Extended acclimatization is required to eliminate stress effects of periodic blood-sampling procedures on vasoactive hormones and blood volume in beagle dogs

Abstract

SummaryImportant in all experimental anim al studies is the need to control stress stim uli associated with environmental change and experimental procedures. As the stress response involves alterations in levels of vasoactive hormones, ensuing changes in cardiovasc ular param eters may confound experimental outcomes. Accordingly, we evaluated the duration required for dogs (nˆ4) to acclimatize to frequent blood sam pling that involved different procedures. On each sampling occasion during a 6-week period, dogs were removed from their pen to a laboratory area and blood was collected either by venepuncture (days 2, 15, 34, 41) for plasma renin act ivity (PRA), epinephrine (EPI), norepinephrine, aldost erone, insulin, and atrial natriuretic peptide, or by cannulat ion (dogs restrained in slings; days 1, 8, 14, 22, 30, 33, 37, 40 ) for determination of haemat ocrit (HCT ) alone (days 1 to 22 ) or HCT with plasma volume (PV; days 30 to 40). PRA was higher on days 2 and 15 compared with days 34 and 41 and had decreased by up to 48% by the end of the study (day 41 vs day 15; mean=SEM: 1.18 =0.27 vs 2.88 =0.79 ng ANG I=ml=h, respectively). EPI showed a tim e-related decrease from days 2 to 34, during which mean values had decreased by 51% (mean=SEM: 279 =29 vs 134 =20.9 pg=ml for days 2 and 34, respectively), but appeared stable from then on. None of the other hormones showed any signi®cant variabi lity throughout the course of the study. HCT was relatively variable between days 1 to 22 but stabili zed from day 30, after which all mean values were approxim ately 6% lower than those between days 1 and 8. We conclude that an acclimatization period of at least 4 weeks is required to eliminate stress-related effects in dogs associated with periodic blood sampling.Keywords Stress response; beagle dogs; blood collection; vasoactive hormones; haematocrit T he dog is the most frequently used nonrodent species in toxicology and cardiovascular pharmacology studies. T his preference stems from both the substanti al experience accrued and the relative ease of monitoring haemodynam ics in this species (Dogterom e t a l. 1992, Greaves 2000). Important in all anim al studies is the need to control stress stim uli associated with environmental change and experimental procedures. Such factors are wide-ranging and evoke both physical and psychological responses that include initiation of complex adjust ments in cardiovasc ular control (Sgoifo e t a l. 1999, Benson e t a l. 2000). In the acute stress response, increased activity of the hypothalam ic-pituitary±adrenal axis

A canine model of septic shock: balancing animal welfare and scientific relevance

“…Moreover, the nonsurvivors' blood urea nitrogen levels were never elevated out of proportion to creatinine, as one would expect with intravascular volume depletion. The rise in hematocrit in nonsurvivors is most consistent with greater intravascular autotransfusion of blood from the spleen as described in this species in the setting of stress (51). Lastly, pancreatitis is a common and serious problem in this species (24).…”

Effects of anesthetic drugs on canine splenic volume determined via computed tomography

“…22 Moreover, it may require up to 40 days for the Hct to normalize after a stressful event. Although dogs were allowed time to acclimate to positioning on the CT table, there likely was some stress.…”

Pathogenicity and Rapid Growth Kinetics of Feline Immunodeficiency Virus Are Linked to 3′ Elements

“…This may have related to the fact that control cats had low neutrophil counts at seven time points; factors such as cage environment, allergies, or stress can contribute to variability in hematology parameters [40]. One FIV-PCenv cat also experienced neutropenia from day 46–95 PI, and two different FIV-PPR cats experienced neutropenia on days 3 and 173 PI, respectively.…”