OF VETERINARY MEDICINE. 195 



It is directly connected with a plethora in the blood of nitro- 

 genized constituents with extreme nervous and muscular dis- 

 order. The poisoning is seemingly not present when the animal 

 is taken from the stable, yet some cases develop a fatal attack 

 while being harnessed and hooked up, before leaving the wagon 

 floor. It would seem as if the aspiratory power of the chest 

 under the sudden exertion of the over-fed animal speedily drew 

 from the liver and abdominal veins (portal system; the accumu- 

 lated store of nitrogenous matter in an imperfectly oxidized or 

 elaborated condition, and as if the blood surcharged with these 

 materials was unable to maintain the healthy functions of the 

 nerves and muscles. The pathology, however, is little under- 

 stood. We must content ourselves for the present with theories. 



DISEASES OF THE CIRCULATORY SYSTEM. 



There are three means of determining the diseases of the 

 heart and blood vessels ; — inspection, palpation and auscultation. 

 By inspection you detect any change in the position of the heart 

 and the force of the heart beat can be determined. The character 

 and rhythm of the pulse you get by palpation. Auscultation 

 reveals the sounds of the heart. The heart has a normal sound 

 and any deviation from this can be detected by auscultation. 



The various phenomena of the heart diseases are (1) Lan- 

 guor; (2) Impeded respiration during the exercise, often 

 amounting to distressing dyspnoea; and (3) Condition of the 

 visible mucous membranes. 



The diseases of the heart are divided into two classes, — func- 

 tional and organic. The functional are acute and are three in 

 number, palpitation (thumping), cyanosis (blue disease) and 

 syncope (faiting fit). Spasm of the diaphragm, sometimes 

 spoken of as thumps, is often mistaken for palpitation. The 

 organic diseases of the heart are chronic or structural diseases. 



PALPITATION AND SINGULTUS. 



Palpitation (thumps) is a tumultuous action of the heart. It 

 IS a disturbance of the rhythmic action of the heart and is some- 



