70 A. E. Hamerton—Diseases of Aviary Birds


In the aviaries of the London Zoological Gardens, where my experience

has been gained, the respiratory diseases above named are by far the

most destructive, and affect mainly small species. The lungs of birds

are so closely fixed to the parietes that there is little room for expansion ;

any inflammatory condition is, therefore, often quickly fatal. Congestion

of the lungs may be defined as a condition of active hypersemia of the

organs, that is revealed by areas of deep red, almost purple, discoloration,

which, on compression between finger and thumb, exude frothy fluid.

The portion of lung affected contains some air, and does not sink in

water. The whole lung is cedematous and boggy from oozing of fluid

into the air spaces. On microscopic examination the air spaces of the

lung are patent, but most of them contain some coagulum, leucocytes,

and red blood cells. An extension of this process results in plugging of

the tertiary bronchi and their diverticula with exudate, and consolida¬

tion of groups of lobules, which form a patch of consolidated lung that

sinks in water, a condition of bronchopneumonia. Sometimes the whole

of one lung and a large part of the other may be found firmly consolidated

and hepatized, and sinks like a stone in water ; a condition resembling

acute lobar pneumonia of mammals. These conditions come on

suddenly : the bird may appear well in the evening, and is found dead

at the bottom of its cage next morning. The disease is not usually

diagnosed before death, and I know of no treatment. Cold and fog,

or a dusty, stuffy atmosphere appear to be predisposing causes.


(2) Diseases of the Alimentary System. — (a) Catarrh of intestine ;

(6) enteritis and gastritis ; (c) faecal impaction and intestinal obstruction.

Catarrh of the intestines and enteritis are the next most common causes

of death in cage birds. In most cases no specific bacterial or parasitic

cause can be determined, and the distinction between catarrhal inflam¬

mation and enteritis is somewhat arbitrary, and depends mainly upon

the intensity of the lesions as seen by the naked eye, or as may be

indicated before death by the character of the diarrhoea from which

the birds suffer. In catarrh of the intestines there is swelling and

oedema of the intestinal mucosa, and in chronic cases the mucosa may

have atrophied and disappeared from portions of the bowel. The lumen

of the gut often contains undigested seeds or sand, and there is always

great excess of mucous exudate. In enteritis the gut is more severely



