Vertebral polyostotic lymphoma in a young dog.

An unusual clinical presentation of lymphoma with vertebral involvement in a dog is reported. A 20-month-old intact female Golden Retriever presented with progressive paraparesis and anorexia. Complete blood count and serum biochemistry profile demonstrated pancytopenia and hypercalcemia. Ventral fusion of the lumbar vertebrae by new bony tissue deposition was evident on X-ray and CT scan. Fine needle aspiration revealed neoplastic lymphoid cells in lymph nodes and bone marrow. Histologically, vertebral bone and osteophytes, liver, bone marrow, kidney, and lymph nodes were diffusely infiltrated by neoplastic, lymphoid cells, with scant cytoplasm and round hyperchromatic nuclei. Polyostotic and medullary T-cell lymphoma with spondylosis was diagnosed. Lymphoma mainly affecting bone is uncommon in the dog. The present case differs from previously described polyostotic lymphomas in clinical signs of the disease, mainly attributable to spondylarthrosis. In addition, lymphomatous proliferation was associated with osteoproductive lesions of the vertebrae.     

Fucosidosis in an English Springer Spaniel presenting as a malabsorption syndrome

A case of alpha-fucosidosis in a 2-year-old male English Springer Spaniel presented as a malabsorption syndrome without any clinical neurological abnormalities. The dog had a history of chronic weight loss, diarrhoea, mild anaemia, hypoproteinemia and reduced jejunal absorption of D-xylose. A diagnosis of fucosidosis with intestinal malabsorption was based on these findings, markedly reduced plasma fucosidase levels and the diffuse infiltration of the lamina propria and submucosa of the stomach, small intestine, Peyer's patches and mesenteric lymph nodes by macrophages with finely vacuolated cytoplasm. Cytoplasmic vacuolation was also a feature of cells of the pancreas, thryroid, parathyroid and adenohypophysis and the epithelia lining respiratory airways and the urogenital tract. Neurons of the autonomic plexuses of the gastrointestinal tract and the urinary bladder as well as those of the brain, spinal cord, spinal ganglia and retina were also vacuolated. The profound decrease in sigma-fucosidase activity in the brain, liver and kidney was accompanied by a marked increase in 6 other lysosomal enzymes, especially beta-n-acetyl glucosaminidase.     

STUDIES ON THE PATHOGENESIS OF BOVINE EPHEMERAL FEVER

A study of the pathogenesis of bovine ephemeral fever confirmed that the major clinical signs were fever lasting no more than 2 days, with increased respiratory rate, dyspnoea and some degree of lameness. Haematological observations revealed a neutrophilia with a left shift and a lymphopaenia at the time of peak clinical reaction. The net result was a slight leucopaenia on the day after this reaction. The most prominent pathological changes involved the lungs and synovial joints. Pulmonary emphysema and alveolar collapse with bronchiolitis, degenerative changes in synovial membranes and increased synovial fluid were observed. Specific fluorescence indicating the presence of BEF viral antigen could be detected at the time of peak clinical response in individual cells in the lungs, spleen and lymph nodes as well as neutrophils. Before and after the peak fever some fluorescence was seen in cells which appeared to be reticular cells in the lymph nodes. Viral isolation in mice could be made from blood, lungs, spleen and lymph nodes over a period of no more than 3 days. It is postulated that viral growth takes place mainly in the reticuloendothelial cells in the lungs, spleen and lymph nodes and not in vascular endothelium or lymphoid cells.     

