Antimicrobial testing of selected fluoroquinolones against Pseudomonas aeruginosa isolated from canine otitis.

A total of 100 Pseudomonas aeruginosa (P. aeruginosa) isolates were collected over a 1.5-year period from cases of canine otitis. Sensitivities to enrofloxacin, marbofloxacin, and orbifloxacin were determined using minimum inhibitory concentration testing (MICT). Isolates were also tested for sensitivities to enrofloxacin and marbofloxacin using disk-diffusion susceptibility testing (DDST). Isolates were significantly more sensitive to marbofloxacin than to enrofloxacin (z = -4.57; P<0.05) or orbifloxacin (z = -5.02; P<0.05). Agreement was 87% between MICT and DDST for marbofloxacin, with approximately equal numbers of overestimation and underestimation errors. Agreement was 74% between MICT and DDST for enrofloxacin, but DDST tended to overestimate the number of enrofloxacin-susceptible strains. These results suggest that marbofloxacin is more effective against P. aeruginosa than either enrofloxacin or orbifloxacin and that relying on DDST may lead to ineffective enrofloxacin treatment.

Diseases of the ear pinna.

In conclusion, there are a wide variety of dermatologic diseases that can affect the ear pinnae. Most of these disorders are manifestations of a generalized dermatosis. Therefore, when pinnal lesions are present, a thorough diagnostic workup is indicated.

Diaphragmatic and perineal hernias associated with cutaneous asthenia in a cat.

An 11-year-old cat was evaluated because of dyspnea. Since 11 months of age, the cat had hyperextensibility of the skin consistent with cutaneous asthenia. Radiographic examination revealed a diaphragmatic hernia with intestinal loops in the thorax. Electron microscopic examination of skin specimens revealed collagen fibers of highly variable diameter, consistent with cutaneous asthenia. The diaphragmatic hernia was surgically repaired and healed well. Four weeks later, a left-sided perineal hernia was repaired surgically, and 4 months later, a right-sided perineal hernia was repaired surgically and colopexy and cystopexy were performed. All surgical procedures were successful and tissues healed well. Dermatosparaxis is a rare hereditary disorder that commonly results in cutaneous fragility and hyperextensibility in affected animals. The diagnosis depends on clinical findings and light and electron microscopic changes in affected tissues. Surgical repair can be performed successfully in an affected cat, and healing of incisions can occur without complications.

Evaluation of the effect of pH on in vitro growth of Malassezia pachydermatis.

The purpose of this study was to evaluate the effects of pH on the growth of canine Malassezia pachydermatis isolates in vitro. Yeast growth was monitored by measuring the optical density with a spectrophotometer. The growth of American Type Culture Collection and field strains of M. pachydermatis was optimal between the pH values of 4.0 and 8.0, and inhibited at the ranges of 1.0 to 3.0 and 9.0 to 10.0. An analysis of covariance showed no significant differences among the growth curves at pH levels 5.0 to 8.0. Although specific contrast tests showed that the growth slope at pH 4.0 was significantly different from that at pH 5.0 to 8.0, only small, random differences were found when the growth slope at pH 4.0 was compared to the individual slopes at pH 5.0, 6.0, 7.0, and 8.0. The findings of this study suggest that topical acidifying products could be beneficial therapeutic options for cutaneous yeast infections in dogs.

The effects of four acidifying sprays, vinegar, and water on canine cutaneous pH levels.

This study determined the extent and duration of cutaneous acidification caused by a single application of four acidifying sprays, vinegar, and water. Multivariate repeated measures analysis of variance revealed a significant difference between the six sprays (F = 15.3; P < or = 0.001). Linear contrast tests showed that the effects of the acidifying sprays were significantly different from vinegar and water (F = 6.0; P < or = 0.001), and vinegar was significantly different from water (F = 13.8; P < or = 0.001). The acidifying sprays decreased cutaneous pH to < 6.0 for a mean range of 50 to 65 hours, while vinegar did so for a mean of 12 hours.

A comparative review of cutaneous pH.

This review describes the role of pH in cutaneous structure and function. We first describe the molecules that contribute to the acidity or alkalinity of the skin. Next, differences in cutaneous pH among species, among individuals of the same species and within individuals are described. The potential functions of cutaneous pH in normal and diseased skin are analysed. For example, cutaneous pH has a role in the selection and maintenance of the normal cutaneous microbiota. In addition, cutaneous acidity may protect the skin against infection by microbes. Finally, there is evidence that a cutaneous pH gradient activates pH-dependent enzymes involved in the process of keratinization.