Prolactin and growth hormone immunoactivity in canine mammary adenomas and adenocarcinomas.

It is now widely accepted in human medicine that prolactin (PRL) and growth hormone (GH) function in the mammary gland in an autocrine and paracrine manner in tumour formation. The aim of this study was to compare PRL and GH immunoactivity in canine mammary tumours submitted for histopathologic evaluation. Formalin-fixed specimens from spontaneously occurring mammary adenomas and adenocarcinomas from 24 female client-owned dogs were used. Information pertaining to the reproductive status of the patient at the time of mammary tumour diagnosis was obtained from each of the submitting veterinarians. Tissues were paraffin-embedded and sectioned (5 µm) onto charged slides. All slides were deparaffinized and rehydrated. Endogenous peroxidase activity was inactivated with 3% H2 O2, and non-specific binding was blocked. Polyclonal rabbit antihuman PRL (DAKO A0569) and GH antibody (DAKO A0570) were applied at a 1:250 and 1:200 dilutions, respectively. A universal rabbit negative control (DAKO N1699) was used. Slides were then reacted with anti-rabbit horseradish peroxidase followed by Nova Red Peroxidase substrate. Slides were counter-stained with haematoxylin, dehydrated and mounted. Tumour type and reproductive status at time of tumour diagnosis were compared individually between tumours that were negative or positive for PRL and GH using a two-tailed analysis of variance. Significance was defined as p < .05. There was no significant relationship between tumour type and PRL and GH presence. In addition, reproductive status at the time of tumour removal was found to be not significant. These results vary from previous reports in canine mammary tumours and warrant further investigation.

Cardiac-gated computed tomography angiography in three alpacas with complex congenital heart disease.

BACKGROUND: The prevalence of congenital heart disease is higher in camelids than in other domestic species and complex defects, often involving the great vessels, are more frequently encountered in llamas and alpacas than in other species. Some of these complex defects can be difficult to accurately characterize via echocardiography, the most commonly used diagnostic imaging technique to evaluate the heart in veterinary patients. Contrast-enhanced, electrocardiogram (ECG)-gated computed tomography (CT) has proven utility for the evaluation of human patients with certain congenital heart defects, including those with conotruncal septation defects and other abnormalities involving the formation of the great vessels. METHODS: Three alpaca crias, 4 days, 5 weeks and 14 months of age were clinically evaluated and subjected to a complete color-flow Doppler echocardiogram and a contrast-enhanced ECG-gated CT. RESULTS: These alpacas exhibited a variety of clinical findings including lethargy, failure to thrive, exercise intolerance, heart murmur, and/or respiratory difficulty. All three crias were subsequently diagnosed with complex cardiac defects including pulmonary atresia with a ventricular septal defect (VSD), a truncus arteriosus with a large VSD, and a double outlet right ventricle with a large VSD and aortic hypoplasia. In each case, the diagnosis was confirmed by postmortem examination. CONCLUSION: Color flow echocardiographic evaluation identified all of the intra-cardiac lesions and associated flow anomalies but contrast-enhanced ECG-gated CT permitted more accurate assessment of the morphology of the extracardiac structures and permitted a more precise determination of the exact nature and anatomy of the great vessels.

[Leptospirosis with necro-haemorrhagic cholecystitis in a Boxer puppy]. / Leptospirose mit hämorrhagisch-nekrotisierender Cholezystitis bei einem Boxerwelpen.

A Boxer puppy from the island of Rügen, which was properly vaccinated according to its age, was presented with acute gastrointestinal symptoms. The presumptive diagnosis of leptospirosis with acute renal failure, hepatic damage, and jaundice was confirmed by seroconversion (increased titre to 1 : 800 in a non-vaccine serogroup 4 weeks after disease onset). Cholecystitis was diagnosed based on clinical symptoms and sonographic results. After an initial improvement, the puppy's condition deteriorated and cholecystectomy was performed. Histopathological diagnosis indicated a haemorrhagic necrotizing cholecystitis.

HDAC8 and STAT3 repress BMF gene activity in colon cancer cells.

