Hypercalcaemia in dogs with dermatopathies… do you measure calcitriol?
Our considerations in the differentials for hypercalcaemia in dogs and cats include:
Hyperparathyroidism
Addisons disease (hypoadrenocorticism)
Renal disease
Vitamin D toxicity
Granulomatous disease
Osteolysis
Idiopathic
Neoplasia
Spirious / Laboratory error
(I remember this as HARDGOINS). There are additional diagnostics we can do in addition to total calcium, and ionised calcium the biologically important metric for considartion: including measuring calcitriol, parathyroid hormone, parathyroid related protein.
Endogenous calcitriol production and ionized hypercalcemia in 7 dogs with chronic dermatopathy of infectious and noninfectious etiology (2016-2024) Open Access
Journal of Veterinary Internal Medicine, Volume 40, Issue 2, March-April 2026, aalag038, https://doi.org/10.1093/jvimsj/aalag038
Published:
11 March 2026
Abstract
Background
Hypercalcemia associated with granulomatous disease in dogs can present a diagnostic challenge.
Hypothesis/Objectives
Excessive endogenous, extrarenal calcitriol production is a potential mechanism of ionized hypercalcemia in dogs with granulomatous skin conditions.
Animals
Hypercalcemic client-owned dogs (n = 7) with chronic skin disease seen in general and specialty practices with calcium profiles submitted to a university veterinary diagnostic laboratory by the attending clinician.
Methods
Descriptive case series reporting clinical presentation, laboratory findings, treatment, and outcome of 7 hypercalcemic dogs with dermatopathies of varying etiology.
Results
Panniculitis was confirmed histologically in 5 dogs (idiopathic, n = 4; presumed bacterial, n = 1). The other 2 dogs had severe generalized demodicosis (n = 1) and demodectic/sarcoptic mange with superficial and deep pyoderma (n = 1). Initial testing showed clinically relevant parathyroid-independent ionized hypercalcemia, undetectable parathyroid hormone-related protein concentration, and 25-hydroxyvitamin D concentration close to or below the lower reference limit in all dogs. Calcitriol concentration was above reference interval in 6 dogs at initial testing, and near the upper reference limit in 1 dog 29 days after presentation. In all cases, normalization of calcium and vitamin D homeostasis paralleled clinical improvement with appropriate therapy for the underlying skin condition.
Conclusions and clinical importance
Ionized hypercalcemia apparently mediated by excessive extrarenal calcitriol production can be seen in dogs with granulomatous skin disease. Calcitriol measurement should be included with other calcium-related testing in the workup of unexplained hypercalcemia with concurrent chronic skin disease.
