Computed tomographic diagnosis of necroulcerative reticulorumenitis with portal venous gas in a lamb

A 2-month-old, intact male Merino sheep was presented for acute inappetence and pyrexia. Contrast-enhanced abdominal computed tomography identified reticulorumenal intramural gas with suspected ruminal ulceration, arborizing portal venous gas, and mild peritoneal fluid. The lamb was treated medically for presumptive ulcerative reticulorumenitis and non-septic peritonitis. Over 10 days, the lamb initially showed mild improvement before clinical deterioration and was ultimately euthanized. Definitive diagnosis of necrotizing, ulcerative reticulorumenitis was made via necropsy with histopathology. An underlying cause was not determined.Key clinical message:Contrast-enhanced computed tomography was effective in identifying gastric emphysema and portal venous gas associated with reticuloruminal ulceration.     

VERTEBRAL OSTEOSCLEROSIS IN A CAT SECONDARY TO RHABDOMYOSARCOMA

A 5–year–old cat was presented for pelvic limb weakness. Sclerosis of the vertebral body of T–10 was visible on thoracic radiographs. A compressive lesion at this area was noted on myelography. A tumor was partially removed at surgery, but the cat was killed because of poor postoperative response. Rhabdomyosarcoma was diagnosed at necropsy, with bone marrow necrosis and myelofibrosis, and new bone proliferation of the body of T–10. Causes of bone necrosis are discussed.     

Specific contrast ultrasound using sterically stabilized microbubbles for early diagnosis of thromboembolic disease in a rabbit model

Specific contrast ultrasound is widely applied in diagnostic procedures on humans but remains underused in veterinary medicine. The objective of this study was to evaluate the use of microbubble-based contrast for rapid ultrasonographic diagnosis of thrombosis in small animals, using male New Zealand white rabbits (average weight about 3.5 kg) as a model. It was hypothesized that the use of microbubble-based contrast agents will result in a faster and more precise diagnosis in our model of thrombosis. A pro-coagulant environment had been previously established by combining endothelial denudation and external vessel wall damage. Visualization of thrombi was achieved by application of contrast microbubbles [sterically stabilized, phospholipid-based microbubbles filled with sulfur hexafluoride (SF₆) gas] and ultrasonography. As a result, rapid and clear diagnosis of thrombi in aorta abdominalis was achieved within 10 to 30 s (mean: 17.3 s) by applying microbubbles as an ultrasound contrast medium. In the control group, diagnosis was not possible or took 90 to 180 s. Therefore, sterically stabilized microbubbles were found to be a suitable contrast agent for the rapid diagnosis of thrombi in an experimental model in rabbits. This contrast agent could be of practical importance in small animal practice for rapid diagnosis of thrombosis.     

Association between the genetic similarity of the open reading frame 5 sequence of Porcine reproductive and respiratory syndrome virus and the similarity in clinical signs of Porcine reproductive and respiratory syndrome in Ontario swine herds

A study of Ontario swine farms positive for Porcine reproductive and respiratory syndrome virus (PRRSV) tested the association between genetic similarity of the virus and similarity of clinical signs reported by the herd owner. Herds were included if a positive result of polymerase chain reaction for PRRSV at the Animal Health Laboratory at the University of Guelph, Guelph, Ontario, was found between September 2004 and August 2007. Nucleotide-sequence similarity and clinical similarity, as determined from a telephone survey, were calculated for all pairs of herds. The Mantel test indicated that clinical similarity and sequence similarity were weakly correlated for most clinical signs. The generalized additive model indicated that virus homology with 2 vaccine viruses affected the association between sequence similarity and clinical similarity. When the data for herds with vaccine-like virus were removed from the dataset there was a significant association between virus similarity and similarity of the reported presence of abortion, stillbirth, preweaning mortality, and sow/boar mortality. Ownership similarity was also found to be associated with virus similarity and with similarity of the reported presence of sows being off-feed, nursery respiratory disease, nursery mortality, finisher respiratory disease, and finisher mortality. These results indicate that clinical signs of PRRS are associated with PRRSV genotype and that herd ownership is associated with both of these.     

Radiographic characterization of enlarged sternal lymph nodes in 71 dogs and 13 cats

In this retrospective study, radiographically enlarged sternal lymph nodes (LNs) were evaluated in 71 dogs and 13 cats for average size, location, and most representative radiographic view. Concurrent clinical diagnoses were also noted and grouped into one of three following categories: neoplastic, inflammatory, or hematologic. There were no statistically significant differences in LN size between lateral views within each species. Enlarged sternal LNs were more cranially positioned in dogs than cats. No statistical difference was noted between right and left laterals, as to on which projection the enlarged sterna lymph nodes was seen best. Neoplastic disease (78.9%) was the most prevalent condition seen in association with LN enlargement in dogs, followed by primary infectious or inflammatory diseases (14.1%) and various hematologic conditions (7.0%). In cats, neoplasia was also most common (69.2%), followed by inflammatory diseases (30.8%). No hematologic conditions were noted in cats. The most common etiologic agent seen concurrently with enlarged sternal LNs in both dogs (33.8%) and cats (38.5%) was malignant lymphoma. The results of this study provide a clinically useful representation of the average size and location of radiographically enlarged sternal LNs for dogs and cats. The diseases represented demonstrate the wide spectrum of potential causes of sternal lymphadenopathy.     

IOHEXOL AND IOPAMIDOL MYELOGRAPHY IN THE DOG: A CLINICAL TRIAL COMPARING ADVERSE EFFECTS AND MYELOGRAPHIC QUALITY

In a blind clinical trial, adverse effects after iohexol and iopamidol myelography were evaluated in 151 dogs. Eighty-one dogs were given iohexol (240 mgI/ml) and 70 dogs were given iopamidol (200 mgI/ml) by pre-determined assignment. Each dog was evaluated postmyelographically for seizures, hyperthermia, prolonged recovery from anesthesia and intensification of pre-existing neural signs. Myelographic quality was evaluated with a subjective scoring method. In comparing iohexol and iopamidol groups, there was not a statistically significant difference in the incidence of adverse effects or in myelographic quality. Iopamidol and iohexol appeared to be equally efficacious for routine canine myelography.