Metastatic balloon cell melanoma in a dog

Background: Balloon cell melanoma is a rare variant of amelanotic melanoma that is difficult to differentiate from sebaceous cell carcinoma, liposarcoma, and other clear cell neoplasms without immunohistochemistry or ultrastructural evidence of melanin or melanosomes. Objective: The purpose of this report was to describe the clinical, cytologic, histologic, immunohistochemical, and ultrastructural findings in a dog with metastatic balloon cell melanoma. Methods: A 6‐year‐old female Golden Retriever was evaluated for a white, flocculent infiltrate in the anterior chamber of the left eye and an enlarged left prescapular lymph node. Cytologic evaluation of the eye and lymph node were performed following aqueocentesis and fine‐needle aspiration, respectively. The affected lymph node was examined histologically and stained for cytokeratin, vimentin, S‐100, and Melan A. Following euthanasia a necropsy was performed and samples of the affected lymph node were examined by electron microscopy. Results: Cytologic examination of the lymph node and aqueocentesis sample revealed round neoplastic cells that had abundant clear vacuolated cytoplasm. A tentative diagnosis of metastatic sebaceous cell carcinoma or clear cell neoplasm was made. Histologically, the affected lymph node had similar polygonal clear cells arranged in sheets and packets divided by delicate fibrovascular stroma. Immunohistochemical staining of the cells was negative for cytokeratin but positive for vimentin, weakly positive for S‐100, and strongly positive for Melan A. At necropsy, metastatic lesions were identified in the diaphragm, heart, lung, kidneys, left eye, prescapular and sublumbar lymph nodes, and multiple skin sites. Ultrastructural examination of neoplastic lymph nodes revealed many membrane‐bound vacuoles, myelinlike figures, and rare melanosomes. Conclusion: Immunohistochemical staining and ultrastructural features of the neoplastic cells supported a diagnosis of metastatic balloon cell melanoma.     

Disseminated histiocytic sarcoma with peripheral blood involvement in a Bernese Mountain dog

Abstract: A 6‐year‐old Bernese Mountain dog was presented with a history of lethargy and weight loss of 2 weeks duration. On physical examination the dog had pale mucous membranes and tachypnea. Ultrasound examination revealed hepatomegaly, splenomegaly, and mesenteric lymphadenomegaly. Results of a CBC included marked normocytic normochromic nonregenerative anemia, marked thrombocytopenia, and moderate leukocytosis with mild neutrophilia and a large population of unclassified round cells (6.2 × 10³/μL). The unclassified cells occasionally were bi‐ or multinucleated and had variably abundant pale basophilic cytoplasm that contained multiple irregular clear vacuoles and occasionally erythrocytes. Fine needle aspirate specimens of the mesenteric lymph nodes and spleen were composed of a population of round pleomorphic cells with the same features as the circulating cells. On flow cytometric analysis of peripheral blood, the unclassified cells expressed CD18, CD45, CD11c, CD1c, and CD14; immunocytochemical analysis of blood smears also indicated the cells were positive for CD1c, CD1a, and CD11c. The dog died a few hours after referral. The histologic interpretation of samples collected from spleen, liver, and lymph nodes was malignant neoplasia of histiocytic origin. Immunohistochemical staining yielded negative results for CD11d, a marker of red‐pulp macrophages, ruling out hemophagocytic histiocytic sarcoma. Based on clinical and pathologic findings, the final diagnosis was disseminated histiocytic sarcoma (DHS) with peripheral blood involvement. To our knowledge, DHS in a dog with evidence and immunophenotyping of neoplastic cells in peripheral blood has been reported only rarely.     

Immunohistochemical and histopathological findings of ovine pulmonary adenocarcinoma (Jaagsiekte) in Egyptian sheep

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring retrovirus-induced transmissible lung cancer in sheep. Lungs and associated (bronchial and mediastinal) lymph nodes of seven sheep with OPA were examined. Lungs had few multifocal consolidated slightly elevated gray to white masses ranging from 0.5 to 3 cm in diameter. Histopathologically, these masses appeared as well-differentiated acinar adenocarcinoma with little evidence of anaplasia. The acini composed of well-differentiated cuboidal to low columnar epithelium with clear or vacuolated cytoplasm and low mitotic index. No metastases were observed in the bronchial and mediastinal lymph nodes of any animal. The presence of Jaagsiekte sheep retrovirus (JSRV) was demonstrated in the lungs by immunohistochemistry. JSRV protein was detected in all tumor epithelial cells, histologically normal alveolar type II cells, and few bronchiolar epithelial cells, alveolar macrophages, lymphocytes, and plasma cells. This study is the first to confirm the presence of natural OPA in Egypt.     

