The human-canine environment: a risk factor for non-play bites?

Few dog bite risk factor studies have been conducted. This veterinary clinic-based retrospective cohort study was aimed at identifying human-canine environmental risk factors for non-play bites in Kingston, Jamaica (660) and San Francisco (SF), USA (452). Data were analysed using modified Poisson regression with confounders selected using directed acyclic graphs (DAGs) and the change-in-estimate procedure. Dogs acquired for companionship were more likely (RR=1.66; 95% CI 1.02-2.70) to bite than those acquired for protection. Routinely allowing a dog into the presence of visitors was also positively associated with it biting. A dog sleeping in a family member's bedroom was a risk factor for biting in Kingston (RR=2.54; 95% CI 1.43-4.54) but not in SF, while being able to leave the yard unaccompanied was a risk factor for biting in SF (RR=3.40; 95% CI 1.98-5.85) but not in Kingston. Overall, dogs which were less restricted in their interactions with humans were at elevated risk for biting. An observed association with dog bites in one cultural setting might not exist in another.     

Haemophilus somnus (Histophilus somni) in bighorn sheep.

Respiratory disease and poor lamb recruitment have been identified as limiting factors for bighorn-sheep populations. Haemophilus somnus (recently reclassified as Histophilus somni) is associated with respiratory disease in American bison, domestic sheep, and cattle. It is also harbored in their reproductive tracts and has been associated with reproductive failure in domestic sheep and cattle. Therefore, reproductive tract and lung samples from bighorn sheep were evaluated for the presence of this organism. Organisms identified as H. somnus were isolated from 6 of 62 vaginal but none of 12 preputial swab samples. Antigen specific to H. somnus was detected by immunohistochemical study in 4 of 12 formalin-fixed lung tissue samples of bighorn sheep that died with evidence of pneumonia. Notably, H. somnus was found in alveolar debris in areas of inflammation. The 6 vaginal isolates and 2 H. somnus isolates previously cultured from pneumonic lungs of bighorn sheep were compared with 3 representative isolates from domestic sheep and 2 from cattle. The profiles of major outer membrane proteins and antigens for all of the isolates were predominantly similar, although differences that may be associated with the host-parasite relationship and virulence were detected. The DNA restriction fragment length profiles of the bighorn-sheep isolates had similarities not shared with the other isolates, suggesting distinct phylogenetic lines. All of the isolates had similar antimicrobial profiles, but the isolates from the bighorn sheep produced less pigment than those from the domestic livestock, and growth of the former was not enhanced by CO2. Wildlife biologists and diagnosticians should be aware of the potential of these organisms to cause disease in bighorn sheep and of growth characteristics that may hinder laboratory detection.     

Otoscopic evaluation of the ear canal.

Otoscopic evaluation of the external ear canal and tympanic membrane is the first diagnostic procedure that should be performed in animals presented with otitis externa. It is important to become familiar with the normal structures of the ear to identify any abnormalities. The video otoscope greatly enhances visualization of these structures as well as aiding in retrieval of foreign bodies, biopsy of masses, and performance of a myringotomy. In some cases, a complete otoscopic examination is not possible on the first visit, and the animal may require anti-inflammatory medications or otic flushing to visualize the entire ear canal as well as the tympanic membrane. The purpose of the otoscopic examination is to address the otitis by evaluating the condition of the ear, looking for any masses or foreign bodies; noting the presence, consistency, and color of any exudate; and evaluating the patency of the tympanic membrane. Once a complete otic evaluation has been performed, additional diagnostics as well as a treatment plan can be formulated.     

Tetratrichomonas spp. and Pentatrichomonas hominis are not persistently detectable after intravaginal inoculation of estrous heifers

Virgin heifers (44) were intravaginally inoculated at estrus with low (10(6)) or high (10(8)) doses of live Tetratrichomonas sp., Pentatrichomonas hominis (P. hominis), or Tritrichomonas foetus (T. foetus). Controls were inoculated with Diamond's trypticase yeast extract maltose media. Genital infection was determined by culture of cervico-vaginal mucus (CVM) in Schneider's media and InPouch TF as well as by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP). The presence of trichomonads in fecal samples was determined by culture in Schneider's medium and PCR/RFLP. In CVM samples, tetratrichomonads were found by PCR/RFLP and Schneider's culture only sporadically at intermittent weeks. The presence of tetratrichomonads was not associated with the dose in the experimental vaginal inoculation since Tetratrichomonas sp. appeared more frequently in heifers inoculated with a low dose of tetratrichomonads than in heifers inoculated with a high dose of tetratrichomonads. Moreover, Tetratrichomonas spp. were isolated not only in heifers inoculated with tetratrichomonads but also in control heifers and in heifers inoculated with P. hominis. In feces, Tetratrichomonas spp. were frequently identified by culture in Schneider's and by PCR/RFLP in heifers of all groups. P. hominis was never found in CVM or feces by any method. Based on the common appearance of tetratrichomonads in feces and vaginal secretions, it appears that tetratrichomonads were detected periodically in the vagina of heifers as a consequence of repeated contamination from feces and not as a result of experimental infection. In summary, in this study, the strains of Tetratrichomonas sp. and P. hominis did not establish persistent infection in heifers.     

