Congenital Infections of Calves 665 



When the immediate cause of death has been pneumonia, 

 the principal lesions are naturally found in the lungs. In 

 most cases only the anterior lobes are involved, but some- 

 times even the diaphragmatic lobe is largely solidified. The 

 pneumonic areas are whitish or grayish-white, mottled, and 

 feel much like the normal pancreas. Pleuritis is seldom 

 seen. Microscopically the affected area is filled with enor- 

 mous numbers of polymorphonuclear leucocytes, which give 

 to the lung its grayish, mottled appearance. The condition 

 is one of severe purulent broncho-pneumonia. In the milder 

 cases, associated with hacking cough, there are few to many 

 small circumscribed pneumonic areas, from the size of a 

 pinhead to that of a pea. The synovial membranes of the 

 femoro-tibio-patellar, tarsal and carpal joints may be in- 

 flamed. The pyemic abscesses usually have weak, atonic 

 walls. The predominant organism encountered is of the 

 colon group and offers nothing remarkable in cultures or by 

 staining. 



The period and avenues of invasion of the calf need 

 to be comprehended before intelligent control is possi- 

 ble. It has now been made perfectly clear that calf septi- 

 cemia, dysentery, arthritis, pneumonia, and the other phe- 

 nomena grading off imperceptibly from these to ideal health, 

 are due fundamentally to an intra-uterine infection not sep- 

 arable from the infections causing abortion and fetal diar- 

 rhea. This has already been discussed. It is equally clear 

 that post-natal infection occurs, chiefly through the mouth 

 in contaminated food. Probably some cases are due to navel 

 infection. 



The handling of calf sepsis, dysentery, pneumonia, arth- 

 ritis, and those types of infection shading off gradually to 

 health and not definitely perilous to life, has a dual meaning 

 in animal husbandry which should be fully comprehended. 

 There are two widely different conceptions of curing a dis- 

 ease, or some phenomenon called disease. The common 

 meaning of cure is the rescue of the patient from death. In 

 such infections as those now under consideration, especially 

 when dealing with purebred calves designed for breeding 



