[Suspected hippocampal sclerosis in an european shorthair cat diagnosed with polycythemia vera]. / Verdacht auf Hippocampussklerose bei einer Europäisch-Kurzhaar-Katze mit der Diagnose Polycythaemia vera.

A 7-year-old male castrated cat was presented because of an acute onset of lethargy and vestibular ataxia. The cat was diagnosed with polycythemia vera. Later the patient developed additional clinical signs including orofacial twitching, aggressivity, hypersalivation, circling and a head tilt. A magnetic resonance imaging was performed and revealed hippocampal alterations compatible with hippocampal sclerosis. The presented case report describes the clinical signs and hematologic findings in a cat with polycythemia vera and the response of treatment. Another part is the discussion about the hypothesis that the hippocampal alterations were due to a cerebral hypoperfusion caused by the polycythemic condition.

Acute cerebrovascular event in a dog with polycythemia vera.

A 1-year-old neutered male Labrador retriever mixed breed dog was referred for peracute onset of ataxia and seizures. Hematocrit at presentation was 84%. Magnetic resonance imaging of the brain revealed a lesion in the right caudate nucleus consistent with infarction. Postmortem findings were consistent with polycythemia vera and presumed secondary cerebral infarction.

Événement cérébrovasculaire aigu chez un chien atteint de polycythémie vraie. Un Labrador retriever mâle âgé de 1 an a été référé pour l'apparition suraiguë d'ataxie et de crises d'épilepsie. L'hématocrite était de 84 % à la présentation. L'imagerie par résonance magnétique du cerveau a révélé une lésion dans le noyau caudé droit compatible avec à un infarcissement. Les résultats post mortem étaient conformes à une polycythémie vraie et à un infarcissement cérébral secondaire présumé.(Traduit par Isabelle Vallières).

Diagnosis and Management of Polycythemia Vera in a Ferret (Mustela putorius furo).

A 5-y-old female ferret (Mustela putorius furo) was evaluated for diarrhea, anorexia, and lethargy for 1 wk. Only mild dehydration was detected on physical examination. CBC analysis revealed marked erythrocytosis with an unremarkable plasma biochemistry panel; follow-up CBC analyses revealed a consistent primary erythrocytosis. Whole-body radiographs and abdominal ultrasonography were unremarkable except for a small nephrolith in the right kidney and a small cyst in the left kidney. The plasma erythropoietin level was 17.0 mIU/mL and considered normal. In light of the diagnostic work-up and consistent erythrocytosis, a diagnosis of polycythemia vera (primary erythrocytosis) was made. The initial presentation of diarrhea resolved after treatment with oral metronidazole (20 mg/kg PO BID for 7 d). Treatment for the polycythemia consisted of a phlebotomy initially followed by chemotherapy with hydroxyurea (10 mg/kg PO BID). During the subsequent 12 mo, the hydroxyurea dose adjusted according to follow-up CBC results, and finding an optimal dosage regimen proved to be challenging. One year after the initial diagnosis, the ferret presented to an emergency clinic for acute and severe hemorrhagic diarrhea and died shortly thereafter. The postmortem diagnosis was acute venous infarction of the small and large intestine. To our knowledge, this report is the first to describe the diagnosis and long-term management of polycythemia vera in a ferret and the use of hydroxyurea for this purpose.

Diagnosis and Treatment of Primary Erythrocytosis in a Dog: A Case Report.

Primary erythrocytosis, or polycythemia vera, is a myeloproliferative disease caused by the exaggerated increase of erythroid precursor cells in the bone marrow. We report the case of an 11-year-old male mixed-breed dog that had tachypnea and spastic tetraplegia. There was a significant increase in hematocrit. After phlebotomy and fluid therapy, the dog's condition improved. A diagnosis of primary erythrocytosis was supported by serum levels of erythropoietin. The dog responded well to treatment with administration of hydroxyurea (15 mg/kg), phlebotomies, and fluid therapy. However, after 18 months, he had an acute recurrence of clinical signs and was euthanized. We observed that long-term maintenance with hydroxyurea at a dosage of 15 mg/kg every 48 hours was adequate for managing polycythemia vera, with a survival time of 18 months in the present case. However, longer dose intervals are likely not appropriate. We believe that this may be helpful to other veterinarians facing the same problems in the treatment of polycythemia vera.

Polycythemia vera in a dog presenting with uveitis.

