title: Age-related changes in hematologic and serum biochemical variables in dogs aged 16-60 days.
abstract: BACKGROUND
  The literature reporting hematologic and serum biochemical variables in puppies is limited. As puppies are physiologically different from adult dogs, an age effect would be expected.
  
  
  OBJECTIVE
  We aimed to describe age-related changes in hematologic and serum biochemical variables in puppies aged 16-60 days and compare the results to reference intervals (RI) for adults. Our second aim was to determine RI for this age group.
  
  
  METHODS
  A total of 227 blood samples were collected from 101 clinically healthy puppies, mainly mixed breeds. To assess the effect of age, the results were compared to RI for adult dogs, and variations within the age period 16-60 days were studied. Reference intervals for the groups 16-24, 28-45, and 46-60 days of age were determined.
  
  
  RESULTS
  Lower values in puppies compared to adults were found for RBC, HGB, HCT, concentration of albumin, globulin, total protein, creatinine, and sodium:potassium ratio. Higher values in puppies compared to adults were found for activities of ALP and CK, and concentrations of inorganic phosphorus, calcium, and potassium. For MCV, MCHC, albumin:globulin ratio, and glucose concentration, different values in puppies compared to adults were found for some of the age groups. No age-specific differences were found compared to RI for adults regarding WBC, absolute counts of lymphocytes, neutrophils, monocytes, eosinophils, and platelets, RDW, activities for AST, ALT, amylase, lipase, and concentrations of bile acids, cholesterol, urea, sodium, and chloride.
  
  
  CONCLUSIONS
  Our results support that age has a significant effect on several hematologic and serum biochemical values in puppies, warranting age-specific RI.
authors.affiliation: Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, Oslo, Norway.
authors.forename: Runa
authors.initials: R
authors.lastname: Rørtveit
authors.forename: Bente K
authors.initials: BK
authors.lastname: Saevik
authors.forename: Anna V
authors.initials: AV
authors.lastname: Eggertsdóttir
authors.forename: Ellen
authors.initials: E
authors.lastname: Skancke
authors.forename: Frode
authors.initials: F
authors.lastname: Lingaas
authors.forename: Stein I
authors.initials: SI
authors.lastname: Thoresen
authors.forename: Johan H
authors.initials: JH
authors.lastname: Jansen
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001774:Blood Chemical Analysis / Q000662:veterinary; D004285:Dogs / Q000502:physiology*; D005260:Female; D006403:Hematologic Tests / Q000662:veterinary; D008297:Male; D010338:Pathology, Clinical; D012016:Reference Values
keywords: Blood; canine; clinical pathology; puppies; reference intervals