Comparison of standard single-bite with multiple-bite biopsy forceps for collection of gastrointestinal biopsies in dogs: a prospective study.

Various types of endoscopic biopsy forceps have been investigated in dogs. The Multibite (MB) are multiple-bite forceps that collect up to four tissue specimens in a single pass through the endoscope, reducing procedure time. The authors prospectively investigated its clinical utility by comparing procedure times and diagnostic quality of samples obtained with the MB to that of biopsies performed with a single-bite forceps (SB), in 21 dogs with gastrointestinal disorders. When comparing the depth, crush artefacts and diagnostic adequacy of the gastric and duodenal biopsies, there was no significant difference between the MB and SB forceps. The procedure time was significantly longer with the MB. There was no learning curve effect, and there were no reported adverse events. This study failed to demonstrate any significant clinical advantage associated with the use of the Multibite forceps over that of conventional disposable SB forceps.

The dog as an animal model for bladder and urethral urothelial carcinoma: Comparative epidemiology and histology.

Despite the recent approval of several novel agents for patients with metastatic urothelial carcinoma (UC), survival in this setting remains poor. As such, continued investigation into novel therapeutic options remains warranted. Pre-clinical development of novel treatments requires an animal model that accurately simulates the disease in humans. The aim of the present study was to evaluate the dog as an animal model for human UC. A total of 260 cases of spontaneous, untreated canine primary urethral and urinary bladder UC, were epidemiologically and histologically assessed and classified based on the current 2016 World Health Organization (WHO) tumor classification system. Canine data was compared with human data available from scientific literature. The mean age of dogs diagnosed with UC was 10.22 years (range, 4-15 years), which is equivalent to 60-70 human years. The results revealed a high association between UC diagnosis with the female sex [odds ratio (OR) 3.51; 95% confidence interval (CI) 2.57-4.79; P<0.001], surgical neutering (OR 4.57; 95% CI 1.87-11.12; P<0.001) and breed (OR 15.11 for Scottish terriers; 95% CI 8.99-25.41; P<0.001). Based on the 2016 WHO tumor (T), node and metastasis staging system, the primary tumors were characterized as T1 (38%), T2a (28%), T2b (13%) and T3 (22%). Non-papillary, flat subgross tumor growth was strongly associated with muscle invasion (OR 31.00; P<0.001). Irrespective of subgross growth pattern, all assessable tumors were invading beyond the basement membrane compatible with infiltrating UC. Conventional, not further classifiable infiltrating UC was the most common type of tumor (90%), followed by UC with divergent, squamous and/or glandular differentiation (6%). Seven out of the 260 (2.8%) cases were classified as non-urothelial based on their histological morphology. These cases included 5 (2%) squamous cell carcinomas, 1 (0.4%) adenocarcinoma and 1 (0.4%) neuroendocrine tumor. The 2 most striking common features of canine and human UC included high sex predilection and histological tumor appearance. The results support the suitability of the dog as an animal model for UC and confirm that dogs also spontaneously develop rare UC subtypes and bladder tumors, including plasmacytoid UC and neuroendocrine tumor, which are herein described for the first time in a non-experimental animal species.

Novel characteristics identified in two cases of feline cowpox virus infection.

CASE SERIES SUMMARY: This case series discusses novel characteristics identified in two cases of cowpox. One presented with upper airway signs, and was identified to have a focal laryngeal lesion. The other had central neurological signs at the terminal stages, with intracytoplasmic inclusion bodies identified within the cerebral hemispheres on histopathology. RELEVANCE AND NOVEL INFORMATION: Currently, cowpox would be an unlikely consideration in patients with neurological signs or upper respiratory noise. These cases both document novel presentations of cowpox infection, which clinicians should be aware of and consider as differential diagnoses in patients with these atypical presentations.

Outcome and Prognostic Factors for Canine Splenic Lymphoma Treated by Splenectomy (1995-2011).

