Apple Seed Cyanide in Dogs: The Per-Weight Math

Updated May 2026

A FEW SEEDS: NOT A CLINICAL CONCERNREMOVE SEEDS AS A HABIT

How many apple seeds will kill a dog?

No realistic accidental amount. Reaching a lethal cyanide dose takes the seeds from dozens of apples, all thoroughly chewed: roughly 75 to 300 chewed seeds for a 10lb dog, 225 to 900 for a 30lb dog, and 450 to 1,800 for a 60lb dog (the seeds from about 10 to 40, 30 to 110 and 55 to 225 whole apples respectively). Those are deliberately cautious theoretical maxima from the per-weight table below.

One whole apple holds only about 5 to 10 seeds, dogs almost never chew small hard seeds, and whole swallowed seeds pass largely undigested, releasing only a trace of their amygdalin. So the seeds from one or two apples are not a poisoning concern for a healthy adult dog. A very small dog that deliberately chewed a large quantity, or any dog that ate crushed seeds (juicer or food-processor pulp), is the exception: call ASPCA Animal Poison Control on (888) 426-4435.

The short answer

Apple seeds contain amygdalin, a cyanogenic glycoside that can release hydrogen cyanide when the seed is broken and exposed to digestive enzymes. The headline number people search for, "how many seeds is lethal," resolves to several hundred thoroughly chewed seeds for a typical dog. Whole swallowed seeds pass largely undigested and release minimal cyanide. The practical guidance from the ASPCA Animal Poison Control Center is to remove seeds as a routine habit but not to treat accidental swallowing of a few seeds as an emergency in a healthy adult dog.

How many apple cores would it take to kill a dog?

One whole apple core holds the seeds of one apple, roughly 5 to 10 of them. Reading the per-weight math below in core terms: even the deliberately cautious, fully-chewed-seed threshold works out to the seeds from about 10 to 40 apples (so 10 to 40 cores) for a 10lb dog, 30 to 110 cores for a 30lb dog, and 55 to 225 cores for a 60lb dog. Those are theoretical maxima that assume every seed is extracted and thoroughly crushed.

In a real incident the dog swallows the cores whole, and whole seeds pass largely undigested while releasing only a small fraction of their amygdalin. So no realistic number of accidentally eaten cores delivers a lethal cyanide dose to a healthy adult dog. Where multiple cores do become dangerous, the concern is gastrointestinal obstruction, particularly in small dogs, not seed cyanide.

What amygdalin actually does

Amygdalin is a cyanogenic glycoside found in the seeds of apples, pears, cherries, peaches, apricots and bitter almonds. The molecule itself is inert. When a seed is mechanically broken (chewed) and the contents meet the enzyme beta-glucosidase (present in the seed and in the gut microbiome), amygdalin is hydrolysed and one of the breakdown products is hydrogen cyanide (HCN). The Merck Veterinary Manual entry on cyanide poisoning in animals covers the mechanism and clinical signs.

Hydrogen cyanide poisons cells by blocking cytochrome c oxidase in the mitochondrial electron-transport chain. At a toxic dose this produces oxygen starvation at the cellular level, with clinical signs that include rapid breathing, weakness, dilated pupils, bright red mucous membranes, seizures and, at lethal dose, death within minutes to a few hours. The Merck reference cites a roughly 2 mg/kg lethal hydrogen cyanide dose in most mammals as the working threshold.

The numbers, plainly

The amygdalin content of apple seeds varies by cultivar, growing conditions and seed maturity. Bolarinwa et al. (2015, published in Food Chemistry) measured a range of roughly 1 to 4 milligrams of amygdalin per gram of seed across fifteen cultivars (Golden Delicious highest at about 3.9 mg/g). An apple seed weighs only about 0.03g, so each seed actually holds well under a milligram of amygdalin; the per-seed value used in the table below is set deliberately higher than that so the resulting toxic-dose seed counts stay cautious rather than optimistic. Not all amygdalin converts to cyanide; the molar ratio is roughly 0.06 mg HCN per 1 mg amygdalin under ideal in vitro hydrolysis conditions. In a live digestive tract, conversion is partial and depends heavily on seed breakage.

