Multiple myeloma with associated polyneuropathy in a German shepherd dog

A 12-year-old female, neutered German shepherd dog developed progressive hindlimb followed by forelimb ataxia leading to tetraplegia. Neurological examination suggested lower motor dysfunction. Biochemical evaluation revealed a monoclonal hypergammaglobulinaemia, hypoalbuminaemia and hypercalcaemia. Multiple lytic lesions were identified radiographically in numerous bones. A bone marrow aspirate confirmed the diagnosis of multiple myeloma, with large numbers of plasma cells seen in clusters. An electromyogram revealed positive sharp waves and fibrillation potentials in the skeletal muscles of the limbs, suggesting a polyneuropathy. The dog was treated with chemotherapy using melphalan and prednisolone. Both the hypergammaglobulinaemia and the polyneuropathy resolved and the dog had normal motor function four weeks after commencing treatment. Polyneuropathy may occur as a paraneoplastic syndrome secondary to myeloma, and in this case was reversible following treatment of the underlying disease.     

Immunoglobulin A monoclonal gammopathy in two horses with multiple myeloma

The clinical findings in two horses with secretory multiple myeloma and secondary immunoglobulin A (IgA) monoclonal gammopathy were non-specific and included weight loss, pale mucous membranes, limb oedema and bacterial respiratory tract infection. Consistent laboratory abnormalities included hyperproteinaemia, hyperglobulinaemia, hypoalbuminaemia and hypercalcaemia. The diagnosis was based on the presence of IgA monoclonal gammopathy in serum and urine and bone marrow plasmacytosis (> 10 per cent). One horse was euthanased; it had neoplastic plasma cell infiltrates in its kidneys, spleen, liver, bone marrow, myocardium and adrenal glands. The other horse was treated for a bacterial pneumonia and was still alive six months after it was first examined.     

Bone marrow necrosis in a cat infected with feline leukemia virus

A one-year old castrated male cat was admitted to the hospital with vomiting and diarrhea. Laboratory examination revealed pancytopenia and positive for FeLV antigen. A bone marrow examination indicated necrosis of the nucleated cells. Based on these findings, the cat was diagnosed as bone marrow necrosis. Pancytopenia was effectively treated with corticosteroids. Re-examination of the bone marrow confirmed a recovery of normal hematopoietic cells with a infiltration of many macrophages. It is strongly suspected that the bone marrow necrosis in this case could be associated with a bone marrow suppression due to FeLV infection.     

Primary penile adenocarcinoma with concurrent hypercalcaemia of malignancy in a dog

A 13‐year‐old male neutered Siberian husky crossbreed dog was presented with a 3‐week history of haematuria and penile swelling. Clinical examination and computed tomography demonstrated a soft‐tissue mass located at the base of the penis without signs of other primary tumours or metastasis. Clinicopathological findings revealed paraneoplastic hypercalcaemia. Fine‐needle aspiration cytology of the mass suggested an epithelial tumour with several criteria of malignancy present. Following surgical excision of the mass, the hypercalcaemia resolved. Histopathology and immunohistochemistry revealed features consistent with an adenocarcinoma. Despite thorough examination, no perineal or anal sac tumour was found. To the authors’ knowledge, this is the first reported case of a penile adenocarcinoma with hypercalcaemia of malignancy.     

Bone marrow necrosis and myelophthisis: manifestations of T‐cell lymphoma in a horse

