Why an 8 kg dog can't handle a leafy handful
That buffet raid delivered more roughage than your terrier's system can comfortably process at once. While Swiss chard isn't immediately toxic, the combination of high fiber and oxalates in several raw leaves acts like a digestive irritant. At this dog's size, you're looking at potential stomach discomfort simply from the volume—like a child eating an entire head of lettuce in one sitting.
The oxalate content becomes concerning because small breeds already have higher relative risk for urinary issues. Unlike a single leaf that might pass through uneventfully, this amount could slightly increase urine oxalate levels temporarily. Watch closely for any straining during urination over the next 48 hours, as that's when oxalate-related irritation would appear.
What to expect in the first 12 hours
Most dogs react to excess raw greens with obvious digestive signs. Your terrier may vomit up some partially chewed leaves within 6 hours, possibly with frothy bile. The high fiber content can also lead to softer stools or mild diarrhea as the system tries to process all that plant matter. These symptoms alone don't require emergency care unless they persist beyond 24 hours.
Less common but more serious would be signs of urinary discomfort—frequent small pees, whimpering while urinating, or licking the genitals excessively. These warrant same-day veterinary attention given your dog's size and the amount consumed. Have fresh water available to help flush the system.
Why this differs from gradual exposure
A single large ingestion like this buffet incident carries different risks than daily small amounts. The sudden fiber overload stresses digestion immediately, while the oxalate surge is more about temporary kidney processing strain. Dogs that regularly eat oxalate-rich foods face cumulative risks for crystal formation, but your scenario is an acute volume issue.
That said, the oxalates from this one event won't 'stick around' to cause later stones unless your dog has pre-existing urinary conditions. The concern here is primarily the leafy bulk and possible short-term irritation. If your terrier has ever had bladder issues before, this amount justifies a precautionary vet call.
When to upgrade from watchful waiting
For an otherwise healthy 8 kg dog, vomiting once or having one loose stool can be managed at home with a bland diet. But three red flags mean you should skip the waiting game: vomiting more than twice in 8 hours, refusing water for over 12 hours, or any urinary straining. Small dogs dehydrate quickly, and urinary blockages become emergencies faster in petite breeds.
Going forward, remember that terriers are notorious counter-surfers. At holiday gatherings, place veggie trays out of leaping range—what's a harmless human portion becomes a risky meal for a dog this size. If your pup enjoys greens, occasional cooked and chopped spinach (lower in oxalates) makes a safer treat alternative.
The full verdict, portion guidance and serving notes are collected on the Swiss chard food facts page.