Multiorgan reaction suspected in association with sulphonamide antimicrobial administration in a dog, a case report

Authors: Haggard SW, Hugo TB, Lawson KL
Publication: Australian Veterinary Practitioner, Volume 55, Issue 2, pp 61-71, Jun 2025
Publisher: Australian Veterinary Association

Animal type: Dog
Article class: Clinical Article

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Abstract:

Potentiated sulphonamides, such as trimethoprim-sulfamethoxazole, are commonly prescribed antibiotics in veterinary medicine to treat infections of multiple body systems. Their usage is associated with adverse reactions involving multiple organs that range from mild to fatal. This case report describes a severe multi-organ reaction post high dose sulphonamide administration in a dog. Disease manifestations included thrombocytopenia, anaemia, hepatopathy, keratoconjunctivitis sicca, and cutaneous eruptions. Diagnosis and treatments are described in detail. The patient was discharged following sixteen days of hospitalisation. Seventy-four days post discharge, the dog was euthanised for clinical findings consistent with cardiogenic pulmonary oedema. Whilst sulphonamide reactions are typically reported as idiosyncratic, the prolonged, high dose administration in this case is suspected to have exacerbated the severity of this patient’s adverse drug reaction, although this cannot be confirmed in this case.

Keywords: Hypersensitivity, trimethoprim-sulfamethoxazole, idiosyncratic reaction, adverse reaction, hepatopathy, keratoconjunctivitis sicca, cutaneous eruption, thrombocytopenia

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