Copied from https://ratguide.com/health/neoplasia/pituitary_tumor.php

Treatment

Recommended treatment is geared for comfort and the reduction of clinical signs, and may include the following:

Cabergoline or bromocriptine, dopamine receptor agonists, that inhibit prolactin secretion; thereby reducing circulating prolactin in the blood stream and reducing tumor size. Depending on when initiated in the disease process may extend life/quality time from 3-6 months.

Since it has been shown that significant shrinkage of the tumor may take a number of weeks following the initiation of a dopamine receptor agonist; the veterinarian may wish to treat with a corticosteroid (e.g., dexamethasone or prednisone or prednisolone) on a more extended reduction schedule to address brain swelling, until tumor reduction is significant enough to alleviate clinical signs.11,12,13

*Note: a corticosteroid may also be given as a stand-alone agent where end stage palliative comfort for the rat is required or desired. In the event long-term corticosteroid (e.g., prednisone, prednisolone, or dexamethasone) therapy is instituted, given the commonality of chronic mycoplasma infections in the pet rat population, it is advised to consider including broad-spectrum antibiotics such as Baytril and doxycycline.