria fungal contamination in food products

Alternaria sp. are important fungal contaminants of vegetable, fruit, and grain products, including Alternaria alternata, a contaminant of tomato products. To date, the Howard method, based on microscopic observation of fungal filaments, has been the standard examination for inspection of tomato products. We report development of a polymerase chain reaction (PCR)-based method for detection of Alternaria DNA. PCR primers were designed to anneal to the internal transcribed regions ITS1 and ITS2 of the 5.8S rRNA gene of Alternaria but not to other microbial or tomato DNA. We demonstrate use of the PCR assay to detect Alternaria DNA in experimentally infested and commercially obtained tomato sauce and tomato powder. Use of the PCR method offers a rapid and sensitive assay for the presence of Alternaria DNA in tomato products. The apparent breakdown of DNA in tomato sauce may limit the utility of the assay to freshly prepared products. The assay for tomato powder is not affected by storage time.