Immune-mediated hemolytic anemia in a horse

An 18-year-old Quarter Horse gelding was determined to have immune-mediated hemolytic anemia after detection of autoagglutination of RBC spherocytosis as well as a positive direct Coombs test result. A lack of response to treatment with corticosteroids necessiated the administration of cyclophosphamide and azathioprine. The anemia resolved after treatment with chemotherapeutic drugs.     

Hemolytic anemia caused by Babesia gibsoni infection in dogs.

Babesia gibsoni caused severe hemolytic anemia in 11 dogs from southern California. The most common clinical signs of B gibsoni infection were lethargy, anorexia, anemia, and thrombocytopenia. Acute infection with B gibsoni may be misdiagnosed as autoimmune hemolytic anemia. Diagnosis was most reliably determined by identification of the intraerythrocytic parasites on Giemsa-stained blood smears. The pathogenicity of B gibsoni, difficulties in diagnosis, the parasite's resistance to treatment with available drugs, and frequent interstate movement of dogs indicate that this disease may be a serious threat to dogs throughout the United States.     

Positive Coombs' test results in two dogs treated with amiodarone

Effects of amiodarone, an antiarrhythmic drug that is effective in suppressing severe ventricular arrhythmias that are refractory to other antiarrhythmic drugs, were evaluated in 2 dogs with cardiac disease. One dog was a Doberman Pinscher with cardiomyopathy that developed severe thrombocytopenia after receiving amiodarone for 7 months. The second was a Giant Schnauzer with acquired mitral valve degeneration that developed regenerative anemia after receiving amiodarone for 5 months. Results of direct Coombs' tests were positive in both dogs. Adverse effects of amiodarone are numerous; in dogs, the most common adverse effects are anorexia and hepatotoxicosis. Frequent CBC and serum biochemical analyses should be performed when amiodarone is administered with the intent of continuing the drug indefinitely.     

Equine immune-mediated hemolytic anemia associated with Clostridium perfringens infection

Background: Previous studies have suggested an association between equine immune-mediated hemolytic anemia and clostridial infections or neck abscesses.
Objective: The purpose of this report was to describe and characterize the hematologic abnormalities in a horse with Clostridium -associated immune-mediated hemolytic anemia. We also retrospectively evaluated hematologic abnormalities in 8 horses with clostridial myositis or subcutaneous emphysema.
Methods: A 7-year-old Foreign Warm-Blood gelding was evaluated for anemia and a cervical abscess. CBCs and reticulocyte counts were obtained using an Advia 120 analyzer and evaluation of Wright's-stained smears. All cases of equine Clostridium spp. myositis or subcutaneous emphysema over a 7-year period were identified in a retrospective search of the University of Minnesota Veterinary Teaching Hospital database. Clinical, hematologic, and microbiological findings were recorded.
Results: Clostridium perfringens genotype A was isolated from the neck wound of the gelding. The CBC was characterized by severe regenerative anemia, intravascular hemolysis, and RBC agglutination. A direct Coombs' test was positive. Moderate numbers of spheroechinocytes were observed. The total automated reticulocyte count was 4.5% (56,700/μL), with most reticulocytes having low absorbance (mature reticulocytes). The anemia responded to penicillin and steroidal and nonsteroidal immunosuppressive drugs. Of 8 horses with myositis, all of which involved the cervical region, 5 were anemic, 1 had a positive direct Coombs' test, and 2 had increased numbers of type III echinocytes and spheroechinocytes.
Conclusions: The presence of type III echinocytes or spheroechinocytes may be helpful in diagnosing immune-mediated hemolytic anemia associated with clostridial infections in horses. Automated reticulocyte counts may detect very low levels of reticulocytosis in hemolytic anemia in horses.     

Idiopathic immune-mediated hemolytic anemia in a calf.

Severe anemia was found in a 4-month-old heifer, which was admitted with a 1-day history of anorexia, signs of depression, and recumbency. A diagnosis of immune-mediated hemolytic anemia (IHA) was made on the basis of a Coomb's titer of 1:128 and decreased resistance to osmotic stress, as determined by an RBC fragility test. Anaplasmosis and leptospirosis were ruled out as possible causes of the IHA. Other causes of hemolytic anemia, including intoxication by copper, water, Brassica spp, or drugs were ruled out. Therefore the IHA was considered idiopathic. Treatment consisted of supportive therapy, oxytetracycline, and dexamethasone. After 60 days of treatment, CBC, Coomb's test result, and RBC fragility were within normal limits.     

