Interpreting abnormal CBC and chemistry values in dogs and cats

A reference for veterinarians on what a high or low result on a dog or cat CBC, chemistry panel or urinalysis can point to, what can shift it artificially, and the next test, with a citation for each.

Reviewed by Brian Toncray, DVM · October 22, 2026

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Reading a value against the reporting lab's own interval

A reference interval is an estimate of the distribution of values in healthy, comparable animals, and decisions to pursue a diagnosis are often triggered by a value outside it¹. Laboratories determine their own intervals or validate intervals transferred from another source, such as an analyzer manufacturer, for the method they actually run¹. The ACVIM panel on canine hyperadrenocorticism made the same point for endocrine tests, recommending that reference ranges be re-established as test technology changes².

That is why this site publishes no numbers. Check your lab's range, printed beside the result, and read every value on these pages as above, within or below that interval. A value just outside the interval in a well patient is a prompt to look at the rest of the panel and, often, to repeat it, since a single time point is less reliable than a series³.

When the sample moved the number

Some abnormal results describe the tube rather than the patient. Platelet clumping in EDTA is a common cause of a falsely low platelet count in dogs and cats⁴. Akitas and several other East Asian breeds can carry red cells rich in potassium, so their serum potassium can read high without disease^5,6. Ionized calcium is most reliable when the sample is handled anaerobically⁷. Each topic page lists the artifacts for its own values under Can shift it artificially.