958 
ANIMAL DISEASES 
Figure 13. — Intra-alveolar verminous pneumonia in a 
sheep. Photomicrograph of a portion of a granuloma- 
tous nodule caused by adults, larvae, and ova of 
MuUerius capUlaris. The arrow indicates a section of 
an adult in a bronchiole. HE x 125. 
for about 3 % of deaths of adult sheep although 
the prevalence may be as high as 10% in indi- 
vidual flocks. 
SUMMARY 
Each species of experimental animal has its 
own complement of spontaneous diseases. The 
majorit}^ of the respiratory diseases described, 
however, are infectious diseases that could be 
prevented or avoided through the use of tech- 
niques alreadj' established for germfree-deriva- 
tion and subsequent maintenance under specific 
pathogen-free conditions. 
REFERENCES 
1. Catcott, E. J., Ed. Canine medicine. Amer. Vet. 
Publ., Inc., Wheaton, HI., 1968. 
FiGUBE 14. — Lateral surface of the o%nne lung with nod- 
ular verminous pneumonia from which the photo- 
micrograph in Figure 13 was taken. 
Figure 15. — Nodules of caseous necrosis in the lung 
and mediastinal lymph nodes of a sheep. The lamel- 
lated appearance of the lesions is characteristic of ca- 
seous lymphadenitis caused by Corynebacterium 
ovis. 