Sideroblastic anemia in 7 dogs (1996-2002)

Sideroblastic anemia is an anemic condition characterized by chronic hypochromic anemia and the presence of large iron deposits in erythroid cells. Seven dogs with sideroblastic anemia were evaluated retrospectively. Historical, clinical, and clinicopathologic findings were reviewed to determine whether the condition was idiopathic or associated with disease conditions or drug or toxin exposure. Associated diseases were identified in 6 affected dogs and included acute hepatitis, pancreatitis, acute hepatitis and pancreatitis, inflammatory disease, glomerulonephritis, and myelofibrosis. None of the dogs had a history of recent exposure to drugs or toxins. One dog had no evidence of associated disease. Regardless of the associated disease condition, sideroblastic anemia was characterized by moderate to severe nonregenerative and frequently hypochromic anemia with prominent dysplastic features in bone marrow that were most prominent in the erythroid series. Survival varied from days to years. Identification of large numbers of siderocytes or sideroblasts in blood or bone marrow is inconsistent with a diagnosis of iron deficiency and should prompt a search for inflammatory disease conditions, including hepatitis, pancreatitis, and glomerulonephritis.     

黄芪多糖铁对小白鼠缺铁性贫血的药效学研究

为评价黄芪多糖铁对缺铁性贫血小白鼠的补铁作用,采用苯肼诱导法制成小白鼠贫血模型。以硫酸亚铁和右旋糖酐铁为对照药物,在给药后第2天、第5天、第10天进行尾部采血,测定各组小白鼠不同时期血液中的红细胞数、血红蛋白、血清铁及血清铁蛋白含量。结果表明,黄芪多糖铁可以显著提高贫血小鼠的红细胞数、血红蛋白、血清铁及血清铁蛋白含量。     

应用聚合酶链反应检测鸡传染性贫血病毒

根据鸡传染性贫血病毒（CAV）Cux－1株的基因序列,设计了一对引物,用这对引物对三株CAV的核酸模板进行PCR扩增,结果均能特异性地扩增出420bp的片段,但对其它5种禽病病原体核酸模板的扩增,结果均为阴性,该PCR能检出10fg鸡传染性贫血病毒DNA模板。     

Penicillin-induced immune-mediated hemolytic anemia in a horse.

A 5-year-old female American Quarter Horse was determined to have immune-mediated hemolytic anemia after detection of a positive response to a direct Coombs' test. Penicillin-induced immune-mediated hemolytic anemia was confirmed via a direct antiglobulin test, using penicillin-coated RBC. The horse was clinically improved and the anemia resolved in response to supportive care and discontinuation of penicillin treatment. Penicillin should be considered a possible cause of immune-mediated hemolytic anemia in horses.     

Citrobacter freundii septicemia in two dogs.

A 4-month-old Maltese puppy and a 7.5-year-old Collie were diagnosed with septicemia associated with Citrobacter freundii. The puppy died soon, after developing weakness and mucohemorragic diarrhea. The Collie had immune-mediated hemolytic anemia and thrombocytopenia and was treated with immunosuppressive drugs before being euthanized. Gross examination of the puppy revealed mucohemorrhagic intestinal contents. Focal necrotic hepatitis, fibrinous peritonitis, interstitial pneumonia, and hemorrhagic gastrointestinal contents were observed in the older dog. Histologically, there was a diffuse, moderate, histiocytic meningitis in the puppy and a focal fibrinonecrotic hepatitis in the adult dog. Lesions in both dogs contained numerous gram-negative rods. Citrobacter freudii is a potential cause of monomicrobic bacteraemia-septicemia in puppies or immunocompromized adult dogs.The gastrointestinal tract is probably the main site of entry.     

Influence of drug treatment on survival of dogs with immune-mediated hemolytic anemia: 88 cases (1989-1999)

OBJECTIVE: To evaluate association of various treatments for immune-mediated hemolytic anemia with survival to discharge in dogs. DESIGN: Retrospective cross-sectional analysis. ANIMALS: 88 dogs with idiopathic immune-mediated hemolytic anemia. PROCEDURE: Medical records of dogs with immune-mediated hemolytic anemia treated between August 1989 and August 1999 were examined. Survival to discharge, PCV at referral, autoagglutination, and drug treatment and dosage were recorded. RESULTS: Treatments included administration of prednisone, dexamethasone, azathioprine, danazol, cyclosporine, cyclophosphamide, bovine hemoglobin solution, and human immunoglobulin. Overall mortality rate was 50.5%. Significant associations with death were not detected for use of azathioprine, cyclosporine, danazol, or human immunoglobulin. A significant difference in mortality rate was not detected between use of multiple immunosuppressive drug treatments and use of single immunosuppressive drugs. Use of cyclophosphamide and bovine hemoglobin solution were associated with significant increases in relative risk of death CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that use of cyclophosphamide and bovine hemoglobin solution in treatment of idiopathic immune-mediated hemolytic anemia may be associated with increased risk of death.     

