Many analytes, such as steroids (Corticosterone, etc.); cyclic nucleotides (cAMP and cGMP); or small lipids (PGE2, PGFM, etc.) are exactly the same regardless of their source. Samples of these molecules from any species should therefore be usable in ELISAs or CLIAs, even if they have not been specifically tested.
In addition, kits that measure the activity of a sample, such as the Glutathione S-Transferase (K008-F1) or PKA (K027-H1) Activity Assays, or that detect the presence of an analyte without using antibodies such as the Nitric Oxide (K023-H1) or Hemoglobin (K013-H1) Detection Assays, are not limited in any way by a species-specific interaction and therefore will work with samples from any species. All kits that fall into these categories are indicated as “Multi Species” on their product pages. Those kits that are limited to certain validated species will include that in their name, such as the Cystatin C Human Immunoassay kit (K012-H1).