Compared to small animals, measurement of various biochemical analytes in exotic species is quite limited due to differences in physiology and metabolism and the small amount of blood volume that can be withdrawn at a single sampling. Typically, samples are collected into heparin (green top tubes) to maximize plasma yield versus serum, where it is difficult to obtain sufficient serum off a clot for analysis. Generally, microtainers (tubes that hold 0.5 to 1 ml of blood total) are used, which also helps plasma harvesting. We usually require two full heparin microtainers to obtain sufficient plasma from most exotic species for biochemical analysis. This allows us just enough sample to run the analysis and perform repeats to recheck results, if needed, or obtain accurate values when analyte concentrations are high (after sample dilution). At Cornell University, we offer a non-mammalian panel, which was established with input from our wild-life and exotic animal clinicians. This panel consists of the following:
- Electrolytes: Sodium, potassium, chloride. These are interpreted similarly to that for mammalian species, with some unique species peculiarities. For general methods and test interpretation for all species, please refer to the relevant pages under the electrolyte section of the chemistry pages.
- Minerals: Calcium and phosphate. These are interpreted similarly to that for mammalian species, with the attending non-mammalian species differences. For general methods and test interpretation for all species, please refer to the relevant pages under the mineral section of the chemistry pages.
- Renal markers: Since non-mammalian species do not produce urea, uric acid is used as the marker of renal function. As for mammalian species, renal function will alter electrolytes and minerals.
- Liver markers: We run both AST and GLDH as markers of liver injury. As for mammals, AST is also found in high concentrations in muscle, whereas GLDH is relatively liver specific in non-mammalian species. Information on general test procedures and interpretation can be found on the relevant pages under the liver injury section of the chemistry pages.
- Protein: We only run total protein in non-mammalian species. This is because albumin measurement is inaccurate in these species with the bromcresol green method (the most common method used to measure albumin in mammalian species). We recommend serum electrophoresis for more detailed assessment of the different types of protein in non-mammalian species.
- Energy metabolism: We measure glucose in non-mammalian species. Information on methods and general test interpretation is provided under the energy metabolism section of the chemistry pages.
- Muscle: We measure CK activity. This is mostly to aid with interpretation of AST results (since AST is found in both muscle and liver) but also as a marker of muscle injury. Very high CK activity (>50,000 U/L) is seen in birds after trauma. Please refer to the muscle section of the chemistry pages for information on interpretation of CK values and method of measurement.