A 2-year-old, castrated male, mixed-breed dog presented with a 1-month history of red eyes and intermittent vomiting and a 2-week history of polyuria and polydipsia. Bilateral anterior uveitis and active chorioretinitis in the left eye were found on ophthalmic examination. Complete blood counts demonstrated evidence of an increased red blood cell mass. Thoracic and abdominal radiographs, abdominal ultrasonography, and Doppler echocardiography were unremarkable. Serum erythropoietin level was low-normal, consistent with a diagnosis of polycythemia vera. Resolution of all systemic and ocular signs occurred, and remission was achieved following phlebotomy and treatment with oral hydroxyurea.

Leeching as initial treatment in a cat with polycythaemia vera.

Polycythaemia vera was diagnosed in a three-year-old domestic shorthaired cat referred because of seizures and a high packed cell volume (PCV). Laboratory examination revealed severe erythrocytosis (PCV 79 per cent). Diagnosis was reached by excluding causes for relative and secondary absolute polycythaemia. As phlebotomy proved impossible for initial treatment due to hyperviscosity, four leeches were used to suck blood and the PCV was consequently reduced to 64 per cent. A further 24 hours later, when bleeding at the sites of sucking had stopped, the PCV was 56 per cent. Long-term management of the condition was achieved with hydroxyurea (100 mg/cat once daily) and intermittent phlebotomy. Initial treatment using leeches in cases of polycythaemia vera is a simple, non-invasive, well tolerated and effective method where phlebotomy is not possible.

Some aspects of erythrocyte metabolism in a dog with polycythaemia vera.

An 11-year-old female crossbred dog showed signs of polyuria, polydipsia, vomiting, posterior weakness and ataxia. Clinical and laboratory findings suggested the diagnosis of polycythaemia vera. The haematological values shown over a six-month period are presented. In four samples some aspects of erythrocyte function (glucose-6-phosphate dehydrogenase [G6PD] and pyruvate kinase [PK] activities, 2,3 diphosphoglycerate [2,3 DPG] concentration, osmotic fragility and intracellular sodium and potassium concentrations) were studied. Variable activities of G6PD and PK, probably related to different reticulocyte number, were detected together with normal osmotic fragility and intracellular sodium and potassium concentrations. 2,3 DPG concentration was higher than normal in all four samples. This could be interpreted as a response to a low tissue perfusion rather than a higher content of 2,3 DPG in red blood cells from the polycythaemic dog.

Myeloproliferative disease in a calf.

A myeloproliferative disease was found in a 128-day-old Holstein female calf. The tumour consisted chiefly of primitive cells, and more mature cells, many of which were positive for haemoglobin, were admixed with them. Binucleated cells at various stages of maturation were occasionally seen, and siderosomes were confirmed in both primitive cells and more mature cells by electron microscopy. The primitive cells resembled proerythroblasts, and this tumour, thought to be an acute type neoplasm of the erythroid system, was distinguishable from chronic erythremic myelosis and polycythemia vera.

Polycythemia vera in a cat and management with hydroxyurea.

Polycythemia vera (PV) was diagnosed in a four-year-old domestic shorthair evaluated for hind-limb ataxia, extension of all claws, and difficulty in jumping to elevated surfaces. Mild cardiac hypertrophy also was diagnosed. Initial laboratory evaluation revealed polycythemia (packed cell volume [PCV], 75%) and normal serum total protein (7.5 g/dl). Definitive diagnosis of PV was reached by excluding causes of relative and secondary absolute polycythemia using radiography, ultrasonography, and blood gases, and by measuring serum erythropoietin concentration by radioimmunoassay (13 mU/ml) and an enzyme-linked immunosorbent assay (ELISA) method (8.0 mU/ml). Bone-marrow biopsy revealed relative erythroid hyperplasia characteristic of myeloproliferative disease. Clinical signs were controlled with hydroxyurea (12.2 mg/kg body weight) and occasional phlebotomy. Polycythemia vera is an uncommon feline disease, and clinical reports on the use of hydroxyurea to manage the condition in the cat are lacking.

Polycythaemia vera in a dog treated by repeated phlebotomies.

Polycythaemia vera (PV) was diagnosed in a dog by demonstration of an increased red cell mass in association with normal arterial oxygen saturation and the absence of conditions known to be associated with secondary polycythaemia. The dog was treated exclusively by repeated phlebotomies and replacement of the removed volume by colloid and crystalloid solutions. It survived for one year and was generally free of signs.

Polycythaemia vera in a dog.

An 8-month-old Dachshund showed signs of severe depression and intermittent, mild generalised seizures. A diagnosis of polycythaemia vera was made and the clinical signs ascribed to the hyperviscosity associated with this condition. Treatment by phlebotomy was initiated before the dog died.