Canine bicavitary carcinomatosis with transient needle tract metastasis diagnosed by multiplex immunocytochemistry

A 6‐year‐old, male castrated, mixed‐breed dog was referred to the James L. Voss Veterinary Teaching Hospital at Colorado State University for bicavitary effusion. On examination, the dog was tachycardic and tachypneic with bilaterally decreased lung sounds. Thoracic and abdominal ultrasonic examination revealed pleural and peritoneal effusions, which were aspirated and submitted for fluid analysis and cytology. Both cavity fluids were classified as exudates with a large population of vacuolated mononuclear cells. Multiplex immunocytochemistry (ICC) for cytokeratin and vimentin demonstrated exclusively cytokeratin expression, indicating these cells were of epithelial origin. A full diagnostic evaluation was performed, including CBC, clinical chemistry, a pet‐side test for heartworm disease, ehrlichiosis, Lyme disease, and anaplasmosis, imaging modalities of thorax, abdomen, and heart, urinalysis, and fine‐needle aspirations of spleen, liver, and popliteal lymph nodes. The dog was diagnosed with pleural and peritoneal carcinoma with presumed carcinomatosis. A single dose of intracavitary carboplatin was administered before discharge, and over a period of 2 weeks, 5 thoracocenteses were performed. A subcutaneous mass was noted at a thoracocentesis site one week after initial presentation. Cytology of the mass was consistent with carcinoma, and neoplastic seeding of the tumor cells from the thoracocentesis was suspected. The dog was euthanized 15 days after the first visit, and a necropsy was performed. Findings were consistent with carcinomatosis secondary to anaplastic pulmonary carcinoma with transient subcutaneous seeding of neoplastic cells during routine thoracocentesis. This case demonstrates the utility of multiplex ICC in the clinical setting.     

Localisation of swine hepatitis E virus in experimentally infected pigs

The distribution of intravenously inoculated swine hepatitis E virus (HEV) was assessed by in situ hybridisation for a period of 50 days. Evidence of apparent clinical disease was found in only one pig in the HEV infected group. The only gross lesion observed was mildly enlarged mesenteric lymph nodes at 50 days post infection (dpi). Histopathologically, mild lymphoplasmacytic infiltration and focal hepatocellular necrotic lesions were found in HEV-infected pigs. Swine HEV nucleic acids were detected by RT-PCR in the faeces at 3 dpi in 100% of the 18 pigs infected with the virus. Thereafter, the number of positives declined.The most consistent and intense signal was found in the liver of infected animals using in situ hybridisation. The positive cells were hepatocytes, Kupffer cells, bile epithelial cells and interstitial lymphocytes. Swine HEV RNA was localised in the cytoplasm of the hepatocytes, with a slightly granular pattern of staining, but hybridisation signals were not observed in degenerative or vacuolated hepatocytes. HEV was much less frequently detected in extrahepatic tissues such as lymph nodes, tonsil, spleen and small and large intestine. It was concluded that swine HEV had replicated primarily in the hepatocytes and infection resulted in subclinical infection with minimal histopathological changes in the liver.     

Hemorrhagic disease in dogs infected with an unclassified intraendothelial piroplasm in southern Brazil