Immune-mediated hemolytic anemia induced by penicillin in horses

Three horses developed severe, immune-mediated hemolytic anemia after treatment with penicillin. The horses had positive direct antiglobulin (Coombs) tests and high titers of IgG antibody that agglutinated penicillin-coated equine red cells. Two of the horses were tested for antibodies to autologous red cell antigens; autoantibodies were not present. Titers of antipenicillin antibody decreased after penicillin was discontinued but IgG antibody was detectable months after recovery. One of the horses was challenged with penicillin; antibody titer increased slightly, but anemia did not develop. Antipenicillin antibody of the IgM class was present in low titer in 23 (77%) of 30 non-anemic horses tested. Apparently, the horse is similar to man in that penicillin-induced anemia is rare but the percentage of individuals with antipenicillin antibody is high.     

Primary pure red cell aplasia in dogs: 13 cases (1996-2000)

OBJECTIVES: To examine clinical features, laboratory test results, treatment, and outcome of dogs with pure red cell aplasia (PRCA). DESIGN: Retrospective study. ANIMALS: 13 dogs with severe nonregenerative anemia and bone marrow erythroid aplasia. PROCEDURES: Medical records of dogs determined to have PRCA on the basis of results of blood and bone marrow analysis between 1996 and 2000 were reviewed. Criteria for inclusion in the study were severe nonregenerative anemia (Hct < 20%; reticulocyte count < 1.0%), selective erythroid aplasia in bone marrow, and lack of underlying diseases that may have caused the anemia. RESULTS: Median age of dogs was 6.5 years. Females were significantly overrepresented. Median Hct was 10%, and median reticulocyte count was 0.1%. Direct Coombs' test results were negative for all dogs tested, and spherocytosis was evident in 2 dogs. All dogs were treated with prednisolone, and 2 dogs were treated with prednisolone and cyclophosphamide. Responses to treatment were complete, partial, and poor in 10, 1, and 2 dogs, respectively. Median time required to achieve an increase of 5% or more in Hct was 38 days, and median time to complete remission was 118 days. Of 10 dogs for which follow-up information was available, only 1 required long-term immunosuppressive treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with PRCA appear to respond readily to treatment with immunosuppressive drugs; however, hematologic responses may not be observed for weeks to months after initiation of treatment.     

Immune-mediated Hemolytic Anemia and Thrombocytopenia in the Dog: A retrospective study of 55 cases diagnosed from 1979 through 1983 at the Western College of Veterinary Medicine

All recognized cases (n = 55) of immune-mediated hemolytic anemia and immune-mediated thrombocytopenia in dogs presented to the Western College of Veterinary Medicine from 1969 through 1983 were reviewed. Specific areas of concern were: association with other conditions, therapeutic response, prognosis, relapse rate and final outcome. Of these 55 cases, 19 were immune-mediated hemolytic anemia, 26 were immune-mediated thrombocytopenia and 10 were both immune-mediated hemolytic anemia and thrombocytopenia. Females were slightly over-represented and the mean age was 6.4 years. Therapy consisted of various combinations of immuno-suppressive drugs and in some cases, whole blood transfusion and splenectomy. No firm conclusions could be made regarding therapeutic efficacy, as a result of variation in treatment protocol and the occasional unavailability of follow-up data. Well over half of all cases were diagnosed as idiopathic. Precipitating factors or diseases most frequently implicated in secondary immune-mediated thrombocytopenia or hemolytic anemia were: recent vaccination, drug therapy, obstetrical complications, stress, recent viral infection and neoplasia. Twice as many cases of immune-mediated hemolytic anemia were seen in the cooler months (October to March), although this could not be related to antibody class or thermal reactivity. Immune-mediated thrombocytopenia both as a single disease and combined with immune-mediated hemolytic anemia had no seasonal incidence. History, clinical findings and hematological and clinical chemistry findings were consistent with data previously reported, with the exception of icterus, which appeared to be of higher incidence than most reports, being present in almost 50% of immune-mediated hemolytic anemia cases. Just over half of all dogs survived, although the survival rate was highest for immune-mediated hemolytic anemia, followed closely by immune-mediated thrombocytopenia and lowest for the combined disease. Immune-mediated thrombocytopenia most frequently ran a relapsing course requiring long-term or intermittent therapy.     

