842 Nettlerash. 



ally so miicli serum collects between the corium and the Mai- 

 pigiiian layer that vesicles form (U. vesiculosa et bullosa, Pom- 

 phosis) wliich later on burst and heal with scab formation. 

 It is also exceptional (e. g., in purpura) that urticaria attacks 

 the mucous membranes of the eyes, nose, vagina or rectum ; the 

 elevations in the nose may temporarily hinder respiration. Now 

 and then edematous swellings also arise at the same time. In 

 general the disease is quite benign and assumes greater impor- 

 tance only if it often recurs in an animal (U. chronica, IJrti- 

 catio). 



In cows nettlerash develops occasionally owing to food of bad 

 quality or after a sudden change of food. It is then usually very ex- 

 tensive, affecting the body, lips, wings of the nostrils and eyelids as 

 well as the neighboring mucous membranes of the natural openings of 



Fig. 120. Xettlerash. 



the body and the larynx. In the neighborhood of the perineum knotty 

 doughy swellings arise, which may hinder defecation more or less. 

 While these swellings develop, the animals may be restless and constantly 

 shift their weight from one foot to another. In conse(iuence of the 

 laryngeal involvement the animals may die of suffocation, while otherwise 

 the attack rarely lasts more than 5 or 6 hours (Lucet, Tapken, Albrecht, 

 Schleg, Wyssmann). Concerning the symptomatology of the mild form 

 of erysipelas in swine see Vol. I. 



In urticaria caused by stinging nettles one notices severe itching, and as a 

 result restlessness or licking and rubbing of the affected parts of the body. In 

 dogs severe rhinitis, stomatitis and pharyngitis may develop. Several dogs died 

 from thes-e affections. Holterl)ach believes that the cause of the fatal termination 

 is found in the absorption of toxic substances, similar to snake venom, from the 

 nettle hairs, and not in local inilanunatory procesf-es as is assumed by Rohr. 



