THE DURAL TAIL SIGN IN THE DIAGNOSIS OF MENINGIOMAS

In humans the dural tail is a sign seen on contrast enhanced T1 weighted magnetic resonance images. This finding is considered specific for meningioma. The purpose of this study was to determine how often the dural tail occurs in cats and dogs and whether it is a specific sign for meningiomas in these species. MR examinations for eighteen dogs and four cats with proven diagnoses were reviewed. Diagnoses included ten meningiomas (seven dogs and three cats), three gliomas, two pituitary tumors, single examples of two other tumor types and five patients with mass lesions due to inflammatory disease. Contrast enhanced T1 weighted images were evaluated independently by three of the authors for the presence of a dural tail, without knowledge of the diagnoses. The results were compared to the diagnosis for each patient and the performance of individual reviewers compared. When their results were averaged, the reviewers reported the presence of a dural tail in 6 of 10 (60%) meningiomas, although detection varied between observers from 40% to 80%. Each reviewer had one false positive result, two reported a dural tail with a chromophobe adenocarcinoma and one with a toxoplasma meningoencephalitis. When a dural tail is seen an associated mass is most likely a meningioma. It is uncertain whether the dural tail represents neoplastic infiltration beyond the margins of the meningioma. This should be considered when planning treatment.     

Flaviviruses in South Africa: pathogenicity for sheep

Sheep are susceptible to at least 5 of the 10 flaviviruses known to be present in South Africa. Sheep, 7-9 months of age, injected with Wesselsbron, West Nile, Banzi, Uganda-S and AR 5189 (an unidentified virus related to Banzi and Uganda-S), responded with a moderate febrile reaction, a low grade viraemia of short duration and the production of virus neutralizing antibodies. The most pronounced manifestations of infection were encountered in pregnant ewes. Infection with West Nile, Banzi and AR 5189 resulted in abortion, stillbirth and neonatal death, characterized by congenital abnormalities of the brain.     

Evaluation of a thoracic focused assessment with sonography for trauma (TFAST) protocol to detect pneumothorax and concurrent thoracic injury in 145 traumatized dogs

Objective: To estimate the relative accuracy of a thoracic focused assessment with sonography for trauma (TFAST) protocol for rapid diagnosis of pneumothorax (PTX) and other thoracic injury in traumatized dogs. Design: Prospective case series. Setting: Private veterinary emergency center. Animals: One hundred and forty‐five client‐owned dogs evaluated within 24‐hours of injury. Interventions: Thoracic focused assessment with sonography for trauma protocol. Measurements and Main Results: Traumatized dogs were evaluated with a conventional ultrasound (US) machine using a standardized 4‐point thoracic FAST protocol before thoracic radiography (CXR) and thoracocentesis. PTX was diagnosed by the absence of the ‘glide sign,’ defined as the lack of the normal dynamic interface between lung margins gliding along the thoracic wall during respiration. Concurrent thoracic trauma was diagnosed by the presence of pleural or pericardial fluid or the presence of a ‘step sign,’ defined as an abnormal glide sign. Accuracy of TFAST was calculated relative to CXR findings. Results: Overall sensitivity (Se), specificity (Sp), and accuracy of TFAST relative to CXR were 78.1% (95% CI; 61.5, 89.9), 93.4% (95% CI; 87.4, 97.1), and 90.0%, respectively. Se and Sp were higher in dogs with penetrating trauma (93.3%, 96.0%) and for the evaluator with the most clinical experience (95.2%, 96.0%); only Se between the most experienced compared with others was statistically significant (P<0.05). TFAST documented other concurrent thoracic injury. Median time for TFAST was 3 minutes. Conclusions and Clinical Relevance: TFAST has the potential to rapidly diagnose PTX and other thoracic injury and guide therapy, including potentially life‐saving interventions, in traumatized dogs.     

MR EVALUATION OF INTRA AND EXTRACRANIAL EXTENSION OF NASAL ADENOCARCINOMA IN A DOG AND CAT

Nasal adenocarcinomas have been reported to extend into the cranial vault and cause neurologic disease. This report discusses a dog and cat with nasal adenocarcinoma which extended into the retrobulbar space, base of the cranial vault and adjacent soft tissues. The invasive characteristics of the neoplasms were documented by magnetic resonance imaging (MRI). Documentation of the extent of tumor is important if radiation therapy or surgery is planned. MRI was valuable in identifying extracranial and intracranial tumor invasion in these patients.     

Does control of bovine viral diarrhoea infection make economic sense?

AIM: To provide an economic analysis of the costs of control or eradication of bovine viral diarrhoea (BVD) against the estimated costs of the disease. METHODS: A decision-tree approach was adapted to an analysis of the costs of bovine viral diarrhoea virus (BVDV) infection and that of three main control options (vaccination, test-and-cull, and increased biosecurity) and their combinations, to the dairy industry in New Zealand. The model was based on an average herd of 322 milking cows. Endemic, epidemic and sporadic effects of BVDV infection were modelled in the herd, to derive an estimate of costs. RESULTS: The cost of BVDV infection to an infected average-sized dairy herd in New Zealand was estimated to be NZ $11,334 (or NZ $35.19 per cow) per annum, and NZ $48,311 over 10 years. Based on these calculations, the estimate of the annual cost of BVDV infection to the dairy industry in New Zealand was in excess of NZ $23 million per annum. While all of the control options required financial input, the rate of return compared with the cost of BVD, when viewed over a 10-year term, was as high as 123%. CONCLUSIONS: All control options offered considerable savings compared with the cost of BVD infection, and control is economically favourable. Uncertainty over the likely efficacy of the control options under field conditions in New Zealand would not allow a firm choice of one option over another at this stage, and more work on determining the efficacy of those control options in New Zealand is needed.     

Intracranial migration of Eucoleus (Capillaria) boehmi in a dog

A 4‐year‐old, spayed‐female great Dane was referred for surgical treatment of a suspected meningioma, diagnosed on magnetic resonance imaging 10 days prior to presentation. The suspected meningioma was removed via image‐guided stereotactic craniotomy. Histopathological diagnosis was severe, locally extensive, chronic meningoencephalitis with an intralesional nematode egg. The egg was morphologically consistent with Eucoleus boehmi, and aberrant migration into the cranial cavity was the presumed cause of this lesion. Three faecal samples were collected and revealed 4+ E. boehmi eggs. Treatment involved 110 mg/kg fenbendazole (Panacur, Intervet) orally twice daily for 14 days. Nematodes including E. boehmi are a previously un‐recognised source of intracranial disease in dogs, and should be considered as a differential for mass‐like lesions visualised by magnetic resonance imaging.     

Flaviviruses in South Africa: diagnostic procedures

Employing rabbit immune serum, 10 flaviviruses known to be present in South Africa could be divided into 5 serological subgroups. The subgroups conform to the general pattern described for the group. Sera from experimentally infected calves and lambs were monospecific in neutralization tests, but cross-reacted in haemagglutination inhibition tests. These results suggest that sheep and cattle sera from the field can best be tested by microneutralization tests. The greater sensitivity of embryonated hen's eggs for some viruses and of one-day-old mice for other viruses necessitates the employment of both systems for the isolation of flaviviruses from field specimens.