Ehrlichia and Babesia infections in dogs in The Netherlands

A retrospective study was performed at the Department of Clinical Sciences of Companion Animals at Utrecht University amongst 75 dogs diagnosed with a Babesia canis and/or an Ehrlichia canis infection. The majority of the dogs had visited an endemic area (most often the Mediterranean area or the Dutch Antilles), but two dogs became infected with Babesia in the Netherlands. Babesia infections were associated with a stay in an endemic area and an incubation period that are both significantly shorter (less than 3 months) than those for Ehrlichia and co-infections (more than 3 months). Reasons for the owner to seek veterinary attention (lethargy, anorexia, fever), findings from the physical examination (pale mucous membranes, hepato-/splenomegaly) and laboratory results (anemia, thrombocytopenia, hypo-albuminemia) were highly aspecific, making serology or PCR mandatory for diagnosing infections. Antigenic stimulation by the parasite sometimes resulted in immune-mediated diseases such as immune-mediated hemolytic anemia, thrombocytopenia, glomerulonefritis, and polyarthritis and in the case of ehrlichiosis in hypergammaglobulinemia. Specific therapy (imidocarb-diproprionate and/or doxycycline) was necessary, and because combined infections were common, it was considered appropriate to administer both drugs while the definitive diagnosis was being established. The prognosis was reasonably good, with almost half of all patients showing no clinical signs after treatment, although Babesia and co-infections were associated with a significantly longer survival sometimes resulted than Ehrlichia infections.     

Drug-induced thrombocytopenia

A variety of drugs may cause thrombocytopenia. Although it occurs more often than drug-induced anemia it is less well understood because techniques for studying drug-platelet-immune interactions have been unavailable until recently. The mechanisms by which drugs cause thrombocytopenia are varied. Bone marrow suppression or increased peripheral destruction of platelets could be involved. Nonimmunologic as well as immunologic mechanisms may also occur. These different mechanisms of drug-induced thrombocytopenia are reveiwed. Diagnostic methods and treatment are also summarized.     

Heinz body anemia in a dog that had been sprayed with skunk musk

A 5-year-old pit bull-type dog was examined because of lethargy and black feces, and a presumptive diagnosis of methemoglobinemia was made on the basis of grossly visible brown discoloration of the mucous membranes and urine. Heinz body formation was seen on examination of blood smears, and severe anemia developed 3 days later. The dog did not have any history of exposure to toxins or drugs that have been associated with Heinz body formation. The only remarkable historical finding was that the dog had been wandering loose the day prior to initial examination and returned home smelling strongly of skunk spray. Skunk spray contains thiols and other compounds that are strong oxidizing agents. It was speculated that the methemoglobinemia and Heinz body anemia were a result of exposure to these compounds. Skunk interactions with dogs usually have malodorous but otherwise harmless results. However, findings in this dog suggest that more serious consequences may develop in isolated cases.     

ACVIM consensus statement on the treatment of immune‐mediated hemolytic anemia in dogs

Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.     

Demonstration of equine infectious anemia virus in primary leukocyte cultures by electron microscopy.

Electron microscopy was used to demonstrate the presence of viral particles in primary cultures of leukocytes taken from a horse after SC inoculation with the Wyoming strain of equine infectious anemia virus. Unlike previous studies, the exposure virus was not passaged through cell culture prior to horse inoculation. Cultures were begun approximately 1 week before and 1 week after the 1st pyrexic period after inoculation. In both samples, viral particles and cytoplasmic alterations were observed resembling those previously reported in equine infectious anemia virus and other retravirus-infected cells.     

Hematologic features of iron deficiency anemia in llamas.

Iron deficiency anemia was identified and characterized in three 14 to 29-month-old male llamas (llama Nos. 1-3) from separate herds in Colorado. The identification of iron deficiency anemia was based on hypoferremia (serum iron = 20-60 micrograms/dl), erythrocytic features, and hematologic response to iron therapy. The anemia was moderate and nonregenerative and characterized by erythrocyte hypochromia, microcytosis (mean cell volume = 15-18 fl), and decreased mean corpuscular hemoglobin concentration (36.0-41.0 g/dl). Morphologic features unique to llamas with iron deficiency anemia included irregular distribution of hypochromia within erythrocytes and increased folded cells and dacryocytes. The cause of iron deficiency was not determined. The llamas were treated with various doses and schedules of parenteral iron dextran. Two of the llamas were monitored for up to 14 months after the start of iron therapy and experienced increases in hematocrit and mean cell volume values. In one llama, progressive replacement of microcytic cells with normal cells was visualized on sequential erythrocyte volume distribution histograms following iron therapy.