Care of the canine and feline neonate: part 2 (Proceedings)
Physical examination of the newborn is important to look for congenital defects and early signs of illness or potential for illness since deterioration of neonates can occur suddenly and progress rapidly. Prematurity as well as labor that is difficult or prolonged contribute to poor vigor of offspring.
Physical examination of the newborn is important to look for congenital defects and early signs of illness or potential for illness since deterioration of neonates can occur suddenly and progress rapidly. Prematurity as well as labor that is difficult or prolonged contribute to poor vigor of offspring. A soft, warm surface should be provided for examination of the neonate. Ideally, the physical exam should take place away from the mother in an area that has not been recently exposed to pets with infectious disease. Inspection of the newborn's hair coat may reveal that the dorsal aspect of the feet have a paucity of hair, which can be a subtle clue that the newborn is slightly premature. The following responses should be checked in all neonates to help determine their strength and general health:
1. Suckle response- Gently insert a clean, warm finger into the newborn's mouth. The normal newborn will suck on the inserted finger.
2. Righting response- Place the neonate on its back on a towel. The normal neonate will right itself quickly when placed in this position.
3. Rooting response- Using the fingers of one hand, encircle the puppy or kitten's muzzle close to the eyes. The normal neonate will respond by pushing vigorously against the encircling fingers.
Although checking these responses and the anogenital reflex described below may provide some limited information about the neurologic system, neonatal neurologic evaluation is difficult due to incomplete development of neuronal pathways.
A rectal temperature should be part of the general physical examination. The normal body temperature in neonates is lower than that of an adult due to undeveloped shivering and peripheral vasoconstriction abilities, lack of body fat, and a comparatively large body surface area. In the first week of the newborn's life the body temperature is in the range of 95° – 99° F, rising to a range of 97° – 100° F during the 2nd week, and reaching an adult range by the 4th week of life. Neonates that have low body temperatures and will not remain with the mother and rest of the litter should be placed in a small box with bedding and warmed carefully using a hot water blanket, rice socks, a heating lamp, an incubator, or a circulating water blanket. Avoid the use of heating pads. Neonates that have poor suckle, righting, and/or rooting responses or that consistenly have a low body temperature should be further evaluated for illness and monitored closely. The neonate's heat rate and character of heart sounds should be evaluated along with the respiratory rate and character. Normal heart rate for the newborn is approximately 200 BPM and normal respiratory rate is in the range of 15 – 35 breaths per minute. Although cardiac murmurs associated with congenital defects or other illness may be detected on auscultation of the chest, it should be remembered that innocent murmurs may also be present, especially in large to giant breed dogs. Urine and feces can be evaluated by stimulating urination and defecation through gently stroking the anogenital area (anogenital reflex) with a moist cotton ball. Newborn puppies and kittens should be examined for signs of trauma sustained during delivery, including inspecting the umbilicus for discharge, redness, or swelling since umbilical infection can lead to life-threatening septicemia. Neonates should also be inspected for the presence of congenital defects such as cleft palate or lip, atresia ani, open fontanelles, limb deformities, stenotic nares, cardiac defects, umbilical or inguinal hernia, anasarca ("walrus puppies"), and swimmer puppies ("flat-puppy syndrome"). In breeding programs the hereditary and ethical aspects of congenital defects which have been identified should be discussed with the breeder.
General considerations for care and monitoring of the newborn during the first two weeks of life are listed below:
1. Monitor weight of the neonate closely. Frequently one of the first signs of illness in neonates is failure to gain weight. A feline neonate weighing < 90 grams at birth has a poorer chance for survival.
OPTIMUM BIRTH WEIGHT FOR NEONATES
2. Due to the neonate's lower body temperature, the ambient temperature should be maintained in a range of 86° – 90° F where the puppies or kittens are housed. The temperature can gradually be lowered over the next few weeks to 75° F.
3. If desired, dewclaw removal and tail docking may be performed in appropriate breeds at 3 – 5 days of age.
4. Deworming for hookworms and roundworms with pyrantel pamoate (Nemex®) should be initiated at 2weeks of age and repeated every 2 weeks until weaning
5. External parasites should be addressed as previously described in the description of care for the pregnant and lactating bitch or queen.
6. Observe the neonate for crusts, pustules, focal areas of alopecia, and/or moist exudative lesions which can indicate the presence of pyoderma, dermatophytosis, parasites, or irritants and treat appropriately, including environmental measures needed for control. Umbilical infections usually occur during the first four days of life and may result from genital infection of the bitch or queen frequently resulting from stool contamination. Umbilical infection can lead to a local abscess or septicemia. Treatment of an abscess generally includes draining and flushing the abscess, antibiotics, and supportive care. Preventative measures include umbilical disinfection at birth, proper sanitation, and antibiotic administration for genital infection of the bitch prior to whelping or queening. Neonatal conjunctivitis can occur and often results in bulging of the eyelids due to purulent exudate accumulating behind them prior to opening at 8 – 10 days of age. Treatment consists of application of warm compresses to the eyelids followed by gentle separation of the eyelid margins with subsequent topical antibiotic ointment administration.
