Ciprofloxacin as a representative of disk diffusion in vitro susceptibility of enrofloxacin for bacterial organisms from the middle-ear tissue of dogs with end-stage otitis externa

The purposes of this study were to determine whether ciprofloxacin disk diffusion susceptibility test (DDT) results could be used to assess the in vitro susceptibility of otic bacterial organisms to enrofloxacin and to determine the effect of concurrent enrofloxacin administration on the DDT results for enrofloxacin and ciprofloxacin. Thirty dogs with end-stage otitis externa undergoing unilateral total ear canal ablation were enrolled. The dogs were randomized to one of four enrofloxacin-treatment groups or to the control group. Each dog in the treatment groups received two intravenous doses of enrofloxacin prior to surgical removal of the middle-ear tissue while the control group did not receive any enrofloxacin. One dog was excluded from the study as no middle-ear tissue was removed during surgery. Twenty-four dogs were in the enrofloxacin-treatment groups and five dogs were in the control group. In 12 of 29 dogs (41.4%), 14 of 82 (17.1%) of bacteria had discrepancies in DDT results for enrofloxacin and ciprofloxacin. Discrepancies between the control group and treatment groups were not significantly different even though the percentage of discrepancies for the combined treatment group was 19.4% compared to 6.7% for the control group. In this study, ciprofloxacin DDT results were not an accurate indicator of the in vitro susceptibility of enrofloxacin for bacteria isolated from the middle-ear tissue of dogs with end-stage otitis.     

Control of feral cats on sub-Antarctic Marion Island, Indian Ocean

Since their introduction in 1949, feral cats have caused extensive damage to seabird populations on sub-Antarctic Marion Island, Indian Ocean. This paper reports on the first four years of an eradication programme launced in 1986. Eight hundred and seventy-two cats were shot dead and 80 trapped during 14 725 hours of hunting. Cats sighted per hour of night hunting and kills per hour decreased dramatically. Hunting success (cats killed as a proportion of those seen) decreased. The only reliable indication of the decrease in density as a result of hunting was the decrease in the number of cats seen per hour of night hunting. By the end of the third season it was apparent that hunting alone was no longer removing sufficient animals to maintain the population decline, and trapping was incorporated into the eradication programme.     

Comparison of surgical techniques for synovectomy in New Zealand White rabbits with induced inflammatory arthritis

OBJECTIVE: To compare effects of synovectomy performed by use of monopolar radiofrequency energy (MRFE) versus mechanical debridement in rabbits with induced inflammatory arthritis. ANIMALS: 25 mature female New Zealand White rabbits. PROCEDURE: Inflammatory arthritis was induced in both femoropatellar joints of each rabbit. Joints then were treated by mechanical debridement or MRFE treatment or served as sham-operated controls. Rabbits were euthanatized 2 weeks or 3 months after surgery. Biopsy specimens of synovium were analyzed by use of light microscopy. RESULTS: At 2 weeks after surgery, samples from MRFE-treated joints had fewer plasma cells and more heterophils than the other 2 groups and more lymphocytes than sham-operated controls, whereas samples from mechanically debrided joints had greater numbers of lymphocytes and heterophils than sham-operated controls. At 3 months after surgery, samples from MRFE-treated joints had fewer plasma cells than sham-operated controls, more heterophils than mechanically debrided and sham-operated controls, and more macrophages than mechanically debrided joints. There was no difference in synovial ablation, synovial proliferation, or fibrosis among the 3 groups at 2 weeks or 3 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results of this study documented a similar degree of synovial ablation when comparing use of MRFE to mechanical debridement. In rabbits with this method of induced inflammatory arthritis, there were no detectable benefits of MRFE or mechanical debridement on the synovium, compared with results for sham-operated control joints, at 2 weeks and 3 months after surgery for most of the synovial variables evaluated.     

Quantitation of house dust mites and house dust mite allergens in the microenvironment of dogs

OBJECTIVE: To quantitate the density of Dermatophagoides farinae and D pteronyssinus and concentrations of house dust mite (HDM) allergens (Der f 1, Der p 1, and Group 2 allergens) in the indoor microenvironment of dogs. SAMPLE POPULATION: 50 homes in Columbus, Ohio. PROCEDURES: In each home, samples of dust were collected from 3 locations in which dogs spent most time. Whenever possible, the species of mites collected was identified. Mite density (mites/g of dust) was assessed, and allergen concentrations were assayed by standardized ELISAs. Relative humidity and temperature in each home were monitored during a 5-day period. Characteristics of homes and sample sources were evaluated. RESULTS: Dust samples from all 50 homes contained > or = 1 HDM allergen; Der f 1 and Der p 1 were detected in 100 and 74% of homes, respectively. Fifteen homes had HDMs; compared with D pteronyssinus, D farinae was found more commonly (14/15 homes) and at a higher density. Basements, homes without central air-conditioning, and dog beds that were > or = 1 year old had high HDM allergen concentrations. Homes with > or = 2 microg of Der f 1 or Group 2 allergens/g of dust or > or = 100 mites/g of dust were significantly more likely to have a maximum relative humidity > or = 75%. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated the presence of HDMs and HDM allergens in the specific microenvironment of dogs in homes. Factors associated with high levels of exposure were identified, which may be associated with increased risk for sensitization and development of atopic diseases.     

