Why cats like tuna
Dear Readers: According to a scientific study by Scott J. McGrane and associates, cats have receptors in their taste buds that detect umami, the savory flavor found in meat – and tuna in particular. In cats, as in humans, the umami receptors are triggered by a combination of amino acids and nucleotides. Cats’ taste buds seem to be particularly attuned to histidine and inosine monophosphate: compounds that tuna contains in high amounts.
In tests, 25 cats were given their choice of plain water or water flavored with various umami compounds. The histidine/inosine monophosphate flavor “was one of the most preferred combinations,” said McGrane. “It really seems to hit that umami sweet spot.” (Full study: “Umami taste perception and preferences of the domestic cat [Felis catus], an obligate carnivore,” published in Chemical Senses, summarized on Science.org, Aug. 25)
“Why cats have a hankering for tuna in the first place remains a mystery,” says the Science.org writeup. After all, cats “evolved in the deserts of the Middle East about 10,000 years ago, where fish of any kind was unlikely to be on the menu.”
Indeed, there are few, if any, fish in deserts! But I checked other research reports and solved this “mystery.” The domestic cat is a descendant of Felis lybica, the African wildcat. Wildcats hunt primarily mice, rats, birds, reptiles and insects. It is likely that the insects in wildcats’ diet contain the same amino acids and nucleotides that cats like to eat, as would the insectivorous reptiles and birds that consume these insects before being consumed by the cats.
So tuna likely contains similar nutrients to the ones cats have enjoyed since their early days in the desert. However, because of mercury and other contaminants, and the fact that many cats are allergic to fish, I do not advise feeding tuna to cats. We should be helping the oceans restore their natural biodiversity, currently under threat from climate change and the overharvesting of marine life for human consumption and livestock feed.
Cat food manufacturers are certainly aware of cats’ affinity for tuna, using it to make their products more appetizing. But also, we may soon see high-nutrient ingredients derived from farmed insects being added to cat and dog foods. They are approved in Europe for pet foods, and also as food additives in various products for human consumption.
Dear Dr. Fox: I was reading an article on PETA’s website regarding the drawbacks of cat trap-neuter-release (TNR). You were quoted as saying, “It is time to work for responsible solutions.” I was wondering if you had any thoughts on what those responsible solutions might be. The communities outside of Las Vegas are looking for answers to this issue.
D.H., Las Vegas
Dear D.H.: First, I wish all veterinarians and everyone involved in cat rescue and rehabilitation would read the excellent study by Bailey H. Eagan and associates that was published in the Journal of the American Veterinary Medical Association in September (“Daily gabapentin improved behavior modification progress and decreased stress in shelter cats …”).
It should be noted that all these caged cats had double-compartment portalized enclosures with separate litter box, bed and “hide box,” which I consider most important in reducing fear.
An alternative is group housing (after vaccinating, neutering, and screening the cats for disease and parasites). Shy cats see other cats interacting with caregivers and soon come around and can be adopted out eventually. Those who do not can become permanent residents in these enclosed cat sanctuaries. No cats should be released outdoors to fend for themselves, which can put their health and lives at risk, as well as public health and wildlife. Cats are predators and will decimate local populations of songbirds and small mammals.
See these related posts on my website: drfoxonehealth.com/post/outdoor-catswildlife-and-human-health and drfoxonehealth.com/post/releasing-cats-tolive-outdoors-humane-environmentaland-one-health-concerns.