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How pleuro-pneumonia is spread
EDITORIAL ARTICLES.
349
Leaving out of account the protective effect of vaccination (with the virus of cow-pox) against human small-pox, we have now clear experimental evidence that inoculation with the organism of one disease may exercise a protective influence with regard to a totally different disease. As an example of this we may refer to the interesting experiments regarding the antagonism of the bacillus of blue pus and the anthrax bacillus described in the previous pages of this number. But it might be replied that there is no analogy between setoning, and inoculation with a culture or other matter containing specific micro-organisms. The reply would be over hasty, for in a certain sense setoning is undoubtedly an inoculation. The suppuration which follows the introduction of a seton is certainly caused by the introduction of pyogenic organisms, and it is not far-fetched or ridiculous to suppose that the products generated by these organisms in the tissues might be diffused throughout the body, and leave the animal protected against black-quarter. We do not wish to be 'understood to express any belief in the efficacy of setoning; indeed we have no expectation that the operation will stand the only decisive test. But if it is protective it ought to be universally put into practice, and if it has no effect the sooner the delusion is exploded the better. Much credit is therefore due to the Midland Counties' Society for having taken the matter up, and the result of their experiments will be awaited with considerable interest. Meanwhile we take this opportunity to intimate to our readers that we can now supply them with vaccin on the shortest notice. On receipt of a letter or telegram specifying the number of animals to be inoculated we shall forward immediately by post the proper quantity of vaccin, together with full directions for carrying out the operation. It ought to be added that a hypodermic syringe of known capacity and carefully graduated is required. A suitable instrument has been made to our order by Messrs Gardner, 32 Forrest Road, Edinburgh. The syringe ought to be exclusively reserved for these inoculations, but in the event of its being employed for other purposes it must ce sterilised before it is again used for black-quarter inoculations.
HOW PLEURO-PNEUMONIA IS SPREAD. IN the controversy that was recently waged in this country regarding the relative merits of inoculation and slaughter as a means of eradicating pleuro - pneumonia, it was strongly urged by the opponents of inoculation, and as persistently denied by its advocates, that an animal might carry a pleuro-pneumonic lesion in its lung, and serve as a centre of infection to other animals, and yet present
EDITORIAL ARTICLES.
all the symptoms of perfect health. Numerous instances of this kind have been observed and recorded in our own country, and the matter is really one which can be considered open to doubt only by those of no experience, and those who deny the existence of everything that has not come under their own immediate observation. There are probably few veterinary surgeons who are not convinced that slaughter of both diseased and contaminated cattle is the only method of dealing with pleuro-pneumonia that holds out any hope of ultimate success, but it is not unlikely that the great expense connected with the carrying out of the "stamping out" method, and the apparent increase in the number of outbreaks since th8.t was put into force, will be seized upon by those who found inoculation lucrative, to support their prediction that general slaughter will yet have to be abandoned, and a system of general or partial inoculation introduced. In anticipation of such an outcry it may not be waste of space to narrate here a most instructive case recently recorded by Professor N ocard. 1 During the present year the French Committee for Epizootics deputed one of its members to carry out an inquiry regarding the origin of a series of cases of pleuro-pneumonia which had been notified in several of the departments in the north-east of France. The inquiry proved most clearly that all these cases had their origin in the importation of Belgian animals by two French dealers. In the case of one outbreak all the animals slaughtered as being attacked with the acute form of pleuro-pneumonia had been raised on the farm or purchased more than a year previously. The disease did not exist on any other farm in that or the neighbouring communes. The only cattle recently introduced into the affected premises were two cows, which were in the primest condition and presented every appearance of perfect health. After a prolonged examination the local veterinary surgeon had affirmed that the two cows presented no symptoms permitting him to suspect the existence of pleuro-pneumonia. From inquiries made it was ascertained that the two cows had been bought in one of numerous localities into which pleuro-pneumonia had been imported by Belgian cattle, and, on the other hand, that no other cow had recently been introduced into the byre in which the outbreak occurred. No other conclusion was therefore possible than that the disease had been imported by one or other of these cows. The inspector sent to investigate the outbreak accordingly made application to the Central Authority for permission to order the immediate slaughter of the two cows in conformity with the French statute. One of the animals was pregnant and almost at full term, and, at the request of the owner and the local veterinary surgeon, the representative of the Central Authority consented to delay the slaughter of this cow until after parturition, on the express condition 1
ReeueI! de MM. Vet., Oet. 1890.
