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 (PaO2 < 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.