Inflammatory or other diseases of the above glands are most frequent in entire animals. As a group they are uncommon, and are still ill-recognised and ill-described, being seldom identified except on post-mortem examination.
Fig. 241.—View of Cowper’s gland and of its compressing muscles. (After Cocu.) 1, Cowper’s gland; 2, compressing muscle; 3, accelerator urinæ muscle turned back to expose the gland; 4, sphincter of the urethra.
The cause of inflammation of the prostate, of the vesiculæ seminales, and of Cowper’s glands is probably an ascending infection of the urethra and neighbouring channels, a fact which explains the comparative rarity of such conditions in castrated animals.
The pathogenic germs penetrate from the urethra into the excretory ducts of the glands, obtain a lodgment in the culs-de-sac of the glands themselves, and thus produce simple or suppurative inflammation.
The symptoms may easily be mistaken, to some extent at least, for those of acute cystitis or cystitis due to the presence of a calculus, and it is only by rectal examination that the diagnosis can be made.
The first symptom is defective micturition, which occurs in jets, is intermittent and painful, and sometimes causes slight groaning. It is accompanied by vesical colic, spasmodic lifting of the hind legs, and more or less unsuccessful expulsive efforts.
These symptoms are of reflex or mechanical origin, and are due either to direct compression of the urethra by an hypertrophied and inflamed gland, or to spasm of the vesical sphincter. The urine passed, unlike that in cases of acute cystitis or in cystitis due to calculus, is of a normal character. Rectal examination usually reveals distention of the bladder, and hypertrophy and exceptional sensitiveness at certain points.
If the painful and hypertrophied area is over the neck of the bladder, this indicates that the lobes of the prostate are affected. If, however, the affected parts are situated on the sides of the neck and along the posterior pointed end of the bladder (Fig. 239), the vesiculæ seminales are affected; finally, if the painful points are directly above the ischial arch and below the sphincter ani, Cowper’s glands are the seat of disease (Fig. 240).
To diagnose these conditions requires very close and careful examination. They may easily be mistaken for acute cystitis, though the character of the urine should suggest doubts and lead to rectal examination.