COMPARATIVE ORGAN IMAGING: THE GASTROINTESTINAL TRACT

Diagnostic radiology of the esophagus, stomach, small and large intestine, mesentery, and pancreas is reviewed. Survey and contrast radiography remain the principal imaging methods used to evaluate gastrointestinal diseases in animals. Of the other imaging techniques, scintigraphy has potential in assessment of esophageal and gastric motility disorders, and detection of intestinal hemorrhage. Ultrasonography is useful for imaging the pancreas and gastrointestinal mass lesions.     

Ultrasonographic diagnosis of congenital portosystemic shunt in 14 cats

Twenty-four cats with clinical and, or, clinico-pathological signs compatible with portosystemic shunting were examined prospectively using two-dimensional grey-scale, duplex and colourflow Doppler ultrasonography. Diagnosis of congenital portosystemic shunt was subsequently confirmed in 14 cats using operative mesenteric portography and surgery. Of the 14 affected cats, nine were purebred; eight were male and six female. The mean age at the time of diagnosis was nine months (range four to 27 months). Ultrasonographic evidence of a small liver was present in seven cats (50 per cent); visibility of intrahepatic portal vessels was reduced in three (21 per cent). An anomalous blood vessel was identified ultrasonographically in each cat; in 10 cats (71 per cent) the vessel was observed to originate from the portal vein and drain into the caudal vena cava. Abnormally variable portal blood flow waspresent in eight of the 10 cats in which it was measured. At surgery, six shunts were intrahepatic and eight extrahepatic; the ultrasonographic diagnosis of intra- versus extra-hepatic shunt was correct in 13 cats (93 per cent). No anomalous blood vessels or abnormalities affecting the portal vein were detected ultrasonographically in any of the 10 cats that did not have congenital portosystemic shunting. Hence, the accuracy of ultrasonography for diagnosis of congenital portosystemic shunting in this series was 100 per cent.     

Evaluation of mating systems involving five breeds for integrated beef production systems: III. Integrated system.

Angus (A), Charolais (C), Hereford (H), Limousin (L), and Simmental (S) breeds were included in deterministic computer models simulating integrated cow-calf-feedlot production systems. Three mating systems were used: pure-breeding and two-and three-breed rotational crossbreeding. Breed information was taken from the literature. Herd sizes were unrestricted; however, 100 heifers were saved as replacements. Cows were removed for reproductive failure, age (greater than 10.5 yr), or death. Calves produced in the cow-calf segment were fed in a custom feedlot to four slaughter end points: 440 d, 457 d, 288-kg carcass weight, and low Choice. All animals were fed to requirements. Cull cows were slaughtered after weaning. Biological and economic efficiencies improved with crossbreeding; however, rankings of breed combinations depended on how efficiencies were measured (weight, lean, or value basis). Among purebreds, reproductive performance had a large influence on breed rankings at age and weight end points, whereas feedlot performance was important at the low Choice end point. Crossbred combinations involving British (A or H) and Continental (C or S) breeds were more efficient than other crossbred combinations at all end points. However, choosing specific breed combinations for integrated systems depends on slaughter end points, market end points (weight vs lean), and measures of efficiency (weight, lean, or value basis).     

THE FIRST TWENTY-ONE YEARS OF VETERINARY DIAGNOSTIC ULTRASOUND

The veterinary literature of 1966–1986 was searched for articles and books related to the use of diagnostic ultrasound in animals. There were 492 references, categorized as follows: general, 30; small animal applications, 169; large animal applications, 248; blood pressure measurement, 23; ultrasound-guided biopsy, 4; miscellaneous, 18.     

Idiopathic thrombocytopenia in Cavalier King Charles Spaniels

OBJECTIVE: To determine the prevalence of asymptomatic idiopathic macrothrombocytopenia in the population of Cavalier King Charles Spaniels (CKCS) in New South Wales (NSW) and to determine if it exhibits an autosomal recessive inheritance pattern. We also aimed to determine if significant differences existed when counting platelets manually, by auto analyser or by blood smear estimation in CKCS and mixed breed dogs. METHODS: Blood was collected from 172 dogs (152 CKCS and 20 mixed breed) and placed into sodium-citrate anticoagulant. Platelet counts were performed manually, by auto analyser and by blood smear estimates in CKCS and mixed breed dogs. Blood smears were also examined for platelet clumping and erythrocyte, leukocyte and platelet morphology. Pedigree analysis was performed to determine if an autosomal recessive inheritance pattern was supported. RESULTS: A statistically significant difference was found in platelet counts between CKCS and mixed breed dogs (P < 0.0001). CKCS had a platelet count that was 32% that of the controls (95% confidence interval, 28 to 37%). There was no significant difference between methods used to count platelets. Thirty percent of CKCS had macrothrombocytes. Pedigree analysis and examination of obtained and expected segregation ratios from 17 CKCS families supported an autosomal recessive pattern of Mendelian inheritance. CONCLUSIONS: A high prevalence of idiopathic macrothrombocytopenia exists in CKCS in NSW and automated or blood smear estimates are sufficient to count platelet numbers. Data supports an autosomal recessive inheritance pattern.     

DIAGNOSIS OF CALCIFICATION ON ABDOMINAL RADIOGRAPHS

A wide variety of normal and pathologic factors may induce intraabdominal calcification. In general, the most reliable indication of the cause of a calcification is its location; therefore, if the affected organ can be identified the radiographic diagnosis is often straightforward or, at least, limited to relatively few possibilities. With this principle in mind, a series of patients with abdominal calcification are described for the purpose of illustrating the appearance of calcification of various abdominal organs. In addition, etiology for the calcification in each patient is discussed. Certain extraabdominal calcifications which may be seen on abdominal radiographs are also mentioned.     

Treatment of a prolapsed lumbar intervertebral disc in a ferret

A seven-month-old, male ferret had acute paraplegia and radiographs showed signs of disc prolapse between the second and third lumbar vertebrae (L2/3). Hemilaminectomy was performed to decompress the spinal cord. Histological examination revealed that the extradural material was consistent with annulus fibrosus and the L2/3 articular facets were enlarged as a result of bone remodelling. The ferret became ambulatory one month postoperatively. Five months postoperatively, the ferret had normal posture with mild proprioceptive deficits in the pelvic limbs, and fusion of the L2 and L3 vertebral bodies.     

Radiographic findings in 16 dogs infected with Angiostrongylus vasorum

Thoracic radiographs of 16 dogs infected naturally with Angiostrongylus vasorum showed signs of bronchial thickening, an interstitial pattern and a multifocal and/or peripheral alveolar pattern. In dogs treated with fenbendazole, follow-up radiographs showed that the alveolar pattern had resolved and a mild, hazy interstitial pattern had developed. In contrast with dogs with heartworm (Dirofilaria immitis), no pulmonary vascular lesions were identified.