DISEASES OF THE RESPIRATORY PASSAGES 173 



a gelatinous, colorless substance. (For location of this sinus 

 see Fig. 2, No. 31.) 



These swellings may disappear in a few days or weeks or 

 may remain for several months. In the latter instance th(? 

 swelling may contain a cheesy material of foul odor, and in 

 some cases cause death. 



Treatment. — Open the swollen part and allow the morbid 

 collection to drain out. In addition, use the same treatment 

 as outlined under roup. 



CHICKENPOX 



This disease affects chickens, turkeys, pigeons and geese. 



Cause. — Some investigations indicate that it is due to an 

 ultra-microscopic virus (germ) and that the same germ is also 

 the cause of avian diphtheria, or roup. The two conditions 

 are, in many cases, found associated. (An ultra-microscopic 

 germ is one that will pass through the pores of porcelain 

 filters and cannot be seen with the microscope or grown in 

 visible quantities upon culture media.) 



In structure the nodules resemble an epithelioma. Con- 

 tagious chiekenpox can be transmitted from an emulsion of 

 the material of a pox nodule, by inoculating the face and 

 comb of a healthy bird. 



It has been proved that a maceration of the scrapings from 

 the pox in physiological salt solution and injected subcutane- 

 ously, will render immunity against further inoculation of 

 the disease by scarification and introduction of the virus in 

 the face and comb. 



One investigator has claimed that chiekenpox is due to a 

 protozoon (an animal parasite microscopic in size), but other 

 investigators have failed to find this organism. 



Symptoms. — The disease appears as small nodules, varying 

 nin-point size up to the size of a pea, or even much larger. 

 It mav be accompanied by roup ; in fact, we have studied 

 both diseases in the same flock, an occurrence w^hich is not 

 uncommon. The question naturally arises. Are both due to 

 filtrable viruses, and are both present in the same outbreak, 

 or are both due to the same cause? Fig. 65 illustrates a 

 case of this disease. The nodules or pimples are at first 

 smooth and firm. They may be red and have a hyperemic 

 zone. Later the surface may ulcerate and spread until a sore 

 a half-inch in diameter is observed. With proper treatment 

 these usually heal. The general tendency of chiekenpox is to 

 run a mild course. 



]\rosquito bites form red pimples, Avhich must be differenti- 

 ated from pox nodules. 



