Here's How Long Dogs Can Go Without Food
If a garden-variety dog could talk it'd probably inform humans that starvation sets in roughly five seconds after the plastic on a slice of processed cheese makes that distinctive crinkly noise. Canis familiaris may be blessed with a bountiful assortment of endearing eccentricities (post-poop grass kicking notwithstanding), but they're not well known for honesty when it comes to meal-times. While it's scientifically accurate that denial of doggy nom-noms (DDNN) can elicit a veritable hell-storm of sullen looks, judgment snuffles and symphonically pitiful whining (ear-muffs recommended), the truth is a skipped meal here or there won't make much of a dent in a dog's long-term well-being. But when does righteous dog hanger turn into something more serious? Here's what impartial human scientists have to say on the matter (and canine gluttons aren't going to like it).
Two days without food is usually no big deal
A healthy garden-variety mutt can go without food for a good 48 hours without too much physical distress, and a two-day fast may actually be a pretty good idea for a dog with a mild case of the grumble guts (not to mention human family members cursed with a heightened sense of smell). Writing for PetMD, Jennifer Coates DMV explains. "I don't worry when a sick dog doesn't feel like eating for a couple of days. If the gastrointestinal tract is involved in the dog's illness a few days 'off' can give it a chance to recuperate."
Much like humans then, fasting for a few days gives a canine's gastrointestinal tract a much-deserved mini-vacation from the rigors of digestion (particularly if it ate a chipmunk well past its best-consumed-by date) and after two days a dog will usually bounce right back into regular eating with no lasting health implications.
When does starvation become life threatening?
While there's not a lot of detailed research on canine starvation specifically (which non-psychopaths will probably agree is a really good thing), research on how mammals generally respond to a complete absence of nutrients reveals that the starvation process is surprisingly complex. The point of no longer being able to sustain life depends on a ton of factors, from existing health conditions to body size, to activity level. According to Vladimir Negron in "Caring for an emaciated dog", a medium-sized dog will likely start to burn into its fat reserves within five days of starvation, and once biology's last-ditch fatty insurance policy runs dry its organs will start to slowly break down. The point of expiration from that point may take a couple of days. It may take weeks. Needless to say, the journey to that point is an agonizing one.
Our species has had a millennia-long love affair with dogs in one form or another, so for many folks, the thought of a distressingly hangry mutt is almost viscerally horrible to contemplate. The good news is, like humans, a canine can manage a couple of days without its dog food without much of a problem. But with over 3.3 million dogs abandoned in the US each year, unfortunately for many dogs, the problem is a lot direr than a skipped meal or two.