Histone deacetylase (HDAC) inhibitors are undergoing clinical trials as anticancer agents, but some exhibit resistance mechanisms linked to anti-apoptotic Bcl-2 functions, such as BH3-only protein silencing. HDAC inhibitors that reactivate BH3-only family members might offer an improved therapeutic approach. We show here that a novel seleno-α-keto acid triggers global histone acetylation in human colon cancer cells and activates apoptosis in a p21-independent manner. Profiling of multiple survival factors identified a critical role for the BH3-only member Bcl-2-modifying factor (Bmf). On the corresponding BMF gene promoter, loss of HDAC8 was associated with signal transducer and activator of transcription 3 (STAT3)/specificity protein 3 (Sp3) transcription factor exchange and recruitment of p300. Treatment with a p300 inhibitor or transient overexpression of exogenous HDAC8 interfered with BMF induction, whereas RNAi-mediated silencing of STAT3 activated the target gene. This is the first report to identify a direct target gene of HDAC8 repression, namely, BMF. Interestingly, the repressive role of HDAC8 could be uncoupled from HDAC1 to trigger Bmf-mediated apoptosis. These findings have implications for the development of HDAC8-selective inhibitors as therapeutic agents, beyond the reported involvement of HDAC8 in childhood malignancy.

One hundred two tumors in 100 goats (1987-2011).

Of 1146 caprine necropsy or biopsy specimens submitted from 1987 through 2011 to the Veterinary Diagnostic Laboratory at Oregon State University, 100 goats (8.7%) had 102 tumors. Detailed records were available for 89 cases. Fifty-five goats were female, 17 were castrated males, and 12 were intact males. Breeds included 21 Nubian, 16 Pygmy, 10 Pygora, 8 Alpine, 4 Angora, 4 Saanen, 2 Toggenburg, and 9 crossbred goats. Dwarf, Nubian, and Saanen goats were overrepresented and Alpine and Boer goats underrepresented among cases with neoplastic disease in comparison to submissions overall. Age ranged from 7 months to 19 years (median, 7 years). Histopathology was performed on 97 tumors. Lymphoma (n = 17) was the most common tumor, followed by cutaneous squamous cell carcinoma (n = 10) and thymoma (n = 9). Most lymphomas were multicentric. All 7 mammary neoplasms were adenocarcinomas. Five of 7 vascular proliferations were hemangiosarcomas. All 4 melanocytic tumors were classified as (malignant) melanoma. Rarely reported caprine tumors included a choroid plexus carcinoma, 2 rhabdomyosarcomas, and 3 pheochromocytomas. Cutaneous round cell tumors were provisionally diagnosed as 2 histiocytomas and 5 mast cell tumors. Single cases of previously unreported caprine tumors included amyloid-producing odontogenic tumor, myxosarcoma, sebaceous carcinoma, apocrine sweat gland adenoma, and thyroid carcinoma. Nonneoplastic entities included 2 cases of mammary fibroadenomatous hyperplasia and single cases of vascular hamartoma, cervical adenomatous hyperplasia, and cervical leiomyofibromatosis. The results of this 25-year retrospective study indicate that lymphoma in particular and tumors in general are common in goats.

Vertebral fractures in two alpaca crias with rickets syndrome.

CASE REPORT: Two dark-coloured alpaca crias aged 5 and 5.5 months, respectively, born in September in the Pacific Northwest, USA, were presented for evaluation of acute recumbency. Both crias had cervical spine fractures and one had additional fractures in other locations within the spine. Both crias had valgus deformities of the forelimbs and one had similar deformities of the hindlimbs. Both crias showed characteristic radiological signs of rickets syndrome, including wide, irregular physes, cupping of the metaphyses, bowing of long bones, pathological fractures and enlarged costochondral junctions. One cria responded clinically to treatment with parenteral administration of vitamin D. The other cria was euthanased because of the multiple spinal fractures and postmortem examination supported the diagnosis of rickets syndrome. CONCLUSIONS: Hypovitaminosis D is associated with abnormal bone formation in young growing animals. The clinical and laboratory findings of rickets syndrome in camelids in the Pacific Northwest, and other regions with low annual sunlight exposure, have been described, although there are only few reports of the radiological signs associated with this condition in camelids and other animals. Additionally, vertebral fractures have not been previously reported in animals with rickets syndrome. Because vertebral fractures were identified in both crias in this report, it suggests that this is a common and clinically important manifestation of the disease in alpaca crias. Hence, in geographic regions with low sunlight exposure, rickets syndrome should be considered as a differential diagnosis in crias presenting with clinical signs consistent with vertebral fracture.

