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Biomedical subjects

E J Rosser

Publications and source records attributed to E J Rosser.

At least 19 recordsLinked to original sources
PubMed1996

Quantity and distribution of Malassezia organisms on the skin of clinically normal dogs.

OBJECTIVE: To define the extent to which Malassezia organisms can be recovered from the skin of clinically normal dogs and to assess differences in organism recovery related to anatomic sampling site and to method of collection. DESIGN: Prospective, controlled study. ANIMALS: 19 clinically normal dogs. PROCEDURE: The number of Malassezia pachydermatis organisms were determined in fungal cultures of samples obtained from the skin of clinically normal dogs, using an adhesive tape method to obtain samples from 10 sites/dog. Additionally, 3 methods (direct impression, swabbing technique, and superficial skin scraping) that are commonly used for obtaining samples for cytologic examination were evaluated. RESULTS: Malassezia organisms were found in low numbers as part of the microflora of the skin of clinically normal dogs. Number of organisms differed significantly for various anatomic locations (chin, highest number; inguinal and axillary regions, lowest number). Malassezia organisms were identified more frequently by use of adhesive tape and fungal culturing than by the methods used for cytologic examination. However, comparing methods used for obtaining samples for cytologic examination with each other, marked differences were not detected in our ability to recover yeast organisms among the 3 techniques. CLINICAL IMPLICATIONS: Although Malassezia spp is part of the microflora of the skin of clinically normal dogs, it is extremely difficult to detect the organism by any of the 3 sampling methods used for sample collection for cytologic examination. Therefore, anatomic site and method of sample collection should be considered when attempting to make a diagnosis of Malassezia dermatitis.

Animals↗
PubMed1995

Infectious crusting dermatoses.

Although there are numerous dermatoses in the horse in which the formation of crusts occurs, there are two relatively common and important infectious crusting dermatoses, namely, dermatophytosis and dermatophilosis. This article reviews the current concepts regarding the etiology and pathogenesis of each disease, as well as the more common clinical presentations, methods of diagnosis, and treatment.

Actinomycetales Infections↗
PubMed1993

Diagnosis of food allergy in dogs.

The diagnosis of food allergy was confirmed in 51 dogs while the responsiveness to a 60-day home-cooked restricted dietary trial (elimination-diet trial) was evaluated. The primary clinical sign of allergy detected and evaluated in all dogs was persistent and nonseasonally pruritic skin disease. The duration of time between starting the elimination-diet trial and remission of clinical signs was recorded. Dogs were then reexposed to diets that had been fed before testing, and the duration of time before pruritus recurred was recorded. The elapsed time during which dogs were being fed an elimination diet before remission of clinical signs was 1 to 3 weeks in 13 dogs, 4 to 6 weeks in 25 dogs, 7 to 8 weeks in 10 dogs, and 9 to 10 weeks in 3 dogs. Findings indicated that the recommendation of a 3-week elimination-diet trial for diagnosis of food allergy was adequate for only 25% of the dogs. It is recommended that test diets be fed for at least 10 weeks before a food allergy is ruled out.

Animal Feed↗
PubMed1993

Pharmacokinetics of L-thyroxine after its oral administration in dogs.

Twelve mature (5 sexually intact males, 4 castrated males, and 3 females) mixed-breed dogs were surgically thyroidectomized and used in a Latin-square design pharmacokinetic study of orally administered L-thyroxine. The dogs were treated with 44, 22, and 11 micrograms of L-thyroxine/kg as a single morning dose or in divided doses, morning and evening. Serum concentration of thyroxine (T4) was evaluated to determine a number of pharmacokinetic variables for comparison. Mean steady-state concentrations (Css) were determined from the area under the curve. Variables were analyzed for comparisons between dosages by use of ANOVA. Concentration at steady state was highest for dogs of the 44-micrograms/kg of body weight once-daily group and was lowest for dogs of the group given 11 micrograms/kg in 2 daily doses. Single daily administration resulted in higher Css, except at the 22-micrograms/kg/d dosage. Clearance was faster for the 22- and 44-micrograms/kg/d dosages than for the 11-micrograms/kg/d dosage. The half-life (t1/2) and mean residence time (MRT) also were shorter for the 44-micrograms/kg/d dosage, possibly indicating more rapid elimination of the drug at higher doses and dose-dependent kinetics. Perhaps, as the dogs' metabolism increased with higher iodothyronine concentrations, hormone degradation was accelerated. Interval (divided vs single dose) caused some expected changes: maximal concentration was higher and minimal concentration was lower when single administration was used. These undulations resulted in iodothyronine concentrations above the physiologic range for a number of hours, whereas concentration closer to physiologic ranges was achieved by use of divided doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1990

