"you would eat (anything) you could lay your hands on"
Largely rubbish, but there are scintillas of truth behind the thought. Narayanan Krishnan, the ex-celebrity Indian chef, gave up his celebrity and his wealth to found and run a refuge in Southern India to feed and care for the starving rejects of that society, after he came across an old man so hungry he was eating his own excrement (or as you would say round here, poo).
But, curiously, cannibalism and the eating of companion animals is much less common than teacake's cynicism would suggest.
There are many stories of people starving to death and NOT eating their fellow humans, or sacrificing their faithful dogs or cats, but rather dying first.
Don't judge all by your own standards, teacake; thankfully, others live by different codes.
BB