Normal hemoglobin concentration (Hb, g/dl) is about one-third (33%) of the packed cell volume (PCV) in normal dogs, cats, horses, cows, sheep, goats, and pigs.
So, in a cat with a PCV of 30%, the Hb will be roughly 10 g/dl.
And in a dog with a PCV of 45%, the Hb will be roughly 15 g/dl.
Remember, Hb is a protein in erythrocytes that helps to transport oxygen.
Follow this link to see Small and large Animal reference values.
One exception to the 33% rule is South American camelids, whose hemoglobin is 40%-45% of the PCV, presumably an adaptation to high altitude, lower oxygen environments.
