Nutritional secondary hyperparathyroidism in six cats

Abstract

Nutritional secondary hyperparathyroidism (NSH) was diagnosed in six cats during a three-year period, based on clinical, radiographic and laboratory findings. Clinical signs were attributable to severe osteopenia (n = 5) and hypocalcaemia (n = 4), which had resulted in spontaneous fractures of long bones, scapulae, pelvis, nasal bones, or spine, and in excitation, muscle twitching or seizures, respectively. Serum parathormone levels were markedly elevated, and 1,25(OH)2-vitamin D3 mildly elevated, whereas 25(OH)-vitamin D3 was mildly decreased compared to age-matched healthy cats. Treatment was limited to short-term parenteral calcium gluconate injections, as clinically indicated, a balanced diet and cage rest, which resulted in quick clinical recovery in four cases. The remaining two cats had to be euthanased because of progressive neurological deficits secondary to spinal fractures. At the time of writing, a multitude of commercial balanced diets is widely available and diseases secondary to dietary deficiencies have become rare. Nevertheless, NSH is still an important clinical entity, and should be considered in growing cats presenting with spontaneous fractures or seizures.

A Case of Nutritional Secondary Hyperparathyroidism in a Siberian Tiger Cub

“…Serum inorganic phosphorus concentration and alkaline phosphatase may appear high but should be interpreted carefully because of high value in growing animals. As one report [7], cats that diagnosed as nutritional secondary hyperparathyroidism showed markedly increased serum parathormone levels and vitamin D(1,25(OH)2-vitamin D3; 25(OH)-vitamin D3) in the laboratory findings. Results of hematological and serum chemistry profiles are consistent with those described above in this case.…”

Nutritional secondary hyperparathyroidism in a white lion cub (Panthera leo), with concomitant radiographic double cortical line : clinical communication

“…Since then the incidence and severity of NSH in kittens and puppies has decreased, and is rarely seen. Other names that have been used to describe NSH include: juvenile osteoporosis, feline nutritional osteodystrophy 16,20 , paper bone disease, Siamese cat disease and osteogenesis imperfecta 16 . Osteogenesis imperfecta is a heritable condition in man (rare in animals) caused by a structural defect in type 1 collagen, which constitutes the majority of the non-mineral bone matrix.…”

“…Parathyroid hormone also mobilises calcium from bone in an attempt to maintain plasma calcium levels. Continued ingestion of a calcium-deficient diet results in the parathyroid gland secreting larger quantities of parathyroid hormone, resulting in a hyperparathyroid state 3,9,20 . Vitamin D deficiency plays a minor role in NSH where adequate amounts are supplied by the diet 3,5,9 .…”

“…Occasionally seizures have been documented 20 . Typical radiological signs of osteopaenia include generalised decreased bone opacity, thinned cortices and course trabeculation 12 .…”

“…Typical radiological signs of osteopaenia include generalised decreased bone opacity, thinned cortices and course trabeculation 12 . Pathological fractures, spinal curvature changes and pelvic deformation are often a sequel to longstanding osteopaenia 20,22 . A double cortical line is frequently seen in humans with various forms of osteopaenia but is a rare finding in small animals 12 .…”