Why your border collie is in acute danger
Granules are designed to stick to moisture—when your dog ate them, they adhered to his throat and stomach lining, continuously releasing toxin. At 15 kg, his size might delay symptoms, but the granules' slow dissolution means poisoning can worsen over 8+ hours. Look for dirt around his mouth—dogs often paw at their faces as throat muscles start twitching.
Don't wait for tremors—call your vet now with the product name. Granule formulas vary in concentration, and some contain additional herbicides that attack the liver. Your dog may need blood tests every 6 hours to monitor enzyme spikes.
How your shih tzu absorbs poison without eating any
Small dogs absorb toxins through their paw pads—at 4 kg, just walking on treated grass then licking paws could deliver a dangerous dose. Check between your shih tzu's toes for granules stuck in fur. If he's walked outside today, wipe his paws with damp paper towels (not baby wipes—their chemicals may interact with pesticides).
Watch for excessive nose licking—a sign of nausea from minimal exposure. Keep him off carpets where pesticide dust could settle—small dogs breathe in more contaminants relative to their size when sniffing floors.
Lawn treatment aftermath for both dogs
Watering the lawn won't dilute the granules—it makes them release toxins faster. Restrict all pets to paved areas for at least two weeks. If your border collie recovers, don't let him dig—old granules resurface and remain deadly for months. Consider replacing the top 3 inches of soil in his favorite digging spots.
After rains, check patio edges where runoff concentrates pesticides. Small dogs like your shih tzu may drink puddles containing dissolved chemicals—always provide fresh indoor water bowls during treatment periods.
Why size differences change symptoms
Your border collie might show classic drooling and stumbling, while the shih tzu could develop silent symptoms like rapid breathing from diaphragm weakness. Smaller dogs often collapse without warning because their nervous systems reach overload faster—don't assume he's safe just because he didn't eat granules directly.
If either dog has seizures, note the duration—organophosphate seizures often last under 30 seconds but recur in clusters. This timing helps vets distinguish them from epilepsy. Keep other pets away during episodes—some dogs become briefly aggressive post-seizure.
The step-by-step response, from the first minute to the vet visit, is in our Organophosphate Insecticide Toxicity in Dogs and Cats emergency guide.