Dog weightLethal HCN dose (~2mg/kg)Equivalent fully-converted seeds (chewed)Apples needed
5lb (2.3kg) toy~4.6 mg~38 to 153 seeds~5 to 20 apples worth
10lb (4.5kg) small~9 mg~75 to 300 seeds~10 to 40 apples
30lb (13.6kg) medium~27 mg~225 to 900 seeds~30 to 110 apples
60lb (27.2kg) large~54 mg~450 to 1800 seeds~55 to 225 apples
100lb (45.4kg) giant~90 mg~750 to 3000 seeds~95 to 375 apples

Assumptions: 1 to 4 mg amygdalin per gram of seed (Bolarinwa et al., 2015); apple seeds are small (about 0.03g each), so the true per-seed content is a fraction of a milligram and the per-seed value behind this table is a deliberately cautious overestimate; 0.06 mg HCN released per 1 mg amygdalin at full hydrolysis; 8 seeds per medium apple; 2 mg/kg lethal HCN dose (Merck Veterinary Manual). Real-world hydrolysis is partial and whole swallowed seeds release only a small fraction of this, so the genuine threshold is higher (safer) than the figures shown. These are order-of-magnitude theoretical maxima, not a precision interval.

Why "chewed" is the load-bearing word

Apple seeds have a hard outer testa (seed coat) that resists digestion. Dogs do not deliberately chew small hard seeds. In typical apple-stealing incidents, the seeds are either swallowed whole inside a core or chewed only superficially. Intact seeds pass through the gastrointestinal tract within 24 to 36 hours largely unchanged, releasing only the small fraction of amygdalin that escapes through the seed coat.

This is the mechanism that turns an alarming theoretical lethal-dose math into a low-risk practical reality. The pet-poison literature, including the Pet Poison Helpline apple entry, treats accidental whole-seed ingestion in healthy adult dogs as monitor-at-home unless a very large quantity was deliberately chewed.

When the math stops being reassuring

Scenarios where the per-weight numbers above understate the risk:

Clinical signs that warrant a vet call

Cyanide poisoning produces rapid-onset clinical signs (minutes to a few hours after exposure to a toxic dose). If you see any of these within 4 hours of suspected seed ingestion, call ASPCA Animal Poison Control on (888) 426-4435 or proceed to an emergency vet:

Rapid or laboured breathing
Excessive drooling
Bright red gums (cherry red)
Dilated pupils
Weakness, ataxia, collapse
Seizures
Vomiting with bitter-almond odour
Sudden lethargy disproportionate to anything else going on

The absence of any of these signs 6 hours after suspected ingestion is reassuring. Cyanide poisoning does not have a long incubation period; if it was going to develop, it usually has by then.

