Glucocorticoids are the cornerstone of immunosuppression for canine immune-mediated hemolytic anemia (IMHA), and anticoagulant therapy should be initiated at the time of diagnosis. Case fatality rates approach 50%, with thromboembolic disease among the most common causes of death, and thromboembolism has been estimated to occur in up to 50–80% of affected dogs.Journal of Vete…

Immunosuppression: First-Line

Prednisone or prednisolone is first-line immunosuppression, with dexamethasone used parenterally in dogs that cannot tolerate oral administration.Journal of the… A reported induction protocol uses dexamethasone at 0.5 mg/kg IV q24h, transitioning to prednisone at 2 mg/kg PO q12h once oral administration is feasible.Journal of the… Methylprednisolone is an acceptable alternative with similar anti-inflammatory potency to prednisolone and prednisone, and is available as an injectable formulation useful in the acute phase.Journal of Vete… Many dogs can be managed satisfactorily with glucocorticoids alone; others develop life-threatening disease or severe steroid-induced adverse effects requiring additional immunosuppression.Journal of Vete…

Immunosuppression: Second-Line

Second-line agents — mycophenolate mofetil (MMF), cyclosporine, azathioprine, and leflunomide — are added when glucocorticoid monotherapy is insufficient or adverse effects are unacceptable.Veterinary Clin…+1 The addition of a second immunosuppressive agent allows more rapid glucocorticoid tapering, which is particularly relevant in larger-breed dogs where corticosteroid intolerance is more prevalent.Journal of Vete… A clear survival benefit of adding second-line drugs to a standard steroid protocol has not been established.Journal of Vete…

Cyclosporine is a commonly used second-line agent; one protocol uses 2.5 mg/kg PO q12h, which is considered therapeutic based on prior IMHA studies, though the ACVIM consensus statement recommends a higher dose.Journal of Vete… Cyclosporine administration is associated with a significant increase in thromboxane A2 synthesis in dogs, particularly at peak blood concentrations with immunosuppressive dosing, which may increase the risk of thrombus formation.Journal of Vete… Azathioprine does not increase thromboxane synthesis, and MMF is associated with a reduction in thromboxane synthesis in animal models.Journal of Vete… Therapeutic drug monitoring is recommended to enhance utility and maximize safety of both cyclosporine and MMF.Veterinary Clin…

Antithrombotic Therapy

Antithrombotic therapy is essential and should be started at diagnosis, given the prothrombotic and proinflammatory state of IMHA.Veterinary Clin… Both the ACVECC and ACVIM guidelines recommend antithrombotic therapy in non-associative IMHA.Journal of Vete…

Anticoagulant drugs are recommended in preference to antiplatelet drugs for prevention of venous thromboembolism, as venous thrombi are fibrin-rich.Journal of Vete… If antiplatelet drugs are used, clopidogrel is preferred over or combined with aspirin.Journal of Vete… Unfractionated heparin dosing should be individualized based on anti-Xa monitoring; activated partial thromboplastin time is used as a surrogate when anti-Xa is unavailable, though it may be less reliable for confirming therapeutic concentrations.Journal of Vete…

Enoxaparin dosing is contested. A dose of 0.8 mg/kg SQ q6h has been shown to produce no significant anticoagulant activity in healthy dogs based on human anti-Xa targets.Journal of Vete… A dose of 1.3 mg/kg SQ q8h has been proposed to achieve or exceed target human anti-Xa levels.Journal of Vete… Clopidogrel alone versus a multi-agent antithrombotic protocol showed no significant difference in definitive thrombus formation in one cohort of non-associative IMHA dogs.Journal of Vete…

Supportive Therapy

Packed red blood cell transfusion is indicated to support blood oxygen content in severely anemic dogs.Veterinary Clin… Gastroprotectants and antimicrobials are used on a case-by-case basis without clear consensus on precise indications.Journal of Vete… Intravenous immunoglobulin (hIVIG) is used as salvage immunomodulation; thromboprophylaxis is particularly important in dogs receiving hIVIG given the additive hypercoagulable risk.Journal of Vete…

Emerging and Salvage Therapies

Therapeutic plasma exchange (TPE) is an adjunctive option for severe or refractory IMHA. In dogs with immune-mediated hematologic disorders treated with membrane-based TPE, the response rate in IMHA was 83% (versus 65% in controls), and 82% of TPE-treated dogs survived to discharge (versus 69% in controls); however, these differences were not statistically significant, and TPE dogs were more often refractory to initial immunosuppression (71%) than controls (43%).Journal of Vete… A protocol of three TPE treatments 24 hours apart has been described; in one case of severe IMHA with bilirubin encephalopathy (total bilirubin 48.1 mg/dL), a fourth treatment on day 6 was required to achieve autoagglutination-negative status and neurological recovery.Journal of the… Complications were observed in 35% of TPE treatments.Journal of Vete… Future therapies under investigation include anti-CD20 monoclonal antibodies and complement inhibitors.Veterinary Clin…

Monitoring

Therapeutic drug monitoring is recommended for cyclosporine and MMF to maximize efficacy and minimize toxicity.Veterinary Clin… Hematological variables including leukocytosis, band neutrophilia, monocytosis, and thrombocytopenia are associated with disease severity and prognosis in IMHA, likely reflecting severe inflammation or thromboembolic events.Journal of Vete… Anti-Xa monitoring is the recommended standard for individualizing unfractionated heparin dosing.Journal of Vete…

Would you like guidance on how to taper glucocorticoids and when to discontinue second-line immunosuppression once remission is achieved?