6 VETERINARY STUDIES 



actinomycosis, caused by a fungus and characterized by enlarge- 

 ment and destruction of the bones of the upper or lower jaw 

 especially. Big head (osteoporosis), which affects the bones of 

 the horse, usually including the head bones. The bones become 

 very light in weight and very fragile. 



Common disorders of the teeth are: variations from normal 

 number more or less ; improper fit, parrot mouth where the 

 upper incisors overhang the lower ; undue relative width of the 

 upper jaw, leading to uneven wear, ragged edges, and injury 

 to cheeks or tongue; caries (decay) ; and toothache with abscess 

 at the root. 