7. Monitor newborn puppies and kittens for potential signs of developing illness such as lack of activity, isolation from the rest of the litter, failure to nurse, failure to gain weight, excessive crying, and low or high body temperature. The occurrence of any of these signs warrants further evaluation by the veterinarian.
If supplemental nutrition and other care is required for weak neonates or neonates from a large litter or if it is necessary for the pet owner to raise orphaned puppies or kittens, the following guidelines may be helpful:
1. A lactating foster mother is ideal for raising orphaned newborn puppies or kittens but is often not available.
2. Appropriate body temperature must be maintained, keeping in mind that the neonate's normal body temperature is lower for the first few weeks of life compared to that of an adult.
3. If colostrum was not received, ideally serum antibodies should be given as described in "Care of the Canine and Feline Neonate: Part 1".
4. Commercial formulas such as Esbilac™ for puppies or KMR™ for kittens are generally preferred to homemade formulas. Powdered formula is more economical and can be stored in undiluted form in the freezer for up to 6 months. Opened canned formula or diluted powdered formula should be kept under refrigeration for no longer than 48 – 72 hours.
a. Diarrhea (usually green to yellow, watery stool) may occur initially when feeding formula and can be avoided or improved by feeding formula diluted by 25% with water for a few days.
b. Homemade formulas using cow and goat milk are not recommended due to the low fat and protein content and the high lactose content as compared to milk from the canine or feline mother.
c. The newborn should be handled gently before feeding to provide exercise and promote muscular and circulatory development.
5. Bottle feeding
a. Milk replacer may be fed through a bottle with a nipple if a strong suckle reflex is present.
b. The nipple should be placed into the newborn's mouth at a raised angle with the neonate's head extended upward. The contents of the bottle should never be squeezed into the neonate's mouth due to the possibility of causing aspiration pneumonia.
6. Tube feeding is the fastest and preferred way to feed orphaned or weak neonates.
a. A French-size 5 – 8 red rubber catheter is commonly recommended for feeding.
b. The distance from the last rib to the tip of the nose of the newborn should be marked on the catheter as a guide for insertion.
c. The lubricated tip of the tube should be inserted into the open mouth of the neonate while the head is held in a slightly upward position.
d. The feeding tube should slide easily through the esophagus without meeting resistance or causing the puppy to cough.
e. Discontinue insertion when the marked area is at the tip of the nose.
f. Slowly administer the warmed milk replacer by syringe over a 2-minute period through the feeding tube
7. Volume and frequency of feeding (puppies)
a. 1st week of life- 60 ml/lb/day in divided doses every 2 – 4 hours
b. 2nd week of life- 70 ml/lb/day in divided doses every 4 – 6 hours
c. 3rd week of life- 90 ml/lb/day in divided doses every 4 – 6 hours
d. 4th week of life (if needed)- 100 ml/lb/day in divided doses every 6 hours
e. Ultimately the volume and frequency of milk replacer to be supplemented to weak neonates or neonates from large litters will be determined by the amount it takes to achieve acceptable daily weight gain
8. Volume and frequency of feeding (kittens)
a. 1st week of life- 5 – 12 ml/100gm/day in divided doses every 2 hours
b. 2nd week of life- 20 ml/100 gm/day in divided doses every 2 – 4 hrs
c. 3rd week of life- 25 ml/100 gm/day in divided doses every 4 – 6 hours
d. 4th week of life- 30 ml/100 gm/day in divided doses every 4 – 6 hrs
e. 5th week of life (if needed)- 35 ml/100gm/day in divided doses every 4 – 6 hrs
9. A gruel of commercial puppy or kitten food may be started as early as the 3rd week of life for puppies and the 4th week of life for kittens with gradual reduction in milk replacer until only the commercial food is fed 3 –4 X/day
10. Additional fluid (water) may be needed in ill neonates
11. For the first 3 weeks of life, puppies and kittens should be stimulated to defecate and urinate after feeding by swabbing the anogenital area with a dry or moistened cotton ball
12. If the newborn becomes constipated, a warm water enema with a drop of dish soap may be needed
13. At .least once weekly the neonate being fed should be washed gently with a soft, moistened cloth.
Fading puppy/kitten syndrome refers to a collection of diseases that cause similar signs in the newborn and often result in death. Although it is sometimes difficult to definitively diagnose the underlying cause of the neonate's illness antemortem, most serious illnesses in the neonate cause hypohydration/hypovolemia, hypothermia, and hypoglycemia. Addressing these needs as early in the course of the disease as possible often gives the affected newborn its best chance for survival:
Neonates have increased demand, increased loss, and decreased ability to synthesize glucose. Glucose may be given by administering 12.5% dextrose (dilute 50% dextrose 1:4) IV at a dose of 1 ml/kg followed by a CRI of isotonic fluids with 1.25% - 5% dextrose. Less severely affected neonates with a body temperature in the normal range can be given a 5 – 10% glucose solution by stomach tube at a dose of 0.25 ml/30 gm. Carnitine supplementation can cause improvement or prevention of hypoglycemia by enhancing the ability of the liver to convert fat into glucose.. In the stable patient L-carnitine can be given orally at a dose of 50 mg/kg q12 hrs.