Serum and tissue cage fluid concentrations of ciprofloxacin after oral administration of the drug to healthy dogs.

Ciprofloxacin, a fluoroquinolone antimicrobial agent, was administered orally to 4 healthy dogs at dosage of approximately 11 and 23 mg/kg of body weight, every 12 hours for 4 days, with a 4-week interval between dosing regimens. Serum and tissue cage fluid (TCF) concentrations of ciprofloxacin were measured after the first and seventh dose of each dosing regimen. The peak concentration was greatest in the serum after multiple doses of 23 mg/kg (mean +/- SEM; 5.68 +/- 0.54 micrograms/ml) and least in the TCF after a single dose of 11 mg/kg (0.43 +/- 0.54 micrograms/ml). The time to peak concentration was not influenced by multiple dosing or drug dose, but was longer for TCF (6.41 +/- 0.52 hour) than for serum (1.53 +/- 0.52 hour). Accumulation of ciprofloxacin was reflected by the area under the concentration curve from 0 to 12 hours after administration (AUC0----12). The AUC0----12 was greatest in the serum after multiple doses of 23 mg/kg (31.95 +/- 1.90 micrograms.h/ml) and least in the TCF after a single dose of 11 mg/kg (3.87 +/- 1.90 micrograms.h/ml). The elimination half-life was not influenced by multiple dosing or dose concentration, but was greater for TCF (14.59 +/- 1.91 hours) than for serum (5.14 +/- 1.91 hours). The percentage of TCF penetration (AUCTCF/AUCserum) was greater after multiple doses (95.76 +/- 6.79%) than after a single dose (55.55 +/- 6.79%) and was not different between doses of 11 and 23 mg/kg. Both dosing regimens of ciprofloxacin resulted in continuous serum and TCF concentrations greater than 90% of the minimal inhibitory concentration for the aerobic and facultative anaerobic clinical isolates tested, including Pseudomonas aeruginosa.

Administration, Oral↗
PubMed1989

Serum and tissue fluid norfloxacin concentrations after oral administration of the drug to healthy dogs.

Norfloxacin, a 4-quinolone antibiotic, was administered orally to 4 healthy dogs at dosages of 11 and 22 mg/kg of body weight, every 12 hours for 4 days, with a 4-week interval between dosing regimens. Serum and tissue cage fluid (TCF) norfloxacin concentrations were measured at 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, and 12 hours after the first and seventh dose of each dosing regimen. When administered at a dosage of 11 mg/kg, the mean peak serum concentration (Cmax) was 1.0 microgram/ml at 1 hour, the time of mean peak concentration (Tmax) after the first dose. After the seventh dose, the Cmax was 1.4 micrograms/ml at Tmax of 1.5 hours. The Tmax for the TCF concentration was 5 hours, with Cmax of 0.3 microgram/ml and 0.7 microgram/ml after the first and seventh dose, respectively. When administered at a dosage of 22 mg/kg, the serum Tmax was 2 hours after the first dose, with Cmax of 2.8 micrograms/ml. After the seventh dose, the serum Tmax was 1.5 hours, with Cmax of 2.8 micrograms/ml. The Tmax for the TCF concentration was 5 hours after the first and seventh doses, with Cmax of 1.2 micrograms/ml and 1.6 micrograms/ml, respectively. After the seventh dose, the serum elimination half-life was 6.3 hours for a dosage of 11 mg/kg and was 6.7 hours for a dosage of 22 mg/kg. For serum concentration, the area under the curve from 0 to 12 hours (AUC0----12) was 8.77 micrograms.h/ml and 18.27 micrograms.h/ml for dosages of 11 mg/kg and 22 mg/kg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1988

Evaluation of the patient with otitis externa.

