How are levels of calcium controlled in the healthy animal?
Calcium levels are controlled by a pair of parathyroid glands. The two tiny glands are embedded in the thyroid gland, which sits just below the larynx or “voice box” overlying the windpipe. The parathyroid glands are responsible for monitoring the calcium level in the blood. When calcium levels are too low, the glands release a hormone called parathyroid hormone (PTH), which acts to return calcium levels to normal.
Incidence of Calcium Disturbances in Dogs
For dogs, 44,366 records were identified across the 9.5-year period. After removal of subsequent or follow-up analyses, the initial analyses from 15,277 individuals remained. Of these, 1,643 electrolyte profiles documented hypercalcemia. After removal of two profiles from dogs that were dead-on-arrival there were 1,641 profiles with hypercalcemia, corresponding to an incidence of canine hypercalcemia of 10.7% (1,641/15,277). Hypocalcemia was documented in 1,468 profiles. After removal of one profile from a miscoded Fennec fox there were 1,467 profiles with hypocalcemia, corresponding to an incidence of canine hypocalcemia of 9.6% (1,467/15,277).
Differential diagnoses include:
History should be obtained including duration of clinical signs, any changes to drinking, energy levels or behaviour and potential access to toxins, medication or diet for possible hypervitaminosis D. A thorough physical examination is very important to carefully assess peripheral lymph nodes and a rectal examination should also be performed.