Search Results

Abstract

Objective—To compare reactivities to intradermal injection of extracts of Dermatophagoides farinae, Dermatophagoides pteronyssinus, house dust mite mix, and house dust in dogs suspected to have atopic dermatitis.

Design—Retrospective study.

Animals—115 dogs.

Procedures—Records of all dogs suspected to have atopic dermatitis that underwent intradermal testing between October 1996 and July 1998 were reviewed. Reactivities to intradermal injection of crude mixed house dust mite (1:25,000 wt/vol) and crude house dust (25 PNU/ml) extracts were compared with reactivities to intradermal injection of individual extracts of D farinae and D pteronyssinus (1:50,000 wt/vol).

Results—Ninety dogs were confirmed to have atopic dermatitis including 61 of the 69 dogs with positive reactions to either or both of the individual house dust mite extracts. Intradermal testing with the mixed house dust mite extract had sensitivity of 75%, specificity of 96%, and accuracy of 83%. Intradermal testing with the house dust extract had sensitivity of 30%, specificity of 93%, and accuracy of 56%.

Conclusions and Clinical Relevance—Results suggest that use of crude mixed house dust mite and crude house dust extracts for intradermal testing in dogs is not as accurate a method of determining house dust mite hypersensitivity as is the use of individual D farinae and D pteronyssinus extracts mainly because of the high percentage of false-negative results. Extracts of individual house dust mites are recommended for intradermal testing of dogs suspected to have atopic dermatitis. (J Am Vet Med Assoc 2000;217:536–540)

Abstract

Objective—To use an amplified ELISA technique to document the presence and quantify the concentration of the house dust mite allergen, Der f 1, in skin and coat dust samples collected from dogs.

Animals—29 pet dogs of various breeds.

Procedure—Dogs were weighed, and body surface area in square meters was determined. Skin and coat dust samples were obtained by vacuuming dogs. Collected dust was analyzed by use of standard and amplified ELISA techniques.

Results—By use of the standard ELISA technique, Der f 1 was detected in skin and coat dust samples from 6 of 29 (21%) dogs. Mean concentration of Der f 1 in the 6 samples with positive assay results was 16.16 ng/mL (range, 5.61 to 31.24 ng/mL). Samples with negative assay results were retested for dust mite allergen by use of an amplified ELISA technique; an additional 14 dogs had positive assay results. Mean concentration of allergen was 0.36 ng/mL (range, 0.19 to 2.20 ng/mL). Combining both techniques, 20 of 29 (69%) dogs had positive assay results for Der f 1.

Conclusions and Clinical Relevance—Results of our study indicate that house dust mite allergens are present on the skin and in the coat of dogs, and this source of allergen may act as a reservoir for allergen exposure in hypersensitive dogs. Use of an amplified ELISA technique to determine environmental concentrations of house dust mite allergens in homes and on dogs will help to identify the relationship between immunologic findings and environmental exposures in dogs with atopic dermatitis. (Am J Vet Res 2003;64:162–165)

Abstract

Objective—To compare clinical efficacy of pulse administration with itraconazole versus once daily administration for the treatment of cutaneous and otic M pachydermatis infection in dogs.

Design—Randomized controlled trial.

Animals—20 dogs.

Procedure—Dogs were treated with itraconazole orally (n = 10/group), using a pulse administration regimen (5 mg/kg [2.3 mg/lb], PO, q 24 h for 2 consecutive days per week for 3 weeks) or once daily administration (5 mg/kg, PO, q 24 h for 21 days). No other treatment was permitted. On days 0 and 21, clinical severity of cutaneous and otic disease was assessed, and samples were collected for cytologic examination and yeast culture. Cytology (sum of the mean number of yeast organisms per oil immersion field for affected sites) and culture (mean of the score for extent of yeast growth for samples from affected sites) scores were calculated.

Results—For dogs in both treatment groups, clinical severity of cutaneous and otic disease was significantly decreased by day 21, but decrease in severity was not significantly different between groups. Similarly, skin cytology, skin culture, and ear culture scores were significantly decreased on day 21, compared with day 0, for both groups, but decreases were not significantly different between groups except that dogs in the pulse administration group had a significantly greater decrease in ear culture scores than did dogs in the daily administration group. However, when cytology scores only for ear samples were analyzed, day 21 score was not significantly decreased, compared with day 0 score, for either group.

Conclusions and Clinical Relevance—Results suggested that both pulse administration and once daily administration of itraconazole were efficacious in the treatment of M pachydermatis cutaneous infection in dogs. However, adjunctive treatment may be needed in dogs with M pachydermatis otitis. (J Am Vet Med Assoc 2002;220:1807–1812)

Abstract

Objective—To determine the prevalence of late-phase reactions to intradermal testing with Dermatophagoides farinae in healthy dogs and dogs with atopic dermatitis and an immediate reaction to D farinae.

