“Sweet Taste in the Cat and the Taste-Spectrum”, 1951 (; backlinks):
…Zotterman explained his results by the statement that “the cat, as opposed to the dog, has no liking for sugar or sweet tasting food in general”. I have previously reported that every animal which I had tested accepted sucrose solutions eagerly when hungry. This included even such unlikely subjects as spiders, rabbits, mantids, snails, and quail.
With this in mind, Beverly Cox, a student at this college, and I tested cats for acceptance of, or better, preference for sweet solutions and found that cats accept sucrose as a food when offered in diluted milk, easily distinguishing diluted milk with sugar from the same without sugar.
10 cats (5 adults, 5 kittens) were housed in small animal cages and were given water ad libitum, but were deprived of food for various intervals of time before testing. A period of 24 hours of inanition proved to be quite satisfactory.
Then each cat was offered two similar dishes containing solutions—one contained milk diluted with 4× its volume of water, the other contained milk similarly diluted but with sucrose added to make it 0.5M1 with respect to sucrose. Diluted milk was selected as the medium for the sucrose after it was found that consumption of water or water with sugar was too little to give reliable results. Whole milk was unsuitable, because this was taken avidly by hungry cats with or without sucrose added. Diluted milk, on the other hand, was either refused or taken in very small amounts by the cats after they sampled it, while the same diluted milk to which sugar had been added was taken eagerly by all of the animals. By randomizing the positions of the containers in the cages in replicated tests, it was easy to determine that the cats could distinguish between the two solutions, and that, once both had been sampled, they would take only the one containing sucrose.
…Suffice it to say that cats can distinguish “sweet” things from “non-sweet”, and that they do “like” the “sweet”, if conditions are right.
A possible explanation for the lack of success in finding nerve potentials on stimulation with sucrose has already been offered.3…On the basis of this theory, the reason for the lack of success in finding sweet taste fibers would be that the necessary end-organs, being only the most sensitive, are present in the smallest numbers. With whole nerve preparations, the potentials might thus be too small or might be masked. With single fiber preparations, the chances that any specific fiber would be from one of these organs would be small.