OBJECTIVE: To assess the outcome of canine splenic lymphoma treated with splenectomy and to evaluate prognostic factors, including involvement of other sites, adjuvant chemotherapy, and the effect of World Health Organization (WHO) histological classification of canine malignant lymphoma. DESIGN: Multi-institutional, retrospective study. ANIMALS: Client-owned dogs (n = 28). METHODS: Medical records (1995-2011) of dogs with a histological diagnosis of splenic lymphoma and treated by splenectomy submitted by Veterinary Society of Surgical Oncology members were reviewed. Included were dogs treated with or without adjuvant therapy. Overall survival, disease-free interval, and cause of death were determined. Prognostic factors and the WHO histological classification of canine malignant lymphoma were evaluated with respect to outcome. RESULTS: Dogs with splenic lymphoma treated by splenectomy had a 1-year survival rate of 58.8%, after which no animals died of their disease. B cell lymphoma held a better prognosis for survival than other variants of splenic lymphoma. Marginal zone lymphoma and mantle cell lymphoma were the most common B cell lymphoma subtypes in our study. Hemoabdomen and clinical signs related to splenic lymphoma, including abdominal distention, lethargy, and anorexia, were poor prognostic indicators, whereas disease confined to the spleen was a positive prognostic indicator. Pre- or postoperative adjuvant chemotherapy did not provide a survival benefit. CONCLUSION: Based on our sample population, splenectomy alone was an effective treatment for splenic lymphoma in cases with disease confined to the spleen. Chemotherapy may not improve survival in cases of lymphoma restricted to the spleen.

A preliminary survey of the histopathological features of skin from the planum nasale and adjacent skin of dogs unaffected by dermatological or respiratory disease.

BACKGROUND: There is a general belief that immune system cells are present in larger numbers in the planum nasale and adjacent haired skin than in other locations in the dog. However, little published information about the normal histological appearance of the skin of this area exists. HYPOTHESIS/OBJECTIVES: The aim was to obtain information about the normal histological appearance of canine skin for specific anatomical regions of the planum nasale and the haired skin adjacent to the planum nasale. ANIMALS: Samples from three sites were obtained from the planum nasale and adjacent haired skin of 25 dogs of varying age, breed and sex, with no evidence of dermatological or respiratory disease. METHODS: Samples were analysed to determine and quantify the immune system cells present in the samples. Slides were stained with haematoxylin and eosin or toluidine blue; immunohistochemical stains for CD3 and CD79a were applied. RESULTS: Immune system cells, including lymphocytes and plasma cells, were either very rare or present in low numbers. The majority of lymphocytes were of T-cell origin, with only infrequent B cells identified. Samples contained numerous melanophages, consistent with pigmentary incontinence, regardless of the presence or absence of inflammatory cells. Mast cells and plasma cells were present in low numbers. CONCLUSIONS: Inflammatory change noted in diagnostic biopsies from this area from dogs with clinical disease is likely to be of pathological significance. However, pigmentary incontinence appears to be common at this site in clinically normal dogs without significant inflammatory cell infiltration and is therefore not necessarily of pathological significance when seen in isolation in this location.

Hemipelvectomy: outcome in 84 dogs and 16 cats. A veterinary society of surgical oncology retrospective study.

OBJECTIVE: To report clinical findings, perioperative complications and long-term outcome in dogs and cats that had hemipelvectomy surgery for treatment of neoplasia. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Dogs (n = 84) and cats (16). METHODS: Medical records (January 2000 to December 2009) of dogs and cats that had hemipelvectomy at participating institutions were reviewed. Postoperative progress and current status of the patient at the time of the study was determined by either medical record review, or via telephone contact with the referring veterinarian or owner. RESULTS: Complications were infrequent and usually minor. Hemorrhage was the main intraoperative complication; 2 dogs required blood transfusion. One dog developed an incisional hernia. In dogs, hemangiosarcoma had the worst prognosis with a median survival time (MST) of 179 days. MST for chondrosarcoma (1232 days), osteosarcoma (533 days), and soft tissue sarcoma (373 days) were not statistically different. Median disease-free interval (DFI) for local recurrence of all tumor types was 257 days. Cats had 75% survival at 1 year, which was significantly longer than dogs. CONCLUSIONS: Survival times for most tumor types can be good, but surgical margins should be carefully evaluated to ensure complete tumor removal. Adjuvant therapies may be advisable particularly for dogs to reduce rates of local recurrence or distant metastasis.

