Gastric dilatation and volvulus in a brachycephalic dog with hiatal hernia

A brachycephalic dog was presented with an acute onset of retching and abdominal discomfort. The dog had a chronic history of stertor and exercise intolerance suggestive of brachycephalic airway obstructive syndrome. Radiographs were consistent with a Type II hiatal hernia. The dog was referred and within hours of admission became acutely painful and developed tympanic abdominal distension. A right lateral abdominal radiograph confirmed gastric dilatation and volvulus with herniation of the pylorus through the hiatus. An emergency exploratory coeliotomy was performed, during which the stomach was derotated, and an incisional gastropexy, herniorrhaphy and splenectomy were performed. A staphylectomy was performed immediately following the exploratory coeliotomy. The dog recovered uneventfully. Gastric dilatation and volvulus is a potentially life‐threatening complication that can occur in dogs with Type II hiatal hernia and should be considered a surgical emergency .     

Pharmacokinetics and preliminary safety data of a single oral dose of bosentan,a dual endothelin receptor antagonist,in cats

The objective of this study was to evaluate the pharmacokinetic properties and adverse effect profile of single‐dose oral bosentan, a dual endothelin receptor antagonist, in healthy cats. Pharmacokinetic parameters were determined following a single mean ± SD oral dose of 3.2 ± 0.6 mg/kg of bosentan in 6 adult cats. Blood was collected for quantification of bosentan via high‐performance liquid chromatography with ultraviolet detection. Blood and urine were evaluated for CBC, plasma biochemical profile, and urinalysis, and repeat physical examinations were performed to evaluate for adverse effects. The mean terminal half‐life of bosentan was 20.4 ± 17.2 h. The mean peak plasma concentration was 0.49 ± 0.24 g/mL, and the mean time to maximum plasma concentration was 6.8 ± 8.6 h. The area under the curve was 5.14 ± 3.81 h·μg/mL. Oral bosentan tablets were absorbed in cats, and no clinically important adverse events were noted. Further evaluation of repeat dosing, investigation into the in vivo efficacy of decreasing endothelin‐1 concentrations in cats, as well as safety in conjunction with other medications is warranted.     

The resistance of meat chickens vaccinated by aerosol with a live V4 Newcastle disease virus vaccine in the field to challenge with a velogenic Newcastle disease virus

Meat chickens housed on a commercial broiler farm in Australia were vaccinated once at 10 to 11 days-of-age by aerosol with live V4 Newcastle disease virus (NDV) vaccine. Groups of vaccinated and unvaccinated birds were flown to Malaysia, where they were challenged with a virulent strain of NDV. Survival rates in vaccinated chickens challenged 7, 14, 21 or 31 d after vaccination were 0.47, 0.77, 0.97 and 0.92, respectively. All unvaccinated chickens died due to Newcastle disease (ND) following challenge. Chickens in Australia and Malaysia were bled and the serums tested for haemagglutination-inhibiting (HI) antibody to NDV. Many vaccinated birds with no detectable antibody, and all birds with a log2 titre of 2 or greater, survived challenge. The results showed that this V4 vaccine induced protective immunity in a significant proportion of chickens within 7 d of mass aerosol vaccination. This early immunity occurred in the absence of detectable circulating HI antibody. Non-HI antibody mediated immunity continued to provide protection up to 31 d after vaccination. Almost all vaccinated birds were protected within 3 w of vaccination. It is concluded that the V4 vaccine is efficacious and could be useful during an outbreak of virulent ND in Australia.     

Clinical and pathological findings of Babesia infection in dogs

The clinical and pathological findings of Babesia infection in 32 dogs in northern Australia are presented. Eleven different breed types were represented from 6 localities in north Queensland and one locality in northern Western Australia. Twenty three (72%) were males. Babesia-infected dogs were grouped by the degree of haematological disturbance and clinical severity: Acute babesiosis (25/32), all pups with severe haemolytic anaemia; subclinical carriers (5/32) with non-specific malaise, characterised haematologically by a normal erythrogram but marked leucopenia; chronic anaemia, observed in 2 adult dogs. Pups were azotaemic (serum urea greater than 6.6 mmol/l) and had elevated serum bilirubin levels (20.8 to 48.5 mmol/l). Total serum protein was usually within the normal range. Pups that died were also hypoglycaemic and severely hyperkalaemic (K+ greater than 10 mmol/l). Low parasitaemias in routine blood smears complicated diagnosis but smears made from ear or toe capillaries, or after haematocrit concentration, greatly enhanced finding parasitised cells. At necropsy, pallor and jaundice were the most consistent observations. Haemoglobinuric nephrosis, an active reticulo-endothelial system and capillaries packed with large numbers of infected erythrocytes were the main histopathological findings. A combination of imidocarb dipropionate at 5 mg/kg body weight, given intramuscularly, with fluid therapy and blood transfusion was the most successful treatment.     

Monensin controlled-release intraruminal capsule for control of bloat in pastured dairy cows

Monensin, a polyether ionophore antibiotic, is potentially an important agent for bloat relief in dairy cows grazing temperate legume-based pasture. A series of studies was undertaken to determine the effect of monensin, when delivered continuously in the rumen of lactating dairy cows by means of controlled-release capsules (monensin CRC). Such devices release approximately 300 mg/head/day for 100 d. A short-term pilot study made at Ruakura, New Zealand, tested monensin CRC in cows selected for high susceptibility to bloat and grazing lucerne (Medicago sativa) or red clover (Trifolium pratense). Treatment significantly reduced the incidence of bloat, while milk yield and protein yield were increased. There was no effect on fat yield. Following the pilot study, 6 large-scale field experiments involving a total of 368 lactating dairy cows, were made in Australia and New Zealand to confirm the effectiveness of monensin CRC for bloat control and to measure the effect of such treatment on milk production and composition. A severe bloat problem occurred in 2 experiments, mild bloat occurred in 2 others, while no visual signs of bloat were observed in the remaining 2 experiments. Bloat was significantly (P less than 0.05) reduced by monensin CRC treatment when data was pooled over the 4 experiments in which bloat occurred. Daily milk yield was increased in all experiments from a mean of 17.7 in untreated groups to 18.8 kg/head/day (P less than 0.05) in monensin CRC-treated cows. Protein percentage was not affected by treatment, while there was a decrease from 4.29 to 4.10% fat, although total fat yield was not affected.(ABSTRACT TRUNCATED AT 250 WORDS)