A hemorrhagic disease affecting dogs in Brazil, referred to popularly as "nambiuvú" (bloody ears) and believed to be transmitted by ticks, has been observed in animals infected with an organism described originally in 1910 as a piroplasm, and known locally as Rangelia vitalli. In this series of 10 cases, the disease was characterized by anaemia, jaundice, fever, spleno- and lymphadenomegaly, hemorrhage in the gastrointestinal tract, and persistent bleeding from the nose, oral cavity and tips, margins and outer surface of the pinnae. The ixodid ticks Rhipicephalus sanguineus and Amblyomma aureolatum infested affected dogs from suburban and rural areas, respectively. Laboratory findings included regenerative anaemia, spherocytosis, icteric plasma and bilirubinuria. Those intracellular organisms were found in bone marrow smears but not in blood smears. Microscopically, zoites were seen within the cytoplasm of blood capillary endothelial cells. Parasitized and non-parasitized endothelial cells were positive immunohistochemically for von Willebrand factor (vWF). Langhans-type multinucleate giant cells were observed in the lymph nodes and choroid plexus. There was prominent erythrophagocytosis by macrophages in the lymph node sinuses and infiltration of the medullary cords by numerous plasma cells. Ultrastructurally, this organism had an apical complex that included a polar ring and rhoptries but no conoid. This parasite was contained within a parasitophorous vacuole that had a trilaminar membrane with villar protrusions and was situated in the cytoplasm of capillary endothelial cells. This organism tested positive by immunohistochemistry for Babesia microti. This pathogen was also positive by in situ hybridization for B. microti. Tentative clinical diagnosis in these cases was based on the history, clinical picture, haemogram and favorable response to therapy, and confirmed through microscopic examination of smears from the bone marrow or histological sections of multiple tissues, especially lymph nodes where zoites were most frequently found. The disease was reproduced by intravenous inoculation of blood from a naturally infected dog into an experimental dog. The authors demonstrate in this study that this organism is a protozoa of the phylum Apicomplexa, order Piroplasmorida. This piroplasm seems to be different from Babesia since it has an intraendothelial stage. Molecular phylogenetic analysis is necessary to better characterize this parasite and clarify its taxonomic status.     

Inherited lysosomal storage disease in an English springer spaniel.

Alpha-L-fucosidosis was diagnosed in a 17-month-old English Springer Spaniel with a history of slow development and progressive visual impairment. Lymphocytes and mononuclear cells with vacuolated cytoplasm were seen in a blood smear and in CSF, respectively. A severe deficiency of alpha-L-fucosidase activities in plasma and leukocytes was determined. Histologic examination revealed vacuolation of neurons, macrophages, and epithelial cells in most organ tissues. Canine fucosidosis is a progressive and fatal lysosomal storage disease in English Springer Spaniels. Affected dogs develop a neurologic disorder characterized by progressive motor and mental deterioration. Visual impairment is an unusual primary sign in a dog with alpha-L-fucosidosis.     

Multiple joint metastasis of a transitional cell carcinoma in a dog

An 8‐year‐old castrated male hound mix was referred to the Purdue University Veterinary Teaching Hospital for severe lameness, pollakiuria, and dyschezia. On presentation, the dog was nonweight bearing on the right rear limb and the right carpus was diffusely swollen. Synovial fluid analysis from the right carpus revealed a population of epithelial cells displaying marked anisocytosis, anisokaryosis, multinucleation, and prominent, variably sized nucleoli. A metastatic carcinoma with presumed prostatic or urothelial origin was diagnosed based on cytomorphology. Subsequent cytologic evaluation of peripheral lymph nodes revealed the presence of a similar neoplastic population. The dog was euthanized and synovial fluid from both stifle joints, as well as impression smears of the prostate gland, were collected. Carcinoma cells were identified in each stifle joint and in the prostate gland. Immunocytochemistry was performed on synovial fluid smears from 2 of the joints (right stifle and right carpus) and on impression smears of the prostate gland. The neoplastic population in the joints and prostate gland showed strong immunoreactivity to uroplakin III, a urothelial marker, indicating metastasis of a transitional cell carcinoma to multiple joints. In addition, evidence for epithelial to mesenchymal transition was identified using cytokeratin, an epithelial marker, and vimentin, a mesenchymal marker. A necropsy was performed and histopathology confirmed the presence of metastatic transitional cell carcinoma in various tissues. This case illustrates the importance of considering metastatic disease when a patient is presented with severe lameness and joint pain, and the clinical utility of synovial fluid cytology for diagnosis of metastasis in these cases.     

