The structure of the ileo‐caeco‐golic junction of the domestic fowl (Gallus Gallus L.)

1. The structure of the ileo‐caeco‐colic junction of domestic fowl aged from 3 to 12 weeks was investigated by histological techniques and the preparation of latex casts of the lumina.

2. The caeca open ventro‐laterally from the cranial end of the colon. At this level a muscular ring of tissue, formed from the circular muscle of the lamina muscularis of the ileum, projects into the colon lateral to the caecal openings. The location of this muscular ring is discussed in relation to the possible mechanisms of caecal filling.

3. The longitudinal muscle of the lamina muscularis of the caudal region of each caecum is continuous with that of the colon and ileum. The circular muscle of the lamina muscularis of each caecum begins in the muscularis mucosa of the colon at a distance of 1 to 2 mm from the caecal openings. At the level of the caecal openings the musculature is complex, consisting of parts of the lamina muscularis of the colon, caeca and ileum.

4. The openings of the caeca from the colon are narrow and filled with villi. It is suggested that the junction may be involved in filtering material during the filling of the caeca.     

A comparison of the efficacy of detornidine by sublingual and intramuscular administration in ponies

Preliminary trials established that, whilst detomidine is ineffective if given by stomach tube and is of variable efficacy in food, it can give effective sedation when administered by the sublingual route. A comparison was made in four ponies of the behavioural effects, and the effects on heart rate of detomidine at three dose rates (20, 40 and 80 μg/kg) given either by intramuscular injection or sublingually by squirting the drug under the tongue. Sedation was assessed by measuring the lowering of the ponies' heads and by scoring their responses to a variety of imposed stimuli. Ponies became sedated following detomidine administration at all doses and by all routes. The lowering of the head induced by detomidine was significantly influenced by the dose of drug and by the route of administration. For either route, higher doses produced the greatest effect. There was a significant correlation between the effects produced by the two routes of administration, the lowering of the head following sublingual administration being approximately threequarters of that after the same dose given intramuscularly. Onset of sedation was achieved more rapidly following intramuscular dosing than after sublingual administration. Falls in heart rate were similar after all drug administrations, but bradycardia was never profound. Subsequent clinical experience has proved that, providing adequate time (45 minutes) is allowed for maximal effects, sublingual administration of detomidine (40 μg/kg) can give a useful degree of sedation in horses which are difficult to inject.     

Risk of fatality and causes of death of Thoroughbred horses associated with racing in Victoria, Australia: 1989-2004

REASONS FOR PERFORMING STUDY: Determining the risk of fatality of Thoroughbred horses while racing is essential to assess the impact of intervention measures designed to minimise such fatalities. OBJECTIVES: To measure the risk of racehorse fatality in jump and flat starts on racecourses in Victoria, Australia, over a 15 year period and to determine proportional mortality rates for specific causes of death. METHODS: All fatalities of Thoroughbred horses that occurred during or within 24 h of a race were identified from a database. The risk of a start resulting in a racehorse fatality in all races and within flat and jump races, proportional mortality rates, population attributable risk, population attributable fraction and risk ratios were calculated along with 95% confidence intervals. Poisson regression was also performed to estimate risk ratios. RESULTS: There were 514 fatalities over the 15 year period; 316 in flat races and 198 in jump races. The risk of fatality was 0.44 per 1000 flat starts and 8.3 per 1000 jump starts (18.9 x greater). The risk of fatality on city tracks was 1.1 per 1000 starts whereas on country tracks it was 0.57 per 1000 starts. Of the 316 fatalities in flat races, 73.4% were due to limb injury, 2.5% to cranial or vertebral injury and 19.0% were sudden deaths. Of the 198 fatalities in jump races, 68.7% were due to limb injury, 16.2% to cranial or vertebral injury and 3.5% were sudden deaths. The risk of fatality in flat starts increased between 1989 and 2004 but the risk in jump starts remained unchanged over the 15 year period. CONCLUSIONS: The risk of fatality in flat starts was lower in Victoria than North America and the UK but the risk in jump starts was greater. Catastrophic limb injury was the major reason for racehorse fatality in Victoria but there was a larger percentage of sudden deaths than has been reported overseas. The risk of fatality in jump starts remained constant over the study period despite jump racing reviews that recommended changes to hurdle and steeple races to improve safety. POTENTIAL RELEVANCE: This study provides important benchmarks for the racing industry to monitor racetrack fatalities and evaluate intervention strategies.     

