Perineal Region
The examination from the rear includes assessment of body condition, measurement of rectal temperature, palpation of the coccygeal artery to assess pulse, examination of mucous membranes (female), and collection of urine and feces.
Examination of the tail may also reveal evidence of diarrhea. Chronic diarrhea may be reflected by poor body condition and hair loss from the caudal surface of the rear hind limbs.BODY TEMPERATURE. Rectal temperature in calves ranges between 37.2° and 38.9° C (99° and 102° F) during the first 4 days after birth. Abnormalities of vital signs in neonatal ruminants may be difficult to interpret, as a fever can be transient and patients with septicemia, infection, dehydration, or circulatory shock can be hypothermic or normothermic. Premature calves are prone to hypothermia.313 Hyperthermia during the first week of life has been reported to be common in cloned calves.314
■ TABLE 19.7
Normal Hematology Reference Values for Neonatal Calves154,155
Age
| Parameter | Birth | 24 Hours | 48 Hours | 3 Weeks |
| RBCs (1?106ZμL) | bgcolor=white>9.35 ± 1.028.17 ± 1.34 | 7.72 ± 1.09 | 8.86 ± 0.68 | |
| Hgb (g/dL) | 12.86 ± 1.85 | 10.93 ± 2.05 | 10.49 ± 1.8 | 11.32 ± 1.02 |
| PCV (%) | 41 ± 6 | 34 ± 6 | 32 ± 6 | 35 ± 3 |
| MCV (fL) | 43.2 ± 2.4 | 41 ± 2.8 | 41.1 ± 2.3 | 39.1 ± 1.9 |
| MCHC (g/dL) | 31.3 ± 1.1 | 32.1 ± 0.8 | 32.6 ± 1.0 | 32.8 ± 1.6 |
| Total WBCs/aL | 13.99 ± 5.73 | 9.81 ± 2.8 | 7.76 ± 1.95 | 8.65 ± 1.69 |
| Neutrophils/μL | 10,940 ± 5700 | 6480 ± 2660 | 4110 ± 2040 | 2920 ± 1140 |
| Bands/aL | 100 ± 150 | 310 ±460 | 210 ± 450 | 10 ± 30 |
| Lymphocytes/aL | 2980 ± 2730 | 2730 ± 820 | 2850 ± 880 | 5050 ± 800 |
| Monocytes/aL | 590 ± 660 | 230 ±210 | 350 ± 280 | 620 ± 330 |
| Eosinophils/aL | 0 | 20 ± 40 | 20 ± 30 | 20 ± 40 |
| Basophils/aL | 0 | 0.02 ± 0.05 | 0.02 ± 0.05 | 0.02 ± 0.04 |
| TP (g/dL) | 4.8 ± 0.3 | 6.4 ± 0.7 | 6.4 ± 0.7 | 6.4 ± 0.3 |
| Fibrinogen (mg/dL) | 258 ± 138 | 288 ± 105 | 335 ± 116 | 283 ± 147 |
| Urea nitrogen (mg/dL) | 6.36 ± 2.36 | 7.52 ± 2.13 | 7.52 ± 2.13 | |
| Creatine (mg/dL) | 4.14 ± 1.27 | 1.69 ± 0.35 | 1.27 ± 0.24 | |
| Total bilirubin | 0.34 ± 0.66 | 1.28 ± 0.5 | 0.89 ± 0.41 | |
| Sodium (mEq/L) | 141 ± 3.77 | 135 ± 2.86 | 135 ± 3.68 | |
| Potassium (mEq/L) | 6.1 ± 1.86 | 5.46 ± 0.56 | 5.63 ± 0.96 | |
| Chloride (mEq/L) | 97.39 | 95.76 | 95.28 | |
| Calcium (mg/dL) | 12.24 ± 1.64 | 10.22 ± 1.2 | 10.65 ± 0.56 | |
| Phosphorus (mg/dL) | 8.16 ± 1.39 | 7.22 ± 0.87 | 7.46 ± 0.87 | |
| Creatine phosphokinase (U/L) | 83 ± 42 | 531 ± 532 | 256 ± 364 | |
| Aspartate aminotransferase (U/L) | 18 ± 19 | 99 ± 18 | 72 ± 25 | |
| γ-Glutamyl transferase (U/L) | 8 ± 3 | 1761 ± 1058 | 846 ± 517 |
Hgb, Hemoglobin; MCHC, mean corpuscular hemoglobin concentration; MCV, mean cell volume; PCV packed cell volume; RBCs, red blood cells; TP, total protein; WBCs, white blood cells.
FECES.
In contrast to the adult, rectal palpation of the abdominal structures of the large animal neonate is of limited value. Small amounts of blood may be observed in the feces of healthy calves. Passage of blood and fibrin is associated with inflammatory bowel disease induced by pathogens such as Salmonella and coronavirus that damage the gastrointestinal mucosa. Passage of melena may be associated with infectious enteritis (e.g., clostridiosis, salmonellosis) and necrotizing enterocolitis due to hypoxic-ischemic bowel injury. Infectious diarrhea is the leading cause of mortality in calves between 3 and 21 days of age. Typically more than one pathogen is involved, and the physical examination provides no indication of the etiologic agent. Fecal pH may be used as an indicator to distinguish secretory diarrhea (enterotoxigenic E. coli) from diarrhea associated with malabsorption and maldigestion. Secretory diarrhea produces an alkaline pH, whereas malabsorption and maldigestion are associated with an acidic fecal pH.315 Infectious agents causing diarrhea and ancillary tests available to establish an etiologic diagnosis are discussed in Chapter 20.URINE. Normal urine osmolarity in the 2- to 3-day-old calf has been reported to be 286 to 391 mOsm/L, and urine volume voided is 34 mL/kg/day.316 Congenital abnormalities of the urinary system include ruptured urinary bladder, ruptured ureter, ectopic ureter, blocked urethra, renal agenesis, fused kidney, and polycystic kidneys. Rupture of the urinary bladder at parturition is uncommon in ruminants. Hemodynamically mediated renal disease is observed sporadically in calves after chronic enteritis.317 Prolonged reduced renal perfusion secondary to hypovolemia may lead to ischemia and acute tubular necrosis. Failure to thrive following apparent recovery from diarrhea may reflect compromised renal function.
EXTERNAL GENITALIA. The external genitalia of both sexes should be examined for congenital malformations.
In the calf congenital defects described include ovarian aplasia, duplication of the cervix in Hereford cattle, persistence of the hymen (white heifer disease), and rectovaginal constriction in Jersey cattle. Congenital urolithiasis has been described in calves and lambs. Calcium oxalate is the most commonly reported congenital form of urolithiasis and may be associated with other congenital abnormalities.318 A report of renal oxalosis in a number of Beefmaster calves suggests a possible recessively inherited metabolic defect resulting in primary hyperoxaluria in this breed.319 Freemartins (XX/XY chimeras) occur in more than 90% of bovine320 and 1% of ovine321 female heterosexual twins. Typically freemartins are sterile and have hypoplastic ovaries and internal tubal genitalia; the external genitalia normally are not affected. Males should be examined for cryptorchidism and male pseudohermaphroditism, and both sexes should be assessed for evidence of hermaphroditism (gonads of both sexes).