Green’s Dictionary of Slang

bullshit! excl.

also bull’s foot! bull toads!
[bullshit n.]

(orig. US) rubbish! nonsense!

[US](con. 1899) H.P. Bailey Shanghaied Out of Frisco 95: ‘But, Ben, poor old Senn can’t talk English!’ I broke in. ‘Bull’s foot! He can jest talk English as plain as I can, or the President of the United States!’.
[UK]‘George Orwell’ Down and Out in Complete Works I (1986) 194: There was some silly casus belli about one saying to the other, ‘Bullshit’.
[US] ‘Tillie & Mac with Mr Simpkins and Bubbles’ [comic strip] in B. Adelman Tijuana Bibles (1997) 24: Ah bull shit. I’ll screw him silly any day.
[US](con. 1948) G. Mandel Flee the Angry Strangers 153: Bullshit, Stoney! By God, you gangle-assed fatmouth.
[US] letter 5 Sept. in Edelman Dear America (1985) 179: I said bul----!, that I wasn’t hurt that bad and he had to stay at his gun.
[US]D. Goines Dopefiend (1991) 86: ‘Bullshit!’ Red and Tiny Tim both said together.
[US]W. Wharton Midnight Clear 128: Bull toads!
[Aus]B. Humphries Traveller’s Tool 13: I say a categorical ‘bull-shit’.
[Aus]P. Temple Bad Debts (2012) [ebook] ‘I might have kept him out of jail.’ [...] ‘Bullshit, mate’.
[US]L. Pettiway Workin’ It 114: Little bullshit! I got into fights at school a couple of times, nothing serious. ’Cause she punched me. Little bullshit, you know, ’cause she don’t like me ’cause I was maybe the first one with a pair of sneakers on. Stuff like that.
[UK]K. Sampson Powder 70: Bullshit! I came up with the fucken name so I should know . . . Maybe I just never told anyone why!
[US]C. Cook Robbers (2001) 7: Bullshit, said Edie. They got a law for everything.
[UK]G. Iles Turning Angel 93: ‘Bullshit!’ yells one of the boys.
[UK]S. Kelman Pigeon English 63: Bullshit. I could do it one-handed.