306 DISEASES OF TRUE INFECTION 



A very important and constant symptom of tuberculosis is the grad- 

 ual emaciation of the affected animal, accompanied by exhaustion on 

 the slightest exertion, the hair is hard, dry and bristly, the eyes are 

 sunken, the face drawn and wrinkled, the visible mucous membranes 

 pale or yellowish, the mucous membranes are dry, the pulse small, 

 accelerated, and the heart throbs, the temperature is elevated from 

 time to time, the appetite is irregular but generally small, constipation 

 alternates with obstinate diarrhoea, and finally the animal becomes a 

 skeleton and dies in a state of collapse; at this stage the temperature is 

 apt to be subnormal. The average duration of the disease is from six to 

 eight months. 



Microscopical Demonstration of the Tubercle Bacilli. — The tubercular 

 matter is placed on a glass and allowed to dry in the air; it is then covered 

 with Ziehl's carbol fuchsin solution (1.0 fuchsin, 10.0 absolute alcohol, 5.0 

 carbolic acid, 95.0 distilled water) and heated over the flame for two 

 minutes. Then it is allowed to cool, then washed with distilled water 

 and then put in Gabbet's solution (2.0 methylene blue, 100.0 of 25 per cent, 

 solution of sulphuric acid) ; after lying in this for two minutes it is rinsed 

 with water and is ready for examination. The tubercle bacilli are 

 stained red, the other substances being blue; an oil immersion lens gives 

 the best results. Where the examination must be made as soon as pos- 

 sible, if the preparation is thoroughly dried, it gives almost as good 

 results (see Plates). 



Tuberculin Test. — The inoculation of Koch's tuberculin to deter- 

 mine whether a dog is affected with the disease may be tried, but as a 

 rule is unsatisfactory, the reaction is seldom very pronounced in char- 

 acter, and in the acute stages of the disease it may even give a subnormal 

 temperature; in several instances an animal gave a reaction, but careful 

 examination failed to give any evidences of tuberculosis. Recently the 

 ophthalmic test has come into popular favor in diagnosing tuberculosis 

 in the dog. The method is quite simple. It consists in dropping into 

 the conjunctival sac 1 or 2 drops of tuberculin, especially prepared for 

 this test. If the animal is suffering from tuberculosis, a reaction will be 

 manifest by the development of a conjunctivitis in from eight to twelve 

 hours. There will be excessive lachrymation, injection of the capil- 

 laries of the conjunctiva and even slight suppuration at the inner 

 canthus. In chronic cases the reaction may be overlooked unless the 

 animal is kept under close observation, inasmuch as the acute symp- 

 toms come on and pass off very rapidly. In cases of recent infection 

 the reaction may last for at least twenty-four hours. 



Therapeutic Treatment. — When you have once established the fact 

 that the aninuil is aff(H-t(Ml with the disease, it is the duty of the veterin- 

 arian to warn the owner of the tubercular or suspected dog, of the danger 



