A sick dog can live as long as 3 days to 7 days without food.
The actual length of time that the sick dog can live without food, will also depend on the severity of the dogs illness and the dogs age as well as overall health.
A dog that has a more severe illness can result in the dog dying in a shorter period of time without food.
And younger and healthier dogs can go a bit longer without food before they die.
A dog can survive only a short time as in 24 hours to 48 hours without water but they can survive without food for longer.
Water is essential to the dogs survival so they should have access to water at all times and if they go without water for 24 hours to 48 hours they will likely die before they starve.
Most healthy dogs can go 3 days to 5 days without food.
Although dogs that are sick may not be able to eat for as long and if they haven't eaten within 24 hours it's a good idea to speak with a vet.
Some dogs will eventually return to eating, once they get over their illness.
But if the dog is severely ill and is on the verge of dying they may not eat at all and eventually die.