Why a 15 kg dog faces different risks with quince versus apple
Your dog's size and the quince's raw state create a specific risk profile. While both fruits have seeds containing cyanide-releasing compounds, quince seeds are denser and release more cyanide when crushed. A 15 kg dog would need to chew several apple cores to reach concerning levels, but fewer quince seeds could pose a problem due to their higher concentration.
The raw quince flesh itself brings extra challenges—its astringent tannins and hard texture often cause stomach irritation before cyanide becomes an issue. Watch for excessive drooling or pawing at the mouth first, which signals mouth irritation rather than poisoning. These early signs help you gauge whether it's just discomfort or something more serious.
How much raw quince crosses the danger line
For a dog your size, swallowing one or two whole seeds accidentally likely won't cause harm—the real risk comes from deliberate chewing that cracks the seeds open. If your dog crunched through half a quince's worth of seeds (about 10-12), that warrants immediate vet attention. With apples, the threshold is higher—around 20-30 crushed seeds for a dog this weight.
Timing matters too. Quince seed symptoms—labored breathing, bright red gums—typically appear within 30-90 minutes if enough cyanide is released. Apple seed poisoning, being milder, might take hours to show vague signs like lethargy. In both cases, unchewed seeds passing through whole reduce the risk significantly.
The core differences in toxicity between these fruits
Quince seeds contain amygdalin, the same compound as apple seeds, but in higher concentrations—about 1.5 to 2 times more per seed. They're also larger, making them easier for dogs to break open accidentally while eating the fibrous fruit around them. Apple cores tend to be softer, so dogs often swallow them with less seed damage.
Location within the fruit changes the risk too. Quince seeds cluster tightly at the center, while apple seeds scatter loosely. This means a dog eating quince gets more seeds per bite if aiming for the core. The bitter taste of raw quince often makes dogs spit it out after the first bite, limiting exposure unless they're unusually persistent.
When stomach upset overshadows poisoning risks
With raw quince, gastrointestinal distress usually appears before cyanide becomes a concern. The fruit's high tannin content can cause vomiting within an hour, which ironically helps by expelling seeds before they're fully digested. Dry heaving or diarrhea may follow, especially if your dog ate the fuzzy quince skin that irritates the gut lining.
Compare this to apples—their sweeter flesh encourages overeating, but the stomach handles it better unless seeds are crushed. For your 15 kg dog, monitor the next two bowel movements for whole seeds (a good sign) and check vomit for seed fragments. Persistent retching without seed expulsion means the vet should evaluate possible intestinal blockage from the quince's woody core.
The full verdict, portion guidance and serving notes are collected on the Quince food facts page.