Solitary plasmacytoma of bone in two successfully treated cats.

This is the first report of feline solitary plasmacytoma of bone. We describe the clinical, clinico-pathological, radiographic and pathological findings of two successfully treated cats with long-term follow-up. The first case presented with spinal pain and neurological deficits. Radiographs demonstrated sclerosis of lumbar vertebra L6 and a myelogram confirmed interference to flow of contrast in the L4-7 region. A biopsy of L6 revealed neoplastic plasma cell infiltration. There was no evidence of paraproteinaemia on serum protein electrophoresis. The cat underwent hypofractionated megavoltage radiotherapy. Clinical signs resolved completely and 4 years after diagnosis the cat remains well and has no electrophoretically detectable paraproteinaemia. The second case presented with neurological deficits of the tail and spinal radiographs revealed extensive osteolysis of the sacrum. A biopsy of sacral bone demonstrated neoplastic plasma cell infiltration. The animal was normoglobulinaemic. The cat improved clinically with induction chemotherapy (melphalan and methylprednisolone). The same chemotherapeutics were continued at maintenance doses for 4.3 years, at which time there was recurrence of neurological deficits and a palpable sacral mass. Cytological examination of a fine needle aspirate confirmed recurrence of plasma cell neoplasia. A low concentration monoclonal paraproteinaemia was detected. Vincristine was administered resulting in resolution of neurological deficits and a palpably smaller sacral mass. Eighteen months into vincristine therapy, there was recurrence of clinical signs and the cat was euthanased, more than 6 years after the initial diagnosis.

Subclinical hyperthyroidism in cats: a spontaneous model of subclinical toxic nodular goiter in humans?

INTRODUCTION AND OBJECTIVES: Hyperthyroidism in cats, caused by nodular hyperplasia or adenomas, is clinically and histologically similar to toxic nodular goiter in humans. Subclinical hyperthyroidism in humans is defined as low thyrotropin (TSH) in conjunction with within-reference-range thyroid hormone concentrations, but has not previously been defined in cats. The objective of this study was to test the hypothesis that euthyroid senior cats with low TSH have histological evidence of thyroid nodular hyperplasia and/or adenoma. DESIGN: Thyroid glands removed postmortem from four groups of cats (n = 73) were examined histologically and scored in a blinded fashion. Clinically euthyroid senior (>7 years) cats were divided into two groups dependent on their TSH concentration--TSH below the limit of quantification (LOQ) of the assay (<0.03 ng/mL; n = 15; UndetectableTSH group) and TSH above the LOQ (>or=0.03 ng/mL; n = 31; DetectableTSH group)--using archived plasma samples, collected 0-6 months antemortem. Thyroids were also scored for two control groups: Young group (cats <6 years old; n = 13) and Hyperthyroid group (clinically and biochemically hyperthyroid cats; n = 14). MAIN OUTCOME: Cats in the UndetectableTSH group had a higher frequency of nodules, a greater percentage of abnormal thyroid tissue, and a higher overall histopathological grade than cats with detectable TSH had. CONCLUSION: Euthyroid (as defined by total thyroxine) senior cats with low TSH are likely to have histological evidence of nodular thyroid disease, and such cats could be considered to be subclinically hyperthyroid.

Bilateral, hypertrophic neuritis of the brachial plexus in a cat: magnetic resonance imaging and pathological findings.

A 9-year-old Burmese cat was presented for investigation of a subacute onset of bilateral forelimb paresis. Magnetic resonance imaging of the cervico-thoracic vertebral column and brachial plexus revealed a bilaterally symmetrical, severe and diffuse swelling of the spinal nerves forming the caudal part of the brachial plexus. Histopathology of the abnormal nerve roots, spinal nerves and brachial plexi showed inflammatory and marked proliferative changes with similar features to that of hypertrophic neuritis of man. Hypertrophic neuritis in man is a rare, tumor-like, chronic inflammatory peripheral nerve disorder of unknown origin most frequently involving the brachial plexus.