Australian Veterinary Journal最新文献

With recent outbreaks of foot-and-mouth disease (FMD) in Indonesia and Bali, industry, government and public concern for its incursion into Australia is increasing. The potential impact of an outbreak on the agricultural industry and national economy could be devastating. To date, research conducted in relation to FMD in Australia predominantly concerns simulations and models performed to predict various outcomes. This project critically appraises the current literature regarding the simulated use of vaccination and its effectiveness for controlling the spread of FMD in Australia in the event of an outbreak. Findings from 10 modelling studies suggest that vaccination is effective at controlling the size and duration of an outbreak (under certain conditions), however, there is less clarity about cost-effectiveness.

Substantiated incidents of poor welfare affecting cattle, sheep and goats (livestock) in non-dairy extensive farming systems continue to occur. This study sought to describe the common causes of poor welfare of livestock and the associated circumstances, by analysing 39 years of de-identified, livestock welfare investigation records. There were a total of 2179 alleged offenders (AOff), defined as individual/s that had an incident of poor welfare affecting livestock on at least one occasion. Approximately 27% of AOff were found to have poor welfare on more than one occasion. The majority of livestock welfare incidents were associated with neglect, more specifically, inadequate nutrition (56%), treatment (65%) and management/husbandry (83%). Records of malicious acts were rare (1%). In the analysis, cases were allocated to 10 animal welfare severity categories (AWSC) based on the number of incidents and visits, whether the AOff reoffended, or if the incident was ongoing and whether the welfare issue was likely to affect the whole herd. A significantly higher proportion of cases in the most severe AWSC had a failure to shear, mark, dip/drench, draft and wean/cull, were overstocked or were not providing proper and sufficient feed, compared to the least severe AWSC (P ≤ 0.05). Reoffending was significantly more likely when animals were found to be injured/unwell, recumbent, stuck in mud/yard/pen or in poor body condition, or when there was a failure to wean/cull, mark, dip/drench and draft. Some of the issues identified here may be risk factors more commonly identified on farms with poor livestock welfare.

Antimicrobial resistance (AMR) is an emerging human and animal issue. The frequency of resistance to high importance antimicrobials, isolation of microbes of One Health importance and the nature and frequency of multi-drug resistant (MDR) profiles in Australian small animal referral practice have not been described previously. Medical databases of two private small animal referral hospitals in Queensland, Australia were reviewed for culture and susceptibility (C&S) results from 1 January to 31 December 2020. Hospital site (H1 and H2), culture sample, C&S results and MDR were documented for samples from services operating at both locations. There were 631 microbial isolates and 386 susceptibility profiles from 438 samples. The predominant organism was Staphylococcus pseudintermedius at H1 (n = 95) and Escherichia coli at H2 (n = 23). The majority of samples were integumentary (H1 n = 216, H2 n = 75) or urogenital (H1 n = 74, H2 n = 70). MDR isolates were reported at both hospitals, and were significantly more likely at H1 (69/262, 26.3% vs. 12/121, 9.9%; P < 0.001). High levels of AMR including MDR profiles were reported at the two hospitals evaluated, but they had significantly different resistance patterns and microbial profiles. These results highlight the need to practice appropriate antimicrobial stewardship in veterinary medicine, and are supportive for individual hospital surveillance with antibiograms.

A number of methods are currently used to predict the optimal date of insemination of the breeding bitch, particularly with the use of frozen–thawed canine semen which has a far shorter lifespan than fresh semen. Aside from confirming cytological oestrus, vaginal cytology is of no assistance in predicting the most fertile day(s) in a bitch; however, a neglected avenue of research suggests that vaginal cytology may be of great importance in confirming the days of optimal fertility retrospectively. Similarly, vaginoscopy provides clues as to the stage of a bitch's cycle but is inadequate as a sole determinant of her most fertile days. Nevertheless, vaginoscopy is useful to identify very late oestrus and the onset of dioestrus, as well as Stage I of labour (cervical dilatation). Due to variations in the rate at which circulating progesterone concentrations rise in individual bitches, the reliability of circulating progesterone concentrations for determining the optimal day(s) of insemination with frozen–thawed semen decreases as values rise. Moreover, progesterone assay results can vary widely due to extrinsic factors such as the time of blood sampling, sample storage conditions and the assay employed. Finally, this review investigates evidence surrounding various insemination routes and suggests that well-performed vaginal insemination, even with frozen–thawed semen, may be an acceptable approach for cases where transcervical insemination is impractical.

A healthy chicken's intestinal flora harbours a rich reservoir of Escherichia coli as part of the commensal microbiota. However, some strains, known as avian pathogenic E. coli (APEC), carry specific virulence genes (VGs) that enable them to invade and cause extraintestinal infections such as avian colibacillosis. Although several VG combinations have been identified, the pathogenic mechanisms associated with APEC are ill-defined. The current study screened a subset of 88 E. coli isolates selected from 237 pre-existing isolates obtained from commercial poultry flocks in Australia. The 88 isolates were selected based on their enterobacterial repetitive intergenic consensus (ERIC) and antimicrobial resistance (AMR) profiles and included 29 E. coli isolates cultured from chickens with colibacillosis (referred to as clinical E. coli or CEC) and 59 faecal E. coli (FEC) isolates cultured from clinically healthy chickens. The isolates were screened for the presence of 35 previously reported VGs. Of these, 34 were identified, with iucA not being detected. VGs focG, hlyA and sfa/foc were only detected in FEC isolates. Eight VGs had a prevalence of 90% or above in the CEC isolates. Specifically, astA (100%); feoB (96.6%); iutA, iss, ompT, iroN and hlyF (all 93.1%); and vat (89.7%). The prevalence of these were significantly lower in FEC isolates (astA 79.7%, feoB 77.9%, iutA 52.5%, iss 45.8%, ompT 50.9%, iroN 37.3%, hlyF 50.9% and vat 42.4%). The odds ratios that each of these eight VGs were more likely to be associated with CEC than FEC ranged from 7.8 to 21.9. These eight VGs may be used to better define APEC and diagnostically detect APEC in Australia. Further investigations are needed to identify the roles of these VGs in pathogenicity.

