Clinical pathology

Blood glucose

Normal blood glucose: 4.4 - 6.6 mmol/L (80 - 120 mg/dL)

Hypoglycemia: < 3.3mmol/L (60mg/dL)

Hyperglycaemia: > 6.6mmol/L (120 mg/dL)

(over 13.75 mmol/L (250 mg/dL) glucosuria will occur)

Blood calcium

Normal blood calcium: 2.1 - 2.9 mmol/L

Hypocalcaemia: < 2.1 mmol/L

PCV and TS

Measurement of packed cell volume (PCV) and total solids (TS) is a quick and easy assessment of anaemia and blood protein which can be performed in the clinic with minimal equipment.

PCV is measured using centrifugation of a microcapillary tube of blood, with measurement of TS by placing a drop of serum on a refractometer (Figure 1).

PCV normal range: 35 - 55%

TS normal range: 55 - 75 g/L

Figure 1 - A refractometer is a useful piece of equipment in any clinic, enabling the veterinarian to evaluate kidney function through measuring Urine Specific Gravity and blood protein by measuring Total Solids in blood serum.

Urine Specific Gravity (USG)

USG can be quickly measured using a refractometer and provides information about the ability of the kidneys to concentrate urine (Figure 1). It should be checked as standard during investigation of renal disease BEFORE intravenous fluids are administered. USG normal range for healthy animals can be anything from 1.001 to 1.065, the urine concentration can provide valuable information during clinical investigation, especially when compared with blood urea and creatinine. If blood serum / plasma urea and creatinine are increased, then the USG should be at least 1.030 (concentrated urine). If the USG is less than this, impaired concentrating ability or renal failure is present. Equally if an animal has a urine concentration of 1.001, then the animal does not have renal failure because the urine is actively diluted.

Don't forget the USG can be falsely increased by protein or glucose in the urine. Concentrating ability in neonates is poor.

Hyposthenuria: 1.000 - 1.008 (the kidneys are able to actively dilute urine)

Isosthenuria: 1.008 - 1.012 (the kidneys are neither concentrating nore diluting urine)