This article considers the history, physical examination, cytologic evaluation of smears and fungal and bacterial culture and sensitivity testing, clinical interpretation of information obtained from a biopsy of the external ear canal, and ancillary aids for the evaluation of the patient with otitis externa.

Animals↗
PubMed1988

Antipruritic drugs.

Symptomatic treatment of pruritus is an important adjunct to the systematic approach of attempting to define the etiology of a pruritic skin disease. This article includes a description of the various systemic and topical antipruritic preparations available to veterinary dermatologists as well as their recommended dosages.

Animals↗
PubMed1988

Bacterial population and histologic changes in dogs with perianal fistula.

Ages of 44 dogs with perianal fistula, ranged from 6 months to 13 years (mean, 5.2 years). German Shepherd Dogs and Irish Setters were statistically (P less than 0.01) over-represented compared with those breeds in a canine hospital population (n = 22,047) for the same period. There was a 2:1 male-to-female ratio, with 38 (86.4%) of dogs sexually intact and 6 (13.6%) of dogs neutered. Eleven types of bacterial organisms were recovered from deep perianal tissues of which Escherichia coli, Staphylococcus aureus, beta-hemolytic streptococci, and Proteus mirabilus were most common. Organisms were not recovered from 7 dogs. Of 93 isolates, 88.3% were susceptible to gentamicin, 80.5% to cephalothin, 79.2% to chloramphenicol, and 74% to trimethoprim-sulfamethoxazole. Fifty-one biopsy specimens from 44 dogs were classified as having early, intermediate-, and late-stage lesions based on the amount of fibrosis, severity of the inflammatory response, and, if present, depth of sinus tracts. In most biopsy specimens, all 3 stages were represented in the same histologic section. In 45 specimens, most inflamed lesions were in the dermis of the zona cutanea. Hidradenitis was present in 22 biopsy specimens and was associated with the formation of epithelial-lined sinus tracts.

Anal Canal↗
PubMed1988

Thyroid and immunologic status of dogs with perianal fistula.

Lymphocyte-proliferation responses, absolute lymphocyte counts, and thyrotropin-stimulation responses were determined in 33 dogs with perianal fistula; serum immunoglobulin values also were determined in 15 of the 33 dogs. Lymphocytes were stimulated with concanavalin A, pokeweed mitogen, and phytohemagglutinin and were cultured with medium containing normal pooled canine serum or fresh patient's autologous serum. Initially, lymphocytes from 9 dogs (27.3%) had depressed stimulation responses to greater than or equal to 1 phytomitogen, and 4 of the 9 dogs had absolute lymphopenia. One month after recovery in these 9 dogs, lymphocytes from 4 dogs (66.7%) had normal proliferation responses. Of immunoglobulin determinations in 15 dogs, serum IgA values were 32 to 185 mg/dl (mean, 69 +/- 10 mg/dl) and were low in 2 dogs (13%), and serum IgM values were 48 to 610 mg/dl (mean, 263 to 46 mg/dl) and were high in 8 dogs (53%). Serum IgG values were 1,050 to 3,220 mg/dl (mean, 2,339 +/- 165 mg/dl) and were high in 10 dogs (71%). After thyrotropin stimulation, 1 dog was considered hypothyroid. Neither pathogenesis nor prognosis of canine perianal fistula was clarified via immunoglobulin concentrations or absolute lymphocyte counts. Based on lymphocyte-proliferation assays, suppression of cell-mediated immunity was probably a result of perianal fistula, rather than a cause of the fistula.

Animals↗
PubMed1983

Cutaneous atypical mycobacteriosis in cats.

Cutaneous infection with atypical mycobacteria was observed in 6 cats. All cats had cutaneous or subcutaneous masses, with or without fistulous tracts. Diagnosis was determined by microbial culture. Transmission studies were done in 1 case. Treatment, which included antibiotics or surgery, or both, was usually unsuccessful, but remission without treatment did occur. In 3 cats available for long-term evaluation, there has been no recurrence of disease.

Animals↗