Abstract: A 14‐year‐old spayed American Paint mare was evaluated for mild colic, anorexia, pyrexia, and pancytopenia. Physical examination revealed mild tachycardia, tachypnea, and pale mucous membranes. Serial laboratory analyses revealed progressive pancytopenia, hyperfibrinogenemia, and hyperglobulinemia. A few large atypical cells were observed in peripheral blood smears. Results of tests for equine infectious anemia and antipenicillin antibody were negative. Serum protein electrophoresis indicated a polyclonal gammopathy. Smears of bone marrow aspirates contained hypercellular particles, but cell lines could not be identified because the cells were karyolytic, with pale basophilic smudged nuclei and lack of cellular detail. A diagnosis of bone marrow necrosis was made. Treatment consisted of antimicrobials, nonsteroidal anti‐inflammatory drugs, and corticosteroids. The pyrexia resolved; however, the pancytopenia progressively worsened and petechiation and epistaxis developed. The horse was humanely euthanized. Postmortem examination revealed a diffuse round cell neoplasm infiltrating the kidneys, spleen, lymph nodes, lungs, and bone marrow. Immunophenotyping results (CD3+, CD79α−) indicated the neoplastic cells were of T‐cell lineage. Infiltration of lymphoma cells into the bone marrow appeared to have resulted in severe myelophthisis and bone marrow necrosis. Bone marrow necrosis has been associated previously with lymphoma in humans and dogs. To our knowledge, this is the first reported case of lymphoma resulting in bone marrow necrosis in a horse.     

Bone marrow hypoplasia in a cat treated with griseofulvin

Three weeks after initiation of griseofulvin treatment for dermatophytosis (40 mg/kg of body weight, q 12 h), an 8-yr-old domestic shorthair cat developed depression, vomiting, and pyrexia. Abnormalities found during physical examination included bilateral mydriasis, visual impairment, grade-II/V systolic murmur and multiple areas of alopecia. The cat was pancytopenic; serum biochemical abnormalities included hyperbilirubinemia, hyperglycemia, hyponatremia, and hypokalemia, and urinalysis revealed proteinuria, glycosuria, and bilirubinuria. Examination of a bone marrow aspirate revealed profound hypoplasia of all precursors. Griseofulvin toxicosis was diagnosed on the basis of the temporal relationship of drug administration with onset of clinical, hematologic, and biochemical abnormalities and failure to identify an infective or neoplastic cause for the bone marrow hypoplasia. The condition was refractory to treatment and the cat was euthanatized. Pathologic changes in the bone marrow were consistent with severe hypoplasia of all bone marrow precursors.     

T-cell-rich B-cell lymphoma in a ring-tailed lemur (Lemur catta).

A 13-yr-old ring-tailed lemur (Lemur catta) was evaluated for depression, anorexia, polyuria, and polydipsia. The lemur was in poor body condition and was anemic, hypoalbuminemic, and hyponatremic. Cytologic examination of aspirates of the spleen, liver, and bone marrow and histopathologic examination of liver and bone marrow biopsies revealed a disseminated round cell tumor. After euthanasia, necropsy revealed hepatomegaly, splenomegaly, and mesenteric lymphadenomegaly. Neoplastic cells were present within the spleen, liver, kidneys, multiple lymph nodes, bone marrow, lung, small intestine, pancreas, and testicle and were composed of large anaplastic round cells in a background of small well-differentiated lymphocytes. Immunohistochemical analysis revealed that the small well-differentiated lymphocytes labeled for the anti-human T-cell marker, CD3, and the large anaplastic round cells labeled with the anti-human B-cell marker, CD79a. On the basis of the immunohistochemical staining results and morphologic appearance, a diagnosis of a T-cell-rich B-cell lymphoma was made.     

Myelophthisic pancytopenia in a pony mare

Myelophthisic pancytopenia was diagnosed in a 10-year-old pony mare with a history of recurring colic and anemia. Physical findings were unremarkable, with the exception of pale mucous membranes. Hematologic analysis revealed nonregenerative pancytopenia. Testing for equine infectious anemia and antiglobulin (Coombs) yielded negative results. The mare was treated with antibiotics, boldenone undecylenate, and corticosteroids, but a regenerative bone marrow response was not seen. Postmortem examination revealed severe myelofibrosis and multiple sites of extramedullary hematopoiesis. Myelophthisic pancytopenia develops when a space-occupying lesion destroys sufficient bone marrow or disturbs marrow architecture, resulting in decreased production capacity. Pancytopenia in the pony of this report resulted from inadequate production of blood cellular components secondary to replacement of the bone marrow by myelofibrosis. Cause of the myelofibrosis was not identified.     

