556 GENERAL THERAPEUTIC MEASURES 



failure to obtain a reaction^ of course, is not positive evidence of health; 

 therefore a careful report is expected concerning the character of lesions 

 shown and the extent of infection disclosed at post-mortem examination 

 of animals which have failed to react to the tests. 



4. Detailed reports of each lot tested should be forwarded promptly 

 to the Tuberculosis Eradication Division, and when possible the intra- 

 dermal and subcutaneous methods should be checked against each other 

 and post-mortem records be made complete. Special reference should be 

 made to isolated, well-encapsulated lesions unaccompanied by evidence 

 of the presence of more active areas of infection. 



The Ophthalmic Test. 



The ophthalmic test at preseiit is not accepted by the bureau for 

 testing cattle for interstate shipment. It is believed, however, that it is 

 valuable as a check test. 



Directions for the Application of the Ophthalmic Test. 



1. Place two tuberculin tablets in the conjunctival sac beneath the 

 lower lid and by holding the hand gently over the eye for a short time 

 (about 45 or 50 seconds) make sure that the disks are not "winked out." 



2. As this is experimental work, observations should be taken at 

 approximately the third hour following the introduction of the tablets 

 and at frequent intervals up to at least 24 hours. If the left eye is 

 always selected for treatment, it follows, of course, that the right eye may 

 be regarded as the control eye. This obviates unnecessary memoranda 

 and assists the inspector in making 'final disposition of the animal, since 

 exudate appearing during the test should be limited to the treated eye. 



3. It should be noted, however, that animals exhibiting well-encap- 

 sulated lesions upon post-mortem examination have been very slow in 

 responding to the test. The prior use of tuberculin by the subcutaneous 

 method sometimes invites a very early response to ophthalmic tuberculin 

 when but a brief period of time intervenes between the two tests. 



4. In the case of an animal whose tested eye exhibits dark, albumin- 

 ous exudate, equivalent in volume to 8 minims or more, the fact should be 

 indicated in reports by the symbol "PX." If the exudate exhibits gran- 

 ular casts or flakes of a yellowish tint, the report should read "PXX." 

 When the exudate tends to smear over the ball and pupil of eye, note the 

 fact with the symbol "PXXX." The word "negative" may be abbreviated 

 "N." It is preferable to use double columns noting such observations, 

 the condition of both the treated and the control eyes, using the upper 

 space for the treated eye thus : 



Remarks 

 Reacted 



(Control) Negative 

 Negative 

 Negative 



5. Each animal should be marked carefully for identification so 

 that, in case of slaughter, the identity of each animal may be traced 

 ■through the Post-morteg^.j,^^g^^^^.jyj5jgjjl^ judged. 



