Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in four calves

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), or Bland-White-Garland syndrome, is a rare congenital malformation described in children and adults. In this condition, the left coronary artery, which normally originates from the left coronary sinus in the aorta, instead originates from the pulmonary trunk, which results in retrograde flow of blood away from the myocardium into the lower-pressure pulmonary artery. Myocardial hypoxic-ischemic injury results in cardiac dysfunction, failure, and eventually in patient death if not surgically repaired. This report describes gross and microscopic findings in 4 beef calves with ALCAPA. All the calves had a history of being found dead with few or no premonitory signs, 2 shortly after sudden strenuous exercise. Gross necropsy lesions suggestive of heart failure included cardiomegaly with atrial and ventricular dilation and/or ventricular hypertrophy, and hepatomegaly. Dissection of each heart revealed the origin of the left coronary artery arising in the pulmonary trunk above the anterior cusp of the pulmonic valve. No degeneration; mineralization; and fiber loss, with replacement by fibrous connective tissue, predominantly in the left ventricular papillary muscle and the interventricular septum. Changes observed in the liver and lungs, including hepatomegaly, sinusoidal congestion, centrilobular fibrosis, and pulmonary congestion, edema, and intra-alveolar pigment-laden macrophages were consistent with heart failure.     

Journal standards

Despite its many imperfections, the peer review process is a firmly established quality control system for scientific literature. It gives readers some assurance that the work and views that are reported meet standards that are acceptable to a journal. Maureen Revington's editorial in a recent issue of the Australian Veterinary Journal (Revington2002) gives a good concise warts and all overview of the process and is well worth reading. I have some concerns about several articles in the December 2002 issue of the New Zealand Veterinary Journal (Volume 50, Number 6), devoted to the health and welfare of farmed deer, that relate to extensive citing of non-peer reviewed papers. I can understand the need for information to flow from researchers to the wider community but that need is already satisfied by publications such as the proceedings of the Deer Branch of the New Zealand Veterinary Association and Proceedings of the New Zealand Society of Animal Production. Non-peer reviewed papers have been cited in the Journal in the past but never to the extent displayed in this particular issue. It degrades the peer-review process and creates an added burden for reviewers who are forced to grapple with the uncertainties of the science in non-peer reviewed citations. One of my fears is that this process allows science from non peer reviewed articles to be legitimised by its inclusion in a peer reviewed journal and perhaps go on to be accepted as dogma. This is a real danger given the difficulties associated with tracing back to original citations and the increasing volume of scientific literature. It also affords opportunities for agencies to pick up questionable and doubtful science and tout it as support for their products or particular points of view. If deer researchers choose to publish most of their work in proceedings then so be it. However this approach, which seems to becoming increasingly prevalent in the deer sector, is questionable from an established science point of view. For my part, I am increasingly reluctant to spend time reading non-peer reviewed material, despite its appeal. At present there are two distinct baskets for scientific literature, one for non-reviewed articles and another for peer reviewed information. I would sincerely hope that we are not going to need another basket as a halfway house for issues that fall in between that classification.     

Prevalence of pharyngeal and laryngeal abnormalities in Thoroughbreds racing in Australia, and their association with performance

REASONS FOR PERFORMING STUDY: Little information is available regarding the prevalence of abnormalities of the upper airway and their association with performance in the general population of Thoroughbred racehorses. OBJECTIVES: To describe the prevalence of selected abnormalities of the upper airway and their association with performance in Thoroughbred racehorses in Australia. HYPOTHESIS: That abnormalities of the upper airway of Thoroughbred racehorses are associated with poor race performance. METHODS: Rhinolaryngoscopy was performed after racing and presence and characteristics of abnormalities of the larynx and pharynx were recorded in a prospective cross-sectional study of Thoroughbred horses racing in Victoria, Australia. RESULTS: Rhinolaryngoscopy was performed once on each of 744 horses over 35 months. Fifty abnormalities of the upper airway were detected in 47 horses (6.3%, 95% confidence interval [CI] 4.7-83%). Epiglottic entrapment was detected in 7 horses (0.9%, 95% CI 0.4-1.9%) and was significantly (P = 0.015) associated with superior performance. Grade 2 asymmetry (4 grade scale) of the left arytenoid cartilage was detected in 9 horses (1.2%, 95% CI 0.5-2.4%) and was also associated with superior performance (P<0.001). Ulceration or erosion of the mucosa of the axial surface of one or both arytenoids was detected in 18 horses (2.4%, 95% CI 13-3.8%) and was not associated with alterations in exercise performance (P = 0.31). CONCLUSIONS: Epiglottic entrapment, Grade 2 laryngeal asymmetry and mucosal erosions detected in Thoroughbred racehorses were not associated with impaired performance; therefore, surgical correction and concern over laryngeal function in horses with Grade 2 asymmetry may not be necessary in individuals performing to expectation.     