Canine adrenal gland volume can be predicted based on body weight and computed tomography (CT) measurements using a validated algorithm. Use of this algorithm to detect adrenal pathology, including hyperplasia, hypoplasia and neoplasia, in clinical cases has not been described. The objective of this study was to illustrate application of the algorithm by estimating subject-specific adrenal gland volume in a historical cohort of dogs with known adrenal disease. Forty-six dogs that underwent CT and subsequent adrenalectomy were included. Clinical records and CT images from dogs that underwent adrenalectomy and histologic examination of the excised adrenal gland(s) were reviewed. Normal adrenal gland volumes for each dog were estimated using the algorithm, and compared with measured volumes of the affected glands. Linear measurement of the largest lesion diameter was also recorded. Fifty-eight adrenal glands were removed from 46 dogs, with pathology confirmed in all glands. Pathology included 28 adenomas, 13 carcinomas, 11 pheochromocytomas and 6 other benign pathologies. The volume of all removed adrenal glands was measured to be larger than the expected normal volume estimated by the algorithm, ranging from 1.1 to 212.9 times larger than estimated. Adrenal glands with malignant and benign pathology showed variable volumes with overlapping ranges recorded. Assessment of the dimensions of any focal lesion against a cut-off of 20 mm failed to discriminate malignancy. This study illustrates and supports the application of a validated volumetric algorithm for estimation of subject-specific adrenal gland volume to identify the presence of pathology and as a tool to assist clinical decision-making.

Urinary tract infections are a common diagnosis in dogs presenting to veterinary practice. Veterinarians often treat suspected infections empirically, either in the absence of culture and susceptibility testing results or whilst waiting for them. This study aimed to identify the bacteria most frequently isolated from canine urinary samples and their antimicrobial susceptibility patterns in South East Queensland (SEQ) to help guide responsible empirical antimicrobial prescription by the veterinary community in this geographical location. Cumulative antibiograms were generated from the results of 1284 culture-positive urinary samples in SEQ, obtained from a commercial veterinary laboratory over a 5-year period. Escherichia coli was the most commonly isolated bacterial species (43%), followed by Staphylococcus spp. (23%), Proteus spp. (21%) and Enterococcus spp. (10%). Of the six most common isolates, 97% had susceptibility to at least one low-importance antimicrobial. Susceptibility to the low-importance and first-line antimicrobial recommendation, amoxicillin, was 81% for E. coli and 24% for Staphylococcus spp. Susceptibility of both E. coli and Staphylococcus spp. to medium-importance and commonly recommended empirical antimicrobials, trimethoprim sulphonamides and amoxicillin–clavulanic acid was ≥85% and >92% for high-importance antimicrobials enrofloxacin and ceftiofur. Of the E. coli and Staphylococcus spp. isolates, 8.8% and 4%, respectively, were considered multidrug resistant. There was no increase in resistance to antimicrobials detected over the study period. Susceptibilities suggest low- and medium-importance antimicrobials remain acceptable first-line empirical treatments. However, this should be continually assessed and updated using local surveillance data.

Cryptococcus is an encapsulated yeast that is found in both yeast and hyphal forms. Cryptococcus neoformans and C. gattii are the most medically important species, causing disease in both immunocompromised and immunocompetent individuals. A large, friable, sublingual mass was surgically resected from the oral cavity of a pink-tongued skink (Cyclodomorphus gerarrdii). Histopathology, fungal culture and PCR testing with Sanger sequencing confirmed granulomatous inflammation containing large numbers of yeasts identified as Cryptococcus neoformans var. grubii. Surgical excision and treatment with oral amphotericin B and terbinafine was unsuccessful in managing the infection. On Day 67 after surgery, Cryptococcus DNA was detected by PCR in the blood but not oral, cloacal or skin swabs. The skink was euthanised 72 days after surgery due to anorexia, weight loss and progressive neurological signs of disease. Necropsy results showed disseminated cryptococcosis, including meningoencephalitis and ventriculitis. Two in-contact pink-tongued skinks remained asymptomatic and PCR-negative during 198 days of observation. This case suggests Cryptococcus infections should be considered for oral masses presenting with or without neurological signs in skinks. Further investigation is required to determine the best treatment options for disseminated cryptococcosis in reptiles. This report describes the third reported case of Cryptococcus in a reptile and the first case of cryptococcosis in a pink-tongued skink. It is also the first report of Cryptococcus in a reptile identified to the variety level using PCR, including in whole blood samples.

Research and enquiry (R&E) is an integral part of veterinary training. It is a foundation of evidence-based practice. In the University of Sydney Doctor of Veterinary Medicine degree R&E culminates in a cap-stone experience in Year 3: a ‘professionally focused project’, a student-driven and academic supported individual research project. The project provides an authentic experience within a veterinary discipline. Students work with an academic advisor who provides guidance for developing and achieving meaningful educational and professional goals. Successful advising depends upon a shared understanding of, and commitment to, the advising process by students, advisors and the university. The R&E mission can be broadly defined as - veterinarians recognise that evidence-based approach to practice, which is based on the scientific method, leads to the generation of new knowledge that underpins the veterinary medical profession.