title: Vitamin D-dependent non-type 1, non-type 2 rickets in a 3-month-old Cornish Rex kitten.
abstract: CASE PRESENTATION AND ASSESSMENT: A 3-month-old female Cornish Rex kitten was found to have non-painful swelling of the carpal and tarsal regions when presented for routine neutering. The kitten was smaller in stature and less active than its siblings and, according to the owner, had a bunny-hopping gait, was reluctant to climb stairs and strained during defecation. Radiography of the affected limbs and a subsequent radiographic survey of the entire skeleton demonstrated features consistent with rickets. The three littermates were clinically and radiographically normal. As a nutritionally complete diet was being fed, it seemed most likely that the kitten had an inborn error related to vitamin D metabolism. Serum biochemistry demonstrated reduced total alkaline phosphatase activity and increased concentrations of parathyroid hormone. Concentrations of 1,25- and 25-hydroxycholecalciferol were markedly reduced, confirming the diagnosis of rickets.
  
  
  METHODS
  The kitten was treated with calcitriol, administered orally once daily, and improved rapidly both clinically and radiologically. Serial laboratory studies suggested that the error in vitamin D metabolism was transient, and, at the time of writing, as an adult, the cat appears to require no ongoing replacement calcitriol therapy.
  
  
  CONCLUSIONS
  This case emphasises the value of examining a full 'calcium profile' via a human or veterinary reference laboratory, and a favourable prognosis in some kittens with rickets makes such investigations worthwhile. Even when finances preclude detailed investigation, trial therapy using a nutritionally complete diet and physiological doses of calcitriol or cholecalciferol is inexpensive and can produce a good response.
authors.affiliation: Sydney Animal Hospitals Inner West, 1A Northumberland Avenue, Stanmore, NSW 2048, Australia.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Phillips
authors.forename: Anne C
authors.initials: AC
authors.lastname: Fawcett
authors.forename: Graeme S
authors.initials: GS
authors.lastname: Allan
authors.forename: Margaret
authors.initials: M
authors.lastname: Wilkinson
authors.forename: David R
authors.initials: DR
authors.lastname: Fraser
authors.forename: Richard
authors.initials: R
authors.lastname: Malik
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000627:therapeutic use; D002371:Cat Diseases / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy; D002415:Cats; D005260:Female; D012279:Rickets / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome; D014807:Vitamin D / Q000097:blood; D014815:Vitamins / Q000627:therapeutic use
chemical_list: D014815:Vitamins; D014807:Vitamin D; D002117:Calcitriol