title: Evaluation of squeeze-induced somnolence in neonatal foals.
abstract: OBJECTIVE
  To test the hypothesis that application of a rope restraint device would result in behavioral, electroencephalographic, and humoral changes consistent with sleep and analgesia in neonatal foals.
  
  
  METHODS
  8 healthy neonatal foals.
  
  
  METHODS
  Following acclimatization to experimental conditions, each foal underwent a series of assessments before and during or at the end of a period of restraint via application of a restraint device (soft linen rope). Assessments included measurements of heart and respiratory rates, rectal temperature, and circulating β-endorphin and steroid hormone concentrations and evaluations of mentation and body position (behavior), electroencephalographic patterns, and pain tolerance.
  
  
  RESULTS
  All foals were lively with apparently normal behavior prior to restraint. During application of the restraint device, foals assumed lateral recumbency with relaxed, somnolent behavior. Heart and respiratory rates and rectal temperature uniformly decreased as a result of the procedure. Electroencephalographic recordings (completed for 3 foals only) revealed patterns consistent with slow wave sleep. Plasma ACTH, dehydroepiandrosterone sulfate, and androstenedione concentrations significantly increased during restraint, compared with prerestraint values. The foals' tolerance to noxious stimuli significantly increased during restraint; however, this was independent of the concentration of circulating β-endorphin.
  
  
  CONCLUSIONS
  In neonatal foals, the evaluated form of restraint resulted in a decrease in heart and respiratory rates and rectal temperature. Squeeze-induced somnolence may resemble the effects of compression of the fetus in the birth canal and lead to inhibition of voluntary activity. Use of this technique to safely restrain neonatal foals during minor procedures warrants further evaluation.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA. toth4@purdue.edu
authors.forename: Balazs
authors.initials: B
authors.lastname: Toth
authors.forename: Monica
authors.initials: M
authors.lastname: Aleman
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Brosnan
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Dickinson
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Conley
authors.forename: Scott D
authors.initials: SD
authors.lastname: Stanley
authors.forename: Nora
authors.initials: N
authors.lastname: Nogradi
authors.forename: Colette D
authors.initials: CD
authors.lastname: Williams
authors.forename: John E
authors.initials: JE
authors.lastname: Madigan
mesh_terms: D000698:Analgesia / Q000662:veterinary; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001774:Blood Chemical Analysis / Q000662:veterinary; D001784:Blood Gas Analysis / Q000662:veterinary; D004569:Electroencephalography / Q000662:veterinary; D005260:Female; D006728:Hormones / Q000097:blood; D006736:Horses / Q000502:physiology*; D008297:Male; D009043:Motor Activity; D017288:Pain Threshold; D012149:Restraint, Physical / Q000379:methods* / Q000662:veterinary; D012894:Sleep Stages
chemical_list: D006728:Hormones