Heart and respiratory rate
Use a stethoscope with a pediatric head for auscultation. Heart rates are usually around 220 beats/min during the first week
of life, with respiratory rates of 10 to 35 breaths/min.3 These gradually decrease to normal adult heart and respiratory rates by 4 weeks of age. Anemic or ill neonates may have a
functional cardiac murmur of grade I to III/VI auscultated at the left base.3 Innocent murmurs not associated with disease or anomalies are common, particularly in large- and giant-breed dogs.7 Auscultation of innocent murmurs is enhanced with excitement and exercise, and they are not accompanied by precordial thrill,
abnormal pulse, or cardiomegaly.7 Such murmurs typically disappear by 4 or 5 months of age.7
Figure 1. A pup positioned for evaluation of the righting response. Note it is already trying to turn over.
On palpation, neonates generally have full, firm bodies. Kittens, in general, have less muscle tone than pups.8 Flaccidity or rigidity of muscles and limbs is indicative of distress.9 Three responses can help you assess the overall condition of the neonate10:
- First is the righting response. Place the neonate in dorsal recumbency on the warmed towel and release it (Figure 1). A healthy, awake neonate will immediately roll sternal (Figure 2). Delay or absence of this response indicates illness, hypothermia, or dehydration.
- The second response is rooting. Form a circle with your thumb and forefinger, and place it around the neonate's muzzle (Figure 3). Healthy neonates will push firmly into this circle, often rising up on their front legs.
- Suckling is the final response. Place a clean finger in the neonate's mouth to assess the strength of suction (Figure 4). Suckling is the most variable of the responses, as a cold or disinfectant-flavored finger can alter the response even in
a healthy neonate.
In my clinical experience, hourly reevaluation of these responses is invaluable in measuring the progress of an ill neonate.
Figure 2. A pup righting itself after being released for righting response.