Why a 25 kg dog's lick differs from chewing
When a dog merely licks a pear seed, the hard outer shell usually prevents any significant toxin release. Cyanide forms when the pit's inner material is crushed or chewed, which requires substantial pressure—something a quick tongue swipe won't achieve. Your dog's size also matters here: a single intact seed passing through a larger digestive system is unlikely to break down enough to pose a threat.
Watch for any attempts to paw at his mouth or signs of discomfort over the next two hours, though these would more likely stem from the seed's physical shape than poisoning. If he starts drooling excessively or seems to struggle swallowing, call your vet—those could indicate the seed is lodged rather than poisoning at work.
The next 12 hours with an intact seed
Since the seed probably wasn't crushed, focus on monitoring his bowel movements instead of poisoning signs. A seed this size may cause mild constipation or slight discomfort when passed, especially if it's his first time ingesting something this hard. You might notice him straining slightly or his stool being drier than usual for a day.
No need to adjust his meals or water unless he refuses to eat—just ensure he stays hydrated. If 24 hours pass without the seed appearing in his stool, or if his abdomen seems tender when gently pressed, a vet visit can rule out intestinal blockage, though this is rare with one seed in a dog his size.
When to upgrade concern beyond observation
Switch from watching to calling the vet if you spot sudden weakness, trouble breathing, or gums turning brick-red—these are late-stage cyanide signs that would only occur if the seed was somehow ground up in his mouth. For context, that'd require audible crunching you'd likely have heard.
More probable but still uncommon are signs of gastrointestinal irritation: vomiting more than once, refusing even favorite treats, or curling up tightly as if in pain. These suggest the seed might be causing physical irritation rather than poisoning, but still warrant professional input given his individual reaction.
Why future pit encounters need different handling
While this incident is low-risk, it's a good prompt to sweep for fallen fruit debris more diligently—dogs often lick first but may chew next time. Pear flesh is safe, so focus on keeping just the pits out of reach during snacks or composting.
If he's prone to scavenging, train a 'leave it' command using high-value rewards. For dogs that persistently investigate food debris, consider a basket muzzle during pear season—it allows panting and drinking while blocking pit access. This single seed lick doesn't require those measures, but it's smarter to prevent a repeat with unknown outcomes.
The step-by-step response, from the first minute to the vet visit, is in our Pear Pits and Seeds Poisoning in Dogs and Cats emergency guide.