Were the salmon and tuna both fresh and about the same in terms of quality? Both fish have the compounds cats like, but I wonder if processing/dolphin content/age may be the cause for their preference.
Both canned, but not the same brand. And even if they were, who's to say whether the sourcing and prep was controlled for in all respects? But it was a consistent observation I noted over multiple cats and multiple brands. They liked both a lot, but salmon seemed to be the clear winner.
My cat also greatly prefers salmon over any other fish or water produce. I've tested it with very fresh, sashimi grade fish and shrimps, canned fish, and fish-flavored treats. He consistently favors salmon and salmon flavor. Some cats are very particular about what they eat.
