Was Leonardo da Vinci a vegan/vegetarian...?

In Leonardo da Vinci Artist, Thinker, and Man of Science (1898), Eugene Muntz wrote, "It appears from Corsali’s letter that Leonardo ate no meat, but lived entirely on vegetables, thus forestalling modern vegetarians by several centuries."

In The Mind of Leonardo da Vinci (1928), Edward MacCurdy wrote:

"…The mere idea of permitting the existence of unnecessary suffering, still more that of taking life, was abhorrent to him. Vasari tells, as an instance of his love of animals, how when in Florence he passed places where birds were sold he would frequently take them from their cages with his own hand, and having paid the sellers the price that was asked would let them fly away in the air, thus giving them back their liberty.

That this horror of inflicting pain was such as to lead him to be a vegetarian is to be inferred from a reference which occurs in a letter sent by Andrea Corsali to Giuliano de’Medici, in which, after telling him of an Indian race called Gujerats, who neither eat anything that contains blood nor permit any injury to any living creature, he adds ‘like our Leonardo da Vinci.’ "

In Leonardo: Discovering the Life of Leonardo da Vinci (English translation 1991), Serge Bramly wrote, "Leonardo loved animals so much, it seems, that he turned vegetarian."

By all accounts, Leonardo was beloved by those that knew him. Paolo Giovio wrote the following, circa 1527, in Leonardi Vincii Vita (translated by Richter and quoted by Vezzosi):

"…His charm of disposition, his brilliancy and generosity was not less than the beauty of his appearance. His genius for invention was astounding, and he was the arbiter of all questions relating to beauty and elegance, especially in pageantry. He sang beautifully to his own accompaniment on the lyre and to the delight of the entire court. He died in France at the age of sixty-seven to the grief of his friends."

In spite of his popularity, da Vinci does seem to have had a misanthropic streak.

From Quaderni d’Anatomia II 14 r housed at the Royal Library at Windsor we find:

" King of the animals–– as thou hast described him–– I should rather say king of the beasts, thou being the greatest––because thou doest only help them, in order that they give thee their children for the benefit of the gullet, of which thou hast attempted to make a sepulchre for all animals; and I would say still more, if I were allowed to speak the entire truth." A little later in the passage he says, "now does not nature produce enough simple (vegetarian food) for thee to satisfy thyself? And if thou art not content with such, canst thou not by mixture of them make infinite compounds, as Platina wrote, and other authors on feeding?" The above translation was taken from Richter. An earlier edition of Richter didn’t include the word vegetarian in the parenthesis.

Excerpt from https://ivu.org/history/davinci/hurwitz.html