338 EXPERIMENTAL INOCULATION OF ANIMALS 



attacks of Psoric Acari, and the infection is readily 

 transmitted to rabbits in neighbouring cages and also 

 to guinea pigs, but not to rats and mice. One species 

 (Sarcoptes minor var. cunicuU) gives rise to the ordi- 

 nary mange. The infection first shows itself as thick 

 yellowish scales and crusts around the nose, mouth 

 and eyes, spreads to the bases and outer surfaces of 

 the ears (never to the inside of the concha), to the 

 fore and hind legs and into the groins and around 

 the genitals. The acari can be readily demonstrated 

 microscopically in scrapings of the skin, treated with 

 liquor potassae. Another form of scabies (due to 

 Psoroptes communis cuniculi) commences at the bottom 

 of the concha, which is filled with whitish-yellow masses 

 consisting of dried crusts, scales, faeces, and dead acari. 

 The base of the ear is hard and swollen, and lifting the 

 animal by the ears as is usually done gives rise to 

 considerable pain; indeed this symptom may be the 

 one which first attracts attention to an infection, which 

 causes progressive wasting and terminates in death. 

 A mixed infection sarcoptic plus psorotic acariasis 

 is sometimes seen. 



If it is decided to try and save animals suffering from 

 infection by these parasites, they must be segregated, 

 the scabs carefully cleaned from the infected areas and 

 the denuded surfaces washed with 5 per cent, solution 

 of Potassium persulphate (a few drops being allowed 

 to run into the concha) , or with a preparation contain- 

 ing equal parts of soft paraffin and vaseline with a few 

 drops of lysol. This treatment should be repeated 

 daily until the acarus is destroyed and the animal 

 has regained its normal condition. The cages should 

 be disinfected and all neighbouring animals carefully 

 examined, and any which show signs of infection 

 should be treated in a similar manner. Favus also 

 attacks the rabbit, and the typical spots are first noted 

 around the base of the ear. 



