Prevalence of canine primary hyperparathyroidism recurrence in Keeshond and non-Keeshond dogs after curative parathyroidectomy

Oral cinacalcet administration decreases serum ionized calcium and parathyroid hormone concentrations in healthy dogs

Cinacalcet is an oral calcimimetic that has potential to non-invasively treat primary hyperparathyroidism in dogs (Canis lupis familiaris). There is minimal data assessing its efficacy in dogs. This study aimed to determine whether a single dose of cinacalcet decreases serum ionized calcium (iCa), total calcium (tCa), and parathyroid hormone (PTH) concentrations. Twelve dogs received a median dose of 0.49 mg/kg (range 0.30-0.69 mg/kg) cinacalcet per os. Venous blood samples were collected at time 0 (before cinacalcet administration), 3, 8, and 24 h following cinacalcet administration. PTH, iCa, and tCa concentrations were measured at each time point and compared to 0 hour concentrations. A significant (50%) decrease in serum PTH occurred at 3 h with a median PTH of 4.6 pmol/L (range 2.7-10.8) at baseline and 1.65 pmol/L (range 0.5-14.7) at 3 h; p = .005. A significant, but not clinically relevant, decrease in serum iCa from a median baseline of 1.340 mmol/L (range 1.32-1.41) to a 3 h median of 1.325 mmol/L (range 1.26-1.39), p = .043, was also observed. tCa concentrations were not different. This study showed that a single dose of cinacalcet leads to transient decreases in iCa and PTH concentrations in healthy dogs.

Surgical description and outcome of ultrasound-guided minimally invasive parathyroidectomy in 50 dogs with primary hyperparathyroidism

OBJECTIVE

To describe the surgical technique and clinical outcome of minimally invasive parathyroidectomy for primary hyperparathyroidism (PHPT) in the dog.

ANIMALS

Fifty client-owned dogs with PHPT that underwent minimally invasive parathyroidectomy.

STUDY DESIGN

Retrospective cohort study.

METHODS

An ultrasound-guided mini lateral approach was made via a plane established between the sternocephalicus muscle and sternohyoideus muscles to expose the thyroid gland and enlarged parathyroid gland. Abnormal parathyroid glands were removed en bloc via partial thyroidectomy. The technique for bilateral disease was similar, the skin incision was made on midline and moved laterally to develop the above-mentioned plane of dissection. Age, sex, breed, bodyweight, ultrasound findings, histopathological diagnosis, surgical time, preoperative clinical signs, and clinical outcome were extracted from the records for descriptive statistics.

RESULTS

A total of 62 glands were surgically removed, including 17 hyperplastic glands (17/62, 27.4%), 34 adenomas (34/62, 54.8%), and two carcinomas (2/62, 3.2%). Hypercalcemia resolved shortly after surgery in 44 dogs (44/45, 97.8%). One dog had recurrent hypercalcemia (1/45, 2.2%), one dog had persistent hypercalcemia (1/45, 2.2%), two dogs had permanent hypocalcemia requiring life-long calcitriol supplementation (2/45, 4.4%), and one dog died from clinical hypocalcemia (1/45, 2.2%).

CONCLUSION

Minimally invasive parathyroidectomy was associated with a low morbidity and led to favorable outcomes in 44/45 dogs in this series.

CLINICAL SIGNIFICANCE

The results of this study supports the use of minimally invasive parathyroidectomy to treat PHPT in dogs.