THE FARMER'S MAGAZINE. 



115 



cattle in different parts of the country. The earliest 

 accounts which we received of the outbreak came from 

 Norfolk, and there seems no reason to doubt that 

 it was here that the disease was first observed. Cattle 

 of all ages and under every variety of system of feeding 

 and management became the subjects of the malady, 

 which was recognised by the existence of vesicles upon 

 the upper surface of the tongue, inside the lips, and the 

 dental pad. Vesicles were also formed between the 

 digits, and occasionally upon the teats and udders of 

 the cows. The existence of these vesicles was associated 

 with a discharge of viscid saliva from the mouth, loath- 

 ing of food, imperfect mastication, suspension of rumi- 

 nation, loss of milk, a tenderness in walking, and general 

 symptoms of febrile action. 



The malady was not confined (o cattle, but sheep, 

 pigs, and domestic poultry of the gallinaceous tribe were 

 likewii^e its subjects. By common consent it was desig- 

 nated the cattle epidemic, but has since been scientifically 

 known as Eczema epizootica, or popularly as " the 

 mouth and foot disease." It has continued from that 

 time to the present, not proving on the whole a de- 

 structive disease to life, but at irregular intervals assum- 

 ing a severer form than ordinary, more particularly in 

 1845 and 1852, and leading on these occasions to a great 

 deterioration in the value of the animals affected. 



Shortly after the appearance of the eczema, namely, in 

 1841, pleuro-pneumonia broke out among the cattle, and 

 it, too, has remained down to the present^time. It is 

 worthy of a passing remark that neither of these were 

 imported diseases. It was not until several months after 

 pleuro-pneumonia had established itself in the country 

 that an alteration took place in the tariff by which live 

 stock came in free of duty, and up to that time the high 

 rate of duty prevented any importations of foreign cattle 

 or sheep being made. This fact in itself is sufficient to 

 prove that the malady was not imported by foreign 

 cattle ; besides which, the parts of the country where it 

 was first observed could not possibly have had any im- 

 diate or direct connection with the ports. Pleuro- 

 pneumonia had no sooner gained a footing, than, follow- 

 ing the laws of all epizootics, it quickly spread over a 

 great breadth of country, and continued to devastate our 

 herds with almost unmigitated severity for the first few 

 years. It has since taken on rather an enzootic form, 

 and has prevailed mostly in such localities and places 

 where secondary causes are in full operation to predis- 

 pose animals to its influence; hence its continuance in 

 the ill-ventilated, over-crowded, and badly-drained 

 cow-sheds of the metropolis and other large towns, and 

 on the "cold retentive soils" and undrained farms 

 in the country, especially such as lie in exposed situa- 

 tions. 



Besides the special cause, or rather, perhaps, special 

 combination of causes, ??hich give origin to the enzootic 

 form of pleuro-pneumonia, its appearance in a cattle- 

 shed, or on a farm, is frequently traceable to the in- 

 troduction of newly-purchased animals, who bring the 

 disease in a latent state with them ; and which, on its 

 declaring itself, extends by ordinary infection to those 

 with whom they are located. Infection we hold to be one 

 of the chief causes of the continuance of pleuro-pneumonia 

 for so many years among us, as every diseased animal, by 

 virtue of the exhalations given off from its body, becomes 

 a focus of the malady, and a new source, whence the 

 poison, so to speak, is disseminated. The same fatality 

 which marks the progress of pleuro-pneumonia here, 

 attends it everywhere ; and throughout the continent it 

 is looked upon as an incurable disease, and dealt with 

 accordingly. Its great fatality arises from the circum- 

 stance that the nature of the chanties which take place 

 in the lungs is such as immediately to arrest their func- 

 tion as perfect aerifying organs, and soon to destroy, to 



a greater or less extent, the integrity of their structure. 

 The true pathology of pleuro-pneumonia is amimg the 

 quc.'ifiones vexatcB of science. In this report we have 

 not immediately to do with this question, still we may 

 observe that the most eminent professors of veterinary 

 medicine throughout Europe hesitate to declare, as some 

 medical men have done, and others also who have pro- 

 bably given but little thought to the subject, that 

 the changes wrought in the lungs are altogether due to 

 inflammatory action. 



In Belgium, in France, and in many parts of Italy, 

 the disease is designated ea;M(?aiftue pleuro-pneumonia — 

 a name which, while it marks a peculiarity in the disease, 

 implies, at the same time, that it differs somewhat in its 

 results from ordinary inflammation of the lungs and 

 their investing membrane, and which is correctly 

 called pleuro-pneumonia. We have no hesitation in 

 giving it as our opinion that the changes which are 

 originally effected in the lung tissue can take place 

 otherwist than by inflammatory action. We observe, as 

 the analogue of these changes, that in the advancement 

 of the disease, the interstitial areolar tissue, contiguous 

 to the more affected parts of the organs, becomes pri- 

 marily choked with serous effusion, which, by its pres- 

 sure upon the air cells and their rete of capillary 

 vessels, obstructs both the admission of air to the cells, 

 and the circulation of the blood through the vessels, and 

 thus leads to an imperfect decarbonisation of the blood, 

 as well as to far more important changes in the fluid 

 itself. Not only, in many diseases, are serous exuda- 

 tions entirely independent of inflammation, but fibri- 

 nous are equally so in the opinion of some of the 

 ablest pathologists of the present day. These deposits 

 may result from the vital force of the vessels being im- 

 paired by some depressive influence acting on the 

 nervous system, either generally or locally, as well as by 

 some unexplained or ill-understood alteration taking 

 place in the composition of the blood, by the existence 

 within it of morbific animal or vegetable products. The 

 fibrinous depositions in pleuro-pneumonia succeeds the 

 seroua, and are probably due to either an alteration 

 in the relative proportion of the component parts 

 of the blood, or an interference with its vitality, 

 brought about by the presence of the special materies 

 morbi of the disease, and which may have entered it in 

 the ordinary manner of infection. The abnormal action 

 which commenced in the parenchyma of the lungs ex- 

 tends towards their investing membrane, when, from the 

 nature of this tissue, as well as from the longer existence 

 of the action itself, an augmented fibrinous exuda- 

 tion takes place upon their surface. We regard, 

 therefore, the implication of the pleura as a character- 

 istic of an advanced stage of the malady, and also of a 

 still further deterioration of the blood. 



Since the appearance of pleuro-pneumonia no other 

 disease of a fatal character and possessing contagious or 

 epizootic properties has shown itself among our cattle ; 

 but in 1847 a very fatal malady broke out among the 

 sheep. This affection was recognised as the small-pox 

 of sheep ; and it was ascertained in the most conclusive 

 manner that it had been introduced here by some 

 " Merinos," which had been shipped at Tonning, on 

 the coast of Denmark, and also by some others 

 shipped at about the same time at Hamburgh for the 

 supply of the English market, and in whose sys- 

 tems the disease was incubated. From the free 

 commingling of these foreign sheep with our own 

 breeds in the London Cattle Market, and also from 

 the circumstance that many of them were purchased by 

 farmers as " stock sheep," the small-pox was soon 

 spread over a great tract of country, proving destruc- 

 tive to life in numerous instances to the extent of even 

 90 per cent. 



