Why nectarines and peaches pose identical risks
Both fruits belong to the Prunus genus, sharing nearly identical chemical profiles in their flesh and pits. The slight fuzz on peaches doesn't change toxicity—it's just a texture difference that some dogs find irritating. Your 12kg dog would need to eat several whole pits from either fruit before cyanide became a concern, making the wedges you described completely safe.
The pit's structure matters more than the fruit type—peach pits tend to be more deeply grooved, potentially trapping more flesh when dogs nibble them. Nectarine pits are smoother but equally hazardous if crushed. Since your dog only ate prepared wedges, neither fruit variety presents additional risks.
How body weight affects fruit tolerance
At 12kg, your dog can safely process more fruit sugars and fiber than smaller pets. Two wedges from either fruit represent less than 5% of their daily food intake by volume. Larger dogs also have more stomach acid to break down plant matter, reducing the chance of digestive upset from occasional fruits.
The real advantage for medium-sized dogs is their ability to pass small pit fragments naturally if accidentally ingested. Still, never assume this makes pits safe—their cyanide content remains dangerous regardless of dog size. What you're seeing is simply greater leeway with flesh portions.
When preparation method changes the risk
Raw versus cooked makes little difference for these fruits' safety—heat doesn't destroy amygdalin in pits, though it softens flesh fibers. What matters is whether skins were left on; peach fuzz can irritate some dogs' throats, while nectarine skins may stick to teeth. Your dog ate peeled wedges, sidestepping both issues.
Commercial fruit preparations sometimes add preservatives or syrups that are worse than the fruit itself. Since you served fresh wedges, you avoided these hidden hazards. Just confirm no pits were used in storage containers—some people keep cut fruit with pits to slow browning.
Long-term considerations for fruit feeding
Regular fruit snacks can lead to weight gain from natural sugars, especially in medium-sized dogs with slower metabolisms. While two wedges occasionally won't harm, daily fruit treats might displace balanced nutrition. Watch for increased thirst or urination—signs your dog is struggling to process excess fructose.
If you alternate between peaches and nectarines, note any preference or reaction differences. Some dogs digest one variety better, though this is individual rather than fruit-dependent. Stick to pitted, skinless portions of either fruit for safest sharing.
The full verdict, portion guidance and serving notes are collected on the Peaches (pitted) food facts page.