Late-phase reactions to intradermal testing with Dermatophagoides farinae in healthy dogs and dogs with house dust mite-induced atopic dermatitis

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: ntradermal 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. CONCLUSIONS 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.     

Detection of trichomonad species in the reproductive tracts of breeding and virgin bulls

Trichomoniasis is a sexually transmitted disease of cattle and a large bowel diarrheal disease of cats caused by Tritrichomonas foetus. Recently, other species of trichomonads have been identified from the prepuce of virgin bulls. It is not clear whether these non-T. foetus isolates are common (nor) or is it clear whether they are also present on the prepuce of breeding bulls. To answer these questions, we first developed an immunofluorescent assay (IFA) with T. foetus-specific monoclonal antibodies for comparison with a T. foetus-specific PCR assay. Results showed that all PCR positive isolates were also IFA positive, whether the isolates were from cats or cattle and PCR negative isolates were IFA negative. Bovine non-T. foetus (non-Tf) trichomonad isolates were detected by both assays in 14 virgin bulls, 10 breeding bulls, 21 bulls of undetermined breeding status (presumably breeding bulls) and 2 cows. These isolates from virgin bulls were mostly Tetratrichomonas spp. whereas the non-Tf isolates from most breeding bulls and the two cows were Pentatrichomonas hominis. All T. foetus isolates were from breeding bulls or bulls of undetermined breeding status. This IFA test which discriminates between T. foetus and non-Tf may be useful as a diagnostic assay, since no effective legal treatment is available, bulls positive for T. foetus are culled. With increasing reports of T. foetus large bowel infection in cats, these monoclonal antibodies may also be useful for diagnosis of feline infection. Since two isolates of non-Tf trichomonads were obtained vaginas of breeding cows, it may be that these parasites are sexually transmitted like pathogenic T. foetus.     

In vitro activity of an ear rinse containing tromethamine, EDTA, benzyl alcohol and 0.1% ketoconazole on Malassezia organisms from dogs with otitis externa

The purpose of this study was to evaluate the in vitro activity of an ear rinse containing tromethamine, EDTA, benzyl alcohol and 0.1% ketoconazole in purified water on Malassezia organisms from dogs with otitis externa. Malassezia organisms were collected from ear swab samples from the external ear canal of 19 dogs with otitis externa plus one control strain of Malassezia pachydermatis. Three test solutions were evaluated: ER (EDTA, tromethamine, benzyl alcohol), ER + keto (EDTA, tromethamine, benzyl alcohol, ketoconazole), and H2O (purified water). Ten-millilitre aliquots of each test solution was transferred into 20 tubes and inoculated with one of the isolates (1 tube per isolate: 19 clinical and 1 control strain). Samples were retrieved from each tube at five time points (0, 15, 30, 45 and 60 min), transferred to Petri dishes, mixed with Sabouraud dextrose agar supplemented with 0.5% Tween 80 and incubated. Following incubation, the plates were examined for growth and colonies counted as colony-forming units per millilitre. The data were analysed using a repeated measures analysis, with pair-wise comparisons of solution-time combinations. There was a significant reduction in Malassezia growth in ER + keto at all time points (P < 0.0001) compared to time zero. Neither ER nor H2O had any effect on the growth of Malassezia. ER + keto was significantly more effective in reducing Malassezia growth (P < 0.0001) at all time points compared to both ER and H2O. ER + keto may be useful in the treatment of Malassezia otitis externa. Future studies should be performed to evaluate the in vivo efficacy of ER + keto as treatment for otic infections caused by Malassezia.     

Mycorrhizal fungi of Eucalyptus in the North Island of New Zealand

Fungal sporocarps of Hydnangium carneum Wallr., Laccaria laccata (Scop. ex Fr.) Berk. ex Br., Scleroderma spp, Hymenogaster spp., Hysterangium spp, Cortinarius spp, etc. were found to be associated with five species of eucalypts Eucalyptus delegatensis R.T. Bak., E. regnans F. Muell., E. nitens Maiden, E.fastigata Deane et Maiden, and E. saligna Sm.) in nurseries or stands in the North Island of New Zealand.A total of 5345 mycorrhizal pieces were plated out in isolation studies. More than 47% of these pieces remained free of fungal outgrowth, 16% yielded dark sterile mycelia, 7% yielded hyaline sterile fungi, 17% produced sporing Fungi Imperfecti, 5.8% were basidiomycetous fungi identified as H. carneum, Scleroderma spp, Paxillus sp. and Hymenogaster albus (Klotzsch) Berk. et Br., and 5.9% were unidentified basidiomycetes.Mycorrhizas were synthesized on eucalypt seedlings by 12 identified basidiomycetes which form sporocarps in eucalypt stands and 12 unidentified basidiomycetes isolated from the mycorrhizas. Under the test conditions two Cortinarius spp and one unidentified basidiomycete did not form mycorrhizas.The results indicate a possible importance of H. carneum as a mycorrhizal fungus of eucalypts in the North Island of New Zealand.