title: Evaluation of serum trace mineral, vitamin D, and sex steroid hormone concentration, and survey data in llamas and alpacas with metacarpophalangeal and metatarsophalangeal hyperextension.
abstract: OBJECTIVE
  To characterize serum trace mineral, sex steroid hormone, and vitamin D concentrations and identify factors associated with metacarpophalangeal and metatarsophalangeal hyperextension in llamas and alpacas.
  
  
  METHODS
  Serum samples from 79 llamas and 15 alpacas and owner survey data for 573 llamas and 399 alpacas.
  
  
  METHODS
  Serum samples were stored at -20°C until analysis and were evaluated for trace mineral, vitamin D, estradiol, progesterone, and testosterone concentrations. Information regarding age of onset, number of affected animals in herd, feed and supplements given, type of housing, and management practices was obtained in an owner survey.
  
  
  RESULTS
  Higher serum zinc and iron concentrations were associated with metacarpophalangeal and metatarsophalangeal hyperextension in camelids, compared with controls. In summer and fall months, vitamin D concentrations were significantly higher in affected camelids than controls. Overall prevalence was 13.3% in llamas, compared with 0.7% in alpacas. No management factors were found to be predictive of this condition. No other factors examined were associated with metacarpophalangeal and metatarsophalangeal hyperextension.
  
  
  CONCLUSIONS
  Despite similar supplementation practices and environmental conditions between affected and unaffected animals, an association of high serum zinc, iron, and vitamin D concentrations in affected camelids, compared with controls, may indicate differences of intake or absorption of dietary supplements.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA. stacy.semevolos@oregonstate.edu
authors.forename: Stacy A
authors.initials: SA
authors.lastname: Semevolos
authors.forename: Shannon K
authors.initials: SK
authors.lastname: Reed
authors.forename: Loren G
authors.initials: LG
authors.lastname: Schultz
mesh_terms: D000818:Animals; D002161:Camelids, New World / Q000033:anatomy & histology* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D005260:Female; D005552:Forelimb / Q000473:pathology*; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006614:Hindlimb / Q000473:pathology*; D007592:Joint Diseases / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D008297:Male; D012621:Seasons; D014131:Trace Elements / Q000097:blood*; D014807:Vitamin D / Q000097:blood*
chemical_list: D012739:Gonadal Steroid Hormones; D014131:Trace Elements; D014807:Vitamin D