210 REPORT OF" THE COMMISSIONER OF AGRICULTURE. 



Ia most of the infected herds there are but one or two sick animals at a time, and 

 frequently there are none ; for where the disease has existed for a certain time the 

 susceptible animals die off and only those which possess a certain immunity from it 

 remain. 



As about 20 per cent, of all tho animals exposed are able to resist the contagion in- 

 definitely, a herd of comparatively insusceptible cattle is in time acquired, and the 

 time necessary for this is shortened both in Baltimore and Brooklyn by the practice 

 of inoculation. 



But these stables and grounds remain infected, and a large portion of the new cows 

 brought into them contract the disease unless they are jireviously protected by inoc- 

 ulation. The practice of inoculation does not destroy the infection ; on the other 

 hand it keeps it up, but it enables dairymen to keep their cows in infected stables 

 without great loss, when without it more than half of the new cows brought into them 

 would surely die. 



Another fact of great importance brought out by the experiments of the French 

 pleuro-pneumonia commission is that about 30 per cent, of the animals exposed to this 

 disease show no symptoms of it beyond a slight cough. Such animals are probably as 

 dangerous toothers as those which have it in a more severe form, and yet they can be 

 transported to various parts of the country without exciting the least suspicion. 



The animal which is supposed to ha ve caused the outbreak in Connecticut was prob- 

 ably in this condition, as a careful examination of her lungs did not enable the veter- 

 inarians to detect any evidences of the disease ; and yet pleuro-pneumonia existed 

 in the stable from which she came, and her admission into the new herd was followed 

 by the seven cases that have been mentioned. Similar instances are referred to again 

 and again by the veterinarians of every country where the disease exists. 



These infected districts, though small, are then a real danger to the whole country, 

 because all tho way from Connecticut to Virginia there is a large and increasing num- 

 ber of herds of thoroughbred cattle, which are frequently shipped to the West and 

 some of which have from time to time been infected with this disease. Fortunately, 

 the owners of thoroughbred cattle have generally had too much regard for their repu- 

 tation to ship cattle when there was any disease in their herds, and the common cat- 

 tle have not been sent to a sufficient distance to do much harm. 



But with the increased price of cattle a large number are being shipped from the 

 East toward the West, and the danger of carrying the disease is consequently increas- 

 ing. If the car-load of cattle shipped from Baltimore to Chester County, Pennsyl- 

 vania, had gone to the ranges of the West, they might have done irreparable harm. 

 Again, the thoroughbred Jersey cow which went from an infected stable in New Jer- 

 say might as readily have been shipped to the West; and I have been informed that 

 if the Connecticut outbreak had occurred a few months later one or more of the herds 

 would have been sent, according to contract, to a Western State. Now, while it is 

 true that pleuro-pnenmonia has existed in the East for forty years without having 

 been carried to the West, it must be admitted, from what has occurred so many times 

 in Pennsylvania and Connecticut, that there has been danger of this, and that this 

 danger is increasing with the larger number of cattle now being shipped in that direc- 

 tion. No doubt this danger has been exaggerated, but the fact that there is danger, 

 and that the disease once carried to the Western herding grounds would probably be 

 beyond our control, if we can judge from the experience of Australia and South Af- 

 rica, is sufficient to show the importance of grappling with it while it can be so easily 

 handled. The rapidity with which a disease spreads on these ranges, when once in- 

 troduced, is illustrated by an occurrence of last summer in Southwestern Texas. A 

 drove of cattle brought a communicable disease to that section, which the array sur- 

 geons believed to be contagious pleuro-pneumonia ; but before any careful examination 

 could be made several hundred cattle had died, and a large territory was infected. For- 

 tunately, investigation showed that this was not pleuro-pneumonia, but a disease which 

 does not outlast a single season of the year. If it had proved to be pleuro-pneumonia, 

 would it not have been a national calamity ? With a large territory already infected, 

 with no money and no power to control the disease, and occurring in summer mouths, 

 before the State and national legislative bodies would convene, it is difficult to see 

 how any effective measure could have been adopted. 



THE INEFFICIENCY OF STATE ACTION. 



Though a number of attempts have been made by the States now infected to rid 

 themselves of pleuro-pneumonia these have generally or always failed, because for 

 various reasons the work was not thoroughly done. We saw the State authorities 

 of Connecticut unable to exterminate the disease a few months ago, when but a sin- 

 gle herd contained sick animals. The stables of Brooklyn were never under com- 

 plete supervision, and some could not be entered by the inspectors even when the 

 State of New York was most active in its endeavors at extirpation ; and though the 

 authorities of New Jersey have been engaged at the same task for rive years, the State 



