Use of endogenous ACTH concentration and adrenal ultrasonography to distinguish the cause of canine hyperadrenocorticism

Twenty-nine dogs were diagnosed with hyperadrenocorticism (HAC). A single determination of endogenous plasma adrenocorticotropic hormone (ACTH) and adrenal ultrasonography were used in a prospective study to differentiate between pituitary-dependent HAC (PDH) and adrenal-dependent HAC (ADH). In 27 out of the 29 dogs (93 per cent), both endogenous plasma ACTH concentrations and adrenal ultrasonography indicated the same cause of HAC. Twenty-one of the 29 cases (72 per cent) were shown to be pituitary-dependent; all had plasma ACTH concentrations of greater than 28 pg/ml (reference range 13 to 46 pg/ml) and both adrenal glands were ultrasonographically of similar size and of normal shape. All 21 cases responded well to mitotane therapy. Six cases (21 per cent) were shown to be adrenal-dependent; all had plasma ACTH concentrations below the limit of the assay (<5 pg/ml) and the presence of an adrenal mass on ultrasonography. The sensitivity and specificity of adrenal ultrasonography and endogenous ACTH determinations to identify the cause of HAC were demonstrated to be 100 per cent and 95 per cent, respectively, for ADH. These discriminatory tests are more accurate than published figures for dexamethasone suppression testing.     

Optimum inclusion of field peas, faba beans, chick peas and sweet lupins in poultry diets. II. Broiler experiments

1.Three experiments were undertaken to determine the optimum inclusion rates of field peas, faba beans, chick peas and sweet lupins in broiler starter and finisher diets in amounts up to 360 g/kg. 2. In experiment A chickens in cages grown to 21 d on diets with field peas and faba beans gave better growth rate and feed efficiency than those with sweet lupins and chick peas. Growth rate and Food conversion ratio (FCR) improved with increasing amounts of faba beans in the diet while for chick peas growth rate and FCR declined. Digesta viscosity and excreta stickiness scores were much higher on diets with sweet lupins. Steam pelleting improved growth rate and FCR on all diets. 3. In experiment B birds were in cages and grown from 21 to 42 d. There were no differences between grain legumes (when combined for all inclusions) for growth rate, food intake or FCR. Viscosity was again much higher on the sweet lupin-based diets while the pancreas was significantly enlarged on the diets with chick peas, as observed previously in chickens grown to 21 d. Steam pelleting of diets gave a consistent and positive response for weight gain and FCR. 4. Experiment C was carried out in pens each holding 60 birds under semi-commercial conditions and grown to 42 d on starter and finisher diets with the same grain legumes as used previously but each at 2 rates of inclusion similar to those in commercial practice. Field peas at 200 to 300 g/kg and chick peas at 150 to 220 g/kg gave inferior growth to faba beans (150 to 180 g/kg) and sweet lupins (120 g/kg). 5. The results of these experiments allowed tentative recommendations to be made to industry for inclusion rates of these cultivars of the 4 grain legumes. These were: field peas 300 g/kg; faba beans 200 g/kg, chick peas 100 g/kg and sweet lupins <100 g/kg. Wet droppings and high gut viscosity were serious problems with sweet lupins although these were not so obvious in experiment C.     

Liver biopsy techniques for adult horses and neonatal foals to assess copper status

Objective To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal.
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares.     

Naphthalophos combinations with benzimidazoles or levamisole as effective anthelmintics for sheep

Objective: To investigate the relative efficacy and safety of the anthelmintic naphthalophos in sheep, either given alone or in combination with benzimidazole (fenbendazole and albendazole) or levamisole anthelmintics.
Design: A parasitological study using faecal egg count reduction tests, a validating slaughter trial and field safety trials.
Procedure: Faecal egg count reduction tests were carried out on 13 farms. Naphthalophos and combinations of naphthalophos with levamisole and fenbendazole were included in the drench tests. On one property a controlled efficacy study was carried out to validate faecal egg count reduction test findings. In this trial, sheep were slaughtered 10 days after treatment and the remaining parasites recovered from the gastro-intestinal tract. Safety trials were carried out on eight farms where approximately 50 000 sheep were treated with naphthalophos and albendazole that were tank mixed in the backpack.
Results: The efficacy of naphthalophos alone in faecal egg count reduction tests ranged from 59 to 98% with one test showing 95% reduction. The efficacy of naphthalophos and levamisole ranged from 74 to 100%, with 5 farms showing 95% reduction. The efficacy of naphthalophos and fenbendazole ranged between 88 and 100% with 95% reduction achieved on 10 farms. The controlled efficacy study showed a good correlation between the faecal egg count reduction tests and numbers of parasites recovered, except for Nematodirus where the faecal egg count reduction tests overestimated efficacy. The mortality rate in the safety trials was 0.05%, with most fatalities occurring on one farm.
Conclusion: The combination of naphthalophos and fenbendazole was more effective than a combination of naphthalophos and levamisole, and will provide a sufficiently safe drench rotation option.     

ACCURACY OF SURVEY RADIOGRAPHIC DIAGNOSIS OF INTERVERTEBRAL DISC PROTRUSION IN DOGS

To assess the diagnostic accuracy of survey radiography for canine thoracolumbar intervertebral disc protrusion, survey radiographs (lateral and ventrodorsal) of 64 dogs with surgically-confirmed thoracolumbar intervertebral disc protrusion, 51 dogs with negative myelograms and 29 dogs with various spinal conditions other than disc protrusion were reviewed by three independent observers who were unaware of any clinical information. There were marked differences in observer performance for diagnosis of intervertebral disc protrusion, although there were no significant differences in intraobserver diagnostic accuracy for small vs. large dogs. Accuracy of observers for determining sites of intervertebral disc protrusion using survey radiography was in the range 51-61%. All observers had low accuracy for identification of second sites of intervertebral disc protrusion. The most useful radiographic sign, narrowed intervertebral space, had only moderate sensitivity (range 64-69%) and moderate predictive value (range 63-71%) for intervertebral disc protrusion. Vacuum phenomenon was an infrequent but accurate sign of intervertebral disc protrusion. Recognition of multiple radiographic signs of intervertebral disc protrusion at one site was associated with increased accuracy of diagnosis. No observer was accurate enough to justify attempting targeted surgical treatment of intervertebral disc protrusion without myelography.