970 Gout. 



these foci a secondary inflammatory reaction occurs with emigration of white 

 blood cells. Almagia found that cartilage tissue of itself decidedly attracts uric 

 acid. 



In disturbances of the renal function from other causes, or 

 in a mechanical impediment to the flow of urine, the storage and 

 deposition of urates occurs even without a previous increase in 

 the formation of uric acid. 



The source of the uric acid are the albumins of the body, both those ingested 

 with the food and those that have disintegrated; in mammalians the nuelein bases 

 are here especially concerned, in birds all albuminous substances. The uric acid 

 content of the blood is therefore probably increased for the reason that the animal 

 ingests an excess of albuminous substances. The fact that among domestic animals 

 birds which even normally eliminate very much uric acid are affected almost 

 exclusively, indicates tJie predisposing influence of the presence of uric acid in 

 large amounts. Nothing positive is known about the cause for the elimination 

 of the urates of sodium and calcium which are in solution in the blood. The fact 

 that the serous membranes and often the joints of the extremities are usually 

 affected, might in part stand in relation to their being constantly subjected to 

 mechanical irritation, and to the very slow blood circulation in the joints as well 

 as in the serous cavities, although it might also be the consequence of some metabolic 

 disturbance of these parts of the body. 



Anatomical Changes. In visceral gout, which is by far the 

 more frequent form, the serous membranes of the thorax and the 

 abdominal cavities, especially the pleurae or the peritoneum, the 

 membranes of the air sacs, the pericardium, also the surface of 

 the heart, and the liver are covered more or less densely with 

 masses that are dust-like or chalky, and mortar-like ; the kidneys 

 are dotted white and the ureters are sometimes filled with white 

 plugs. 



Articular gout, which is much less frequent, atfects prefer- 

 ably the articulations of the feet, less often also those of the 

 wings, leading to swelling of the involved joints, in and around 

 which white chalky swellings or deposits are seen which are 

 like peas to cherries in size. Similar foci are also found in the 

 adjoining bone tissue and bone marrow, in the articular liga- 

 ments and tendons, less often in the cartilages of the larynx, 

 in the vessel walls or under the skin. 



In the chalky masses great numbers of crystals which consist of sodium 



urate are seen under the microscope, especially after the addition of some acid. 



These crystals may sometimes be demonstrated also in organs which present no 

 microscopic changes. 



Symptoms. In articular gout the joints that are affected 

 most frequently are the metatarsal, tarsal and phalangeal 

 joints, and on the wings the elbow joints. There is at first 

 aching, the affected animals moving about only unwillingly and 

 going lame; they remain in one place or stand on one foot in 

 order to ease the pain. If the wings are affected these are kept 

 as quiet as possible, and when the animals are disturbed they 

 flap at most a few times with their wings. At the same time the 

 joints swell (Fig. 171), and while the swellings which are soft 

 and sensitive are at first not sharply circumscribed, later on 

 isolated nodes (tophi s. Noduli arthritici) are more and more 