Thymoma in a dog with a part of granular cell proliferation and concurrent lymphoma cells

A 12-year-old male Shiba dog showed anemia and the swelling of systemic lymph nodes. X-ray and post mortal examinations revealed a anterior mediastinal mass. Histologically, the tumor mass consisted of four different elements; cord-like proliferation of cuboidal epithelial cells, tubular or cystic structures lined with ciliated epithelial cells, proliferation of large round-shaped epithelial cells with PAS-slightly positive granular cytoplasm, and diffuse proliferation of neoplastic lymphocytes. Epithelial cells in cord-like or cystic structures were strongly positive for cytokeratin. Granular or foamy cells were negative for all markers examined and had myelin-like bodies in the cytoplasm by electron microscopy. The neoplastic lymphocytes in the tumor mass were considered being derived from concurrent multicentric lymphoma. Based on these findings, the present case was diagnosed as thymoma with a part of granular cell proliferation and concurrent lymphoma cells.     

Transmission of virus from serosal fluids and demonstration of antigen in neutrophils and mesothelial cells of cattle infected with bovine ephemeral fever virus

Following intravenous injection of bovine ephemeral fever (BEF) virus 6 cattle were autopsied after clinical disease became evident. Fluid from serosal cavities with serofibrinous inflammatory changes showed large increases in neutrophil numbers. BEF virus was detected for the first time in pericardial, thoracic and abdominal fluids. Virus was also detected in synovial fluids, confirming an earlier report of transmission with a synovial fluid sample. Using a direct fluorescent antibody technique, BEF virus antigen was identified for the first time in synovial, pericardial, thoracic and abdominal fluids, in synovial membranes and epicardium. In synovial membranes and epicardium, specific fluorescence was observed in two cell types, mesothelial cells and neutrophils. In the fluids, fluorescence was restricted to neutrophils, the predominant cell type. Specific fluorescence was observed in blood smears from only one animal although blood samples collected at autopsy from all animals contained infective virus.     

Serological, clinical and histopathological changes in naturally infected dogs with Leishmania infantum in the Khemisset province, Morocco

Canine leishmaniasis (canL) is widespread in the north of Morocco and the Leishmania infantum local strains are highly virulent. An epidemiological survey was carried out in 1993-1995 in the Khemisset province. In this region, the severity of the disease was assessed during regular visits to the identified foci by clinical examination of 323 dogs. Clinical signs were protean and occurred in various combinations. Biopsies were made on available sick dogs; the main histological changes were severe infiltration of the spleen, lymph nodes and bone marrow by mononuclear cells and hyperplasia of macrophage cells with amastigotes in their cytoplasm. The seroprevalence among 323 dog sera tested by ELISA showed a rate of 16.71%. The highest prevalence of the disease was 23.6% in the Sid El Ghandour hamlet. A comparison of the results of this study with those from the year following the first examination on the same site (Sid El Ghandour) of 67 dogs showed that the disease prevalence had not increased significantly (23.6% to 25.33%).     

Epididymal interstitial (Leydig) cell tumors in B6C3F1 mice

Six primary interstitial cell tumors of the epididymis were identified from 46,752 male B6C3F1 mice used in chronic toxicity and carcinogenicity studies. Five of the tumors occurred at the end of 2-year studies; none were attributed to treatment. None of the mice with epididymal tumors had a primary testicular tumor. Histologically, tumors were characterized by a nodular or diffuse proliferation of tumor cells in the epididymal interstitium. Most cells were polygonal with highly vacuolated cytoplasm (vacuolated cells) or eosinophilic cytoplasm (eosinophilic cells). Smaller hyperchromatic cells with scant basophilic cytoplasm (basophilic cells) and cells with yellow-brown pigment characteristic of lipofuscin (pigmented cells) were less common. In each tumor two or more cell types were present. Extension of these tumors through the capsule, invasion of the testis, or metastasis did not occur. By electron microscopy both eosinophilic and vacuolated cell types had a large round or oval nucleus with sparse heterochromatin, abundant mitochondria with tubulovesicular cristae, and frequent desmosome structures between cell membranes. Vacuolated cells contained numerous lipid droplets. Morphological features of the epididymal tumors are similar to those of the testicular interstitial (Leydig) cell tumor in mice and rats.     

