534 PEOTOZOAL DISEASES. 



swelling and inflammation of the vulva and. vagina may extend t<'j 

 the udder and lower part of the belly. 



Second period, or period of wheals. — Between the fortieth and 

 sixtieth day the patient, especially if it be a stallion, generally 

 gets an attack of nettle-rash which takes the form of sharply- 

 defined, round, flat eminences, which may be raised about f of an 

 inch above the surface of the skin, and which may vary in size 

 from that of a shilling to that of the palm of the hand. These 

 eminences may appear or disappear very rapidly, and may change 

 their position from time to time. The hair over them stands 

 on end, and the skin which covers them is unusually thick. As 

 a rule, they persist for several weeks, during which time they 

 become moderately hard, and then slowly disappear. Their 

 favourite sites are the croup, neck, shoulders, chest, and belly. 

 Cagny and Gobert regard these wheals as characteristic of dourine. 

 Occasionally, no wheals appear, and flat patches of skin on which 

 the hair stands on end, take their place. Sometimes there is 

 intense itchiness (pruritis) of the skin, which is manifested by the 

 animal rubbing and biting itself, so that extensive sores on the 

 skin are produced; The mucous membranes of both stallion and 

 mare often sho.v white spots, which correspond to the positions 

 previously occupied by ulcers that have healed. The lymphatic 

 glands are often swollen all over the body. The animal gets lame 

 behind, on account of inflammation of the joints and tendons. At 

 this period, affected stallions are unable to cover, and affected 

 mares miscarry, if they are in foal. In the acute form, sudden 

 paralysis sets in after the primary swellings, and death ensues in 

 a few days. 



Third period. — In both stallion and mare, the general symp- 

 toms may develop only after several weeks or even months, and 

 may defer their appearance until the local symptoms have passed 

 off. The first general symptoms are those of depression and weak- 

 ness, and inability to control the movements of the limbs, especially 

 those of the hind ones. Emaciation and symptoms of paralysis 

 become more and more pronounced until the animal is no longer 

 able to get up off the ground and dies from exhaustion, blood 

 poisoning, or inflammation of the lungs. 



POST-MORTEM APPEARANCES.— We find in various parts, 

 infiltration of serous fluid and softening, especially in the testicles 

 and spinal canal. 



DISTINGUISHING DIAGNOSIS.— The only disease for which 

 dourine may be easily mistaken, is an inflammation of the skin 

 and mucous membranes which is known to veterinary surgeons as 



