Progressive alopecia associated with hypoparathyroidism in a Jersey heifer

Background Chronic progressive generalized alopecia in dairy cattle has been anecdotally discussed in veterinary forums. Objective To describe subclinical changes in an otherwise apparently healthy animal with chronic progressive generalized alopecia. Animals One 10‐month‐old Jersey heifer. Methods Case report. Results A heifer was presented for chronic progressive alopecia. The skin was hyperpigmented and very thin (2.4 ± 0.0 mm, compared with 8.1 ± 0.3 mm measured in four contemporaneous Jersey heifers). Histopathological examination of the skin revealed severe epidermal hyperplasia, orthokeratotic hyperkeratosis and diffuse follicular atrophy. Clinicopathological changes included hypocalcaemia that did not respond to calcium therapy. Serum parathyroid hormone (PTH) was not detected, compared with 1.38 ± 0.78 pmol/L in four contemporaneous Jersey heifers. A diagnosis of hypoparathyroidism was made based on hypocalcaemia and low PTH in the presence of normal magnesium levels. The heifer was otherwise healthy and was allowed to continue normal life. A spontaneous abortion occurred at 5.5 months of pregnancy and this was likely due to the presence of twin fetuses. Despite targeted therapy of the ensuing retained placenta, the heifer declined in health and had to be euthanized. From the time of diagnosis with hypoparathyroidism until euthanasia (29 months of age), blood levels of calcium, phosphorus and PTH were regularly monitored. Calcium and phosphorus levels varied widely. Serum PTH was consistently undetectable. At postmortem examination, the parathyroid glands could not be located. Conclusions and clinical importance To our knowledge, this is the first report of naturally occurring hypoparathyroidism in cattle and with a clinical presentation of alopecia. Résumé Contexte Des discussions anecdotiques de forums vétérinaires ont portées sur l'alopécie progressive généralisée chronique chez la vache laitière. Objectifs Décrire les changements subcliniques chez un animal en bon état général, atteint d'alopécie progressive généralisée chronique. Sujets Une génisse Jersey de 10 mois. Méthode Cas clinique. Résultats Une génisse est présentée pour alopécie progressive chronique. La peau était hyperpigmentée et très fine (2.4 ± 0.0 mm, comparé avec 8.1 ± 0.3 mm mesuré pour quatre autres génisses Jersey). L'examen histopathologique de la peau a révélé une hyperplasie épidermique sévère, une hyperkératose orthokératosique et une atrophie folliculaire diffuse. Les