Hormonal, Electrolytic, and Electrocardiographic Evaluations in Bitches With Eutocia and Dystocia

The objective of the study was to assess clinical alterations, electrocardiographic, hematological, biochemical, hemogasometric, electrolytic, and hormone plasma concentrations in bitches with eutocia and dystocia. Overall, 28 bitches (dystocia, n = 22 and eutocia, n = 6) were assessed. The evaluations were performed at 2 time points, M1 (1 hour prepartum-eutocia group and cesarean or clinical intervention-dystocia group) and M2 (postpartum-eutocia or dystocia group and anesthetic recovery-dystocia group). The main clinical finding was the hypothermia (mean: 36.9°C dystocia vs. 36.8°C eutocia). Sinus arrhythmia and tachycardia were the electrocardiographic parameters predominant in eutocia and sinus rhythm in dystocia group. The P wave amplitude, heart rate, creatinine concentration, hematocrit, and hemoglobin were increased in M1 (P < .05), whereas the concentration of TCO₂ was higher in M2. There was an increase in P₄ concentration in dystocia and total T₃ concentrations were increased in M1 in both groups. Total T₄ was higher in dystocia during M1 and in dystocia during M2 in eutocia than in dystocia. We concluded that at 1 hour prepartum or pre-cesarean, there is an increase in heart rate in bitches with eutocia or dystocia, and this finding was correlated to thyroid hormone concentration. P₄ concentrations remained high during dystocia, and hematological and biochemical changes returned to normal after parturition. The evaluation of these parameters in pregnancy can be used as tool to prevent dystocia and consequent fetal death.