Accessory Etiologic Factors of Pneumonia in Rabbits. I: Effect of Putting Brilliant Green into Nasal Passages.

A weak solution (from 0.1 to 0.3 per cent) of brilliant green dropped into the nostrils of rabbits carrying B. lepisepticum incites severe snuffles and pneumonia. In rabbits not carrying the organism naturally, the same effect can be obtained by putting a small amount of culture into the nostrils before the dye is given or 1 or 2 days afterwards. The dye alone has little or no visible effect.

Thirty-two rabbits having very slight serous discharges from the nose, and, a positive lepisepticum culture, were given 0.2 cc. of the solution (0.3 per cent) in each nostril. All of the rabbits developed very profuse nasal discharges, which often caused such obstruction of the nasal passages, that they were forced to breathe through the mouth. To all intents and purposes the rabbits had a very severe and active form of snuffles. Twenty-one of them developed pulmonary infections and died from the 3d to the 15th day after treatment, the average length of life after treatment being 8 days. The others gradually improved after a prolonged siege of snuffles.

The more acutely fatal cases had typical lobar pneumonia, one or more lobes being in the state of complete red hepatization. The other lobes had either a normal appearance or showed some injection, edema or emphysema. Those living longer usually had a general fibrino-purulent pleurisy and pericarditis, and less extensive solidification of the lungs but more pronounced edema and emphysema.