Infiltrative myxoma of the stifle joint and thigh in a domestic rabbit (Oryctolagus cuniculus).

A 5-year-old male domestic rabbit had severe swelling of the left hindlimb. Radiographs demonstrated a proliferative, infiltrative lesion involving the stifle joint, femur and soft tissues of the thigh. Osteomyelitis or neoplasia was suspected and the limb was amputated. Grossly, there was a multilobular mass comprised of cystic spaces containing yellow mucinous material. Microscopically, the mass formed coalescing lobules of stellate to rounded cells embedded in varying amounts of myxoid to collagenous matrix, and some rimmed by narrow walls of metaplastic bone and/or cartilage, and some infiltrated by plasma cells, lymphocytes, heterophils and histiocytes. Immunohistochemically, neoplastic cells expressed vimentin but not cytokeratin, sarcomeric actin, Mac387 or BLA36. Cytokeratin was not detected in normal synovial cells. The radiographic, gross and histological findings were most consistent with synovial myxoma; however, because of the extensive involvement of the limb in the absence of confirmed metastatic disease, the term infiltrative synovial myxoma was applied.

Mesenteric lymphangitis and sepsis due to RTX toxin-producing Actinobacillus spp in 2 foals with hypothyroidism-dysmaturity syndrome.

Actinobacillus suis-like organisms (ASLOs) have been isolated from the genital, respiratory, and digestive tracts of healthy adult horses, horses with respiratory disease, and septic foals. Two foals with congenital hypothyroidism-dysmaturity syndrome from separate farms developed ASLO infection. At necropsy, both had contracted carpal flexor tendons, thyroid hyperplasia, and thrombotic and necrotizing mesenteric lymphangitis and lymphadenitis; one foal also had mandibular prognathism. Numerous ASLOs were isolated from tissues from both foals, including intestine. Biochemical testing and mass spectrometric analysis of the two Actinobacillus isolates did not allow unequivocal identification. Comparative genetic analysis was done on these and similar isolates, including phylogeny based on 16S rRNA, rpoB and recN genes, as well as RTX (repeat in toxin) toxin typing of apxIA-apxIVA and aqxA genes. One isolate was identified as Actinobacillus suis sensu stricto, based on the presence of apxIA and apxIIA but not aqxA, whereas the other isolate had aqxA but neither apxIA nor apxIIA, consistent with A equuli ssp haemolyticus. Based on genotypic analysis of the isolates included for comparison, 3 of 3 equine ASLOs and 2 of 5 A equuli isolates were reclassified as A equuli subsp haemolyticus, emphasizing the importance of toxin genotyping in accurate classification of actinobacilli.

Characterization of the microanatomy and histopathology of placentas from aborted, stillborn, and normally delivered alpacas (Vicugna pacos) and llamas (Lama glama).

From 2002 to 2007, 101 camelid abortions and stillbirths were submitted to the Veterinary Diagnostic Laboratory at Oregon State University (84 alpacas [Vicugna pacos], 13 llamas [Lama glama], 4 unknown). For most cases (n = 67), a cause was not determined by routine testing. Eighty-five submissions included placenta for microscopic examination, of which 55 were from abortions to unknown causes (idiopathic). Microscopic features of placentas from abortion/stillbirth were compared with those from 19 camelids delivered normally (6 alpacas, 12 llamas, 1 unknown) and with those from 4 alpaca fetuses of known gestational age collected during the dam's necropsy. The most common microscopic findings in abortion/stillbirth placentas were mineralization (n = 57) and mucinous edema (n = 27) of the chorioallantoic stroma. One or more of these features were also observed in 22 of 23 placentas from normal pregnancies/deliveries and therefore interpreted as incidental findings. The comparison of alpaca placentas after matching for gestational parameters (crown-rump length, weight, days of gestation; n = 41) revealed hypoplasia of placental villi in 5 of 22 idiopathic abortions and in 1 abortion due to umbilical torsion; hypoplasia was further suspected in an additional 6 abortions of unknown cause and 2 abortions of known cause. The identified villous hypoplasia is assumed to have resulted in placental insufficiency. When placental insufficiency is included as cause, idiopathic abortions are reduced from 66.2 to 47.9% of alpaca cases with histopathologic examination of placenta and from 66.3 to 52.5% of alpaca and llama abortions overall. This study also permitted the generation of a linear regression curve correlating alpaca fetal crown-rump length with fetal age.

