Evaluating fading puppies and kittens

Time is of the essence when working with a fading puppy or kitten. If an owner calls about such a case, schedule the examination immediately, and instruct the owner to bring the dam as well as the entire litter for evaluation. Once the owner arrives, a systematic evaluation consisting of a history, physical examination of the litter and the dam, and specific diagnostic tests will help you narrow the list of possible causes quickly, so you can initiate treatment.

HISTORY

Often, the history is remarkably short for fading puppies and kittens. Breeders should bring records of weight gain since birth and any other data they have collected. Assess the dam's exposure to other dogs or cats during the last third of gestation as well as the travel history of housemates. Questions about husbandry are particularly important. Ask about the location and temperature of the whelping or queening box and its exposure to other animals. In purebred cats, knowing the blood types of the sire and dam is crucial.

Also ask the owners about the nursing and activity of the litter. Normal puppy and kitten neonates sleep and nurse.1 They spend most of their time in a group and cry only briefly.2 Neonates that lie away from the group, cry constantly, are restless, or fail to nurse should be examined at once. The amount of activity increases dramatically after the second week of life.2 By the age of 5 or 6 weeks, sleeping alone can be normal.2,3

Obtain the dam's recent history, including the ease of whelping, appetite, parasite control, diet, vaccinations, mothering skills, and any medications. Family history of neonatal survival can be useful, as can pedigree analysis.

EXAMINING THE NEONATES

Examine all neonates in a litter with even a single affected member. While the bitch or queen should be examined, she will often become distressed when the neonates are handled, so keep her in a separate room while examining the neonates. Bringing the dam and neonates into a clinical setting presents some risk of disease exposure. Assess and discuss this risk with the breeder or owner. Minimize contagious exposure by choosing less busy appointment times, using a special examination room, and considering a house call.

Most equipment needed for neonatal examination is readily available in general practice (Table 1). A warmed table is vital to prevent any additional hypothermia in the neonates. Place thick warmed towels over the examination table surface. The examination room should not have recently housed a patient of the same species with an infectious disease. Using a diffuser of synthetic dog attachment pheromone (D.A.P—Ceva Santé Animale; Veterinary Products Laboratories) in the examination rooms may help calm the bitch and offspring. Feliway (Ceva Santé Animale; Veterinary Products Laboratories) can be used to help calm the queen, but as it is not an attachment pheromone, it will not have the same effect.

Table 1. Equipment for Neonatal Evaluation

Body weight

First assess body weight. Because a weight gain of 5% to 10% a day in puppies and 7 to 10 g/day (0.25 oz to 0.35 oz/day) in kittens is normal, knowing the birth weight should allow assessment of the neonate's weight gain.4 I recommend that breeders weigh neonates twice a day and bring them in for immediate examination if normal daily weight gain does not occur. In my clinical experience, this has resulted in a much higher survival rate than waiting for additional clinical signs to appear. If neonates are similar in appearance, they should be identified in a manner that allows easy differentiation, such as with colored collars.

Temperature

Rectal temperature can be measured with a digital thermometer even in neonatal kittens. A dry neonate immediately postpartum has an average rectal temperature of 96 F (35.6 C).5 During the first week rectal temperature is 95 to 98 F (35 to 36.7 C), and during the second and third weeks it is 97 to 100 F (36.1 to 37.7 C).6 By the fourth week temperatures match those in adults.

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.

Overall condition

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.

Examine the umbilicus carefully. Redness, swelling, or discharge indicate infection, usually bacterial. The dried umbilical cord normally is lost at 2 or 3 days of age.3 Hyperemia and sloughing of the toes, tail, or ear tips are usually caused by sepsis or, in kittens, by neonatal alloimmune hemolytic anemia. Look carefully for congenital defects such as cleft palates (Figures 5 & 6), open fontanelles, and atresia ani (Figure 7).

Figure 3. A normal rooting response. Note the pup is raising itself on its front legs.

Hydration is important to assess, but skin turgor is not reliable in neonates.11 Mucous membranes should be moist and, for the first four to seven days, are hyperemic because of high red blood cell mass.12 Pale mucous membranes with slow capillary refill time indicate 12% to 15% dehydration.12 In kittens, signs of alloimmune hemolytic anemia include dark-red-brown urine, icterus, and failure to nurse and thrive; peracute death may also occur.13

Figure 4. A normal suckle response.

Neurologic examination

A neurologic examination is difficult in neonates, as typical adult responses are not seen until 6 to 8 weeks of age. Flexor dominance is present for the first four days of life, after which extensor dominance persists until 21 days of age.3 Open fontanelles are common in toy breeds, and their clinical relevance can be difficult to determine. Ultrasonography can be performed through the fontanelle to look for ventriculomegaly typical of hydrocephalus.14 However, even ventricular dilation may not correspond to the development of clinical neurologic disease.14

Figure 5. Evaluating the palate.

Developmental benchmarks

Note whether any developmental landmarks are delayed. The eyelids separate between 5 and 14 days. Menace and pupillary light responses are typically present at 21 days. Ear canals open at 6 to 14 days. Other benchmarks include crawling at 7 to 14 days, forelimb support at 10 days, and locomotion at 3 weeks of age.3 These are guidelines only and can vary dramatically among breeds and family lines. Teeth appear at about 6 weeks of age, although this can be considerably delayed in toy breeds.15

Figure 6. A cleft palate and lip.

