Canine Ependymoma: Diagnostic Criteria and Common Pitfalls.

Reports of canine ependymoma are generally restricted to single case reports with tumor incidence estimated at 2% to 3% of primary central nervous system (CNS) tumors. While most commonly reported in the lateral ventricle, tumors can occur anywhere in the ventricular system and in extraventricular locations. Rosettes and pseudorosettes are a common histologic feature; however, these features can be mimicked by other CNS neoplasms. Thirty-seven potential ependymoma cases were identified in a retrospective database search of 8 institutions, and a histologic review of all cases was conducted. Of 37 cases, 22 candidate cases were further subjected to a consensus histologic and immunohistochemical review, and only 5 of 37 (13.5%) were conclusively identified as ependymoma. The neuroanatomic locations were the lateral ventricle (3/5), third ventricle (1/5), and mesencephalic aqueduct (1/5). Subtypes were papillary (4/5) and tanycytic (1/5). Histologic features included rosettes (5/5), pseudorosettes (5/5), ependymal canals (2/5), tanycytic differentiation (1/5), blepharoplasts (1/5), ciliated cells (1/5), and high nuclear to cytoplasmic ratio (5/5). Immunolabeling for GFAP (4/4) and CKAE1/3 (3/4) was found in pseudorosettes, rosettes, and scattered individual neoplastic cells. Diffuse but variably intense cytoplasmic S100 immunolabeling was detected in 3 of 4 cases. Olig2 intranuclear immunolabeling was observed in less than 1% of the neoplastic cells (3/3). Tumors that had pseudorosettes and mimicked ependymoma included oligodendroglioma, choroid plexus tumor, pituitary corticotroph adenoma, papillary meningioma, and suprasellar germ cell tumor. These findings indicate that canine ependymoma is an extremely rare neoplasm with histomorphologic features that overlap with other primary CNS neoplasms.

Diagnosis and treatment of Eimeria macusaniensis in an adult alpaca with signs of colic.

A young adult pregnant alpaca was presented with an acute episode of abdominal pain. Hematology revealed mild anemia, neutropenia with a degenerative left shift and moderate toxic changes in neutrophils, hyperfibrinogenemia, hypoproteinemia, and hypoalbuminemia. Abdominal ultrasound showed a small intestinal segment with severely increased wall thickness and collapsed lumen. Exploratory laparotomy revealed a markedly thickened 60cm jejunal segment with reddened serosa from which a full-thickness biopsy and samples for bacterial culture were obtained. Histopathology revealed severe coccidian enteropathy with secondary bacterial enteritis. Anaerobic culture yielded Clostridium perfringens, while fecal sugar flotation yielded Eimeria macusaniensis and Eimeria punoensis. The alpaca was treated with broad-spectrum antimicrobial drugs, sulfadimethoxine, and anti-inflammatory drugs. The alpaca made a gradual recovery and had a term pregnancy. This communication demonstrates the potential pathogenicity of E. macusaniensis in adult alpacas. Coccidian enteropathy should be considered in adult alpacas with gastrointestinal signs including acute abdominal pain and hypoproteinemia.

Distribution of a lidocaine-methylene blue solution staining in brachial plexus, lumbar plexus and sciatic nerve blocks in the dog.

OBJECTIVE: To determine the influence on the distribution of the volume of a local anaesthetic-methylene blue solution at three different nerve block sites in the dog. STUDY DESIGN: Randomized, controlled, blinded experimental trial. ANIMALS: 23 hound-cross dogs weighing 16-40 kg and aged 2 +/- 0 years (mean +/- SD). METHODS: Dogs were anaesthetized and randomly assigned to three groups of seven or eight dogs each, based on volume administered: low, medium and high volume (L, M and H). Using electrolocation, the injection was performed after a positive response was elicited (flexion of the elbow for the brachial plexus block, quadriceps contractions for the lumbar plexus and dorsiflexion/plantar extension of the foot for the sciatic nerve block). At the brachial plexus site, groups L, M and H received 0.075, 0.15 and 0.3 mL kg(-1), respectively. At the lumbar plexus site, groups L, M and H received 0.1, 0.2 and 0.4 mL kg(-1), respectively. At the proximal sciatic nerve site, groups L, M and H received 0.05, 0.1 and 0.25 mL kg(-1), respectively. Necropsies were performed immediately following euthanasia. Staining of > or =2 cm along the nerve was considered sufficient; the proportions sufficient were compared with Fisher's exact test. The volume was recommended when all the relevant nerves were stained sufficiently in all or all but one of the dogs within the group. RESULTS: In the brachial plexus, only in group H were all the nerves stained sufficiently. In the lumbar plexus site, no statistical difference was found, but we suggest the H group volume to balance sufficient and excessive staining. At the sciatic nerve site, all volumes tested produced sufficient staining in all (or all but one) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Volumes of 0.3 and 0.05 mL kg(-1) produced sufficient distribution for performing brachial plexus, and sciatic nerve blocks, respectively. Additionally, a volume of 0.4 mL kg(-1) might also be adequate for a lumbar plexus block (no statistical significance was reached).

Pituitary-dependent hyperadrenocorticism in a cockatoo.

CASE DESCRIPTION: A 13-year-old female intact Moluccan cockatoo (Cacatua moluccensis) was evaluated because of coelomic distention, presumed to be secondary to an abdominal hernia. The patient also had a history of rapid weight gain and polyuria and polydipsia. CLINICAL FINDINGS: Ultrasonography was used to confirm the existence of a pseudohernia that appeared to contain the small intestines, pancreas, and reproductive tract. Results of plasma biochemical analysis revealed hyperglycemia, hypophosphatemia, and high nonfasting bile acid concentrations and aspartate aminotransferase activity. A CBC revealed a relative heterophilia with a concomitant lymphopenia and mild monocytosis. Histologic evaluation of a liver biopsy specimen indicated chronic hepatic lipidosis. Despite a strong clinical suspicion of hyperadrenocorticism, ACTH stimulation test results were equivocal. TREATMENT AND OUTCOME: The pseudohernia was strengthened with a prolene mesh. Despite ongoing medical and surgical care, the patient developed complications associated with the herniorrhaphy and was euthanatized. The clinical suspicion of hyperadrenocorticism was confirmed on the basis of histologic evaluation of the pituitary gland by use of special stains. CLINICAL RELEVANCE: To our knowledge, pituitary-dependent hyperadrenocorticism has not been previously confirmed in Psittaciformes. The condition should be considered in birds with clinical signs consistent with those observed in mammals. For the cockatoo of this report, ACTH stimulation test results were equivocal and additional diagnostic tests should be developed for avian patients.