Haemolytic anaemia and bilateral uveitis associated with leptospirosis in a 6‐year‐old Quarter Horse gelding

A 6‐year‐old Quarter Horse gelding was presented for bilateral uveitis resulting in vision loss as well as icterus. Anaemia with autoagglutination was consistent with a presumptive immune‐mediated haemolytic anaemia. Urinary PCR was positive for Leptospira spp. and microscopic agglutination test (MAT) titres were elevated to multiple serovars supportive of a diagnosis of leptospirosis. Treatments included broad spectrum antibiotics and aggressive anti‐inflammatory medications. While the horse was hospitalised, the development of bilateral corneal ulcers precluded the use of topical ophthalmic anti‐inflammatories for a number of days. The corneal ulceration resolved, vision returned in both eyes and the immune‐mediated haemolytic anaemia resolved. After 9 days of hospitalisation, oral minocycline was administered for 2 weeks at home as well as low dose oral flunixin meglumine and topical ophthalmic diclofenac and atropine. This case represents the first published case of haemolytic anaemia associated with leptospirosis in a horse.     

Cerebral haemorrhage in a pregnant Standardbred mare with Evan's syndrome

A 3‐year‐old pregnant Standardbred mare was treated at the University of Helsinki Equine Teaching Hospital for severe idiopathic immune‐mediated thrombocytopenia and haemolytic anaemia (Evan's syndrome). Despite initial improvement with supportive care and immunosuppressive doses of corticosteroids and azathioprine, the mare died from a fatal cerebral haemorrhage on Day 21 of treatment.     

Septic funiculitis caused by Streptococcus equi subspecies equi infection with associated immune‐mediated haemolytic anaemia

A 2‐year‐old Quarter Horse gelding presented for anaemia, icterus, depression and intermittent colic 2 weeks after routine castration. Bilateral septic funiculitis with Streptoccocus equi ssp. equi with secondary immune‐mediated haemolytic anaemia were diagnosed. A blood transfusion was required to facilitate general anaesthesia for surgical excision of the septic funiculitis. Antibiotic therapy was provided initially with chloramphenicol and later enrofloxacin. Immunosuppressive therapy was provided with dexamethasone and later azathioprine. The horse responded well to treatment and was discharged 8 weeks after presentation. Streptococcus equi ssp. equi should be considered in cases with septic funiculitis and the potential for a secondary immune‐mediated haemolytic anaemia exists with this bacterial species.     

Cutaneous Alternaria infectoria infection in a dog in association with therapeutic immunosuppression for the management of immune‐mediated haemolytic anaemia

A 4‐year‐old, ovariohysterectomized, English springer spaniel on immunosuppressive therapy was re‐examined for the review of its immune‐mediated haemolytic anaemia and the recent development of skin lesions. For the 3 months since hospital discharge, the dog had been receiving 1.3 mg/kg prednisolone and 2.6 mg/kg ciclosporin, both administered orally twice daily. Physical examination revealed hepatomegaly and multiple, purulent, crusting, erosive to ulcerative lesions over different body areas. Onychorrhexis had occurred on one digit and the underlying corium had blackened. There were two proliferative and one plaque‐like lesions in the mouth. Thick walled fungal hyphae were detected in impression smears from all skin lesions and staining with periodic acid–Schiff’s stain confirmed the presence of multiple fungal hyphae and spores in all biopsies examined. Fungal culture isolated a heavy, pure growth of an Alternaria sp. which was identified as A. infectoria by sequencing the internal transcribed spacer 1 region of the rRNA gene. The animal’s condition prevented detailed investigation of the oral lesions. Withdrawal of the ciclosporin and reduction of the prednisolone dosage resulted in spontaneous resolution of the skin lesions within 40 days. Further gradual decrements in the prednisolone dosage to zero were carried out without recurrence of the immune‐mediated haemolytic anaemia. After 12 months, there has been no recurrence of either the skin lesions or the anaemia. To the authors’ knowledge, this is the first reported case of A. infectoria infection in a dog.     

Immune-mediated haemolytic anaemia associated with a sarcoma in a flat-coated retriever

A seven-year-old flat-coated retriever presented with a history of lethargy, dyspnoea and inappetence of several days' duration. Clinical examination revealed pale mucous membranes and tachypnoea, and haematology demonstrated marked autoagglutination. Thoracic radiographs revealed an increased opacity in the perihilar region. The owners declined further evaluation and the dog was treated symptomatically with immunosuppressive doses of prednisolone and azathioprine. The dog's demeanour improved, although it was eventually euthanased seven weeks later because of dysphagia and worsening dyspnoea. Postmortem examination revealed a widespread, poorly differentiated sarcoma involving the lungs, pericardium, thoracic lymph nodes and spleen. Immune-mediated haemolytic anaemia is a well recognised condition in dogs and is occasionally associated with neoplastic conditions. This is the first case report to describe immune-mediated haemolytic anaemia associated with a diffuse, poorly differentiated sarcoma.     