Variation in gross and histological appearance of the canine pars flaccida

The tympanic membrane is divided into the pars flaccida (PF) and pars tensa. Otoscopic differences in the appearance of the PF in the dog (flat vs. bulging) have been reported anecdotally. The purpose of this study was to histologically examine the canine PF to determine if differences exist between a flat and a bulging PF. We hypothesized that differences in the PF may be structural or due to an increased pressure in the middle ear. Four adult canine cadavers were used (two had bilateral bulging PF, two had bilateral flat PF). The ear specimens were fixed in 10% buffered neutral formalin, decalcified, routinely processed and stained with haematoxylin and eosin, toluidine blue (staining for mast cells), and Verhoeff-van Gieson (staining for elastic fibres). One blinded investigator evaluated each PF histologically. Seven ears (three with bulging PF, four with flat PF) were evaluated in the study. The PF was identified in all seven ears. No histological differences that distinguished a bulging PF from a flat PF were identified. Six ears were evaluated for the presence of mast cells and elastic fibres. Less than one mast cell per x40 field was identified in the PF in five of six ears. No elastic fibres were identified in any of the six PF. Based on the results of this study, it appears unlikely that there is a structural difference that accounts for a bulging PF. Therefore, there may be increased middle ear pressure in dogs with a bulging PF.     

Complementary effect of zoo compost with mineral nitrogen fertilisation increases wheat yield and nutrition in a low-nutrient soil

Excess nitrogen(N) fertiliser use in agriculture is associated with water pollution and greenhouse gas emissions.While practices and programs to reduce N fertiliser application continue to be developed,inefficient fertiliser use persists.Practices that reduce mineral N fertiliser application are needed in a sustainable agricultural ecosystem to control leaching and gaseous losses for environmental management.This study evaluated whether fully or partially replacing mineral N fertiliser with zoo compost(Perth Zoo) could be a good mitigation strategy to reduce mineral N fertiliser application without affecting wheat yield and nutrition.To achieve this,a glasshouse experiment was conducted to assess the complementary effect of zoo compost and mineral N fertiliser on wheat yield and nutrition in a sandy soil of southwestern Australia.Additionally,a chlorophyll meter was used to determine whether there was a correlation between chlorophyll content and soil mineral N content,grain N uptake,and grain protein content at the tillering(42 d after sowing(DAS)) and heading(63 DAS) growth stages.The standard practice for N application for this soil type in this area,100 kg ha^-1,was used with a soil bulk density of 1.3 g cm^-3 to calculate the amount of mineral N(urea,46% N) and Perth Zoo compost(ZC)(0.69% N) for each treatment.Treatments comprised a control(no nutrients added,T1),mineral N only(100 kg N ha^-1,T2),ZC only(100 kg N ha^-1,T7),and combinations of mineral N and ZC at different rates(mineral N at 100 kg N ha^-1+ ZC at 25 kg N ha^-1(T3),mineral N at 75 kg N ha^-1+ ZC at 25 kg N ha^-1(T4),mineral N at 75 kg N ha^-1+ ZC at 50 kg N ha^-1(T5),and mineral N at 50 kg N ha^-1+ ZC at 50 kg N ha^-1(T6)).The T6 treatment significantly increased grain yield(by 26%) relative to the T2 treatment.However,the T7 treatment did not affect grain yield when compared to the T2 treatment.All treatments with mineral N and ZC in combination significantly improved the 1 000-grain weight compared to the T2 treatment.Chlorophyll content was better correlated with soil mineral N content(r = 0.61),grain N uptake(r = 0.62),and grain protein content(r = 0.80) at heading(63 DAS) than at tillering(42 DAS).While ZC alone could not serve as an alternative to mineral N fertiliser,its complementary use could reduce the mineral N fertiliser requirement by up to 50% for wheat without compromising grain yield,which needs to be verified in the field.Chlorophyll content could be used to predict soil mineral N at the heading stage,and further studies are warranted to verify its accuracy in the field.Overall,the application of ZC as part of integrated nutrient management improved crop yield with reduced N fertiliser application.     

Polymer-coated rock mineral fertilizer has potential to substitute soluble fertilizer for increasing growth,nutrient uptake,and yield of wheat

More than half of the fertilizer applied to farmers’ field is lost, causing significant economic losses. To overcome this, a polymer-coated rock mineral fertilizer was investigated using...