THE SPONTANEOUS DISEASES OF ANIMALS 159 



Breeding of small animals. Rabbits, guinea-pigs, white rats, and white 

 mice can easily be bred in the laboratory, and because of their inclination to 

 kill the newly-born animals, it is as well to separate the males from pregnant 

 females. This precaution is absolutely necessary in the case of rabbits and 

 mice, but is less important with white rats and perhaps unnecessary for 

 guinea-pigs. 



B. Large animals. 



[With regard to the housing of large animals such as cattle, sheep, pigs, 

 etc., it is unnecessary to say more than that the houses or pens should be 

 designed on lines similar to those in which they are ordinarily stabled. The 

 structures should be light and well ventilated the floors concreted or cemented 

 and well drained. The walls should be constructed of material which readily 

 lends itself to efficient cleansing with antiseptics. If the stalls be of wood 

 they should be limewashed out with lime mixed with 2 per cent, lysol before 

 a new animal is introduced.] 



SECTION III. THE SPONTANEOUS DISEASES OF EXPERIMENTAL 



ANIMALS. 



Laboratory animals are liable to certain infectious diseases with the more 

 common of which it is important to be familiar because they are sometimes 

 responsible for a heavy mortality among experimental animals. 



Abscess. Large abscesses containing thick, fetid pus not infrequently 

 occur in rabbits in various parts of the body. They lead to a cachectic 

 condition, and ultimately end in death. The disease is contagious. 



The infected animal must be isolated and the cage carefully disinfected. 

 Treatment consists in opening the abscess, evacuating the pus and gently 

 curetting the wall, subsequently washing it out at frequent intervals, and 

 dressing it w r ith antiseptic dressings. 



Acari. An acarus sometimes develops in the external auditory meatus 

 of the rabbit ; it soon invades the middle ear, and causes serious nerve troubles, 

 such as gyratory movements, convulsions and epileptiform seizures which 

 lead to the death of the animal. The disease may be recognized by the 

 yellow crusts which are seen in the rabbit's ear and which, if examined 

 microscopically (Oc. 2, obj. A. Zeiss), are found to be composed of amor- 

 phous debris and numerous acari. The disease is highly contagious but 

 yields to treatment if taken in hand in the early stages. 



Immediately a case is found in the animal house, the infected individual 

 should be killed, unless the experiment be of special interest, in which event 

 it must be isolated and treated. Treatment consists in washing off the 

 crusts formed on the auditory meatus daily with a sponge made by twisting 

 a little piece of wool round a small rod, and dropping a few drops of a O5 per 

 cent, solution of polysulphide of potassium (liver of sulphur) into the ear. 

 The infected animal's cage, and those near it, should be disinfected and the 

 ears of all the other rabbits in the house frequently examined. 



Septicaemias. Rabbits and guinea-pigs are subject to epizootic diseases 

 which, only too often, decimate the population of the animal house in a 

 few days. 



As a rule, rabbits and guinea-pigs are affected at the same time. The 

 animals curl themselves up, their coats are rough, and they suffer from a 

 running from the nose and diarrhoea. Death soon follows these symptoms. 

 Post mortem, lesions of broncho-pneumonia are seen. The disease appears 

 to be due to a small bacillus morphologically similar to Pfeiffer's [influenza] 

 bacillus. 