Pathology and viral antigen distribution of lethal pneumonia in domestic cats due to pandemic (H1N1) 2009 influenza A virus.

A novel swine-origin H1N1 influenza A virus has been identified as the cause of the 2009 influenza pandemic in humans. Since then, infections with the pandemic (H1N1) 2009 influenza virus have been documented in a number of animal species. The first known cases of lethal respiratory disease associated with pandemic (H1N1) 2009 influenza virus infection in house pets occurred in domestic cats in Oregon. A 10-year-old neutered domestic shorthair and an 8-year-old spayed domestic shorthair died shortly after developing severe respiratory disease. Grossly, lung lobes of both cats were diffusely firm and incompletely collapsed. Histologically, moderate to severe necrotizing to pyonecrotizing bronchointerstitial pneumonia was accompanied by serofibrinous exudation and hyaline membranes in the alveolar spaces. Influenza A virus was isolated from nasal secretions of the male cat and from lung homogenate of the female cat. Both isolates were confirmed as pandemic (H1N1) 2009 influenza virus by real-time reverse transcriptase polymerase chain reaction. With immunohistochemistry, influenza A viral antigen was demonstrated in bronchiolar epithelial cells, pneumocytes, and alveolar macrophages in pneumonic areas. The most likely sources of infection were people in the household with influenza-like illness or confirmed pandemic (H1N1) 2009 influenza. The 2 cases reported here provide, to the best of the authors' knowledge, the first description of the pathology and viral antigen distribution of lethal respiratory disease in domestic cats after natural pandemic (H1N1) 2009 influenza virus infection, probably transmitted from humans.

Malignant round cell neoplasia in llamas and alpacas.

Malignant round cell neoplasia was identified in 12 llamas and 12 alpacas aged 0-23 years. Mean age of affected alpacas (3.1 years) was significantly less than that of affected llamas (8.0 years). Tumor cell morphology varied from large and often pleomorphic (11 tumors) to small and often homogeneous (13 tumors). Neoplastic lesions were multicentric in 12 cases. Other sites were gastric (5 cases), intra-abdominal (perirenal; 4 cases), intrathoracic (2 cases), and cervical (1 case). Immunohistochemistry with antibodies to CD79alpha, BLA36, and CD3 identified B-cell lymphoma (12 cases) and T-cell lymphoma (6 cases). Six tumors did not express any lymphoid marker and were further immunostained for neuron-specific enolase (NSE), synaptophysin, S-100, glial fibrillary acidic protein (GFAP), and chromogranin A. All 6 of these tumors were negative for GFAP and chromogranin A but expressed 1 or more of the neural markers NSE, synaptophysin, and S-100 and were classified as primitive malignant round cell tumors (PMRCT). Tumor types could not be distinguished on the basis of animal age, gross pathologic appearance, tumor morphology, or tumor location. All animals with lymphoma and 5 with PMRCT died or were euthanatized. One alpaca with a focal cervical PMRCT lived for at least 20 months after diagnosis. Results of this study indicate that malignant round cell tumors in llamas and alpacas are a heterogeneous group that cannot be distinguished on the basis of signalment, postmortem findings, or routine light microscopic findings. Immunohistochemistry is a valuable diagnostic procedure when evaluating malignant round cell neoplasia in llamas and alpacas.

Diagnostic exercise: epithelioid hemangiosarcoma mimicking metastatic prostatic neoplasia in a dog.