Pilot study investigating the ability of an herbal composite to alleviate clinical signs of respiratory dysfunction in horses with recurrent airway obstruction

Recurrent airway obstruction (RAO), known previously as chronic obstructive pulmonary disease (COPD), is a debilitating respiratory condition that significantly contributes to lost training days and illness in racehorses. Herbs are becoming increasingly popular for the prophylaxis or treatment of the clinical signs of RAO despite a paucity of research on efficacy and safety. We evaluated the ability of an herbal composite containing garlic, white horehound, boneset, aniseed, fennel, licorice, thyme, and hyssop to reduce the clinical signs of RAO, hypothesizing that the product would safely reduce signs and would improve the inflammatory cell profile within the lungs. The composite was fed to 6 horses with symptomatic RAO for 21 d in a crossover manner. Ventigraphs were used to record respiratory rate and intrapleural pressure; the proportion of inflammatory cells in fluid aspirated from the trachea was determined. Blood biochemical and hematologic screening was conducted to identify possible adverse effects. Treatment with the composite did not result in statistically significant changes in any of the parameters evaluated. A trend to a decrease in respiratory rate (P = 0.1) and an increase in the proportion of macrophages (P = 0.1) was observed in the horses receiving the herbal composite compared with placebo. These data indicate a potential for the herbal composite to safely reduce the elevated respiratory rate in horses with RAO. Future research with a greater number of horses is warranted to further characterize the effect of this product on horses with RAO.     

Prospective evaluation of the safety of compounded bulk material L‐asparaginase in dogs with lymphoma

Use of compounded L‐asparaginase became routine in veterinary oncology when manufacturing of Elspar^® was discontinued in 2012. The objective of this study was to evaluate the safety of compounded L‐asparaginase (CLASP, KRS Global Biotechnology, Boca Raton, FL, USA) in comparison with Elspar^® (Lundbeck LLC, Deerfield, IL, USA). In addition, we documented the response to CLASP in combination with a corticosteroid in this population of dogs with lymphoma. Dogs were prospectively treated with 10 000 IU/m² CLASP or Elspar^® subcutaneously. Corticosteroids were administered concurrently. Adverse events (AE) were assessed according to the Veterinary Cooperative Oncology Group Common Terminology Criteria for Adverse Events v1.1 (VCOG‐CTCAE). Response was recorded. Seventy‐three dogs received 75 treatments (CLASP, n = 47; Elspar^®, n = 28). No AE were attributed to CLASP. Grade I and II AE probably or possibly related to treatment were observed following two Elspar^® treatments. The overall response rate to the combination of CLASP and a corticosteroid was 80% (24% CR and 56% PR). In combination with a steroid, the compounded L‐asparaginase evaluated in this study is safe and demonstrates activity against canine lymphoma. In the face of the discontinuation of Elspar^®, veterinarians should seek compounded LASP products that have been tested for activity, purity, and sterility.     

The variation in chemical composition of barley feed with or without enzyme supplementation influences nutrient digestibility and subsequently affects performance in piglets

