GOUT— PODAGRA— ARTHRITIS URICA 355 



(d) Fungi on grains and grasses have been found to be the 

 cause in fowls, (e) Diseases of the kidneys and ureters, in 

 which there is an interference in the elimination of the uric 

 acid compounds, have proved to be important factors in its 

 production. (/) Lack of exercise, confinement of the animals 

 or birds, together with the feeding of highly nitrogenous 

 foods are no doubt the cause of quite a number of cases of 

 gout. Older dogs, and the larger breeds of chickens are most 

 commonly affected. 



Pathogenesis.— The development of gout is probably due 

 to an increase in the production of uric acid, and an inhibition 

 in the elimination of urates, which allows its accumulation 

 in the blood, and in certain cases to be deposited in connec- 

 tion with the tissues. Other theories have been advanced 

 for the development of the disease and have supporters. It 

 is possible also to have the disease develop in cases when 

 there is no increase in the formation of uric acid, but other 

 diseases being present to interfere with the elimination of the 

 uric acid compounds. 



Pathology.— The characteristic lesions found in articular 

 gout are enlargement of the joints of the toes, or wings, and 

 a chalky-like deposit found in the joint proper or in the 

 adjacent tissue. Examination of the bone-marrow, and the 

 ligaments and tendons around the joint will often reveal 

 the same condition. Several joints may be found affected. 

 In visceral gout, the serous membranes of the cavities, the 

 pericardium, air sacs,. and the liver are covered with small 

 nodules containing the same white chalky material. The 

 kidneys contain small white foci, and the ureters are often 

 found filled with a white, pasty mass. Examination of this 

 material under the microscope will reveal the crystals of 

 sodium biurate. 



Symptoms. —The first indications of the condition are 

 usually enlargement of one or more joints, difficulty in 

 walking about, and lameness. The joints most commonly 

 enlarged are the wing joints (birds), and the metatarsal and 

 phalangeal joints in dogs and birds. The animal will stand 

 quietly and refuse to move, but when forced to do so shows 

 considerable pain and lameness. Fowls often assume a 



