Age-related changes in growth and fecal parameters, nutrient digestibility, hematology, and serum biochemistry of...

The objective of this study was to evaluate the effects of age on growth and fecal parameters, nutrient digestibility, hematology, and serum biochemistry of Beagle dogs. A total of 18 healthy Beagles were allotted into three groups according to age (puppy, under 1 year old; adult, 1-7 years old; senior, over 7 years old). The study lasted for 17 days, with a 7-day adaptation period and 10-day evaluation period. During the evaluation period, individual body weight, length, and food intake were estimated and recorded to calculate growth parameters. Fecal samples were collected from all beagles to evaluate fecal score and nutrient digestibility by visual observation and chemical analyses, respectively. Blood samples were collected from each dog to evaluate hematological and biochemical parameters using an automated hematology analyzer and clinical autoanalyzer, respectively. Puppy group had increased (p < 0.05) body weight change during the study compared with adult and senior groups. At the end of the food trial, body condition score of all age groups were ideal. Puppies had higher (p < 0.05) fecal moisture content and diarrhea frequency than adult and senior dogs. Senior group had lower (p < 0.05) apparent total tract digestibility (ATTD) of crude protein than puppy and adult groups. Puppy group had lower (p < 0.05) ATTD of ether extract, crude fiber, and nitrogen-free extract than adult and senior groups. Puppies had higher number of white blood cells and neutrophils at the initial (p < 0.05) and final (p = 0.062) day of the evaluation period than senior dogs. Senior dogs had lower (p < 0.05) levels of serum albumin, glucose, and creatinine during the evaluation than puppies. Puppy group had higher (p < 0.05) serum alkaline phosphate level at the initial and final day of the evaluation than adult and senior groups. In conclusion, our study determined the effect of age on growth and fecal parameters, nutrient digestibility, hematology, and serum biochemistry of Beagle dogs.