EXAMINING THE DAM

A dam with even a single ill neonate should have a complete physical examination with particular attention given to her hydration status, mammary glands including milk production and quality, and vaginal discharge. While some sanguineous vulvar discharge is normal for about six weeks postpartum in bitches, cytologic examination of the uterine discharge obtained from the vagina or vulva should be performed to look for postpartum metritis. Normal postpartum cytology of uterine discharge obtained from the vagina or vulva in bitches may contain uteroverdin (green lochia), red blood cells, and vaginal epithelial cells.16 Numerous neutrophils, degenerate neutrophils, or intracellular bacteria indicate potential metritis. Further evaluation with ultrasonography of the uterus and cultures are then appropriate.16 Queens usually keep themselves very clean and have scant lochia. Evaluate queens that have notable vulvar discharge after parturition is complete and the plancentae have passed. Even if postpartum metritis is subclinical, it can provide a continual source of bacterial contamination for the pups or kittens.

Figure 7. Atresia ani in a puppy.

Mastitis is diagnosed by physical examination of the mammary glands and cytologic evaluation of milk.16 Canine milk normally contains marked numbers of neutrophils and macrophages, so look carefully for degenerate neutrophils and intracellular bacteria.16 As long as the dam will allow nursing, sufficient milk is produced, and no gangrene is present, pups or kittens can nurse mastitic milk.16 Mastitis is a rare cause of sepsis in neonates, but the quantity and nutritional value of the milk may be compromised, so assess each case to determine whether supplementation or removal of the neonates is indicated. Culture of mastitic milk is indicated to confirm appropriate antibiotic choice.16,17

Evaluate the serum ionized calcium concentration if mothering is poor or aggression is shown toward the pups. A decreased serum ionized calcium concentration indicates onset of eclampsia (puerperal tetany) that requires immediate treatment.

SAMPLE COLLECTION AND DIAGNOSTIC TESTS

The next step in assessing a neonate is to obtain appropriate samples and perform other pertinent diagnostic tests.

Blood, urine, and fecal evaluation

Blood is best obtained from the jugular vein with a 22- to 25-ga needle and a 1- to 3-ml syringe. No more than 10% of blood volume should be removed within a 24-hour period. Neonatal blood volume is about 68 ml/kg.9 Replace volume in a 3:1 ratio with crystalloids or a 1:1 ratio if colloids or blood products are used.9

Compare the test result values with those of neonates of the same age rather than with those of adults. Selected values are noted in Table 2 and Table 3, and a complete list has been published elsewhere.3,5,9,18 At a minimum, evaluate the glucose concentration (with a reagent strip), packed cell volume, total protein concentration, and white blood cell count (Unopette system—Becton, Dickinson).

Table 2. Selected Normal Laboratory Values for Puppies*

Urine is easily obtained in neonates by stimulating the vulva or prepuce with a warm, moist cloth or cotton ball. Urine specific gravity is 1.006 to 1.017 before 8 weeks of age.3 A normal proteinuria is present during the first days of life as colostral antibody is processed.3

Process fecal samples with both centrifugation and a direct saline smear to look for trophozoites. Fecal cultures can help diagnose infection with Campylobacter species, Salmonella species, and other enteric pathogens. Recall that severe roundworm and hookworm infestations can be present before patency.

Imaging

Radiography can be useful to evaluate for trauma, pneumonia, and other gross findings, but the lack of fat limits contrast. Use a tabletop technique and fine screen, and decrease the kilovolts peak to half that used for an adult.3 Alternatively, 2 kVp for each centimeter of tissue can be used, up to 80 kVp.3 Ultrasonography, with a 7.5- to 5-mHz transducer, may be used to evaluate the abdomen.3

Table 3. Selected Normal Laboratory Values for Kittens*

Necropsy

The most useful diagnostic test is often necropsy of a deceased neonate. Strongly encourage owners to allow submission of the entire pup or kitten for evaluation and further testing by a veterinary pathologist particularly skilled in reproductive and neonatal disease.* Ship the neonate overnight, refrigerated but not frozen. The pathologist should be allowed to pursue bacterial culture and virus isolation as indicated by the gross findings. While expensive, this procedure will often save others in the litter and can provide vital information to prevent recurrence of the problem at the next breeding. When pathologists are alerted that living littermates are awaiting the diagnosis, timely results are usually provided.

Piecemeal submission of organs, tissues, and microbiology samples may cost as much and provide less information. However, if this is the choice of the clinician and owner, take care to prevent contamination during the gross necropsy, and submit any abnormal organs for histopathology and for culture, virus isolation, or polymerase chain reaction testing as indicated by the gross findings. Contact the laboratory for recommendations for sample submission.

CONCLUSION

Careful history taking and physical examination and diagnostic evaluation of ill neonates can be readily performed. Attention to detail can provide clues to the causes of illness. The initial treatment of fading puppy and kittens, as well therapy for specific causes of the syndrome, is covered in the next article in this symposium.

Joni L. Freshman, DVM, MS, DACVIM

Canine Consultations

3060 Woodview Court

Colorado Springs, CO 80918

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