title: Extralabel use of cabergoline in the treatment of a pituitary adenoma in a rat.
abstract: METHODS
  A 0.65-kg (1.43-lb) 24-month-old sexually intact male albino pet rat was examined because of a 3-week history of hypodipsia, apparent blindness, and sudden change in behavior.
  
  
  RESULTS
  The rat was able to move around its cage but appeared unaware of its surroundings, was visually unresponsive, and seemed unusually aggressive. The rat's hind limbs appeared mildly paretic, and it had sporadic difficulty placing its hind limbs on a flat surface. Given the rat's age, history, and physical examination findings, the primary differential diagnosis was a pituitary tumor. Magnetic resonance imaging (MRI) of the rat's brain was performed and revealed a large pituitary mass, which was indicative of a tumor.
  
  
  RESULTS
  Cabergoline (0.6 mg/kg [0.27 mg/lb], PO, q 72 h) was administered. On follow-up MRI 2 months later, the pituitary mass had substantially decreased in size. For 6 months following the second MRI study, the rat continued to receive the same dosage of cabergoline and had no clinical signs of disease or unusual behavior. However, at 8.5 months after the start of the treatment, the rat was in poor condition and had clinical signs similar to those initially. A third MRI study was performed and revealed substantial regrowth of the mass. The rat was euthanized and a necropsy was performed; a histopathologic diagnosis of pituitary adenoma was made.
  
  
  CONCLUSIONS
  Pituitary adenomas have long been recognized as a common finding in geriatric rats (> 18 months old). Affected rats may respond favorably to oral administration of cabergoline.
authors: Department of Clinical Sciences, Foster Hospital for Small Animals, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA. mayerj@uga.edu
authors: Jörg
authors: J
authors: Mayer
authors: Amy
authors: A
authors: Sato
authors: Matti
authors: M
authors: Kiupel
authors: Julie
authors: J
authors: DeCubellis
authors: Thomas
authors: T
authors: Donnelly
mesh_terms: D000236:Adenoma / Q000188:drug therapy / Q000662:veterinary*; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000077465:Cabergoline; D004873:Ergolines / Q000627:therapeutic use*; D008297:Male; D057805:Pets; D010911:Pituitary Neoplasms / Q000188:drug therapy / Q000662:veterinary*; D051381:Rats; D012376:Rodent Diseases / Q000188:drug therapy*
chemical_list: D000970:Antineoplastic Agents; D004873:Ergolines; D000077465:Cabergoline