The present invention relates to a method of assessing pharmacokinetic properties of a variant of human serum albumin using a non-primate animal species where the native albumin of the animal provides minimal competition for HSA binding to the FcRn receptor in said animal. In the non-primate animal species, the binding affinity of wild type HSA to the native FcRn of said animal is the same as or higher than the binding affinity of the native albumin of said animal to the native FcRn. The present invention also relate to animal models which are particularly suitable for assessing pharmacokinetics of human serum albumin variants.