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.
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*