IN 1942 THE SHEEP population of the United States started on a decline which reached the lowest figure by 1950 for our history of the recorded numbers of sheep. Also in 1942, the drug, phenothiazine, a carbon ring — sulfur compound, was introduced and subsequently put into extensive use as a vermifuge (worm and parasite killer). The use of this drug resulted in the discontinuation of the practice of regularly giving the sheep copper sulfate, or bluestone, formerly used for that treatment.
Now that we are appreciating the significance of many of the trace elements, including cobalt and copper, in the biochemical activities of microbes, plants, animals, and man, and since we are also recognizing the slowly accumulating lethal effects on man and animals by the many sulphonated and chlorinated carbon ring compounds, the phenothiazine as one of them should be coming under question.
Might not the introduction of this drug into regular use as a worm remedy for sheep have some casual connection with the serious decline in the sheep population? These three simultaneous phenomena, namely, (a) the cessation in the use of copper sulfate, (b) the extensive use of phe-nothiazine, and (c) the sudden decline in sheep population ought to prompt every sheep owner to consider the hypothesis — or to ask the question — namely, “Might the change in worming procedure in 1942 have been the cause of the decline in the sheep population?”
One may well raise the question whether the discontinuation of the use of bluestone was not the cause, or at least a contribution, since it meant failure to feed copper as a possibly necessary trace element or its accompanying sulfur as a requisite in making wool fiber which is so high in cystine, the sulfur-carrying protein constituent.
When in Australia scientists have demonstrated the shortage of copper in the soil and the forage as the reason for black wool turning to a gray color, and when in Missouri the sheep born of black wool turn to gray, the withholding after 1942 of the formerly administered copper sulfate may theoretically be considered a reason for the decline in our sheep numbers since that date.
Perhaps our regular dosing with copper was not so much a case of giving medicine to kill worms, as it was a help toward improved nutrition for healthy sheep in which the worms found no place. Copper and sulfur may have been supplementary feed requirements since we are expecting sheep to do well on soils today where nature had never grown any animals of a physiological performance similar to that of the sheep. Have we not probably pushed the sheep off the very fringes of the soil fertility areas on which they can survive or be really healthy? With a sheep population of less than 32,000,000 now when but ten years ago we had 56,000,000, should we not be asking a whole series of questions?
Trace Element Deficiency
The question of the deficiency of trace elements in the soil was brought up some years ago. At first it met with little concern and much less reaction. But trace elements have now come to be used more extensively both as feed supplements and as fertilizer treatments on the soil. Much more suggestive for consideration as the cause behind the sudden decline in the sheep population since phenothiazine was introduced, is the accidental discovery this year, through some experiments with rats, that this drug prohibits the thyroid gland from taking up iodine and from exercising its normal function of encouraging regular growth or normal body metabolism.
Test Shows Thyroid Damage
This report comes from the work of Roy V. Talmade, H. Nachimson, L. Kraintz, and J. A. Green in the Department of Biology, Rice Institute, at Houston, Texas. They were observing the regular movement and concentration of radio-active iodine into the thyroid glands of rats when a supposedly regular batch of the usual feed suddenly prohibited that normal process. It resulted from the mistake in getting a feed carrying some phenothiazine. Then tests of the phenothiazine in separate trials revealed its damage to the function of the thyroid gland of the rat with a severity in the same range of that when thiouracil was administered as 0.1 percent of the same diet for but 16 days.
The gray band of wool in the staple of a black sheep (A) resulted when the sheep grazed on fields deficient in copper and cobalt. The harsh “steely” top portion of the white staple (B) was grown by sheep in similar soil. This is in sharp contrast to the regular crimp in the staple of normal wool (C).
Question Drug
With this fact coming out of the rat laboratory, phenothiazine certainly comes under question. That discovery makes us ask ourselves whether we should not run some metabolic tests or other diagnostic procedures on our sheep fed this drug to learn whether we are not making cretins of them as we see this deficiency among humans suffering from iodine deficiency or from the reduced rate of growth due to the irregularity in metabolism of the mineral iodine.
A news item from Cedar City, Utah, June 6 (Kansas City Star) under the headline, “Utah sheep men are stricken,” told us that “Lambs have been abnormally small this spring and many have died. Some ewes have bare faces and scabby noses as though they have been burned. Some sheep also were reported losing their wool. Dr. John Curtis, State Veterinarian, made the first investigation May 24. He said 500 to 700 lambs and about 100 two-year old ewes died in one herd. He could not diagnose the malady.” The question was raised whether the atomic bomb could be blamed.
Reports from an able veterinarian and a capable student of animal nutrition in Iowa serving the western states, tell us that “Sheep are not growing as they should, and in spite of all the feed supplements we try. The fatalities during the lamb feeding periods are decorating the fences of the feed lots with too many pelts pulled off the dead ones. Such happenings fail to keep up a man’s interest in the sheep business.” It was those observations that prompted him to put the query “We can’t find the trouble in the feed. Could the trouble possibly be in the soil growing the feeds?”
Declining Soil Fertility
In answer to his question, coming likewise from many other livestock folks, one must reply that our declining soil fertility is cutting down the ratio of the proteins to carbohydrates and is giving us “fattening” feeds rather than “growing” feeds. Failure to improve the soils has also suggested the mounting deficiencies in the nutritional qualities of the proteins we grow. They are still only “crude” proteins.
But when these reported troubles are so severe where sheep have been on the range and where they have been doing what they could by their own instinct, it looks as if these troubles fall back on us rather than on the sheep. It is all the more significant that we examine critically in this case, not the sheep nature, but human nature when we use these chemicals carrying the sulphonated carbon ring compounds, or the chlorinated rings. Many of these have always been considered as poisons even if they were not so highly lethal.
The carbon ring structure is not readily broken down by digestion. Nor do the microbes of the soil break it down as they do most other substances which we bury for their disposal through microbial help. Shall we not connect our troubles in growing sheep possibly with our own inclination to use drugs to fight worms, microbes, and diseases when we ought to be looking to better feed and normal nutrition for good health of our animals via more fertile soils?
Reaching Conclusions
Of course, there is always the possible fallacy in drawing the conclusion that when two things happen at the same time, the one must be the cause of the other. In like manner the terrific decrease in sheep numbers, happening just after we quit feeding sheep copper sulfate and began dosing them with phenothiazine may be just a coincidence rather than a cause in the latter for the former. Nevertheless, when the drug has now shown its damage to the health and to the physiological functions of the laboratory rat, no flock owner is going to be kept from putting under question the phenothiazine in sheep feed.
A theory will get attention apparently only when disaster of terrific magnitude befalls one. It would seem well then to put under test the theory which has now become a serious likelihood. Perhaps if properly tested, the sheep themselves will come up with the answer later. Only after the many sheep flock owners attack the problem can the falling curve of our sheep population be reversed and result in restored profit in the form of more lamb and more wool as we learn — from a possibly sad experience — to feed sheep better and to drug them less.