| Verdict for dogs | Generally safe |
| Severity | 1 / 5 — Low risk — fine in moderation for a healthy pet. |
| Safe amount | Small amounts |
| Category | Vegetable |
| Source | VCA Animal Hospitals — pet health library · reviewed 2026-08-07 · confidence: high |
Almost entirely water and very low calorie — a good treat for a dog watching its weight. Slice it; whole chunks are a choking size for small dogs. Skip pickles, which are brined and often contain garlic.
Serve it plain, in small pieces, as an occasional treat. Keep all treats to under about a tenth of daily calories, and introduce anything new in a small amount so you can spot a sensitive stomach.
Never induce vomiting and never give any medicine unless a vet tells you to — it can do more damage than the poison. What we will and won't tell you.
If you're sharing food because you want to treat them, a treat formulated for dogs does the job without the guesswork.
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Can cats eat cucumber? — Feed with caution to cats.
Yes — cucumber is generally safe for dogs in moderation, plain and in small pieces. Almost entirely water and very low calorie — a good treat for a dog watching its weight. Slice it; whole chunks are a choking size for small dogs. Skip pickles, which are brined and often contain garlic.
Usually nothing — in moderation this is a safe treat. If they had a large amount, watch for: Most pets are fine after a small amount; Vomiting, loose stools or a skipped meal if they had a lot; Any new food can upset a sensitive stomach — introduce it in a small amount. Some signs lag by a day — call, don't wait.
The safe amount is small amounts, as an occasional treat rather than a daily habit. Large amounts mainly cause stomach upset; if that doesn't settle within a day, call your vet.