The normal neonate puppies and kittens (Proceedings)

Objectives

To familiarize practitioners with normal and abnormal clinical findings in neonates.

To review diagnostic and treatment modalities of canine and feline neonate.

To promote early recognition of the signs of illness and disease in the neonate.

General Key Points

• The first 3 months of life (Neonatal stage – birth to 2 weeks, infant state – 2 to 6 weeks of age and pediatric stage – 6 to 12 weeks) may be considered the pediatric period in dogs and cats. The neonatal stage is sometimes extended from birth to weaning. It is generally accepted that after 12 weeks of age puppies and kittens become more like adults in the diagnosis and management of most disease processes.

• A complete physical examination of the neonate can be accomplished by following any of a number of routine protocols. Practitioners should establish a procedure for themselves that ensures examination of all the pertinent areas.

• Sick neonates present with a similar pattern of clinical signs, though suffering from a variety of different disease processes. Therefore initial treatment should be directed toward those diseases with a fair to good prognosis, until a specific diagnosis can be ascertained. In general environmental problems, poor mothering or husbandry and bacterial infections carry a more favorable prognosis than viral infections or genetic defects. The old rule "Treat the Treatable" definitely applies.

• Birth weight may be the most accurate predictor of a neonate's chance for survival. Poor weight gain is an early and reliable indicator of illness.

Neonatal Physiology

• Neonates have poor thermoregulatory capability.

• Hepatic and renal functions are decreased in the first few weeks of life.

• Immune function relies on passive transfer of colostral antibodies.

• Nervous system at birth is poorly developed and slow to mature.

• Eyelids and ear canals are not open at birth (generally open at 10-14 days).

Examination Requirements

• Examination of neonates should be in a quiet clean environment on a warm table or towel.

• The dam or queen should always be examined, as should any littermates. Most mothers may remain in the examination room during the handling of their offspring unless they are aggressive or exceedingly anxious.

• A pediatric stethoscope, rectal thermometer and an accurate scale are basic necessities. Postal or food scales are excellent tools for weighing neonates and monitoring weight gain.

History

Weight!!

• Records of birth weight and weight gain are essential.

o Weight should be recorded twice daily for the first week of life.

o Absence of gain or lagging weight gain is indication for immediate examination.

o Some normal pups may not gain or even lose a slight amount (<10%BW) in first 12-24 hours. Loss of greater than 10% is an indicator of severe problem.

• Low birth weights may be due to endocrinopathies, poor maternal nutrition, overcrowding in the uterine environment, congenital abnormalities or infectious disease.

• Puppies or kittens should be individually identified. (By coat color, sex and markings, colored "collars", etc) to assist in accurate record keeping.

• Puppies should double their birth weight in the first 7-10 days.

• Kittens birth weights average 100±10 grams and should double by 2 weeks of age.

• The complete history should include clinical signs and their onset and duration, any treatment administered by the owner and a history of any littermates affected or deceased. Do not overlook the history of the dam's previous litters and the maternal preventive health care. The dam's environment, nutrition during pregnancy and any evidence of dystocia encountered at deliveries should be ascertained. The history of neonatal losses in closely related animals and the kennel or cattery's general health and survival statistics may also be important.

The Healthy Neonate

• Healthy puppies and kittens are plump, sleek and vigorous. They sleep most of the time when not nursing. They will vocalize if separated from their group. Frequent twitches indicating activated sleep patterns are normal.

• Normally present shortly after birth in healthy neonates are the righting, rooting and suckling reflexes.

• Puppies should have good muscle tone and struggle when handled. (Kittens less so than the average puppy.) Neither should not feel limp when held. Flexor muscle tone predominates for first 3-4 days. Extensor tone after 5-8 days of age.

• Normal Heart rate is over 200 beats per minute with a respiratory rate of 15-35 breaths per minute.

• Note the activity of the entire group and each individual prior to handling them.

Physical Examination Procedure

A. Temperature

• Puppy - normal temperatures generally range from 96-97°F in the first week of life. The normal temperature gradually rises to 100°F by the fourth week of life.

• Kittens normally 98°F at birth rising to 100°F by about two weeks.

• Neonates are generally unable to maintain a body temperature of more than 12-15? F above the ambient temperature.

• Due to poor thermoregulatory mechanism puppies and kittens are not only prone to hypothermia, but are also easily overheated. Overheating can result in dehydration and poor weight gain. Overheated neonates may separate themselves from littermates and exhibit bright red, hyperemic mucous membranes.

B. Hydration and Mucous Membranes

• Body weight is 75-80% water at birth.

• Assess hydration by mucous membranes. Should be moist and slightly hyperemic for the first week and a more normal pink afterward.

• Urine color or specific gravity can indicate hydration status. Normal urine in a well-hydrated neonate is clear and isosthenuric.

• Skin turgor, although not a very accurate indicator, may be useful. The ventral abdomen is a good place to examine skin for fine wrinkling that occurs in severe dehydration.

C. Head and Neck

• Assess muscle tone of puppy or kitten. Sick puppies or kittens often feel limp when handled due to decreased muscle tone. Evaluate the rooting and suckling reflexes at this time.

• Examine head for skull shape and open fontanelle.

• Check mouth for severe bite abnormalities, harelip or cleft palate. Assess the oral mucous membranes.

• Examine neck for glandular or lymph node enlargements.

• Nostrils should be open, clean and without discharge. Check for stenotic nares.