This study investigates the effect of dietary supplementation of a β‐glucanase and β‐xylanase enzyme mix to barley based diets, at two different chemical compositions achieved through different agronomical conditions on growth performance, coefficient of apparent total tract digestibility (CATTD) of nutrients, selected faecal microbial populations and faecal scores in piglets. Sixty‐four piglets (11.7 kg (SD 0.96)) housed in pens of two were assigned to one of four dietary treatments (n = 8). The dietary treatments were as follows: (T1) low quality barley diet, (T2) low quality barley diet containing a β‐glucanase and β‐xylanase enzyme supplement, (T3) high quality barley diet and (T4) high quality barley diet containing a β‐glucanase and β‐xylanase enzyme supplement. Piglets offered the low quality barley‐based diet had a higher (p < .05) average daily gain (ADG) (0.73 vs. 0.69 kg, SEM 0.001), gain:feed (G:F) ratio (0.61 vs. 0.58 kg, SEM 0.011) and a higher CATTD (p < .001) of dry matter (DM), organic matter (OM), nitrogen (N), ash, gross energy (GE) and neutral detergent fibre (NDF) compared with piglets offered the high quality barley diet. Piglets offered the high quality barley‐based diet had reduced faecal scores compared to piglets offered the low quality barley‐based diet (2.44 vs. 2.57, SEM 0.036) (p < .05). There was a higher population of Lactobacillus spp. (11.6 vs. 10.5 log gene copy number/g faeces, SEM 0.177) (p < .001) and total volatile fatty acid (VFA) concentration (185 vs. 165 mmol/g faeces, SEM 5.658) (p < .001) in the faeces of piglets offered the high quality barley‐based diet compared to piglets offered the low quality barley‐based diet. The inclusion of a β‐glucanase and β‐xylanase enzyme complex had no effect on any variable measured. In conclusion, the higher quality barley‐based diet showed beneficial effects on the faecal Lactobacillus spp. population and faecal scores of the piglets; however, the higher level of β‐glucans in the diet decreased nutrient digestibility and subsequently decreased the performance.     

Circumcaval ureter associated with an intrahepatic portosystemic shunt in a dog

CASE DESCRIPTION: A 4-month-old Bernese Mountain Dog was examined because of shifting hind limb lameness and lethargy of 2 weeks' duration. CLINICAL FINDINGS: The lameness was attributed to hypertrophic osteodystrophy. Portosystemic shunting was suspected on the basis of low serum albumin concentration and high serum bile acids concentration, and an intrahepatic shunt was identified ultrasono-graphically. Celiotomy was performed, and the shunt was partially closed with a cellophane band. During follow-up ultrasonography 7 months later, dilation of the left renal pelvis and proximal portion of the left ureter was identified. During exploratory celiotomy, the left ureter was found to pass dorsal to the caudal vena cava, and circumcaval ureter was diagnosed. TREATMENT AND OUTCOME: The ureter was transected, repositioned ventral to the vena cava, and anastomosed. Follow-up ultrasonographic examinations revealed gradual resolution of the hydronephrosis and hydroureter. CLINICAL RELEVANCE: Findings suggest that circumcaval ureter should be considered in the differential diagnosis for hydronephrosis and hydroureter in dogs. Partial obstruction of the middle segment of the ureter on ultrasonograms or contrast radiographs should increase the index of suspicion for this condition.     

Susceptibility of Eucalyptus globulus ssp. globulus to sawfly (Perga affinis ssp. insularis) attack and its potential impact on plantation productivity

Sawflies (Perga species) are leaf-damaging pests of the major plantation tree species Eucalyptus globulus ssp. globulus. This work describes the patterns of quantitative genetic variation in susceptibility to attack by Perga affinis ssp. insularis, based on data from a large open-pollinated trial containing genetic material from throughout the geographic range of E. globulus ssp. globulus. Forty three per cent of the trees in the trial exhibited damage from sawflies in either their sixth or seventh growth seasons. The incidence of damage was genetically based, with significant variation between geographic races of E. globulus ssp. globulus and highly heritable (h²=0.43±0.05) variation in damage incidence within races. Susceptibility to sawfly damage significantly affects plant fitness with both genetic and environmental correlations demonstrating that sawfly damage causes slow growth and increased mortality of trees. Mild and severe sawfly damage resulted in 16 and 31% reduction in the basal area of surviving trees, and the effect was consistent across races and families. Based on this data, we propose a model predicting relative plantation productivity of races of different susceptibility under different infestation regimes.