Radiophosphorus (32P) treatment of bone marrow disorders in dogs: 11 cases (1970-1987).

Between March 1970 and February 1987, radiophosphorus (32P) was used to treat bone marrow disorders in 6 dogs; 4 had polycythemia vera and 2 had essential thrombocythemia. Activities of 32P given initially ranged from 2.4 to 3.3 mCi/m2. Four dogs responded well to 32P treatment, with gradual resolution of high RBC or platelet counts. Two of these dogs died of intercurrent disease unrelated to their bone marrow disorder, before blood counts could be stabilized. Two dogs did not respond to the initial 32P treatment nor to additional treatments with 32P, and had clinical signs and blood counts stabilized by use of phlebotomy or chemotherapeutic agents. We reviewed and analyzed 5 other cases of bone marrow disorders in dogs treated with 32P and included the findings from their records with the records of our 6 dogs in this retrospective analysis. Of the 8 dogs with polycythemia vera treated with 32P, 5 were given a single treatment that controlled clinical signs and blood counts for the remainder of the follow-up period. Of the 3 dogs treated for thrombocytosis with 32P, 2 had blood counts that responded to a single treatment.

Polycythemia vera in a cat with cardiac hypertrophy.

Polycythemia vera, a rare and poorly documented disease in cats, was diagnosed in a 4-year-old domestic shorthair cat admitted because of seizures. The diagnosis was made on the basis of high PCV, normal serum erythropoietin concentration (as determined by bioassay, using rabbit bone marrow cells), and elimination of secondary polycythemia as a diagnosis. Cardiac hypertrophy, which might have been secondary to blood hyperviscosity, also was diagnosed. The cat has been treated by periodic phlebotomy and has been without clinical signs of disease for more than 20 months.

Polycythaemia vera in a dog.

Polycythaemia vera or primary polycythaemia is a myeloproliferative disorder which is rare in dogs and cats. A case of polycythaemia vera in a dog is described and the available forms of therapy and the problems connected with therapy which may be encountered by veterinary surgeons in general practice are discussed.

Myeloproliferative disorders.

Myeloproliferative disorders are uncommon in the dog and may be classified as chronic or acute. Excessive proliferation of mature cells leads to an overproduction of terminally differentiated blood cells (chronic MPD). Inability of cells to mature results in the accumulation of poorly differentiated blast cells in the peripheral blood and bone marrow (acute MPD). Because the lesion appears to be at the level of the hematopoietic stem cell, all cell lines in the bone marrow may be affected. Diagnosis depends upon the accurate identification of neoplastic cells and the absence of other diseases associated with bone marrow hyperplasia. The prognosis for chronic MPD is guarded, whereas for acute MPD it is grave. Accurate identification of these disorders in animals is important. Investigation and greater understanding of the pathophysiologic mechanisms may lead to more lasting therapeutic successes in the future.

Primary polycythaemia in a dog.

A 7-year-old, crossbred, desexed bitch had a fluctuating illness of more than 6 months duration, with signs of inappetence, reduced exercise tolerance, restlessness, panting, black diarrhoea, and red eyes and ears. Haematological examination disclosed persistent polycythaemia, reticulocytosis, normoblastaemia , and normal total plasma protein concentration when not dehydrated. Splenomegaly was present, but there was no evidence of significant pulmonary, cardiac or renal disease on physical, radiographic or electrocardiographic examination. Further investigations revealed normal arterial Po2 and oxygen saturation, and increased total erythrocyte volume. Primary polycythaemia was diagnosed. The dog was rendered anaemic by bleeding, then treated with a single injection of radioactive phosphorus. The patient has had no recurrence of signs and remains well 50 months later.

Neoplastic diseases of the haematopoietic and lymphoid tissues.

Systemic lymphosarcomas are common in all species of domestic mammal. A binomial classification of these tumours, based on both the anatomical form (i.e., distribution of lesions) and the type of cytology, is proposed. Mast cell tumours also are common, especially in the dog. The categories of lymphoid neoplasms described are: lymphosarcoma, lymphoid leukaemia, nodular lymphoid hyperplasia, tumours of the immunoglobulin-forming cells, and thymoma. The myeloid neoplasms described are: myeloid leukaemia, erythroleukaemia, acute erythraemia, polycythaemia vera, megakaryocytoid leukaemia, panmyelosis, myelosclerosis, and monocytoid leukaemia. Mast cell tumours are divided into mastocytoma and malignant mastocytosis.