Both neonate puppies and kittens have a lower body temperature than the average adult. The lower body temperatures of puppies and kittens in the first few weeks of life as well as their small body mass make newborns very susceptible to hypothermia, especially when experiencing illness. Most sick puppies and kittens should be warmed by administering warm fluids, placing them in an incubator, or using warm rice socks.
Neonates have a higher fluid requirement than adults due to a higher percentage of total body water and a number of other factors which cause them to be more at risk for developing dehydration and hypovolemia. Conversely, neonates can also become overhydrated easily when fluids are administered. Neither skin turgor nor mucous membrane dryness is a reliable way of assessing dehydration in the neonate. The best way to monitor the hydration of critically ill neonates is to weigh them on a pediatric scale three to four times a day. Following hydration through Hct and total protein values can be a challenge in young puppies and kittens since the total protein values for neonates are normally lower than those seen in adults and because the hematocrit decreases from birth to about a month of age before going back up again.
Although somewhat controversial, lactated Ringer's is often considered to be a preferred fluid for neonates since lactate can be used as a fuel in the neonate in the face of hypoglycemia. Hypovolemia and dehydration most commonly occur in the neonate as a result of fluid loss through the gastrointestinal tract either through vomiting and diarrhea or through lack of intake. For moderate dehydration, a bolus of 30 - 40 ml/kg of LRS can be given followed by a CRI of warm crystalloids at 80 – 100 ml/kg/day. For hypovolemia and severe dehydration warm isotonic fluids should be given as a bolus of 45 ml/kg followed by a CRI of maintenance fluids at a rate of 80 ml/kg/day plus ongoing losses plus adding dextrose to the fluids for hypoglycemia. In critically ill neonates fluids are best given intravenously or intraosseously. Ideally, electrolytes and glucose should be monitored and nutritional support provided in these patients, Less severely affected neonates can be given fluids subcutaneously (dose = 1ml of warmed fluid/30 gm BW) or be supplemented by mouth. Sick neonates should be weighed frequently to help monitor hydration.
Trying to arrive at a definitive diagnosis of the cause of serious illness in the neonate in a timely manner can be very challenging. History and physical findings should be evaluated as with any patient, but since so many of the more serious newborn illnesses have a similar presentation, these parameters may not be as helpful as the practitioner would like in distinguishing the underlying cause of illness. Inquiring about the owner's husbandry practices, health aspects related to the bitch or queen, and neonate birth weight records should be included in the history-taking process. Evaluating both the bitch or queen and littermates in addition to the affected neonate (s) may be helpful in determining the possible cause of illness. It is often advisable to separate the offspring from the bitch or queen when examining the the neonates in order to decrease the stress which may be experienced by the mother in that situation. Important aspects of neonatal physical examination have been described previously in these notes. When examining the bitch or queen, particular attention should be paid to evaluation of the vagina and any vaginal discharge, the mammary glands and associated milk production, hydration status, and the mother's demeanor.
The small size of many neonates and their physical condition can make obtaining blood for evaluation of a lab data base a challenge as well. Basic lab values such as PCV, total protein, WBC count, glucose, and BUN can be obtained from 0.5 ml of blood obtained with a 22 to 25-ga needle and a syringe ≤ 3 ml.. Kittens may need to be tested for feline leukemia virus. Only small amounts of urine are needed for urine dipstick and specific gravity evaluation. Fecal samples should be evaluated by flotation and direct smear for parasites. In some instances, fecal culture may be desirable to detect enteric pathogens. Values for many lab parameters in both the canine and feline neonate differ not only from adult values but change on a weekly basis. Consequently, the practitioner should refer to charts listing blood and urine lab values established for neonatal patients when evaluating data. Although small patient size, lack of abdominal fat, and lack of bone mineralization can pose special challenges, radiographs may also provide valuable information in some seriously ill neonates. Reduction in KVP from adult settings and use of detailed film or screens can improve imaging results. Ultrasonographic examination of the abdomen can usually be performed using a 5 to 7.5-mHZ transducer.
Many neonates will die without a definitive diagnosis having been made. The pet owner should be encouraged to submit the refrigerated body for necropsy to a diagnostic laboratory that has experience with neonatal diseases. Unfortunately, necropsy is the most common and reliable way that the majority of serious neonatal illnesses are definitively diagnosed. Timely necropsy findings can prevent the death of littermates or decrease morbidity and mortality in future litters.
In addition to the nutrition, hypohydration, hypothermia, and hypoglycemia issues previously discussed, supportive care considerations may also involve therapies such as Vitamin K1 (0.5 – 2.5 mg/kg subQ) and oxygen administration. Vitamin K1 may be valuable in the treatment of neonates < 48 hours old due to bleeding tendencies related to decreased thrombin activity present in the first few days of life. Oxygen therapy in neonates is accomplished most efficiently by intranasal administration of oxygen with a FIO = 40 – 60%.
APPENDIX A: CAUSES OF FADING PUPPY/KITTEN SYNDROME