EDITORIAL ARTICLES.
that it should be isolated, kept under strict surveillance by the sanitary official, and immediately slaughtered on the first symptom 'of illness. The other cow was killed there and then, and it was found to be free from pleuro-pneumonia. After several weeks the second cow gave birth to a splendid calf. Up to that time it had retained all the signs of perfect health, it had no cough, the physical examination of its chest always gave negative results, and it gave 20 litres of milk. On the proposition of the local veterinary surgeon, the Prefect of the department requested permission from the Central Authority to delay the slaughter of this cow, and to allow it to remain simply under the surveillance of the sanitary official. At this stage the Committee for Epizootics was consulted, but some of its members were inclined to hesitate, in the belief that a cow that did not cough, that was fat, and that gave 20 litres of milk, could not be the subject of pleuropneumonia. Fortunately, however, other members succeeded in convincing the Committee that pleuro-pneumonia is compatible with every appearance of health, including persistence of the lacteal secretion. The cow was therefore slaughtered, and at the post-mortem it was discovered that one of the lungs contained a chronic pleuro-pneumonia lesion, as large as the fist and in process of being encysted. The lesion was situated in the anterior lobe, where the presence of the scapula made its discovery by auscultation or percussion impossible. In bringing the case before the Societe Central de Medecine Veterinaire, Professor N ocard, who stands to the French Central Authority in pretty much the same relationship as Professor Brown to the Board of Agriculture, said that this case completely proved the necessity of modifying the existing French law, so as to compel the permanent isolation of all animals known to have been exposed to the contagion of pleuro-pneumonia. I t is a curious fact that less than a year ago the inoculators in this country were urging the Government to try in preference to" stamping out" the system of partial inoculation, while in France, where this very system has been in force since I 88 I, the veterinary profession is demanding that the existing law shall be amended so as to assimilate it to that now in operation here. In conclusion it may be said that the before-described case comes most opportunely as a reply to those who from selfish motives, and with a singular indifference to the general interests of British stockowners, have been assailing the Minister of Agriculture for refusing to allow a free entry of United States store cattle to this country. No system of inspection, however honestly and thoroughly it may be carried out, can entirely remove the danger of importing animals from countries that are not known to be free from pleuro-pneumonia.
349
Leaving out of account the protective effect of vaccination (with the virus of cow-pox) against human small-pox, we have now clear experimental evidence that inoculation with the organism of one disease may exercise a protective influence with regard to a totally different disease. As an example of this we may refer to the interesting experiments regarding the antagonism of the bacillus of blue pus and the anthrax bacillus described in the previous pages of this number. But it might be replied that there is no analogy between setoning, and inoculation with a culture or other matter containing specific micro-organisms. The reply would be over hasty, for in a certain sense setoning is undoubtedly an inoculation. The suppuration which follows the introduction of a seton is certainly caused by the introduction of pyogenic organisms, and it is not far-fetched or ridiculous to suppose that the products generated by these organisms in the tissues might be diffused throughout the body, and leave the animal protected against black-quarter. We do not wish to be 'understood to express any belief in the efficacy of setoning; indeed we have no expectation that the operation will stand the only decisive test. But if it is protective it ought to be universally put into practice, and if it has no effect the sooner the delusion is exploded the better. Much credit is therefore due to the Midland Counties' Society for having taken the matter up, and the result of their experiments will be awaited with considerable interest. Meanwhile we take this opportunity to intimate to our readers that we can now supply them with vaccin on the shortest notice. On receipt of a letter or telegram specifying the number of animals to be inoculated we shall forward immediately by post the proper quantity of vaccin, together with full directions for carrying out the operation. It ought to be added that a hypodermic syringe of known capacity and carefully graduated is required. A suitable instrument has been made to our order by Messrs Gardner, 32 Forrest Road, Edinburgh. The syringe ought to be exclusively reserved for these inoculations, but in the event of its being employed for other purposes it must ce sterilised before it is again used for black-quarter inoculations.