Association between exercise-induced pulmonary hemorrhage and performance in Thoroughbred racehorses

OBJECTIVE: To determine whether exercise-induced pulmonary hemorrhage (EIPH) was associated with racing performance inThoroughbred horses not medicated with furosemide and not using nasal dilator strips. DESIGN: Observational cross-sectional study. ANIMALS: 744 two- to 10-year-old Thoroughbred horses racing in Melbourne, Australia. PROCEDURE: Horses were enrolled prior to racing, and a tracheobronchoscopic examination was performed after 1 race. Examinations were recorded on videotape, and presence and severity (grade 0 to 4) of EIPH were subsequently determined by 3 observers blinded to the horses' identity. Race records were abstracted for each horse examined. RESULTS: Overall, 52.1% of horses eligible for participation in the study were examined, and horses that were examined did not differ from horses that were not examined in regard to age, sex distribution, or proportion of horses that won or finished in the first 3 positions. Horses with EIPH grades < 1 were 4.0 times as likely to win, 1.8 times as likely to finish in the first 3 positions, and 3.03 times as likely to be in the 90th percentile or higher for race earnings as were horses with grades > 2. Horses with EIPH grades > 1 finished significantly farther behind the winner than did horses without EIPH. However, odds that horses with grade 1 EIPH would win or finish in the first 3 positions were not significantly different from odds for horses without EIPH. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that EIPH is associated with impaired performance in Thoroughbred racehorses not medicated with furosemide and not using nasal dilator strips.     

Toxicity and efficacy of cisplatin and doxorubicin combination chemotherapy for the treatment of canine osteosarcoma

Thirty-five dogs with appendicular osteosarcoma underwent amputation and chemotherapy with cisplatin and doxorubicin every 21 days for up to four cycles. Sixteen dogs completed all four cycles. Two dogs had therapy discontinued because of metastases. The remaining 17 dogs experienced toxicities necessitating protocol alteration or discontinuation. The median survival time of 300 days was not improved over previously reported single-agent protocols, but the 10 dogs that survived to a year lived a median of 510 days.     

Temporal patterns in bovine tuberculosis in a brushtail possum population contiguous with infected cattle in the Ahaura Valley, Westland

AIMS: To determine temporal and spatial patterns of bovine tuberculosis (Tb) in a population of brushtail possums (Trichosurus vulpecula) free from commercial and recreational hunting and living contiguously with livestock, and to relate these patterns to measures of possum health and density. METHODS: Possums were trapped on 11 lines located on a forest-rough grazing margin in the Ahaura Valley in Westland in 1979-80 and each August from 1992 to 1996, and were examined post mortem for gross lesions indicative of Tb. Infection levels in possums were compared with Th test data from cattle grazing in the same area. RESULTS: Tuberculosis was identified from the trapped sample of possums in 1980. Trapping of further possums on the same trap lines confirmed the presence of the disease each year from 1992 to 1996, and suggested a clustering of infection in time and space. The prevalence of Tb in possums declined with increasing possum population size and well being, and decreasing age. The prevalence of Tb in possums was highest in 1980 and 1992, and appeared to roughly coincide with similar upsurges in Tb in nearby cattle. CONCLUSIONS: Our results suggest that the exceptional levels of Tb recorded in possums in 1992 had a direct effect on possum numbers, and gave rise to very low trap catches in 1993-94. They also suggest that Tb can persist for several years in possum populations existing well below the 5% trap catch targeted by regional councils for Tb possum control.     

Naturally occurring tuberculosis caused by Mycobacterium bovis in brushtail possums (Trichosurus vulpecula): III. Routes of infection and excretion

Mycobacterium bovis was cultured from nine of 25 (36%) tracheal washings but not from any of 38 urine and 38 faecal samples from tuberculous possums cross-sectionally sampled from the wild. One of three tracheal washings, one of three urine samples and one of three faecal samples from terminally ill possums were culture-positive. The respiratory route is implicated as the major route of excretion of Mycobacterium bovis from naturally infected possums in horizontal transmission. Tuberculosis was observed in two young possums and was evidence of probable pseudo-vertical transmission via the respiratory route or ingestion of milk. Discharging fistulae were present in 22 of 71 (31%) cross-sectionally sampled tuberculous possums and were associated with relatively advanced disease. Although the frequent involvement of superficial lymphocentres in early stage disease could not be explained satisfactorily, the respiratory route was implicated as the main route of infection from indirect evidence.     

Genotype x environment interactions in Angus, Brahman, and reciprocal-cross cows and their calves grazing common bermudagrass, endophyte-infected tall fescue pastures, or both forages

Reproductive and preweaning data on 190 Angus (A x A), Brahman (B x B), and reciprocal-cross cows (A x B and B x A) and 434 two- and three-breed-cross calves managed on common bermudagrass (BG), endophyte-infected tall fescue (E+), or a combination of both forages (ROT) were used to evaluate the interaction of forage type with individual and maternal heterosis and maternal and grandmaternal breed effects. Cows were born from 1988 to 1991, and calves sired by 13 Polled Hereford bulls were born from 1995 to 1997. Heterosis for calving rate was larger on E+ than on BG or ROT (P < .05), whereas maternal effects were larger on BG than on ROT (P < .10). Maternal heterosis for birth weight was negative on BG (P < .11) but positive on E+ and ROT (P < .10). Grandmaternal effects were evident on BG (P < .10) and E+ (P < .01) but not on ROT. Forage effects were generally substantial for 205-d weight, calf weaning hip height, and calf weaning weight:height ratio; BG was highest, ROT was intermediate, and E+ was lowest. Maternal heterosis for these traits was generally greater on E+ than on BG (P < .10). Grandmaternal effects for 205-d weight, hip height, and weight:height ratio were not important on any forage. Heterosis for weaning weight per cow exposed was substantial on all forages (P < .01) and was significantly greater on E+ (P < .01) than on BG or ROT, but maternal effects were not significant. Thus, we observed more advantage to Brahman-cross cows over purebreds on E+ than on BG. We also observed that moving cows and calves from E+ to BG in the summer will alleviate some, but not all, of the deleterious effects of E+ on calf growth, although it may be more beneficial for reproductive traits in purebred cows.