Frequently asked questions

How many apple seeds will kill a dog?+
No realistic accidental amount. Reaching the theoretical 2 mg/kg lethal hydrogen cyanide dose takes the thoroughly chewed seeds from dozens of apples: roughly 75 to 300 chewed seeds for a 10lb dog, 225 to 900 for a 30lb dog, and 450 to 1,800 for a 60lb dog (the seeds from about 10 to 40, 30 to 110 and 55 to 225 whole apples respectively, using deliberately cautious per-seed amygdalin assumptions). A whole apple holds only about 5 to 10 seeds, dogs almost never chew small hard seeds, and whole swallowed seeds pass largely undigested while releasing only a trace of amygdalin. So the seeds from one or two apples are not a poisoning concern for a healthy adult dog. The exceptions are a very small dog that deliberately chewed a large quantity, or a dog that ate crushed seeds from juicer or food-processor pulp: call ASPCA Animal Poison Control on (888) 426-4435.
Does the AKC say apple seeds are dangerous to dogs?+
The American Kennel Club confirms apple seeds contain amygdalin and recommends removing seeds before serving apple to dogs. The AKC nutrition guidance frames the risk as real but quantitative: a few accidentally swallowed seeds in a healthy adult dog is unlikely to cause clinical poisoning. See akc.org for the current guidance text.
If a few seeds are usually fine, why do all the safety guides say to remove them?+
Because the cost of removal is essentially zero (a few seconds of preparation) and the worst-case scenario (deliberate chewing, very small dog, cumulative daily exposure, sick dog) is preventable by the habit. The risk math says one-time accidental ingestion is low risk; the practical rule says remove seeds anyway because the rule is simple and removes the question.
What if my dog swallows seeds from a windfall apple in the garden?+
Treat as low-priority monitoring for a healthy adult dog. Whole seeds inside a discarded apple will pass through largely undigested. Watch for 6 hours for any clinical signs; if none appear, the incident is functionally closed. For toy breeds or puppies, or if you suspect a large quantity, call ASPCA Animal Poison Control for case-specific advice.
Is apple seed cyanide cumulative? Does giving apple every day add up?+
Cyanide is rapidly metabolised by the liver (via rhodanese) and excreted; it does not bioaccumulate in the way some heavy metals do. However, daily exposure to seeds with cumulative chewing across the dog's life increases the lifetime probability of a high-exposure incident. The straightforward answer is to make seed removal routine so the question never comes up.
Can hydrogen cyanide poisoning be treated in dogs?+
Yes, if recognised quickly. Veterinary treatment options include sodium nitrite and sodium thiosulfate antidotal therapy, supplemental oxygen, and supportive care. Treatment is most effective when started early; this is one reason the clinical-sign list above matters more than the seed-count math. If symptoms appear, do not wait.
How many apple cores will kill a dog?+
In practical terms, no realistic number of accidentally eaten whole cores will. One core holds the seeds of one apple (about 5 to 10 seeds). Even the cautious fully-chewed-seed math below puts the theoretical lethal threshold at the seeds from roughly 10 to 40 apples (10 to 40 cores) for a 10lb dog, 30 to 110 for a 30lb dog and 55 to 225 for a 60lb dog. Because dogs swallow cores whole and whole seeds pass largely undigested, the cyanide actually released is a small fraction of those maxima. When several cores do pose a danger it is gastrointestinal obstruction, especially in small dogs, not cyanide. Call your vet or ASPCA Animal Poison Control if a small dog swallowed multiple whole cores, or if any dog deliberately chewed the seeds from many apples.
How many apple seeds are toxic to a 10lb (small) dog?+
For a 10lb (4.5kg) dog the theoretical lethal hydrogen cyanide dose is around 9mg, which works out to roughly 75 to 300 thoroughly chewed seeds, the seeds from about 10 to 40 whole apples. Because dogs almost never chew apple seeds and whole seeds pass largely undigested, the seeds from one or two apples are not a clinical concern for a healthy adult dog this size. Toy breeds under 5kg have less margin, so call ASPCA Animal Poison Control if a very small dog deliberately chewed a large number of seeds.
How many apple seeds are toxic to a 60lb (large) dog?+
For a 60lb (27kg) dog the theoretical lethal dose is around 54mg of hydrogen cyanide, equivalent to roughly 450 to 1,800 fully chewed seeds, the seeds from about 55 to 225 apples. A dog this size would have to deliberately chew the seeds from dozens of apples to approach a toxic threshold, so accidental ingestion of a few seeds is not dangerous. At this weight the core's choking and obstruction risk is a more practical concern than the seed cyanide.

Related pages

Dog ate apple seeds (emergency)Dog ate apple coreCore and seeds overviewEmergency protocolApple safety home

Sources: ASPCA Animal Poison Control Center, Merck Veterinary Manual (Cyanide Poisoning in Animals), Pet Poison Helpline (Apple entry), American Kennel Club nutrition guidance, Bolarinwa et al., "Determination of amygdalin in apple seeds, fresh apples and processed apple juices" (Food Chemistry, 2015, 170:437-442). Educational reference only; not veterinary advice.

Updated 2026-04-27