Respiratory Disease in Neonatal Cloned Calves

Abstract

Background: Numerous clinical abnormalities occur in cloned calves during the neonatal period. Objectives: Describe respiratory diseases affecting cloned calves. Animals: Twenty-five cloned Holstein calves. Methods: Retrospective clinical study of the cloned calves born at the Veterinary Teaching Hospital, Saint-Hyacinthe, QC. Results: Records of 31 cloned calves were reviewed. Twenty-five records were included. Four stillborn calves and 2 calves euthanized at birth were excluded. Twenty-two calves suffered from respiratory diseases. Nineteen calves received intranasal oxygen treatment (INO). They were tachypneic (78 breaths per minute) and 5 of them were hypoxemic (PaO 2 o 55 mmHg). Two of 19 calves remained hypoxemic despite INO. Thirteen calves were weaned from INO after a median of 70 hours and were discharged at a median of 5 days of age. Nine calves required ventilatory support: 3 from birth and 6 after INO. Five were successfully weaned from the ventilator after a median of 32 hours and were discharged at a median of 8 days of age. Three calves died and 1 was euthanized because of respiratory disease. Necropsy revealed atelectasis, pulmonary congestion, and alveolar damages.Conclusion and Clinical Importance: Respiratory disease occurs frequently in cloned calves. The most frequent abnormality is hypoxemia because of V/Q mismatch. It is possible to successfully support these calves by INO and mechanical ventilation.

Developmental and Epigenetic Anomalies in Cloned Cattle

“…2002; Wells et al. 2004), including recent reports describing the various neonatal clinical outcomes observed in cloned progeny of both Bos taurus (Brisville et al. 2011; Buczinski et al.…”

“…Anomalies during the perinatal period in 26 cloned calves have been studied (Brisville et al. 2011).…”

Neonatal respiratory distress syndrome and underlying mechanisms in cloned cattle

“…Since the birth of Dolly, the first cloned sheep (Campbell, McWhir, Ritchie, & Wilmut, ; Wilmut, Schnieke, McWhir, Kid, & Campbell, ), somatic cell nuclear transfer has been successfully applied to many species—yet, cloning efficiency remains low in all animals, with <10% of transferred embryos typically resulting in live offspring (Brisville et al, ; Pace et al, ). Neonatal respiratory distress and alveolar collapse are major mortality factors associated with cloned animals after their birth (Brisville et al, ), leading to an overall mortality rate of >11% and accounting for >21% neonatal deaths in cloned animals, including bovine, pig, and sheep (Tables and S1).…”

“…Exogenous surfactants, synthetic or natural, may produce a transient relief to symptoms, but do not alter the course of NRDS (Somaschini et al, ). Indeed, surfactant administration (Carter et al, ) and oxygen therapy (Brisville et al, ) alleviate this syndrome in a small proportion of cloned animals, although a significant number of animals still die.…”

Transcriptomic profiling reveals disordered regulation of surfactant homeostasis in neonatal cloned bovines with collapsed lungs and respiratory distress

“…Surfactant is essential for normal pulmonary function and respiratory rhythm (Whitsett, Wert, & Weaver, ), and surfactant deficiency is suspected to underlie the symptoms of poor pulmonary ventilation and respiratory distress (Hill et al, ). Indeed surfactant (Carter et al, ) and oxygen (Brisville et al, ) therapies were successfully applied, leading to the survival of a small proportion of cloned animals. Whether or not re‐inflation of the alveoli would have occurred without exogenous surfactant is now known (Hill et al, ).…”