I. PHYSICAL EXAMINATION OF THE NEONATE

The puppy should have been weighed at birth and should be weighed once daily thereafter (Figure 13-2). Puppy birth weight varies by breed; estimates for various breeds are 4.2 oz (120 g) for Pomeranians, 9 oz (250 g) for beagles, 17 oz (490 g) for greyhounds, and 22 oz (625 g) for Great Danes. Slight weight loss may occur in the first 24 hours of life. After that, the puppy should gain weight daily, doubling its birth weight by about 7 to 10 days of age.

Figure 13-2 Weighing puppies.

Rectal temperature varies with age and environment. Normal rectal temperature is 96.0° ± 1.5° F (35.6° ± 0.7° C) in the first week of life, 98.6° to 100.0° F (37.0° to 38.2° C) in the second and third weeks of life, and gradually rises to adult levels by the age of 7 weeks.

In the first 2 to 3 weeks of life, puppies spend most of their time sleeping. They huddle together or near the dam and will not ordinarily sleep apart from littermates or the dam until 5 to 6 weeks of age (Figure 13-3). When awake, neonates suckle vigorously. During examination, normal puppies are easily encouraged to suckle the examiner’s fingers or to root against the examiner’s encircled thumb and forefinger (Figure 13-4). Normal neonatal puppies can crawl, suckle, vocalize if distressed, and respond to odor, touch, and pain (Figure 13-5). Assessment of poor muscle tone or observation of decreased activity should prompt veterinary intervention. Pediatric animals that are observed to lie apart from littermates or the dam, cry excessively, are extremely restless, or lying still and nonresponsive should be examined by a veterinarian immediately.

Figure 13-3 Normal huddle of puppies in a litter.

(Courtesy Eileen Bohn.)

Figure 13-4 Puppy “rooting” against examiner’s hand.

Figure 13-5 Normal 2-day old pup.

(Courtesy Mary McKennan.)

Eyelids separate in puppies by about 14 days of age. Occasionally the surface of the eye appears cloudy when the eyelids separate. This is due to fluid movement into the cornea and resolves within 2 to 3 weeks of eyelid separation. The ear canals open at about 6 to 14 days of age. Assessment of hearing at home or in the clinic is difficult. Percussive hearing tests, such as hand clapping out of the animal’s field of vision, are inaccurate because of a lack of reaction in distracted animals with normal hearing (false-negative) and reaction as a result of pressure changes in deaf animals (false-positive). A BAER (brainstem auditory-evoked response) test measures electrical potential from the cochlea, cochlear nerve, and brainstem in response to auditory stimuli. Functional maturity of hearing and an accurate BAER test should be possible by 4 to 6 weeks of age. If the test result is negative, the animal is functionally deaf. Partial deafness is more difficult to assess; changes in ability to detect high and low frequencies vary with age.

The umbilicus falls off or is removed by the dam at 2 to 3 days of age. The umbilicus should be examined for evidence of infection. Traumatic inflammation of the appendages may occur if littermates are suckling on each other. Dehydrated pediatric animals exhibit more wrinkling and less turgor of the skin and deepening of the red color of the ventral abdomen and muzzle. Be aware that normal pups may have quite deep pink coloration of the ventral abdomen and muzzle for the first 5 to 7 days of life (Figure 13-6). Other signs of dehydration include dryness of the eyes and oral mucous membranes and a visible yellow color of the normally dilute urine.

Figure 13-6 Normal pink pup.

(Courtesy Vickie Halstead.)

Puppies can lift their heads at birth. They crawl for the first 7 to 14 days of life and should be able to support weight on their forelimbs by 10 days of age. Normal locomotion is present by 3 weeks of age. An open fontanelle may be palpable on the skull; persistence of an open fontanelle is not invariably associated with neurologic disease.

The heart may be difficult to hear well in puppies because of the small size of the heart and rapid heart rate. Heart rate is 220 beats per minute or greater in the first week of life. Heart murmurs are graded on a scale of I to VI, with grade I murmurs barely audible with a good stethoscope and grade VI murmurs palpable by holding the hand on the chest. Murmurs of grade I to III-VI, most commonly heard at the base of the heart on the left side, are often functional murmurs resulting from anemia, fever, or septicemia. Congenital cardiac abnormalities are usually associated with murmurs of grade III to VI-VI. Lung sounds are auscultated easily using a stethoscope with a pediatric head. Respiratory rate is 10 to 35 breaths per minute in the first week of life and reaches adult levels by 4 weeks of age.