Production of an anticanine globulin (polyspecific) reagent for laboratory investigation

Objectives : Canine allo‐ or autoantibodies are clinically important, but attachment of these immunoglobulin G (IgG) antibodies does not produce observable haemagglutination. Antibody to canine globulins is required to demonstrate sensitisation of red blood cells. Commercial reagents are available, but these often differ in sensitivity and specificity. Rabbit anticanine globulins (polyspecific) were produced for use in canine blood compatibility testing and in the investigation of immune‐mediated haemolytic anaemia. Methods : Canine sera was pooled, IgG was purified and subsequently used to immunise rabbits. A rising titre of anticanine IgG was demonstrated by indirect enzyme‐linked immunosorbent assay. Rabbit anticanine complement was isolated and investigated by agglutination of complement‐coated canine red blood cells. Both antibodies were purified and checked for crossreactivity before being combined to polyspecific anticanine globulins. The obtained reagent was used to indicate sensitised canine red blood cells and free antibodies in three different types of clinical samples, including blood for compatibility testing and that for investigation of immune‐mediated haemolytic anaemia and screening for post‐transfusion alloantibodies and was also compared to commercial Coombs’ reagent. Results : The product provided results in accordance with those from commercial Coombs’ reagent. The sensitivity for canine crossmatching was 100% and specificity for diagnosing immune‐mediated haemolytic anaemia was 87%. Clinical Significance : This product is helpful for canine crossmatching purposes and in the investigation of immune‐mediated haemolytic anaemia.     

Serum cardiac troponin I in dogs with primary immune-mediated haemolytic anaemia

Objectives : The assessment of serum cardiac troponin I concentrations in dogs with a range of nonprimary cardiac illnesses has revealed that cardiac myocyte damage is commonplace in many canine diseases. Whilst it is well established that dogs with fatal immune‐mediated haemolytic anaemia frequently have cardiac pathology based on post‐mortem examinations, there is limited information on the incidence of cardiac myocyte damage in this population of dogs. Methods : Serum cardiac troponin I concentrations were measured in 11 healthy dogs, 27 dogs with primary haemolytic anaemia and 49 hospitalised dogs without primary cardiac or haematological disorders. Results : Dogs with primary haemolytic anaemia have higher serum concentrations of cardiac troponin I than hospitalised ill dogs (P<0.005) and healthy dogs (P<0.01). Using a cut‐off of less than 0.1 ng/mL, 20 of 27 dogs with primary haemolytic anaemia had increased serum cardiac troponin I concentrations, which was a significantly higher proportion compared to the hospitalised ill dogs (P<0.001, 16 out of 49 dogs) and healthy dogs (P<0.05, 3 out of 11 dogs). Clinical Significance : Dogs with primary haemolytic anaemia have a higher incidence of subclinical myocyte damage than healthy dogs or dogs with non‐haematological or primary cardiac illnesses. The prognostic significance of increased serum cardiac troponin I concentrations in dogs with primary haemolytic anaemia merits further investigation.     

Heinz body haemolytic anaemia in a dog secondary to ingestion of a zinc toy: a case report

A 6-year-old Labrador retriever was referred for investigation of severe lethargy and suspected immune-mediated haemolytic anaemia. Clinical examination revealed pale mucous membranes and jaundice. Haematology demonstrated large numbers of Heinz bodies and a marked anaemia, which was strongly regenerative. Serum zinc concentrations were markedly elevated. Analysis of a metal toy vomited by the dog 3 days prior to presentation revealed it to be composed of almost pure zinc. A diagnosis of haemolytic anaemia secondary to acute zinc toxicity was made and supportive therapy instigated. There was a subsequent decrease in numbers of Heinz bodies and a rise in the haematocrit, and the dog made an uneventful recovery. Acute zinc toxicity resulting in haemolytic anaemia is rarely observed, and this case was also unusual in that the main clinicopathological finding was the presence of numerous Heinz bodies without other evidence of oxidative damage to red blood cells.     

