Neonatal Clinical Evaluation, Blood Gas and Radiographic Assessment After Normal Birth, Vaginal Dystocia or Caesarean Section in Dogs

Abstract

This study aimed to standardize signs and diagnostic criteria of respiratory function in newborn puppies delivered normally or after dystocia and caesarean operation. A total of 48 neonates were allocated into groups: eutocia (n = 20), dystocia (n = 8), caesarean (c)-section (n = 20). Neonatal health was assessed using the Apgar score and body temperature was determined at 0, 5 and 60 min after delivery. Venous blood gases (pO(2) and SO(2)) was measured immediately and 60 min after delivery, and a thoracic radiograph was made between 0 and 5 min of life. The c-section group had significantly lower Apgar scores at birth and 5 min. Hypothermia was present at 5 min in the eutocia and c-section groups, and at 60 min in all groups. The eutocia group had an irregular respiratory pattern in 78% of puppies at birth, 27.7% at 5 min and 21% at 60 min compared with 87.5%, 62.5% and 12.5% of the pups in the dystocia group where there was irregular respiratory rhythm, moderate to intense respiratory sounds with agonic episodes. The c-section group had respiratory alterations in 70%, 45% and 16% of puppies at 0, 5 and 60 min, respectively. Radiographic abnormalities were present in 17% of the pups in the eutocia group, 25% of the pups in the dystocia group and 30% of the pups in the c-section group, respectively. The c-section group had significantly lower SO(2) values at 60 min than at birth. All puppies had hypoxaemia, but a significant decrease was observed in the c-section group. Newborn puppies had tissue hypoxia and irregular respiratory pattern at birth. Caesarean-section puppies had lower vitality; however, all developed satisfactory Apgar scores at 5 min of life, regardless of the obstetric condition.

Prenatal and Neonatal Adaptations with a Focus on the Respiratory System

“…In one study, 83% of canine puppies born after eutocic vaginal labour did not exhibit radiographic alterations; however, mild general opacity with a poorly defined cardiac silhouette was observed in 11% of puppies, and moderate pulmonary opacity with a poorly defined cardiac silhouette and bronchia compatible with pulmonary oedema was observed in only 6% of puppies (Silva et al. ).…”

“…Isolated assessment of the respiratory rate is not precise enough to assess newborns with possible respiratory disorders because it does not exhibit a significant correlation with the blood carbon dioxide pressure (PCO 2 ) (Silva et al. ). Therefore, it is recommended to combine respiratory rate measurement with careful auscultation of the lungs and specifically focused diagnostic exams, such as blood gas assessment.…”

“…Upon thorough examination of the respiratory system (pulmonary auscultation), 78% of eutocic canine neonates exhibit irregular respiratory patterns associated with mild‐to‐moderate breath sounds immediately at birth, which decreases to 28% within the first 5 min after delivery (Silva et al. ).…”

“…High respiratory rate associated with high mobility of the chest walls makes it difficult to obtain clear radiographic images and can hinder the diagnosis of the radiographic patterns as diffuse, reticular or interstitial (Silva et al. ). It is worth noting that chest X‐rays of puppies exhibit general interstitial opacity because of the lower volume of air in the alveoli (Haskins ).…”

“…Silva et al. () found that the respiratory rate at 60 min of life was significantly lower in puppies born by caesarean section (C‐section) compared with those born after eutocic vaginal labour. Additionally, 85% of puppies born by C‐section exhibited cyanosis of the mucous membranes at birth, whereas only 30% of those born after a normal delivery did.…”