COMPUTED TOMOGRAPHY-GUIDED PERCUTANEOUS BIOPSY: CRITERIA FOR ACCURATE NEEDLE TIP IDENTIFICATION

Precise localization of the needle tip during CT-guided percutaneous biopsy is considered to be a key element of a successful procedure. To ensure accuracy, the true needle tip must be differentiated from a false or simulated tip which appears when the CT slice encompasses only the shaft of an angled needle. By obtaining images of an aspiration biopsy needle inserted vertically into a phantom and then incrementally tilting the gantry, the authors were able to compare the characteristic features of the true tip to the simulated tip. The true tip was abrupt and distinct and had an adjacent flame-like low density artifact. The simulated tip was indistinct and tapered, yet still produced the adjacent artifact. We concluded that the shape and distinctness of the end portion of the needle itself, rather than the attendant artifact, were the most reliable criteria for accurate needle tip identification.     

ULTRASONOGRAPHY OF ALIMENTARY LYMPHOSARCOMA IN THE CAT

Clinical, radiological and ultrasonographic findings from 22 cats with gastrointestinal lymphosarcoma were reviewed. The most common clinical findings were anorexia, weight loss, vomiting, lethargy, depression, fever, anemia and a palpable abdominal mass. Abdominal radiographs of 12 cats revealed a mass associated with the gastrointestinal tract and/or mesentery, and decreased serosal detail, suggestive of peritoneal effusion. The most common ultrasonographic finding was transmural gastric or intestinal thickening associated with loss of normal wall layering, reduced wall echogenicity and localized hypomotility. As is noted in people, other patterns such as transmural-segmental, transmural-nodular, transmural-bulky and mucosal infiltration were represented. In 3 cats, mesenteric lymph-adenopathy was responsible for most of the mass-effect. Fine-needle aspiration biopsy, automated microcore biopsy, endoscopic biopsy or necropsy confirmed the diagnosis of lymphosarcoma in all cats. Chemotherapy was instituted in 19 cats. Only 6 cats had a complete response to treatment. The results of this study indicate that ultrasonography is a valuable tool for the diagnosis of feline alimentary lymphosarcoma and that biopsies can be obtained under ultrasonographic guidance.     

Update on antifungal therapy.

Fungal pathogens are becoming increasingly important for human and small animal medicine. This article highlights many standards-of-care and new agents for treatment of these pathogens for small animals and people.     

The use of magnetic resonance imaging in the diagnosis of neurological disease

Magnetic resonance imaging (MRI) data were correlated with clinical and cerebrospinal fluid (CSF) findings in one cat and two dogs with brain lesions. In all three cases, localization of the lesions, as determined clinically, was confirmed using MRI. Magnetic resonance imaging also helped us to define the full extent of the lesion(s) in each case. In one case, the lesion would have been diagnosed as purely inflammatory based on the abnormalities in the CSF. The MRI study, however, showed a homogeneous mass with circumferential changes characteristic of peritumoral edema or inflammation. In two cases, the MRI findings were confirmed at necropsy. An MRI study was also done on a normal dog, demonstrating the variable contrast and anatomical detail possible using this technique. We also discuss difficulties in identifying tumor type using MRI.     

Efficacy of two dichlorvos formulations against larval and adult Hyostrongylus rubidus in swine.

Coated (V-13) and uncoated (V-22) formulations of dichlorvos were used to treat experimentally established Hyostrongylus rubidus infections of pigs at intervals after exposure to infective larvae. Both dichlorvos formulations were efficacious against the adult stomach worm H rubidus, but showed little or no activity against 5- or 15-day-old worms. Neither formulation was as effective against H rubidus in sows as in barrows and gilts.     

The re-emergence of indigenous forest in an urban environment, Christchurch, New Zealand

Christchurch, the second largest city in New Zealand is a planned city on a coastal plain on the east coast of the South Island. The birth of the city and the subsequent century of development was characterised by colonial values and tree and garden planting with familiar European species along with those from Australia, North America, and eventually all other continents. The image of an “English garden city” with classical parks of oaks and willow-lined rivers became the accepted norm and the way in which the city has been promoted to potential tourists. Gardening is one of the top two recreational activities and exotic species greatly outnumber native species in the flora and in gardens. This has had serious consequences for the highly fragmented and degraded indigenous vegetation and its co-adapted wildlife. A few hardy indigenous species continued to regenerate through this period, but since the 1970s, there has been a progressive change of attitude and interest in reclaiming the natural heritage of the city, manifest in widespread private and public planting of indigenous species and active habitat restoration. In this article we examine the indigenous and exotic shrub and tree components of the Christchurch flora as planted street trees, in domestic gardens, and in parks. We also present data on shrub and tree regeneration in parks and domestic gardens in the city. Indications are that the more sensitive, less intrusive management of urban environments, combined with the greater density of indigenous seed sources, has allowed regeneration of a wide range of indigenous species across a broad spectrum of habitats – from neglected gardens to pavement cracks to exotic plantations. This is despite the competition from the prodigious seed banks and density of exotic trees, shrubs, and ground covers and albeit minimal impacts of introduced browsing and seed eating mammals. If the present trends continue through appropriate management and facilitation, these tentative signs of native forest regeneration should eventually proliferate into a sustainable mixed origin urban forest that resurrects and preserves the natural character of the region.     

The stress response to environmental change in captive cheetahs (Acinonyx jubatus).

The captive North American cheetah (Acinonyx jubatus) population is not self-sustaining because of high prevalences of unusual diseases and poor reproductive success. Cheetahs are commonly moved between zoos for breeding purposes to maintain genetic diversity within the captive population, and movement may exacerbate infertility and disease. Fecal corticoids were analyzed by radioimmunoassay to measure the stress response of cheetahs to movement between facilities. Fecal samples were collected from 15 cheetahs for 14 days before movement and for at least 30 days after movement. For each cheetah, premovement fecal corticoid concentrations were used to determine baseline and then compared with trends in postmovement concentrations. In general, postmovement corticoid concentrations either increased (n = 8), did not change (n = 2), or decreased (n = 5). Although individual animal differences occurred, corticoid concentrations increased for most animals moved on-exhibit and decreased in animals moved off-exhibit. Animals moving on-exhibit had an 18-times greater risk of having corticoids elevated more than two standard deviations above baseline for 30 days after movement compared with animals that moved off-exhibit. In addition, greater day-to-day variation in corticoids occurred in animals moved on-exhibit. In general, animals with initially low baseline corticoid concentrations had a greater postmovement corticoid response than cheetahs with initially high baseline levels. These results indicate that some cheetahs have a prolonged stress response when moved between facilities, and the magnitude and character of this response is influenced by the exhibit environment.