OK, so the rats and rabbits lived, the dogs developed liver damage.

Ethoxyquin is a chemical used as a preservative in dog food, cat food and HUMAN food. Ethoxyquin was initially registered as a pesticide in 1965, and as a stabilizer and anti-degradation agent for rubber.

From EPA Case 003 the information is:
The primary target organs affected by ethoxyquin in experimental animals are the liver and the kidneys. Dogs are more susceptible to ethoxyquin toxicity than rats with elevated liver enzymes and microscopic findings in the liver occurring at doses as low as 4 mg/kg/day over a 90 day feeding period.

Ethoxyquin did not cause developmental effects in rats tested at doses of 350 mg/kg/day during gestation, or in rats at doses as high as 500 mg/kg of a 67% ethoxyquin formulation, and no developmental effects were seen in rabbits where the maximum dose of 3 mg/kg/day was administered.

OK, so the rats and rabbits lived, the dogs developed liver damage.