Blood smear from a cat: features to "dys"cover

A 4-year-old, spayed female, domestic shorthair cat was presented for lethargy, nonregenerative anemia, and inappetence. Results of a CBC included macrocytic, normochromic, nonregenerative anemia and a glucocorticoid-associated leukogram. On blood smear examination, neutrophils had abnormal features including hyposegmentation and a diffuse chromatin pattern with nuclear filament formation and nuclear blebbing. Microscopic examination of a roll preparation of bone marrow revealed hypolobulated megakaryocytes with asynchronous maturation of nuclei. The granulocytic to erythrocyte (G:E) ratio was 76. Segmented neutrophils had asynchronous maturation and dysplastic features. The entire erythroid lineage was markedly decreased for the degree of anemia and rare dysplastic features were noted in erythroid precursor cells. The interpretation of bone marrow findings was erythroid hypoplasia, megakaryocytic dysplasia, and granulocytic hyperplasia with dysplasia. Histopathologic examination of a bone marrow core sample also revealed myeloid hyperplasia and erythroid hypoplasia. The result of a direct immunofluorescence assay for FeLV performed on the bone marrow roll preparation was positive. A diagnosis of dysmyelopoiesis associated with FeLV infection was made. This case was unique in that the dysplastic changes occurred in cell lines that did not have associated cytopenias. The dysmyelopoiesis most closely resembled myelodysplastic syndrome with refractory cytopenia (MDS-RC); however, secondary dysmyelopoiesis could not be ruled out.     

Multiple cytopenias associated with monocytic proliferation in a dog

An unusual combination of blood cytopenias and monocytic proliferation was observed in a dog. Initial hematologic findings included severe thrombocytopenia, neutropenia, mild nonregenerative anemia and apparently normal bone marrow. Subsequently, a severe persistent monocytosis developed and the bone marrow became populated with monocytes and cytophagic macrophages. Splenomegaly was due to reticuloendothelial hyperplasia and extramedultary hematopoiesis. Treatment consisted of splenectomy and azathioprine but the response was poor and the dog was euthanized. Postmortem examination revealed a hypocellular bone marrow which contained moderate numbers of monocytes and plasma cells. Neoplastic proliferation was absent in visceral organs. No definite diagnosis was established; chronic blood cell consumption, perhaps immune-mediated, may have been responsible for the extensive reticuloendothelial hyperplasia and cytophagia.     

IgA multiple myeloma in a dog

Multiple myeloma was diagnosed in a 10-year-old female Labrador which showed signs of weight loss, lethargy and skeletal pain. Radiography revealed well circumscribed osteolytic lesions in vertebrae, sternebrae, and the left humerus and radius along with generalised osteoporosis. The number of plasma cells in the bone marrow was increased and the serum gamma globulin concentration was elevated. Treatment with cyclophosphamide, mephalan and prednisone successfully controlled the malignancy but also resulted in suppression of the bone marrow. There was a remission time of 21.5 months.     

IgA multiple myeloma in a dog

Multiple myeloma was diagnosed in a lo-year-old female Labrador which showed signs of weight loss, lethargy and skeletal pain. Radiography revealed well circumscribed osteolytic lesions in vertebrae, sternebrae, and the left humerus and radius along with generalised osteoporosis. The number of plasma cells in the bone marrow was increased and the serum gamma globulin concentration was elevated. Treatment with cyclophosphamide, mephalan and prednisone successfully controlled the malignancy but also resulted in suppression of the bone marrow. There was a remission time of 21.5 months.     

Diagnostic use of cytologic examination of bone marrow from dogs with thrombocytopenia: 58 cases (1994-2004)