HOW PLEURO-PNEUMONIA IS SPREAD. IN the controversy that was recently waged in this country regarding the relative merits of inoculation and slaughter as a means of eradicating pleuro - pneumonia, it was strongly urged by the opponents of inoculation, and as persistently denied by its advocates, that an animal might carry a pleuro-pneumonic lesion in its lung, and serve as a centre of infection to other animals, and yet present
EDITORIAL ARTICLES.
all the symptoms of perfect health. Numerous instances of this kind have been observed and recorded in our own country, and the matter is really one which can be considered open to doubt only by those of no experience, and those who deny the existence of everything that has not come under their own immediate observation. There are probably few veterinary surgeons who are not convinced that slaughter of both diseased and contaminated cattle is the only method of dealing with pleuro-pneumonia that holds out any hope of ultimate success, but it is not unlikely that the great expense connected with the carrying out of the "stamping out" method, and the apparent increase in the number of outbreaks since th8.t was put into force, will be seized upon by those who found inoculation lucrative, to support their prediction that general slaughter will yet have to be abandoned, and a system of general or partial inoculation introduced. In anticipation of such an outcry it may not be waste of space to narrate here a most instructive case recently recorded by Professor N ocard. 1 During the present year the French Committee for Epizootics deputed one of its members to carry out an inquiry regarding the origin of a series of cases of pleuro-pneumonia which had been notified in several of the departments in the north-east of France. The inquiry proved most clearly that all these cases had their origin in the importation of Belgian animals by two French dealers. In the case of one outbreak all the animals slaughtered as being attacked with the acute form of pleuro-pneumonia had been raised on the farm or purchased more than a year previously. The disease did not exist on any other farm in that or the neighbouring communes. The only cattle recently introduced into the affected premises were two cows, which were in the primest condition and presented every appearance of perfect health. After a prolonged examination the local veterinary surgeon had affirmed that the two cows presented no symptoms permitting him to suspect the existence of pleuro-pneumonia. From inquiries made it was ascertained that the two cows had been bought in one of numerous localities into which pleuro-pneumonia had been imported by Belgian cattle, and, on the other hand, that no other cow had recently been introduced into the byre in which the outbreak occurred. No other conclusion was therefore possible than that the disease had been imported by one or other of these cows. The inspector sent to investigate the outbreak accordingly made application to the Central Authority for permission to order the immediate slaughter of the two cows in conformity with the French statute. One of the animals was pregnant and almost at full term, and, at the request of the owner and the local veterinary surgeon, the representative of the Central Authority consented to delay the slaughter of this cow until after parturition, on the express condition 1
ReeueI! de MM. Vet., Oet. 1890.
EDITORIAL ARTICLES.
that it should be isolated, kept under strict surveillance by the sanitary official, and immediately slaughtered on the first symptom 'of illness. The other cow was killed there and then, and it was found to be free from pleuro-pneumonia. After several weeks the second cow gave birth to a splendid calf. Up to that time it had retained all the signs of perfect health, it had no cough, the physical examination of its chest always gave negative results, and it gave 20 litres of milk. On the proposition of the local veterinary surgeon, the Prefect of the department requested permission from the Central Authority to delay the slaughter of this cow, and to allow it to remain simply under the surveillance of the sanitary official. At this stage the Committee for Epizootics was consulted, but some of its members were inclined to hesitate, in the belief that a cow that did not cough, that was fat, and that gave 20 litres of milk, could not be the subject of pleuropneumonia. Fortunately, however, other members succeeded in convincing the Committee that pleuro-pneumonia is compatible with every appearance of health, including persistence of the lacteal secretion. The cow was therefore slaughtered, and at the post-mortem it was discovered that one of the lungs contained a chronic pleuro-pneumonia lesion, as large as the fist and in process of being encysted. The lesion was situated in the anterior lobe, where the presence of the scapula made its discovery by auscultation or percussion impossible. In bringing the case before the Societe Central de Medecine Veterinaire, Professor N ocard, who stands to the French Central Authority in pretty much the same relationship as Professor Brown to the Board of Agriculture, said that this case completely proved the necessity of modifying the existing French law, so as to compel the permanent isolation of all animals known to have been exposed to the contagion of pleuro-pneumonia. I t is a curious fact that less than a year ago the inoculators in this country were urging the Government to try in preference to" stamping out" the system of partial inoculation, while in France, where this very system has been in force since I 88 I, the veterinary profession is demanding that the existing law shall be amended so as to assimilate it to that now in operation here. In conclusion it may be said that the before-described case comes most opportunely as a reply to those who from selfish motives, and with a singular indifference to the general interests of British stockowners, have been assailing the Minister of Agriculture for refusing to allow a free entry of United States store cattle to this country. No system of inspection, however honestly and thoroughly it may be carried out, can entirely remove the danger of importing animals from countries that are not known to be free from pleuro-pneumonia.