Hyperkalaemia secondary to suspected transient hyporeninaemic hypoaldosteronism in a dog (<i>in a dog</i>)

Abstract A 12‐year‐7‐month‐old, female, entire beagle dog was presented to a referral hospital in England for a 10‐day history of tachypnoea and lethargy. Angiostrongylus vasorum ELISA test was positive, and the patient was started on fenbendazole. One week later, it became lethargic, anorexic, polyuric and polydipsic, and it was diagnosed with an open pyometra. During hospitalisation and while on treatment for pyometra and angiostrongyliasis, its potassium increased progressively to 7.4 mmol/L [reference interval, RI: 3.4–4.9]. Basal cortisol excluded hypocortisolism. Aldosterone blood concentration was less than 20 pmol/L [RI: 0–393], and plasma renin was 0.06 ng/mL [RI: 0.22–2.4]. The patient was started on mineralocorticoid supplementation (fludrocortisone), and hyperkalaemia normalised within 24–48 hours. The owners stopped the treatment with fludrocortisone after 3 months on their own accord. This patient remains clinically normal with normal electrolytes despite no mineralocorticoid supplementation 4 months after.