D. Extremities

• Assess muscle tone of limbs. Assess the movement of joints and palpate the long bones. Neonates are flexor dominant for the first 3-4 days. Decreased tone maybe indicator of illness.

• Examine footpads and tail. Inflammation may result from littermates excessive suckling on their extremities or from improper or soiled bedding. Tail tip or footpad necrosis can indicate sepsis or another disease process such as neonatal isoerthrolysis.

E. Thorax

• Check thoracic shape for indication of pectus excavatum or "swimmer's".

• Document regular and unlabored respiration.

• Auscult thoracic cavity for heart murmurs or abnormal lung sounds if possible.

F. Abdomen

• Abdomen should palpate full and firm following normal nursing.

• Examine the color and appearance of the smooth skin on the ventral abdomen.

• An enlarged abdomen in an uncomfortable puppy or kitten may indicate illness or aerophagia.

• Patent anal and urogenital openings. Stimulate elimination with warm moist cloth on perineum. (The anogenital reflex). Check for anal redness or irritation and signs of diarrhea.

• Examine umbilicus for hernias or infection. Cord should dry and fall off at 2-3 days of age.

• Testicles "should" be descended, although probably not palpable before 4-8 weeks.

G. Skin

• Skin and coat should appear sleek and clean, without wounds, discharge or debris.

• Check for completeness of haircoat.

• Vulvar discharge from the dam can become adherent to the skin of neonates. This may indicate poor mothering. Affected areas may become infected.

• Check for ectoparasites and treat immediately.

H. Urine and Stool

• Collect urine into small syringe or dry cotton ball. Stimulate urination by utilizing the anogenital reflex.

• Normal urine specific gravity 1.006 – 1.018

• Mild proteinuria is normal in neonates. Mild glucosuria has also sometimes been reported as a normal finding during the first week. Microscopic hematuria may be normal in first few days. Gross hematuria should be investigated.

• Meconium is a soft yellow, brown stool that is passed for first 24-48 hours. Normal neonatal feces are described as pasty and yellow to tan in color, sometimes described as clumps of "birdseed" or "cottage cheese" in form. Stools may not be observed for the first few weeks due to the dam/queens regular grooming of neonates.

• Stools should start to "form" at weaning and pups will gain voluntary control over defecation at about 3 weeks of age.

• Foamy or watery stools and abnormally colored stools (bloody, bright yellow, green or white) may indicate problems and should be investigated.

• Overfeeding can produce watery stools.

Diagnostic testing

A. Blood Collection

• The jugular vein is the most accessible and efficient source of diagnostic blood samples.

• Restraint of neonatal puppies and kittens must minimize stress.

• Newborn kittens total blood volume may be only 6cc. Keep sample size low in first few days of life (0.5ml). A one-pound animal may nave a total blood volume of only 25-400cc.

• Micro tubes or reagent strips may be necessary due to small sample sizes.

B. Serum Chemistries and Hematology

• Neonates have higher red cell mass at birth. During growth ECF volume increases.

• Normal hematocrit at birth of 40%. Decreases to 24% by week 8. Slow increase to adult levels by 20 weeks of age.

• Leukocyte and reticulocyte counts are similar to adults. A stress neutroplilia may result from collection.

• Sepsis can quickly result in neutropenia.

• BUN may be high normal in first few days of life and decline to low normal level after the first week.

• Albumin and creatinine lower than adult normal.

• ALP and GGT elevated. GGT elevation indicates adequate colostral intake.

• Calcium and Phosphorus elevated.

• Electrolytes should be consistent with adult normal.

• Thyroid hormone levels may be elevated in the neonate.

• Suggested minimum database includes Hct, TP, Glucose, BUN, Urine SG and sediment.

C. Radiography and Ultrasound

• Abdominal detail will be decreased due to lack of body fat.

• Decrease KVP and use fine detail film/screens. (2 kVp / cm soft tissue measured)

• Poor mineralization of bones.

• Heart and liver may "appear" larger in the normal neonate.

• Thymus is visible in cranial-ventral thorax.

• Radiographs may aid in diagnosis of conditions such as milk aspiration, pneumonia, aerophagia (bloat), ileus, and hernias in neonates in addition to cardiac abnormalities in older puppies or kittens.

• Ultrasonography has been reported in the diagnosis of hydrocephalus. Large fontanelles may allow access to visualize and measure the ventricles.

D. Necropsy

• Advise necropsy for all deceased neonates. Refrigerate the body (do NOT freeze) until necropsy is possible.

• Some conditions such as herpes in puppies can be rapidly diagnosed by necropsy. Specific treatment of littermates can then be instituted in a timely manner.

• Perform bacterial and viral isolation as indicated, along with histopathology of major organs.

• Full work-up can be very expensive. Advise laboratory that rapid "turn around time" may save other littermates lives.

• Neonates exhibit a number of major differences from adults that should be recognized as "normal" at necropsy. Muscle tissue is paler, the thymus occupies most of the cranial mediastinum, there are decreased adipose tissue stores, brain tissue is softer and there is minimal ossification of bone. Stillborn animals can be differentiated from neonates that survived birth by assessing lung expansion. Float a sample of the lung tissue. A stillborns uninflated lungs should sink.

Summary

• All neonates should have weight gain carefully monitored and recorded

• Sick neonates may appear similar though suffering from very different conditions.

• A thorough examination and history can provide valuable diagnostic and prognostic clues.

• Begin with empirical and supportive treatment for the most common conditions prior to definitive diagnosis.

• Definitive diagnosis is sometimes unattainable and often only obtained by necropsy.

References

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