Why a sensitive stomach makes this riskier
A 12 kg dog with digestive issues reacts more strongly to compost toxins than a healthy dog would. The bacterial overload you're seeing—gas and loose stools—means his system is struggling to handle even this small exposure. Sensitive guts often have weaker barriers, letting more toxins pass into the bloodstream where they can affect the nervous system.
Watch for pacing, drooling, or muscle twitches, which suggest the mold toxins are taking hold. If his diarrhea contains blood or he stops eating, the irritation has moved beyond simple upset. Since you know your dog's baseline, any deviation from his usual 'sensitive stomach' pattern means calling the vet.
What mold hides in wet compost
That damp pile likely contains Penicillium or Aspergillus molds, which produce tremorgenic mycotoxins. These don't always show visible fuzz, so assume they're present. For a dog this size, ingesting even trace amounts can escalate from diarrhea to full-body tremors within hours.
Check the compost for mold-coated food scraps—especially bread, dairy, or decaying fruit. These are mycotoxin hotspots. If your dog licked near them, his current symptoms might be just the first wave. The wobbliness you'd see next isn't from stomach pain but from toxins attacking his nervous system.
Why timing matters with bacterial toxins
Since the lick happened recently, bacteria like E. coli or Salmonella are still multiplying in his gut. The soft stools now could turn to violent diarrhea within 6–12 hours as these pathogens overwhelm his sensitive system. Dehydration is a real risk for smaller dogs—watch for tacky gums or lethargy.
If he develops a fever (over 39°C), the infection has likely spread beyond his digestive tract. Don't wait for vomiting; by then, he may need IV fluids to support his kidneys. Note any changes in urine output, as toxins can damage renal tissue quickly in stressed systems.
When to escalate beyond home care
If gas persists beyond 24 hours or stools remain unformed after two meals, his gut flora needs professional help. Probiotics alone won't fix toxin damage. A vet can prescribe gut protectants and anti-nausea meds tailored for sensitive dogs.
Any twitching, even mild ear or lip tremors, means the mycotoxins are active. Seizures can start suddenly, so don't assume mild symptoms will stay mild. Keep him in a dark, quiet room to reduce neurological stress while you call the vet.
The step-by-step response, from the first minute to the vet visit, is in our Compost Bin Toxins: Dangers to Dogs and Cats emergency guide.