Foot and mouth disease
The "foot and mouth disease," sometimes called hoof-and-mouth disease, is a highly infectious ailment that afflicts cloven-hoofed livestock: cattle, pigs, sheep, goats. The name comes from dangerous blisters that form in the animal's mouth and on its feet. On 16 June 1904, some Dubliners are alarmed about a possible outbreak in Ireland, which could result in an embargo being imposed on the country's cattle.
Foot-and-mouth is a serious plague for farmers, and through the years various steps have been taken to combat its spread: quarantine, vaccination (never highly effective, since the virus mutates rapidly), mass slaughter of affected animals, and trade restrictions. This last concern motivates Mr. Deasy in Nestor. He is alarmed about "our cattle trade," a crucial piece of the Irish economy for several centuries. "You will see at the next outbreak they will put an embargo on Irish cattle," he tells Stephen. The letter to the editor that he is asking Stephen to place in two newspapers is thus a patriotic effort to ward off a potential threat to the Irish economy by taking proactive steps to vaccinate animals against the disease. (The cause was shown to be viral in 1897, but no effective vaccine had been developed by 1904.)
The author of Ulysses shared Deasy's concern. Joyce learned of an outbreak of FMD in Ireland from his friend Henry Blackwood Price in 1912, and incorporated the news when he wrote Nestor five years later. Gifford notes, however, that "The occasion of Mr. Deasy's letter is somewhat anachronistic, since there was no outbreak of foot-and-mouth disease in Ireland in 1904, indeed not until 1912." It is worth thinking about that Joyce, so scrupulous a realist, cared enough about including this detail in his novel that he was willing to accept the anachronism.
In Aeolus, we see Stephen shopping Deasy's letter to Myles Crawford, the editor of the Evening Telegraph, and George Russell, the editor of the Irish Homestead. Deasy has also, he tells Stephen, sent a copy of his letter to "Mr Field, M.P." to lay before "a meeting of the cattletraders' association." In Cyclops Joe Hynes reports that he has attended this meeting—he has come to Barney Kiernan's pub to tell the Citizen about the foot-and-mouth threat—and that Joseph Nannetti has gone to London to take up the matter in Parliament.
The issue excites interest in several other chapters as well. In Eumaeus Bloom comes across Mr. Deasy's letter while reading the Evening Telegraph in the cabman's shelter; he has had his own thoughts about foot-and-mouth disease in Lestrygonians. In Oxen of the Sun the men at the hospital, having heard of the letter published in the Telegraph, talk about "Kerry cows that are to be butchered along of the plague."