Within minutes of delivery, a normal calf is head righting and works its way to sternal recumbency within five minutes. Shortly thereafter, it begins making attempts to stand, and most are standing within an hour of a normal vaginal delivery. The selected clinical parameters of newborn calves shown here correlate well with vitality and are useful to assess newborn calves.
- Rectal temperature: 102-103°F (38.8-39.4°C) right after calving, stable at 101-102°F (38.3-38.8°C) within one hour.
- Heart rate: 100-150 beats per minute, rhythm is regular, pulse is strong.
- Respiratory rate: 50-75 breaths per minute, primarily thoracic effort.
- Hair coat appearance: Placenta covered but not discolored.
- Head, limbs and tongue: No swelling, edema or discoloration.
- Mucous membranes: Pink, moist and refill time < 3 seconds.
- Responsiveness: Responds to stimulation with head shaking and movement of limbs, strong corneal reflex, suck reflex is present.
- Muscle tone: Able to maintain sterna recumbency by five minutes, attempts to stand within 15 minutes, standing by 60 minutes.
- Suckling: Ready to nurse within two hours.
Some of the most important clinical signs that alert you to a calf requiring critical care are obtundation, hypothermia (<101°F; 38.3°C), bradycardia (<80 bpm), dilated, unresponsive pupils, inactivity or flaccidity. While not considered a sensitive indicator of cardiopulmonary arrest in small animals, cyanotic mucous membranes or prolonged capillary refill time can be an indication of the need for circulatory support in newborn calves. Tachypnea (75 bpm) with expiratory cycle accentuation, an abdominal lift or snap, or expiratory grunting may indicate the need for respiratory support. An erratic breathing pattern, with long periods of primary or secondary apnea, should also be viewed as a need for critical respiratory support in the young calf.
This information was presented at the 2009 American Association of Bovine Practitioners annual meeting.