Erythrocyte pyruvate kinase deficiency in three West Highland white terriers in Ireland and the UK

Erythrocyte pyruvate kinase (PK) deficiency is described for the first time in three apparently unrelated West Highland white terriers (WHWT) from Ireland and the UK. All three dogs were diagnosed with markedly regenerative but persistent anaemia and had been treated for presumed immune-mediated haemolytic anaemia (IMHA) before hereditary erythrocyte PK-deficiency was confirmed by breed-specific DNA mutation analysis. This hereditary erythroenzymopathy causes haemolytic anaemia and affects several canine breeds with varying degrees of severity. Although eventually causing osteosclerosis, haemosiderosis and death, PK-deficient dogs can adapt to their anaemia for many years.PK-deficiency should be considered in anaemic WHWTs worldwide particularly in dogs with haemolytic anaemia where evidence for an immune-mediated, infectious or toxic underlying cause is lacking.     

Auto-immune haemolytic anaemia in a horse

A case of auto-immune haemolytic anaemia (AHA) in a 7-year-old, pony gelding is described. Diagnosis was based on a strong, positive reaction to the direct Coombs antiglobulin test and the presence of erythrophagocytosis and spherocytosis in peripheral blood smears. The condition was complicated by an infected haematoma, posterior paresis and urinary incontinence. The triggering mechanism behind the antibody response against the red cells is unknown.     

Circulating lupus anticoagulant and probable systemic lupus erythematosus in a cat

An adult domestic short hair cat was presented in a critical condition with icterus. Various investigations demonstrated the presence of haemolytic anaemia and hepatic abnormalities, as well as significant coagulation defects. Systemic lupus erythematosus (SLE) was suggested as a possible cause.     

Experimental induction of an immunohaemolytic anaemia in the chicken with Salmonella gallinarum endotoxin.

The possibility that the extreme refractoriness of the chicken to injected endotoxin would permit the buildup of sufficient free endotoxin in the circulation to immunologically modify the erythrocytes in vivo and thereby cause them to be eliminated from the circulation was investigated. It was shown that a moderately severe immunohaemolytic anaemia accompanied by a mild spenomegaly could be induced in chickens by single (large) or multiple injections of Salmonella gallinarum endotoxin (SgE). Varying degrees of reticulocytosis, with corresponding decreases in haemoglobin and haematocrit values, were observed from the tenth day after the injection of the SgE. All the injected animals also showed significant immune responses to SgE, peak haemagglutinin titres occurring coincidentally with the peaks of the haemolytic episodes. A similar injection schedule in specifically immune chickens also showed the anaemia appearing much earlier, persisting longer and being much more profound in intensity. It is considered that the in vivo erythrocyte sensitization induced by SgE injection initiates the erythrocytic changes observed and that the underlying mechanism responsible for the subsequent development of the haemolytic anaemia is immunologically mediated.     

A case report of <Emphasis Type="Italic">Mycoplasma wenyonii</Emphasis> associated immune-mediated haemolytic anaemia in a dairy cow

Background and case presentation

A three year old, second lactation Holstein dairy cow presented to the Scottish Centre for Production Animal Health and Food Safety, Glasgow University Veterinary School in November 2014 with a history of post-calving vulval/vaginal bleeding nine days prior to presentation, followed by a sudden reduction in milk yield. Subsequent investigations resulted in a diagnosis of immune-mediated haemolytic anaemia secondary to infection with Mycoplasma wenyonii.

Conclusion

This report of a novel presentation of Mycoplasma wenyonii in a dairy cow illustrates the need to consider M.wenyonii as a potential differential diagnosis when a cow presents with anaemia and will discuss the potential implications of the condition at herd-level.

     

Evaluation of platelet activation in canine immune-mediated haemolytic anaemia

Objectives : To establish whether heightened platelet activation is a common feature of canine immune-mediated haemolytic anaemia, and to evaluate the hypothesis that platelet activation plays a role in the pathogenesis of thromboembolism. Methods : Using whole-blood flow-cytometric analysis, the proportion of activated platelets and platelet-leucocyte aggregates in blood samples from 14 dogs with immune-mediated haemolytic anaemia and 14 healthy dogs was calculated. General linear models with binomial errors were used to compare groups. Results from the immune-mediated haemolytic anaemia-affected dogs were then correlated with established risk factors for thromboembolism in canine immune-mediated haemolytic anaemia, D-dimer concentration and antithrombin activity. Results : There was a strong correlation between platelet activation and severe thrombocytopenia, with heightened platelet activation being observed predominantly in severely thrombocytopenic dogs. Clinical Significance : Dogs with immune-mediated haemolytic anaemia, particularly those with concurrent severe thrombocytopenia, are likely to have heightened platelet activation, which may play a role in the pathogenesis of thromboembolism.     

