Quotes Committee upon Accessory Food Factors (Vitamins), Vitamins: A Survey of Present Knowledge (HM Stationary Office: London, 1932).
Description:

'on the subject of vitamin C and its value to puppies as contained in orange juice (so widely used now - and with seemingly excellent results, I will refer to a point raised by a correspondent who writes:

"Biologists have not yet arrived at a conclusion as to whether dogs need vitamin 'C' at all - for instance, in orange juice - for when fed on  adiet devoid of vitamin 'C' they create it in their bodies and dogs cannot suffer from scurvy. Breeders apparently tink vitamin 'C' is necessary to puppies because it is necessary to babies."

Now this appears to me to be fallacious reasoning. Vitamin "C" is anti-scorbutic - that is to say, "preventive of scurvy." What is "scurvy"? It is a diseased state of the blood, with swollen gums, skin spots, and prostration, attacking sailors and any who feed on salt meat and lack vegetables." So says the "Oxford Doctionary," in plain non-medical language quite intelligible to anybody. Was it not Captain Cook, the famous voyager, whose med suffered so badly from scurvy? And was it not a result of his experiences and the similar experiences of other ships' captains that the stores taken and diet arranged on shipboard were modified until the scourge of scurvy was brought to an end?

Are Dogs Liable to Scurvy?

"There is no longer any doubt that the disease exists in dogs," says Professor Müller, director of the Animals' Clinic at Dresden University - though, as he explains, cases are of rare occurrence. To get the reasons for this would mean embarking upon a long technical dissertation quite unsuited to "Notes for Novices," and it must suffice to say that dogs in a state of nature do to a considerable extent create in their own bodies as a result of the interaction of particular natural foods in their system; and let it not be forgotten that even dogs are prone to chewing on [?]table substances, as every dog-owner knows. Moreover since scurvy, whenever it appears, is always accompanied by soreness of the gums, swollen or [?] joints, and complex changes in the blood (far too technical to enter upon here), it it quite certain that whilst scientists are wrangling about the matter, dog owners will be wise in rejecting the idea that giving of orange juice to puppies is an uneccessary fad. I wonder how many times in my own experience the advice "Give them orange juice" proved on adoption the turning-point in the doubtful progress of puppies, just as it has been a thousand times the salvation of backward human infants!

But inasmuch as what the correspondent from above I have quoted says about biologists "not having arrived at any conclusion as to whether dogs needing vitamin "C" at all is true, let me give the considered opinion of the experts at the Medical Research Council published in the 1932 edition of "Vitamins: A Survey of Present Knowledge" on this subject.

Origin and Function of Vitamin "C."

Under that heading these experts say that:

"Animals derive derive vitamin C - directly or indirectly - from the vegetable kingdom. Different species of animals, however, vary vary greatly in their susceptiiblity and in the amount of antiscorbutic vitamin which they require for growth and sustenance. Thus, wile human beings, monkeys and guinea pigs are susceptible to scurvy, rats, mice and aduly rabbits do not show the characteristic symptoms fo the disease, in spite of deprivation of vitamin C. It appears, however, that the difference between these two classes is one of degree only. It has been shown that rats existing on a scorbutic diet do not thrive so well, and are not so fertile, as those who receive some antiscorbutic material... It is evident that the rat requires vitamin C, but only in small amounts compared with such animals as the guinea pig and monkey. It is of interest that another rodent, the prairie dog of North America, resembles the rat, a young animal growing to four times its weight in six months on a scorbutic diet on [?] [whereas] guinea pigs acquired scurvy in from two to three weeks. The rabbit receiving a scorbutic diet of oats, beans, and water generally loses weight and dies, but does not develop the characteristic symptoms of scurvy. Female rabbits became pregnant, but the young were born dead and showed typical symptoms. The addition of swede j[?] to the diet produced a great great improvement in the condition of the animals, The fowl is also able to subsist on a scorbiutic diet and, like the rat possesses under these conditions a store of vitamin C in the liver... Calves and pigs also thrive without an obvious source of vitamin C, though well-developed scurvy has been occassionally observed in pigs. It is still doubtful whether these animals acquire the vitamin C contained in their livers by the accumulation of traces from their food or by chemical changes from some source of which guinea pigs are not able to avail themselves. Even among the animals which are not subject to typical scurvy three are great differences in requirement. Thus, for protection against scurvy, a monkey weighing 5-7 lbs. requires the same daily dose of orange juice as a guinea pig."

And much more of the same sort. And what appears to me to be so significant in all this is the doubt expressed as to "whether these animals acquire vitamin C contained in their livers by accumulation of traces from their food, or by chemical changes from some other source." When it is borne in mind that cod-liver oil owes its virtues to accumulation from [102-3] the smaller fish who feed upon the minute vegetable life floating on the surface of the sea and are themselves devoured by the cod, the explanation of the automatic production of its vitamin C needs by the dog from its own internal arrangements suggests itself at once.

...

... The Medical Research Council, in the volume to which I have already referred, devote lengthy attention to the effect of heating, drying, and preserving foodstuffs (vegetable) upon the content of vitmain C. The report in detail to the effect that all these processes - cooking, drying, and preserving - tend in varying degrees to destroy the value of foodstuffs. This is a fact that may well be taken note of both as regards diet for human beings and diet for dogs.' (102-3)