title: Effects of racing on reticulocyte concentrations in Greyhounds.
abstract: BACKGROUND
  Greyhounds have several hematologic variables that are outside of the respective reference intervals of other dog breeds. In addition, increases in HCT, total protein and HGB concentration, and RBC and WBC counts occur immediately after exercise; these values return to resting values within a few hour after racing.
  
  
  OBJECTIVE
  This study evaluated the effects of exercise on the concentration of reticulocytes in circulating blood in racing Greyhounds. We hypothesized that reticulocyte numbers are significantly increased immediately after a race, and return to baseline within one to 2 h postrace.
  
  
  METHODS
  Fifty actively racing Greyhounds at the Wheeling Island Racetrack and Casino were included in the study. Samples were collected by jugular venipuncture one day prior to racing at the kennel (resting), immediately after racing, and one to 2 h after the race (recovery). Reticulocyte counts were determined with an IDEXX ProCyte Dx Hematology Analyzer (IDEXX Laboratories, Inc., Westbrook, ME, USA). Due to a nonparametric distribution, the results were statistically compared using the Friedman test.
  
  
  RESULTS
  Reticulocyte concentrations were significantly different among the 3 sample collection times (P < .0001). There was a significant increase in reticulocyte concentration immediately after racing (P < .001); one to 2 h after racing, the reticulocyte numbers decreased significantly (P < .001) to counts comparable to resting samples.
  
  
  CONCLUSIONS
  The increase in reticulocyte concentration is probably related to splenic contraction secondary to the release of catecholamines, although premature bone marrow release could also account for these changes. Thus, it is important to consider a Greyhound's activity and degree of excitement when interpreting selected hematologic data in a clinical setting.
authors.affiliation: Department of Veterinary Clinical Sciences, OSU Veterinary Medical Center, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Horvath
authors.forename: C G
authors.initials: CG
authors.lastname: Couto
authors.forename: K
authors.initials: K
authors.lastname: Yant
authors.forename: K
authors.initials: K
authors.lastname: Kontur
authors.forename: L
authors.initials: L
authors.lastname: Bohenko
authors.forename: M C
authors.initials: MC
authors.lastname: Iazbik
authors.forename: L M
authors.initials: LM
authors.lastname: Marín
authors.forename: D
authors.initials: D
authors.lastname: Hudson
authors.forename: J
authors.initials: J
authors.lastname: Chase
authors.forename: M
authors.initials: M
authors.lastname: Frye
authors.forename: D B
authors.initials: DB
authors.lastname: Denicola
mesh_terms: D000818:Animals; D004285:Dogs / Q000097:blood* / Q000502:physiology; D005260:Female; D006403:Hematologic Tests / Q000662:veterinary; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012016:Reference Values; D017701:Reticulocyte Count / Q000662:veterinary; D012156:Reticulocytes / Q000502:physiology*; D013997:Time Factors; D014903:West Virginia
keywords: Excitement; exercise; peripheral blood cell counts; red blood cells; spleen