Neutrophilic dermatitis and immune-mediated haematological disorders in a dog: suspected adverse reaction to carprofen

This report describes the clinical and pathological findings of a suspected idiosyncratic adverse drug reaction in a young dog. The patient presented with sudden onset, severe skin lesions together with episodes of collapse. Investigations revealed a neutrophilic dermatitis with vasculitis, immune-mediated haemolytic anaemia and thrombocytopenia. Similar pathology has been described in human cases of Sweet's syndrome. The chronology of events suggested an adverse drug reaction to carprofen, although two antibiotics had been prescribed within the dog's recent history. Lymphocyte transformation tests were performed and tended to exclude both antibiotics as the cause of the reaction. To the authors' knowledge, lymphocyte transformation tests have not previously been described with regard to drug hypersensitivity assessment in the veterinary literature, and this is the first peer-reviewed case report of neutrophilic dermatitis and vasculitis with immune-mediated haemolytic anaemia and thrombocytopenia occurring as a suspected adverse drug reaction to carprofen in the dog.     

In this issue – January/February 2010

Septic osteomyelitis in foals  ·  Partial pressure of arterial carbon dioxide during general anaesthesia in horses  ·  Mastocytoma in digital flexor tendons of a horse  ·  Immune-mediated haemolytic anaemia in dogs  ·  Spotted fever group rickettsial antibodies in cats and dogs in Tasmania  ·  Consequences of false-positive results for Chlamydophila abortus in Australian sheep for the rejection of breeder sheep for export  ·  Femoral diaphysis fractures in cattle  ·  Haemolytic anaemia in cattle in New South Wales associated with Theileria infections  ·  Stimulation test for determining the steroidogenic capacity of the parrot testis  ·  Seminoma in a black rhinoceros     

Erythrocyte response to Trypanosoma brucei in experimentally infected dogs.

Trypanosoma brucei infection produced an acute and fatal disease in Nigerian mongrel dogs due to a rapidly developing anaemia. Infected dogs responded with increased reticulocytosis, which was not sustained with chronicity. In comparison the response to artificially-induced haemolytic anaemia was progressive, marked and sustained. The anaemia of T. brucei infection of dogs was either normocytic normochromic in acute infection or microcytic normochromic in chronic infection. Artificially-induced haemolytic anaemia was either macrocytic normochromic or normocytic normochromic. The erythropoietic potential of plasma in vivo in mice increased in T. brucei-infected dogs except at the terminal parasitaemia. The anaemia in Trypanosoma brucei-infected dogs is therefore initially responsive but becomes poorly involved with chronicity.     

Successful treatment of disseminated cutaneous phaeohyphomycosis in a dog

A 7-year-old castrated male Whippet developed deep ulcerative skin lesions whilst receiving immunosuppressive doses of prednisolone and cyclosporine for the treatment of immune-mediated haemolytic anaemia. The lesions were determined to be a phaeohyphomycosis, caused by Curvularia lunata. The dog was treated with a combination of systemic antifungals and weaning off immunosuppressants and made a complete recovery. To the authors' knowledge, this is the first case report of the successful treatment of disseminated cutaneous phaeohyphomycosis in a dog.     

Evaluation of immunosuppressive regimens for immune-mediated haemolytic anaemia: a retrospective study of 42 dogs

Objectives : Immune‐mediated haemolytic anaemia (IMHA) is a severe disease for which evidence is lacking to make informed choices regarding immunosuppressive regimen. The aims of the current study were to determine the effect of different treatment regimens on outcome in affected animals and to identify parameters that may be used as prognostic factors for the disease. Methods : The records of dogs presenting to a veterinary hospital in the period 2002 to 2010 for treatment of IMHA were examined and follow‐up data were obtained. Statistical tests were performed to establish whether treatment regimen affected outcome and to identify prognostic factors for outcome. Results : Treatment regimen had a significant effect on the outcome (measured as survival of hospitalisation) but there were insufficient subjects to determine the cause of the difference. Serum bilirubin and urea concentrations were found to be significant negative prognostic factors for the outcome of IMHA cases and the concentrations of these parameters were significantly different between animals that survived or died while hospitalised. Clinical Significance : This study presents the first report of a significant difference in outcome comparing animals treated with immunosuppressive drugs which are in widespread clinical usage. Although possible confounding factors should be considered, these findings could have major consequences for the treatment of IMHA.     

Autoimmune haemolytic anaemia in eight horses

Autoimmune haemolytic anaemia was diagnosed in eight horses on the basis of a positive Coomb's test. The disease was considered to be idiopathic in three cases and secondary to another condition in five. The clinical signs included dullness and depression, pyrexia, jaundice and haemoglobinuria. In addition to anaemia, haematological evaluation commonly revealed auto-agglutination of red cells and anisocytosis; reticulocytosis and an increased mean corpuscular volume were less commonly observed. Four horses were successfully treated with dexamethasone, but the other four were destroyed or died because of the underlying disease.