A 10-year-old intact male Labrador Retriever dog was euthanized because of rapid deterioration after suffering from mild chronic cough, hematuria, acute blindness, ataxia, and lethargy. Clinical examination revealed blepharospasm and hyphema, with clear discharge from the right eye; a firm mass in an enlarged right testicle; a mass in the irregularly enlarged prostate; and nodules in the left kidney, liver, and spleen detected by abdominal sonography. Cytologic evaluation of fine needle aspirates from the prostate, testis, and kidney comprised large, clustered or individualized, anaplastic cells that lacked convincing tissue differentiation. Necropsy examination revealed an irregularly enlarged prostate with dark tan to red zones and multiple, discrete, beige to dark red nodules that ranged from 0.5 to 6 cm in diameter in the lung, liver, left kidney, right testis, colon wall, stomach wall, and brain. On histologic examination, discrete nests of anaplastic carcinoma-like tumor cells were found in sections of all affected organs. Results of immunohistochemical examination revealed widespread expression of von Willebrand factor and the absence of cytokeratin in neoplastic cells. The diagnosis was metastatic epithelioid hemangiosarcoma, primary site unknown.

Characterization of a novel alphaherpesvirus associated with fatal infections of domestic rabbits.

A virus was found to be associated with a severe disease affecting rabbits on a farm near Anchorage, Alaska. Extracts from the skin of infected rabbits produced syncytia and cell lysis in cultured rabbit skin, rabbit kidney, and Vero cells. Examination of the infectious agent by electron microscopy revealed an icosahedral nucleocapsid surrounded by an envelope with a diameter of about 120 nm, suggesting that it was a herpesvirus. The viral genome was determined to be composed of double-stranded DNA of 120-130 kbp. PCR using degenerate primers to conserved herpesvirus genes was used to amplify sequences from purified viral DNA. Sequencing of these products allowed the design of specific primers so that complete sequence data for a number of genes could be determined. Analysis of these data indicated that the virus is most closely related to bovine herpesvirus 2. The next most closely related viruses are human herpesviruses 1 and 2, and a number of cercopithecine herpesviruses. Experimental exposure of domestic rabbits to the isolate resulted in severe clinical disease and necrosis in the spleen and lymph node. In addition, viral DNA was identified in a variety of tissues by PCR, consistent with a systemic infection. Taken together, these data suggest that this virus is highly pathogenic for domestic rabbits and belongs to the family Herpesviridae, subfamily Alphaherpesvirinae, genus Simplexvirus.

An outbreak of fatal herpesvirus infection in domestic rabbits in Alaska.

A herpesvirus infection affecting mini Rex and crossbred meat rabbits was identified in a rabbitry in Alaska. Illness affected over half of the 55 rabbits on the premises, and 16 rabbits died or were euthanatized because of illness. Disease affected all ages from adults to nursing young and occurred over an approximately 2-month period. Clinical signs included conjunctivitis and periocular swelling, ulcerative dermatitis, progressive weakness, anorexia, respiratory distress, and abortion. Hemorrhagic dermatitis and panniculitis were associated with epidermal microvesicular degeneration, dermal and subcutaneous vascular necrosis, and thrombosis. Eosinophilic intranuclear inclusions consistent with herpesvirus were found within the epidermis and superficial follicular epithelium and within mesenchymal cells within the dermis and subcutis. Syncytial cells containing viral inclusions occurred within the epidermal and superficial follicular epithelium. Other findings were hemorrhagic necrosis of the myocardium with rare intranuclear inclusions within stromal cells, multifocal pulmonary hemorrhage, hemorrhage with sinus erythrophagocytosis in lymph nodes, and massive necrosis and fibrin deposition within red pulp of the spleen. A virus isolated from the skin produced syncytia, intranuclear inclusions, and cell lysis typical of herpesvirus in rabbit kidney cells in vitro. The viral isolate was characterized ultrastructurally as an enveloped virus with icosahedral nucleocapsids 100 nm diameter, consistent with a herpesvirus.

Clinicopathologic features of a systemic coronavirus-associated disease resembling feline infectious peritonitis in the domestic ferret (Mustela putorius).

