DEPARTMENT OF SURGERY. 
617 
that have been improperly or carelessly bred ; they are usually 
marked by a narrow pelvis, sharp croup and a depressed ex¬ 
ternal angle of the ilium. Animals of this conformation are 
very unfavorable subjects for breeding purposes, because dys- 
tokia usually accompanies parturition. 
(/;) Anomalous Deformities of the pelvis are due to an ab¬ 
normal development or the non-development of the bones that 
surround the pelvis. (Fig. 27.) This condition is more common 
in dogs and pigs than in large animals, and the exciting cause of 
this deformity is usually rachitis, osteomalacia, osteomyelitis, os¬ 
titis or osteoporosis. Ostempyesis may cause a condition that will 
interfere with parturition, especially when the inflammation ex¬ 
tends into the soft structures surrounding the pelvic opening. 
Animals suffering from osteomalacia or rachitis may be affected 
with an abnormal curvature of the bones fsteoclampsia) , espe¬ 
cially when the sacrum is involved ; when it is depressed at its 
anterior extremity (lordosis) the condition is not so serious as 
when the posterior extremity is depressed. Any disease of the 
bones of the pelvis may alter their relation ; arrest their devel¬ 
opment ; or change their form to such an extent that it will so 
lessen the size of the pelvic opening that parturition is im¬ 
possible. 
( c ) Accidental Deformities. —Animals that have had frac¬ 
tures of the bones of the pelvis are generally unfit for breeding 
purposes, but all deformities resulting from such accidents do 
not make parturition impossible; a fracture of the external 
angle of the ilium may change the relation of the bones suf¬ 
ficiently to cause dystokia and yet not require Caesarian section ; 
a fracture of the shaft (Fig. 24) is often more serious; and 
those of the pubis and ischium which reduce the size of the 
pelvic inlet are the most serious obstacles in parturition. 
(d) Lordosis and Kyphosis. —Saddle-backed animals in which 
the deformity involves the sacrum are sometimes unfit for breed¬ 
ing purposes, especially when the sacrum is greatly depressed 
and reduces the sacro-pubic diameter of the pelvic outlet; this, 
however, is not a very common condition and one that is easily 
determined by a rectal or vaginal examination. 
Arched-backed animals ( kyphosis ) that have an abnormal 
position of the sacrum may also reduce the size of the pelvic 
opening and cause maternal dystokia, and in such cases the pos- 
terioi extremity is depressed and reduces the lumen of the 
"anal; this conformation is always indicated by the position of 
the croup. Both of the last mentioned conditions when com- 
