Ever wonder what are the normal values for blood chemistry elements for dogs (and cats)? Well, actually "normal" is quite relative. Each veterinary diagnostic lab and "in clinic" laboratory equipment will have its own "normal values" calibrated to standards, so variations in what are called "normal values" should be expected.
The blood chemistry panel is a vital tool in the diagnosis of dog (and cat) diseases. An essential part of a thorough evaluation, most animal hospitals have provisions for evaluating blood chemistry values for dogs (and cats) either on site or via a local veterinary diagnostic laboratory. Newer instrumentation and techniques for evaluating blood chemistry make the use of the information gained from a blood chemistry panel a standard of practice.
There are a number of different metabolic parameters that can be evaluated, and when tied in with other diagnostic entities such as a urine analysis, radiographs (X-rays), physical exam and patient history, an accurate picture of a patient's health status can be assured.
Veterinary medicine, like medicine in general, is truly an art as well as a science. Looking at scientific data alone and turning a cold shoulder to the art will lead any healer astray. Accurate interpretation of scientifically acquired data requires introspection, experience, and a thorough evaluation of the physical and emotional aspects of the patient. Only after combining the two -- the scientific, cold, unemotional facts with the “hands on” evaluation of the entire patient -- will the doctor be enabled to make a proper diagnosis. And for any effective therapy to be instituted, an accurate diagnosis must be established first.
Canine patients of today have a distinct advantage over their predecessors of a few decades ago. Back then, veterinarians had only a few rudimentary tests for blood chemistry components at their disposal.
Today many veterinary clinics have “in house” blood chemistry analyzers that provide a wide variety of information in a matter of minutes. Other clinics rely on local veterinary laboratories that will pick up blood samples and fax or phone the results back to the clinic the same day. This state of the art of veterinary practice was only a dream a few years ago -- now routine blood chemistry evaluation is a standard of practice in every clinic.
The Chemistry Panel
When the patient’s blood is drawn the sample is allowed to clot, then the clear fluid is extracted -- without the fibrin, red and white blood cells, or platelets. Serum, as it's called, is what is presented to the lab for an evaluation of a number of chemicals circulating in the patient’s blood. Each laboratory, including the veterinarian’s "in house" lab, will establish normal values for dogs and other species. The analyzing instrument checks for amounts of these chemicals, which is then generated as printout with the patient's values compared to "normal" values.
Once the scientific data is in the doctor’s possession, the art of veterinary medicine comes into play. (Doctors are taught to “Treat the patient, not the paper”.) For example if the blood value for a chemical that reflects kidney function, such as creatinine, seems to be present in amounts higher than normal, does that unfailingly indicate diseased kidneys? And what if the sodium level seems a bit too high, does that mean there are dysfunctional kidneys or a hormonal imbalance? Or is the dog simply dehydrated because the owners forgot to provide water the previous 18 hours?
The art of medicine requires the practitioner to mentally view the entire canvas of possibilities even before the final painting is fully visible. And because there are so many variables affecting the blood chemistry, many veterinarians require a urine sample to be evaluated at the same time as the blood chemistry is submitted -- otherwise the reliability of indicated abnormal results may be questionable.