The toxicity of caffein in cats is shown to be the same when given by
mouth as when injected subcutaneously, the minimum fatal doses in both
cases being 0.15 gram per kilo. When introduced by the intraperitoneal
route, caffein is, on the contrary, distinctly less toxic. After the
administration of 0.137 and 0.145 gram caffein per kilo (Nos. 93
and 87) salivation in one cat (No. 93) and irritability and muscular
stiffness in the other were the only effects noticed. These symptoms
were no longer observed the next day and the cats appeared to be
perfectly normal. Experiments with larger doses indicate that the
minimum fatal dose by this method of administration is about 0.2 gram
per kilo.