E B Gorenberg1, A L Johnson2, K G Magdesian3, F-R Bertin4, L R R Costa3, M J P Theelen5, S A Durward-Akhurst6, C Cruz Villagrán7, H Carslake8, N Frank9, J E Tomlinson10. 1. Cornell University College of Veterinary Medicine, Ithaca, New York, USA. 2. New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania, USA. 3. University of California Davis Veterinary Medical Teaching Hospital, Davis, California, USA. 4. The University of Queensland School of Veterinary Science, Gatton, Queensland, Australia. 5. Department of Equine Sciences, Utrecht University, Utrecht, The Netherlands. 6. Department of Veterinary Population Medicine, University of Minnesota, St Paul, Minnesota, USA. 7. The University of Adelaide, Roseworthy, South Australia, Australia. 8. School of Veterinary Science, University of Liverpool, Philip Leverhulme Equine Hospital, Cheshire, UK. 9. Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA. 10. Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, Ithaca, New York, USA.
Abstract
BACKGROUND: Primary hyperparathyroidism is uncommon in equids. OBJECTIVES: To describe the diagnostic findings and efficacy of treatment in equids with primary hyperparathyroidism. STUDY DESIGN: Retrospective case series describing 16 horses and one mule. METHODS: Cases were identified by retrospective review of records at Cornell University and via an ACVIM listserv query. Inclusion criteria were an equid with hypercalcemia, normal renal function and high parathyroid hormone (PTH) or histopathological diagnosis of a parathyroid adenoma. Equids with normal PTH and PTH-related protein (PTHrP) in the face of hypercalcemia were included as suspect cases. RESULTS: The most common presenting complaints were weight loss (12/17) and hypercalcemia (10/17). PTH was above reference range in 12/17 cases. Suspected parathyroid tumours were localised in 12/14 equids imaged using ultrasonography alone (2/3), technetium 99m Tc sestamibi scintigraphy alone (1/1) or both modalities (9/10). Three horses did not have imaging performed. Surgical exploration successfully excised tumours in six of 10 cases. Five were located at the thoracic inlet, and surgery resulted in complete cure. One tumour was excised from the thyroid lobe, and the horse remained hypercalcemic. Four other cases explored surgically, four treated medically and three that were not treated also remained hypercalcemic. MAIN LIMITATIONS: The small study size prohibited statistical analysis. CONCLUSIONS: Parathyroid adenomas in equids can be successfully localised with ultrasonography and scintigraphy. Surgical excision appears more likely to be successful for single gland disease at the thoracic inlet.
BACKGROUND: Primary hyperparathyroidism is uncommon in equids. OBJECTIVES: To describe the diagnostic findings and efficacy of treatment in equids with primary hyperparathyroidism. STUDY DESIGN: Retrospective case series describing 16 horses and one mule. METHODS: Cases were identified by retrospective review of records at Cornell University and via an ACVIM listserv query. Inclusion criteria were an equid with hypercalcemia, normal renal function and high parathyroid hormone (PTH) or histopathological diagnosis of a parathyroid adenoma. Equids with normal PTH and PTH-related protein (PTHrP) in the face of hypercalcemia were included as suspect cases. RESULTS: The most common presenting complaints were weight loss (12/17) and hypercalcemia (10/17). PTH was above reference range in 12/17 cases. Suspected parathyroid tumours were localised in 12/14 equids imaged using ultrasonography alone (2/3), technetium 99m Tc sestamibi scintigraphy alone (1/1) or both modalities (9/10). Three horses did not have imaging performed. Surgical exploration successfully excised tumours in six of 10 cases. Five were located at the thoracic inlet, and surgery resulted in complete cure. One tumour was excised from the thyroid lobe, and the horse remained hypercalcemic. Four other cases explored surgically, four treated medically and three that were not treated also remained hypercalcemic. MAIN LIMITATIONS: The small study size prohibited statistical analysis. CONCLUSIONS: Parathyroid adenomas in equids can be successfully localised with ultrasonography and scintigraphy. Surgical excision appears more likely to be successful for single gland disease at the thoracic inlet.
Authors: Sarah F Colmer; Kathryn Wulster; Amy L Johnson; David G Levine; Claire Underwood; Trevor W Watkins; Andrew W Van Eps Journal: J Vet Intern Med Date: 2022-02-12 Impact factor: 3.333