Animals—6 healthy dogs and 20 dogs with atopic dermatitis and immediate reactions to D farinae.

Procedure—Intradermal tests were performed with D farinae at 1:1,000 wt/vol and 1:50,000 wt/vol concentrations, and skin reactivity was evaluated after 0.25, 6, and 24 hours. Serum D farinae-specific IgE antibodies were assayed. Extent of lesions (atopy index) and pruritus (visual analogue scale) were evaluated in dogs with atopic dermatitis.

Results—Late-phase reactions were observed in healthy dogs at 6 hours (n = 2 dogs) and 24 hours (1) with the 1:1,000 wt/vol concentration, and at 6 hours (1) and 24 hours (1) with the 1:50,000 wt/vol concentration of allergen. Late-phase reactions in healthy dogs were only observed in dogs with an immediate reaction to D farinae. Late-phase reactions were observed in 11 of 20 dogs with atopic dermatitis at 6 and 24 hours with the 1:1,000 wt/vol concentration and in 10 of 20 at 6 and 24 hours with the 1:50,000 wt/vol concentration of allergen. There was no difference in mean atopy index, mean visual analogue scale of pruritus, or mean serum D farinae-specific IgE concentration of dogs with a late-phase reaction, compared to dogs without a late-phase reaction.

Conclusion and Clinical Relevance—Late-phase reactions may be observed after an immediate reaction to intradermal skin testing in healthy and allergic dogs but are more commonly observed in dogs with atopic dermatitis. (Am J Vet Res 2002;63:69–73)

Abstract

Objective—To determine whether staphylococcal isolates cultured from pustules and carriage sites in dogs with superficial bacterial folliculitis were genotypically the same strain by use of pulsed-field gel electrophoresis (PFGE).

Animals—40 dogs with superficial bacterial folliculitis.

Procedures—Samples were obtained from 3 pustules and 3 carriage sites (anus, axillary skin, and nasal mucosa). Bacterial culture, morphologic identification, Gram staining, catalase and coagulase tests, speciation, and PFGE were performed.

Results—Of 246 isolates, 203 were Staphylococcus intermedius, 5 were Staphylococcus aureus, 15 were Staphylococcusspp, and 22 were coagulase-negative staphylococcal isolates. No dog had an isolate with the same PFGE pattern as an isolate from another dog. Coagulase-positive isolates from multiple pustules and multiple carriage sites had the same PFGE pattern in 37 of 39 (94.9%) and 22 of 39 (56.4%) dogs, respectively. Coagulase-positive staphylococcal isolates from at least 1 pustule had the same PFGE pattern as an isolate from at least 1 carriage site in 34 of 36 (94.4%) dogs. Ninety-seven of 116 (83.6%) coagulase-positive staphylococcal isolates from pustules had the same PFGE pattern as an isolate from at least 1 carriage site. Sixty-nine of 91 (75.8%) coagulase-positive staphylococcal isolates from carriage sites had the same PFGE pattern as an isolate from at least 1 pustule.

Conclusions and Clinical Relevance—Coagulasepositive staphylococcal strains were heterogeneous among dogs with superficial bacterial folliculitis. In individual dogs, strains from multiple pustules were genotypically the same, and strains from pustules were genotypically the same as strains from carriage sites.

Abstract

Objective—To determine whether coagulase-positive staphylococcal isolates that are genotypically the same strain obtained from pustules and carriage sites of individual dogs with superficial bacterial folliculitis have the same antimicrobial susceptibility phenotype.

Animals—40 dogs with superficial bacterial folliculitis.

Procedures—Samples were obtained from 3 pustules and 3 carriage sites (ie, anus, nonlesional axillary skin, and nasal mucosa) for bacterial culture, morphologic identification, Gram staining, catalase and coagulase testing, antimicrobial susceptibility testing, speciation, and pulsed-field gel electrophoresis (PFGE).

Results—223 isolates from pustules and carriage sites were included. Seventeen susceptibility phenotypes were found among isolates. One hundred twenty-eight (100%) isolates from pustules and 95 (100%) isolates from carriage sites were susceptible to cephalothin; 128 (100%) isolates from pustules and 94 (98.9%) isolates from carriage sites were susceptible to amoxicillin-clavulanic acid; 114 (89.1%) isolates from pustules and 82 (86.3%) isolates from carriage sites were susceptible to erythromycin and lincomycin hydrochloride; and 103 (80.5%) isolates from pustules and 70 (73.7%) isolates from carriage sites were susceptible to trimethoprim-sulfamethoxazole. In 37 of 39 (94.9%) dogs, isolates with the same PFGE pattern from multiple pustules had the same susceptibility phenotype. In 21 of 33 (63.6%) dogs, isolates from multiple carriage sites with the same PFGE pattern had the same susceptibility phenotype.

