Vitamin D Metabolism in Canine Protein-Losing Enteropathy

Decreased vitamin D concentration is a common finding in canine protein-losing enteropathy (PLE). Whether hypovitaminosis D contributes to the pathogenesis or is secondary to PLE is currently undetermined.
• Canine PLE can be a cause of ionized hypocalcemia, which, if severe or with rapid onset, can cause clinical signs such as seizures. Vitamin D supplementation should be considered for dogs with PLE that develop clinical signs secondary associated with ionized hypocalcemia.
•Although low serum vitamin D concentration has been reported to be a negative prognostic factor in canine PLE, it remains unknown whether there are benefits to supplementing vitamin D in dogs that do not show clinical signs of hypocalcemia.
• Dogs with PLE who are supplemented with vitamin D need to have their ionized calcium monitored regularly to avoid iatrogenic hypercalcemia.
• Prospective, longitudinal studies of dogs diagnosed with PLE are required to ascertain whether (1) treatment response is associated with normalization of serum vitamin D concentration without supplementation and (2) supplementation in depleted dogs improves their outcome.