The deciduous teeth are present by 6 weeks of age. Permanent teeth erupt, displacing the deciduous teeth, at 4 to 6 months of age. The small incisors in the front are lost first, and the large canine teeth are replaced last.

II. FIRST AID FOR NEONATES

Sick puppies dehydrate and have a significant decrease in blood sugar concentrations quickly. All first aid administered at home should be undertaken with the intention of getting the puppy to a veterinarian as quickly as possible. Guidelines for first aid are provided here and in various texts (Savant, 2003).

Puppies must be kept warm and must be fed. Hypothermic puppies will not be cared for by the dam. As their hypothermia worsens, their intestinal motility stops, decreasing their ability to digest food. Pups can be kept warm with radiant heat or with carefully placed heating pads or hot water bottles. Be very cautious warming pups with heating pads or hot water bottles if the pup is not mobile because it might be unable to move away from excessive heat and may be burned. Rewarming of hypothermic puppies should be gradual, taking 30 minutes to 2 hours. The neonate should be turned and rectal temperature monitored frequently. Do not warm to a rectal temperature greater than 101° F (36.3° C) so as not to cause dehydration.

Pups must be fed a nonmilk diet until rewarmed to prevent pooling and spoilage of milk products in their stomach. High-calorie supplements are available commercially. Corn syrup can be dissolved in water and fed to the pup with a bottle or feeding tube. Make up each batch as it is to be used, and refrigerate any leftovers. Once the pup is rewarmed, it can be fed milk replacer if the bitch will not allow the pup to nurse (see Chapter 1).

For puppies that have recently died, the followings steps may be taken for resuscitation:

If a pup dies, it is valuable for the remainder of the litter and potentially valuable for the kennel to know the cause of death. If a large number of animals are affected, sacrifice of a failing animal may be indicated. If the pup is to be submitted for necropsy, it should be wrapped in plastic and refrigerated. Do not freeze the pup; freezing and thawing distort tissues and make diagnosis more difficult. The pup should be submitted to the veterinarian’s office or diagnostic laboratory within 24 hours of death. Although necropsy is expensive and is reported to identify cause of death in only about a third of submissions, the diagnosis of a specific condition may enhance the veterinarian’s ability to treat the remaining littermates or control a colony-wide problem.

III. SAMPLE COLLECTION FROM NEONATES

Collection of blood from puppies can be difficult because the animal may be wriggly and the veins are very small and collapse easily. Blood is usually most easily collected from the external jugular vein in the neck (Figure 13-7). Urine can be collected by stimulating the genital area for a free catch. Another technique is to allow the puppy to urinate onto a human incontinence pad, remove the urine-soaked inner cotton layer, place it in a syringe, and press out the urine with the plunger. The recommended minimum database for assessment of sick pediatric patients is a hematocrit and total protein to assess for anemia; blood glucose concentration to assess for septicemia (whole-body infection); blood urea nitrogen to assess the kidneys and hydration status; and urine specific gravity and sediment.

Figure 13-7 Venipuncture in a pup.

(Courtesy Dr. Patricia Olson.)

IV. THERAPY OF NEONATES

Drug therapy is complicated by the animal’s inability to metabolize drugs consistently and by the lack of research regarding use of drugs in pediatric animals. For that reason, choice of drug and dose used are educated guesses in the vast majority of cases. Questions to be asked before any drug is given to a puppy include the following:

General principles of antibiotic therapy are that oral antibiotics are not well absorbed in pediatric animals; so if a serious bacterial infection must be treated, antibiotics should be administered intravenously or into the bone marrow cavity. All antibiotic therapy carries some risk, and no antibiotic is absolutely “off-limits” if it is the only one that will save the animal’s life. For information about relative safety of antibiotics, see Chapter 3.

A final point to consider regarding therapy for neonates is the uptake of antibiotics or other medications indirectly through the milk. If the bitch is receiving a drug that is soluble in fat, it will move readily into the milk and be ingested and absorbed by the pup. There is no information in the veterinary literature regarding the extent to which this happens in dogs. However, research in human medicine and in dairy cattle suggests the following: