Overview
Primary hyperparathyroidism (PHPT) is an adult-onset disorder of calcium metabolism. Parathyroid hormone, produced by the parathyroid glands, is normally secreted in response to low blood calcium levels. In PHPT affected dogs the parathyroid glands produce too much parathyroid hormone, which leads to the depletion of calcium from bones and hypercalcemia in the blood.
The Keeshond is a breed that is affected by PHPT which is inherited as an autosomal disease in this breed.
Affected dogs may show significant polyuria (excessive urine production) and polydipsia (excessive thirst) along with bone pain, lethargy and depression, oral discomfort and a variety of gastrointestinal signs. However, signs can be subtle and are often ignored as normal aging changes. The disorder presents a significant welfare concern as it may lead to renal failure if parathyroidectomy (removal of one or more parathyroid glands) is not performed.
The DNA test assays for a variant that is very strongly associated with PHPT in Keeshonds. We have tested DNA from multiple Keeshonds that have a confirmed clinical diagnosis of PHPT, and they all carry the PHPT variant. We have also identified a small number of Keeshonds that carry the variant but that do not have a confirmed diagnosis of PHPT, which might be because they are too young to show signs of the disease, or because the signs are subtle and might not have been noticed by their owners. The variant is rare within the general Keeshond population and so can be considered a good indicator of PHPT risk.
A manuscript describing the PHPT variant is being prepared for publication.