Conclusions and Clinical Relevance—In dogs with superficial bacterial folliculitis, most coagulase-positive staphylococcal isolates from pustules that are genotypically the same strain will have the same susceptibility phenotype and treatment may be based on empiric antimicrobial selection or susceptibility testing of 1 lesional isolate.

Abstract

Objective—To determine the concentration of house dust mite (HDM) allergens, Der f 1 and group 2, on the skin and hair of dogs and whether associations exist between the presence of Der f 1 and group 2 allergens on the skin and hair of dogs and household and dog characteristics.

Animals—63 pet dogs from 50 homes.

Procedure—Dogs were weighed and body surface area in square meters was determined. Skin and hair samples were obtained by vacuuming dogs. Collected dust was analyzed by use of standard ELISA techniques.

Results—HDM allergen was detected in 21 of 59 skin and hair samples. Presence of group 2 allergen on skin and hair of dogs was significantly associated with long hair, compared with short or medium length hair. Median house dust sample concentrations of Der f 1 and group 2 allergens were high in homes with dogs that had skin and hair samples that were positive for Der f 1 and group 2 allergens. Dogs with skin and hair samples that were positive for Der f 1 and group 2 allergens resided in homes with a high number of house dust samples that were positive for Der f 1, group 2, or both allergens and in homes with a mean house dust sample allergen concentration of ≥ 2 µg/g of dust.

Conclusions and Clinical Relevance—Associations exist between environmental HDM allergen concentrations and HDM allergens on the skin and hair samples of dogs. Environmental allergen load is a major factor in accumulation of allergens on the skin and hair of dogs. (Am J Vet Res 2005;66:143–149)

Abstract

Objective—To compare results of intradermal tests (IDT), conducted using environmental allergens, in horses without atopy and horses with chronic obstructive pulmonary disease (COPD).

Animals—38 horses (22 horses without atopy and 16 horses with COPD).

Procedure—All horses were examined (physical examination, hematologic examination, serum biochemical analyses, examination of bronchoalveolar lavage fluid). An IDT was conducted, using a full panel of 73 allergens consisting of grasses, weeds, trees, molds, and insects. Results of the IDT were evaluated 30 minutes and 4, 6, and 24 hours after injection of allergens. Horses without atopy were euthanatized, and gross and histologic changes of lung parenchyma were assessed.

Results—Horses without atopy had a greater number of positive immediate and late-phase reactions than did horses with COPD. Horses with COPD did not have a significantly greater number of positive reactions than horses without atopy at any time period for any allergen group (grasses, weeds, trees, molds, and insects).

Conclusions and Clinical Relevance—Positive results of IDT document allergen-specific hypersensitivity but do not necessarily distinguish clinically relevant reactions from subclinical reactivity in horses with COPD. Interpreting the clinical relevance of results of IDT requires a thorough knowledge of the medical history, physical examination findings, and environment of each animal. (Am J Vet Res 2001;62:389–397)

Abstract

Objective—To compare results of intradermal tests (IDT) for environmental allergens at 30 minutes and 4, 6, and 24 hours after injection in horses without atopy and horses with atopic dermatitis (AD) or recurrent urticaria (RU).

Animals—22 horses without atopy, 10 horses with RU, and 7 horses with AD.

Procedure—In all horses, medical history was obtained, and results of physical examination, hematologic examination, serum biochemical analyses, examination of bronchoalveolar lavage fluid, and IDT with 73 allergens were examined.

Results—Horses with AD or RU had a significantly greater mean number of positive reactions for IDT, compared with horses without atopy. Horses with AD had a significantly greater number of positive reactions than horses without atopy in every allergen group at all time periods, except for molds at 4 and 24 hours. Horses with RU had a significantly greater number of positive reactions than horses without atopy in every allergen group, except for molds at 30 minutes and 4 and 6 hours, trees at 4 and 6 hours, and grasses at 4 hours.

Conclusions and Clinical Relevance—A significantly greater number of positive reactions for IDT in horses with AD or RU, compared with horses without atopy, provides evidence of type-I IgE-mediated hypersensitivity for these diseases. Evaluation of results of IDT performed in horses with AD or RU is useful in determining specific allergens for the formulation of immunotherapy along with providing identification of allergens that could be useful when creating avoidance strategies. (Am J Vet Res 2001;62:1051–1059)