| Calcipotriene, used to treat psoriasis in humans, is available as an ointment or cream (0.005% or 50 µg/g). Calcipotriene is a novel structural analog of calcitriol (1,25-dihydroxycholecalciferol), the most active metabolite of cholecalciferol (vitamin D3). Accidental ingestion of 40-60 µg/kg of calcipotriene in dogs has been associated with life-threatening hypercalcemia. Clinical signs usually occur within 24-72 hr of ingestion and include anorexia,
vomiting, diarrhea, polyuria, polydipsia, depression, and weakness. Serum calcium is usually elevated within 12-24 hr and may remain above normal for weeks. This is usually accompanied by an increase in serum phosphorous concentration and calcium phosphorous product (Ca × P) and soft tissue mineralization. Acute renal failure as evidenced by elevated BUN and creatinine levels, coma, and death occur in severe or untreated cases. |
| Treatment of calcipotriene toxicosis involves standard decontamination (emesis induction, administration of activated charcoal and a cathartic) and reduction of serum calcium concentrations by saline diuresis, furosemide, and corticosteroids, with or without salmon calcitonin treatment (see
principles of treatment of hypercalcemia,
Principles of Treatment of Hypercalcemia). Recent reports indicate that concurrent use of pamidronate (1.3-2 mg/kg diluted in saline and given IV over 2 hr) in dogs may be a useful adjunctive therapy. Calcipotriene toxicosis cases usually require monitoring of serum calcium, phosphorous, BUN, and creatinine for several days or even weeks. Signs of renal failure are managed with ongoing supportive fluids. |
