638 
HEREDITARY DISEASES OF HORSES. 
in healthy subjects by extraneous causes, but producible by 
inoculation, occurring in animals of certain constitution, and 
owing its development, in great part, to hereditary predis- 
position. There are three subdivisions of specific inflam- 
mation — the rheumatic, occurring in the various sorts of 
rheumatism, and nearly allied to it, the gouty, which, how- 
ever, is peculiar to man; the scrofulous or strumous, oc- 
curring in pulmonary consumption ; and the syphilitic, 
also peculiar to man, but occurring in the horse in the form 
of glanders, In the horse the two latter diatheses are more 
intimately connected than in man, and often concur. 
Rheumatism is neither so common, nor are its symptoms so 
well marked, in horses as in cattle. When, however, it does 
occur in the horse, it manifests the same well-known appear- 
ances which characterise it in all animals. It affects the 
fibrous tissues of joints, the coverings of muscles, tendons, 
and ligaments, and the valves about the heart and larger 
vessels, and manifests a peculiar tendency to shift from one 
part of the body to another, often affecting in succession all 
the larger joints ; at one time chiefly located in the neck, and 
at another in the back and loins, while in many of its more 
acute attacks it appears to involve almost every portion of 
fibrous and fibro-serous tissue throughout the body. In all 
its varied types it exhibits a full, strong, hard, and unyielding 
pulse, caused by the inflammation involving the serous and 
fibro-serous tissues of the heart and circulating vessels. 
During its existence various excrementitious matters accu- 
mulate in the blood, and its fibrinous constituents are found 
to exceed their normal proportions, as indicated by the pro- 
duction of the buffy coat on the blood. In severe or badly- 
treated cases the inflammation is very apt to be transferred 
from the joints and muscles to the heart and its investing 
membrane, and it is the danger of this change in the seat of 
the disease that renders rheumatism so formidable, and often 
so fatal. It always leaves the parts affected so altered as to 
be extremely predisposed to subsequent attacks ; and it is 
more than probable that this altered condition is reproduced 
in the progeny of rheumatic subjects, and constitutes in 
them the inherent tendency to the disease. 
Horses sometimes suffer from rheumatic inflammation in 
the fibrous sheathing envelopes of the muscles of the neck, 
constituting what is popularly known as the chords . When 
thus affected the animal is very stiff, remains as much as 
possible in one position, and is unwilling to bend his neck 
either to one side or another, or to elevate or depress his 
head. There is always more or less fever, with a strong full 