Fucosidosis in a domestic shorthair cat

This paper documents the first reported case of fucosidosis in a cat. The cat presented with signs of forebrain and cerebellar dysfunction and a magnetic resonance imaging scan of the brain suggested a degenerative or metabolic disease process. A fine needle aspirate of grossly normal lymph nodes revealed vacuolated lymphocytes and a renal biopsy of an irregular shaped kidney identified vacuolated tubular epithelial cells. A white cell lysosomal enzyme screen revealed negligible α-fucosidase activity. Fucosidosis should be considered in the differential diagnosis of young cats with cerebellar dysfunction and must be added to the list of lysosomal storage diseases affecting the cat.     

Polyarthritis associated with visceral leishmaniasis in a juvenile dog

Canine visceral leishmaniasis (CL) is a zoonosis and a chronic systemic disease characterized by a wide spectrum of clinical signs, including, in rare occasions, polyarthritis. This report describes a case of CL in an 8-month old male boxer dog with a history of lameness, fever and lymphadenopathy. A definitive diagnosis of CL was based on the observation of the Leishmania amastigotes seen concomitantly, and for the first time, in the lymph nodes aspiration smears (in macrophages), synovial fluid (in macrophages and neutrophils) and blood (in neutrophils). Despite this extensive dissemination of the parasite, the animal was successfully treated with a multi-step combination of meglumine antimoniate, aminosidine and allopurinol.     

Ultrastructural Studies of Paratuberculosis (Johne’s Disease) in Goats

Biopsy material of the ileum and corresponding mesenteric lymph nodes from 10 naturally infected goats was studied. In ileum a loss of epithelial cells and infiltration of epitheloid cells, macrophages and a low number of lymphocytes, plasma cells and occasional eosinophils were seen. Ultrastructurally, the epithelial cells showed degenerative changes. Epitheloid cells were characterized by a large nucleus and a wide cytoplasm rich in free ribosomes.Macrophages had been fixed in the process of engulfing bacteria or contained bacteria in phagosomes and phagolysosomes. Large phagolysosomes were common. In macrophages with many or large phagolysosomes, few or no lysosomes were observed. Degenerative changes were seen in macrophages containing many bacteria. Degenerative changes of capillary endothelium were observed. The intercellular spaces were distended by oedema and contained cell debris.The mesenteric lymph nodes were infiltrated with epitheloid cells and macrophages. The ultrastructural picture of these cells was almost identical to that of the ileum.The differences between the changes found in naturally infected and experimentally infected animals are discussed. It is concluded that the mode of infection, the number of bacteria to which the animal is exposed and the intervals between events of exposure may play a role.     

Disseminated liposarcoma in a dog.

A 9-year-old, female Mongrel dog was presented for posterior hindlimb weakness, inability to stand, and pain in the lumbosacral and pelvic regions. Radiography revealed a lytic lesion extending from L5 to L6 to the ilium. At necropsy, an 8 x 2 to 3.2 x 3 cm, irregular, white, firm mass was identified extending from the left dorsolateral aspect of the L6 vertebrae to the sacrum, crossing the sacroiliac joint to the ilium, and reaching the acetabulum without affecting the joint cartilage. Tumor masses were also present bilaterally near the costochondral junction of several ribs. White, soft nodules were present in the heart, pericardium, lungs, spleen, and kidneys as well. Histologically, osteolysis with disruption of the cortical bone and reactive bone with the presence of multinucleated osteoclasts was noted. Neoplastic cells consisted of variable, small basophilic round cells (SBRC) with very scant cytoplasm, larger polygonal cells with abundant eosinophilic cytoplasm, and vacuolated cells resembling adipocytes. Within the marrow cavity, vacuolated cells with necrosis predominated, whereas in periosteal areas, polygonal and vacuolated cells that were mixed with a lower percentage of SBRC were more common. In the lungs and heart, SBRC predominated, and in the spleen, polygonal cells were more numerous. Tumor cells stained positive for vimentin and S-100 and stained negative for CD99, neuron-specific enolase, synaptophysin, chromogranin A, cytokeratins, desmin, myoglobin, and actin. This tumor most likely arose from the marrow cavity of the L6 and later invaded through the vertebral body into adjacent vertebrae and various visceral sites.