OBJECTIVE: To determine the diagnostic use of cytologic examination of bone marrow from dogs with thrombocytopenia. DESIGN: Retrospective case series. ANIMALS: 58 dogs with thrombocytopenia. PROCEDURES: Medical records were searched and reviewed for dogs with thrombocytopenia. Dogs that had thrombocytopenia and cytologic examination of bone marrow were included in the study. Dogs with other hematologic abnormalities, with a previous diagnosis of hematopoietic neoplasia, or that had previous treatment with cytotoxic drugs were excluded. Bone marrow cytologic findings were reviewed. Results were compared between dogs with severe thrombocytopenia (< 20,000 platelets/microL) and dogs with mild to moderate thrombocytopenia (20,000 to 200,000 platelets/microL). RESULTS: 58 dogs met the inclusion criteria. Of 55 dogs with diagnostic bone marrow aspirates, 36 had severe thrombocytopenia. Cytologic evaluation of bone marrow did not reveal substantial nonmegakaryocytic bone marrow abnormalities or result in a definitive diagnosis in any of these dogs. Nineteen dogs with mild to moderate thrombocytopenia had diagnostic bone marrow aspirates. Bone marrow cytologic findings revealed nonmegakaryocytic abnormalities in 4 of these dogs. Significantly fewer dogs with severe thrombocytopenia had abnormalities identified on cytologic examination of bone marrow, compared with dogs with mild to moderate thrombocytopenia. CONCLUSIONS AND CLINICAL RELEVANCE: Cytologic examination of bone marrow is unlikely to provide specific diagnostic or prognostic information in dogs with severe thrombocytopenia.     

A clinical case of chicken infectious anemia disease and virus DNA detection in naturally infected broilers in Greece

In this study, chicken infectious anemia virus (CIAV) DNA was detected from 12-day-old broilers. Clinical history showed that the clinical features were diarrhea, blue wing disease, depression, and death. Necropsy findings were pale liver, severe atrophy of bursa of Fabricius and thymus, and discoloration of the bone marrow as well as hemorrhages subcutaneously and a few in skeletal muscles. The majority of the necropsied broilers had developed gangrenous dermatitis. Histopathology showed hypoplasia of bone marrow and depletion of lymphocytes in spleen, bursa, and subcapsular thymic cortex. Karyorrhexis of lymphocytes was scattered in the thymic cortex and most pronounced in the bursal follicles. Eosinophilic intranuclear inclusion bodies were mainly located in lymphocytes of thymus, with a few in hemopoietic cells of bone marrow. CIAV DNA was detected by polymerase chain reaction from bursa, thymus, and bone marrow. A virus strain was detected and genetically characterized in 639 base pairs of VP1 gene. Phylogenetic analysis revealed that the Greek isolate was clustered together with isolates from Alabama, China, Slovenia, and Bangladesh.     

Retrospective assessment of tolerability and efficacy of zoledronate in the palliative treatment of cancer-bearing dogs

Zoledronate is a bisphosphonate frequently used for the treatment of hypercalcaemia of malignancy and tumour-associated bone pain in dogs, however, there is a paucity of information regarding its use in veterinary medicine. The aim of this retrospective study was to report the tolerability of zoledronate in the palliative treatment of cancer-bearing dogs and secondarily to to assess the efficacy of zoledronate for the treatment of hypercalcaemia of malignancy. Thirty-seven dogs (22 with tumour-associated bone pain and 15 with hypercalcaemia of malignancy) that received 114 zoledronate infusions were included. Tolerability was assessed by the absence of post-zoledronate hypocalcaemia or other adverse events as defined by Veterinary Cooperative Oncology Group-Common Terminology Criteria for Adverse Events criteria. Efficacy was assessed by comparison of available ionized calcium levels before and after zoledronate administration in hypercalcaemic dogs. In 79% of zoledronate infusions, no adverse events were reported. The majority of adverse events which occurred in the other 21% of infusions could be attributed to concurrent chemotherapy or the underlying neoplastic disease. There was a small but significant increase in creatinine following treatment with zoledronate, however, none of the dogs developed clinically significant renal disease. In eight hypercalcaemic dogs with available ionized calcium following zoledronate administration, ionized calcium decreased rapidly within 7 days following treatment with zoledronate. Zoledronate is well-tolerated with few recorded adverse events, however, monitoring of serum creatinine is advised. Zoledronate seems to be effective in the treatment of hypercalcaemia of malignancy.     

Aplastic anemia in a clydesdale foal: A case report

A nine-week-old Clydesdale foal was presented with severe anemia, panleucopenia and thrombocytopenia. Bone marrow biopsy revealed marrow fat and bone spicules but was almost acellular, indicating the existence of aplastic anemia. Histological examination of marrow obtained at post mortem examination revealed only occasional nests of mononuclear cells. Marked biliary hyperplasia was present in the liver. The etiology was uncertain but a toxic insult resulting in aplastic anemia and hepatic disease may have occurred in utero or in the neonatal period. This appears to be the first report of aplastic anemia in a foal.     

