Canned food first appeared in the early 1900's, complete compound dry feeds appeared in the 50's and 60's. Dog meal (to be mixed with meat) was certainly available in the 1880's. Before diet aimed specifically at dogs, there was always the knacker - the person who took fallen and condemned stock for rendering. Going back into the mists of time there were trenchers - slabs of rough bread used before plates were generally available - they were destined to be dog food at the end of the meal.
You could have:4 dogs: 2 alive and 2 dead3 dogs: 1 alive and 2 dead as 1 alive dog ran away3 dogs: 2 alive and 1 dead as 1 dead dog has been removed2 dogs: 2 dead dogs as the alive dogs ran away2 dogs: 2 alive dogs as the dead dogs have been taken away.1 dog: 1 alive dog as 2 dead dogs have been removed and 1 alive dog ran away1 dog: 1 dead dog as 2 alive dogs ran away and 1 dead dog has been removedno dogs: the dead dogs have been removed and the 2 alive dogs were taken away by the authorities for the sake of the welfare of the two alive dogs as the death of the 2 dogs was caused by your animal cruelty.........................................................................................................................................................................You still have 4 dogs 2 are dead 2 are alive
about 10000
For as long as people have been alive.
For as long as man has been alive
Rats have been alive for hundreds of years. Rats have been alive for around for at least 900 years on Earth.
120 years
Igneous rock has never been alive.
Most dogs (of no health issues) usually stay alive for 13-15 (or longer) years
yes dogs have been walking since a long time
Millions of years
765 years
about 2500 years