CHANGES IN SOME RED-BLOOD-CELL AND CLINICAL LABORATORY PARAMETERS IN YOUNG AND OLD BEAGLE DOGS

Routine laboratory and lipid peroxidase parameters in the blood of Bea gle dogs under 1 year of age (7 males, 7 females) and over 9 years of age (7 males, 7 females) were compared. The mean corpuscular haemoglob in (MCH) and haemoglobin (Hb) values, plasma total protein (TP) and gl obulin concentrations in the older dogs were significantly higher than in the younger ones by 13%, 6%, 10% and 15%, respectively. The plasma inorganic phosphate concentration, however, was 30% lower in the olde r dogs than in the young ones. The concentration of malondialdehyde (M DA) was 30% higher, while the glutathione peroxidase (GSH-Px) and supe roxide dismutase (SOD) activities were around twice as high in the old er dogs as in the young ones. However, in the older males the concentr ation of reduced glutathione (GSH) was 43% and in the older females 9% less than in the young ones. Extremely high levels of MDA and low lev els of GSH were only found in the older males. GSH-Px and SOD activiti es were significantly higher in the older male dogs than in the young ones. The activities of these enzymes were highest in the older female s. From our results, we suspect that old dogs, especially males, are p articularly exposed to the harmful effects of free radicals and lipid peroxidation.