“That the chief diseases of the cow are the lough, swellings of the udder, and cowpox; that the two former are the most common, the latter being rarely seen except in spring and summer.
That cowpox begins with white specks upon the cow’s teats, which, in process of time, ulcerate; and, if not stopped, extend over the whole surface of the teats, giving the cow excruciating pain.
That, if this disease is suffered to continue for some time, it degenerates into ulcers, exuding a malignant and highly corrosive matter; but this generally arises from neglect in the incipient stage of the disease, or from some other cause he cannot explain.
That this disease may arise from any cause irritating or excoriating the teats; but that the teats are often chapped without the cowpox succeeding. In chaps of the teats, they generally swell; but in the cowpox, the teats seldom swell at all, but are gradually destroyed by ulceration.
That this disease first breaks out upon one cow, and is communicated by the milker to the whole herd; but if one person was confined to strip the cow having this disease, it would go no farther.
That the cowpox is a local disease, and is invariably cured by local remedies.
That he never knew this disease extend itself in the highest degree to the udder, unless mortification had ensued; and that he can at all times cure the cowpox in eight or nine days[1077].”
No account of cowpox in the cow has ever been given which differs materially from that of this experienced Gloucester cow-doctor in 1798[1078]. Cowpox is not only a local disease, but it is peculiar to certain individuals of the species, namely cows in milk; in them it occurs on the teats, so that it was correctly known in Norfolk by the name of pap-pox. The common observation has been that one cow starts it, and that an infection is rubbed into the teats of others by the fingers of the milkers. The cow which develops this ulceration of the paps is usually either a heifer in her first milk, from which the calf has been taken away, or a cow in milk which has been bought in a market, with the udder “overstocked” or left distended for appearance sake, but as yet with no blemish of the paps. The cause of cowpox is the rough handling of a highly sensitive part, which was originally adapted only for the lips and tongue of the calf. Ceely, a correct observer in the Vale of Aylesbury, uses no exaggerated phrase when he speaks of “the merciless manipulations of the milkers.” Men milkers are well known to lack the delicate tact of women; and cowpox has been most common in the great dairying districts where men-milkers are employed. But in some animals cowpox may be produced even under gentler handling or with slighter provocation, of which I give a recent case from my notebook, taken during a visit to the country:
27 April, 1891. Case of cowpox. A maid in the service of Mr J. R. has on the ulnar side of the fore finger of the right hand, over the joint of the first and second phalanges, a collapsed bleb the size of a sixpenny piece, pearly white round the margin, bluish towards the centre, which is brown. The forefinger, as well as the wrist and hand generally, bears traces of recent inflammation, and was said to have been greatly swollen and painful, the pain extending up the arm. There is a symmetrical rash of bright red papules on both arms as high as the elbows, more copious and bright on the right arm but abundant on the left also. The papules are elevated and pointed, with a small zone of bright redness of the skin round the base of each. The history is as follows: A cow was bought four or five weeks ago to supplement the supply of milk from the three ordinarily kept. The new comer proved “tough” to milk, so that the maid was obliged, contrary to usual practice, to take the paps in the cleft of the fore and middle fingers; under this mode of “stripping,” the animal would hardly stand quiet to be milked. After a time it was found that one of the paps had a black crust upon it, which might have covered originally a chap of the skin. The crust would have been displaced in the milking, and would have grown again; the sore beneath soon healed. Only one pap was affected. None of the other cows was infected. The “tough” cow was at length sold as an unsatisfactory milker, and had been sent to a distance on the morning of the day on which these notes were made. The maid’s finger began to be affected after two or three weeks of milking the cow, the beginning of the large and tumid bluish-white vaccine vesicle having been like a small wart.
Jenner’s opinion that cowpox was a specific disease “coeval with the brute creation,” and that it had been the parent of the great historical smallpox of mankind, is not now received as correct. His other opinion, that cowpox was derived from the hocks of horses affected with “grease,” which held a central place in his original essay, especially in connexion with his doctrine of “true” and “spurious” cowpox, was rejected by most of his contemporaries, and is perhaps unsupported by anyone at the present time[1079].