At admission, the serum phosphate concentrations had been measured in all the dogs in Group L and in 11/13 dogs in Group R. One dog in Group L had severe hypophosphatemia (0.84 mg/dL); this patient received preventive supplementation with potassium phosphate and did not show the clinical signs associated with hypophosphatemia during the protocol with IM insulin lispro. Here, INS is linked to hypophosphatemia.