1 82 Diseases of the Circulntoyy System. 



palliative in the mildest forms of the disorder, the most 

 useful agents being mild doses of calomel given altern- 

 ately with iodide of potassium, the animal needing perfect 

 quiet. 



The Pericardium or Heart-Bag surrounds the 

 heart and provides the fluid which moistens the surface 

 during action. It usually suffers from disease in company 

 with the pleura, or lining membrane of the chest, from 

 which it derives a layer, internally, and externally. An 

 abnormal accumulation of thin reddish-looking fluid 

 (serum) is the common result, producing inconvenience 

 in proportion to the quantity, such as interference by 

 pressure with the functions of the heart, as indicated by 

 feeble pulse, obscuration of the heart sounds, tendency to 

 fainting, anaemia, local dropsies, and eventually death. 

 The disease is, however, rare in the dog, but as a result 

 of injury is most common, bruising, puncture, or rupture 

 from violent causes being the common forms. 



Invasion by Parasites. — Canine HcEmatozoa is not 

 an unfrequent event in dogs of the British Islands. The 

 records of other countries where malarious influences 

 abound furnish more frequent evidences. Two worms 

 have been recognised : Filaria inimitis or Ca?iis co7'dis, 

 and Filaria sanguinolenta^ the former being generally 

 understood to be the embryonic form of the latter. 



Filaria imviitis is said to be probably present in at 

 least two-thirds of the dogs in the Chinese Empire, as 

 estimated by microscopical examination of the blood. 

 Singularly enough the embryos, though so numerous, do 

 not occasion any appreciable inconvenience to the host, 

 but move about briskly in a serpentine form within the 

 blood-vessels. When fully developed as parent worms 

 they take up their position within the heart, in some 

 instances bundles or clusters of them being found, and 

 individuals varying from one or two inches to six or seven 

 in length. The general results of the presence of these 

 worms is their interference witli the valves, between 

 which they may be forced by such bodily efforts as induce 

 an inordinate flow of blood. The effects are seen some- 

 what later, as at the end of one or two days the animal 