Hypercalcaemia associated with granulomatous lymphadenitis and elevated 1,25 dihydroxyvitamin D concentration in a dog

A seven-year-old Labrador was presented with weight loss and mild generalised lymphadenopathy. Histopathology of an excised lymph node by the referring veterinarian demonstrated granulomatous lymphadenitis. At the time of referral, fine-needle aspirates of the lymph nodes confirmed the presence of ongoing granulomatous inflammation. Further investigations revealed marked hypercalcaemia, a low parathyroid hormone concentration, a parathyroid hormone related protein concentration within the reference range, and an elevated serum concentration of 1,25 dihydroxyvitamin D. An underlying cause of the granulomatous lymphadenitis could not be identified. The clinical signs, hypercalcaemia and elevated serum concentrations of 1,25 dihydroxyvitamin D resolved following prednisolone treatment. In contrast to dogs, hypercalcaemia occurred secondarily to granulomatous disease and elevated 1,25 dihydroxyvitamin D concentrations is a well-recognised condition in human beings. To the authors' knowledge, this is the first case report to describe elevated serum calcium and 1,25 dihydroxyvitamin D concentrations in a dog with histologically confirmed granulomatous disease.     

Tumor staging in a Beagle dog with concomitant large B-cell lymphoma and T-cell acute lymphoblastic leukemia

An 8-y-old spayed female Beagle dog was presented with peripheral lymphadenomegaly. Lymph node cytology and flow cytometry led to the diagnosis of large B-cell lymphoma (LBCL). We detected minimal percentages of LBCL cells in peripheral blood and bone marrow samples. However, a monomorphic population of neoplastic cells different from those found in the lymph node was found in the bone marrow. T-cell acute lymphoblastic leukemia was suspected based on flow cytometric immunophenotyping. PCR for antigen receptor rearrangement (PARR) revealed clonal rearrangement of both B-cell and T-cell receptors, and the presence of both neoplastic clones in the lymph node, peripheral blood, and bone marrow. The dog was treated with multi-agent chemotherapy but died 46 d following diagnosis. Tumor staging and patient classification are needed to accurately establish a prognosis and select the most appropriate therapeutic protocol.     

Acute myelomonocytic leukemia (AML-M4) in a dog with the extradural lesion

A two-year-old dog having presented with neurological signs showed marked leukocytosis and appearance of blast cells in the peripheral blood. Hematological and bone marrow examination showed an increase in blasts having both myeloid and monocytic cells characteristics. The dog was diagnosed with acute myelomonocytic leukemia (AML-M4) on the basis of bone marrow findings. Although the dog was treated with a multi-combination chemotherapy, the neurological abnormalities progressed and the dog was euthanized. Myelographic examination and necropsy revealed the extradural lesion formed by AML-M4 around the cervical spinal cord and this lesion was considered as a cause of the neurological signs.     

Cells infected with Jaagsiekte sheep retrovirus are detected in the bone marrow of asymptomatic sheep

Ovine pulmonary adenocarcinoma (OPA) is a transmissible lung cancer caused by Jaggsiekte sheep retrovirus (JSRV). It is difficult to identify animals infected with JSRV but are clinically healthy. The virus does not induce a specific antibody response and, although proviral DNA sequences of JSRV can be found in mononuclear blood cells, the detection is inconsistent. The aim of this study was to investigate the presence of JSRV in the bone marrow of infected sheep and develop a more consistent screening method. Immunohistochemical examination of bone marrow samples from 8 asymptomatic JSRV-infected sheep revealed the presence of positively labelled cells. However, JSRV could not be detected by a highly sensitive polymerase chain reaction (PCR) in bone marrow aspirates periodically collected from these animals. Results suggest that JSRV-infected cells may be present in the bone marrow of symptomless animals, but the number is below the detectable level for PCR. Therefore, this technique does not seem to be helpful for preclinical diagnosis of OPA.