From 2002 to 2007, 23 ferrets from Europe and the United States were diagnosed with systemic pyogranulomatous inflammation resembling feline infectious peritonitis (FIP). The average age at the time of diagnosis was 11 months. The disease was progressive in all cases, and average duration of clinical illness was 67 days. Common clinical findings were anorexia, weight loss, diarrhea, and large, palpable intra-abdominal masses; less frequent findings included hind limb paresis, central nervous system signs, vomiting, and dyspnea. Frequent hematologic findings were mild anemia, thrombocytopenia, and hypergammaglobulinemia. Grossly, whitish nodules were found in numerous tissues, most frequently the mesenteric adipose tissue and lymph nodes, visceral peritoneum, liver, kidneys, spleen, and lungs. One ferret had a serous abdominal effusion. Microscopically, pyogranulomatous inflammation involved especially the visceral peritoneum, mesenteric adipose tissue, liver, lungs, kidneys, lymph nodes, spleen, pancreas, adrenal glands, and/or blood vessels. Immunohistochemically, all cases were positive for coronavirus antigen using monoclonal antibody FIPV3-70. Electron microscopic examination of inflammatory lesions identified particles with coronavirus morphology in the cytoplasm of macrophages. Partial sequencing of the coronavirus spike gene obtained from frozen tissue indicates that the virus is related to ferret enteric coronavirus.

Myonecrosis in three horses with colic: evidence for endotoxic injury.

Three horses with colic, clinical evidence of endotoxaemia and high serum activities of creatine kinase and aspartate aminotransferase were examined postmortem. The horses were diagnosed with severe ulcerative colitis, pyloric ulceration and stenosis with colonic sand impaction, and colonic obstruction due to faecaliths. There was no gross or histological evidence of muscle trauma. Their semimembranosus muscles had scattered acute to subacute segmental necrosis of the myofibres, suggestive of endotoxin-induced muscle injury.

Fatal yew (Taxus sp) poisoning in Willamette Valley, Oregon, horses.

Despite the well-founded reputation of plants of the genus Taxus as being amongst the most toxic plants for domestic livestock in the US, there are surprisingly few published case reports of yew poisoning in horses. This report documents 2 acute fatalities in horses in the central Willamette Valley, OR associated with the consumption of Taxus sp. The predominant features of the intoxication were peracute death, with no signs of struggling or convulsions, in otherwise fit and well managed adult horses. The most significant gross necropsy findings were limited to pulmonary congestion and hemorrhage, suggestive of acute circulatory disturbance. A diagnosis of Taxus sp poisoning was confirmed on the basis of a history of potential exposure, by the identification of yew leaves in the gastric contents of the horses, and by the subsequent identification of yew clippings in the pasture. The literature relevant to Taxus sp poisoning in horses is reviewed.

Functional cystic thyroid adenoma in a cat.

A 9-year-old cat with hyperthyroidism was referred for radioactive iodine treatment. The cat also had a ventral cervical mass that the owners reported had been present for several years and had increased in size during the past few weeks. On physical examination, the mass was found to have caused lateral displacement of the trachea, esophagus, jugular vein, and common carotid artery. The mass was aspirated and was determined to be cystic in nature. Concentrations of thyroid hormones in the cystic fluid were similar to serum concentrations, and nuclear scintigraphy revealed thyroactive tissue lining the cyst wall. Magnetic resonance imaging suggested that the cyst originated from the right lobe of the thyroid gland. The cat was treated with sodium iodide I 131 but died 4 days later, presumably as a result of aspiration of gastric or esophageal contents. A necropsy was not performed, but histologic examination of a biopsy specimen of the mass indicated that it was a cystic thyroid adenoma.

Toxoplasmic encephalitis in a free-ranging Rocky Mountain bighorn sheep from Washington.

A 4-mo-old free-ranging Rocky Mountain bighorn sheep (Ovis canadensis canadensis) from the Hells Canyon area (Washington, USA) was diagnosed with encephalitis associated with Toxoplasma gondii infection. The sheep had concurrent pneumonic pasteurellosis and resided in a geographic area with endemic Pasteurella-associated pneumonia and mortality in bighorn sheep. The brain had multifocal necrotizing and nonsuppurative encephalitis with intralesional protozoa. The protozoa were identified as T. gondii by immunohistochemistry. To our knowledge, this is the first report of T. gondii infection in a Rocky Mountain bighorn sheep.