Why mold makes this a double threat
Azaleas are already dangerous due to grayanotoxins, but mold adds tremorgenic mycotoxins that attack the nervous system. These can cause muscle tremors, seizures, and high fever — symptoms that overlap with the plant's own effects on the heart. Your dog may show both sets of signs: first drooling and weakness from the azalea, then shaking and overheating from the mold.
Because the leaves were decomposing, toxins may have concentrated as the plant broke down. Even if your dog ate fewer leaves than usual, the mold means this isn't a typical azalea case — it's two poisonings at once.
What to watch in the next two hours
First signs often include excessive drooling, vomiting, or pawing at the mouth as the grayanotoxins irritate the gut. For a 12 kg dog, these may appear within 90 minutes. The mold's effects can take slightly longer — watch for twitching ears or legs, then full-body tremors.
Any seizure-like activity means the mycotoxins are affecting the brain. Combine that with azalea's heart-slowing effect, and the risk of collapse is high. Don't wait for multiple symptoms — early intervention is key.
Why size matters less here
With most toxins, a 12 kg dog has more leeway than a tiny pet, but moldy azalea changes that. The tremorgenic compounds are potent even in small amounts, and the grayanotoxins don't depend on body weight alone — they disrupt cell channels directly.
Your dog's weight won't protect him from the combined assault. Even if he spit out most leaves, mold spores could have been ingested. This isn't about the volume eaten — it's about two different toxins working fast.
When compost makes it worse
Leaves left overnight likely fermented, which can increase mycotoxin production. The damp environment also breaks down plant cell walls, potentially releasing more grayanotoxins than fresh leaves would.
Compost piles often contain other moldy items too — if your dog ate anything else from there, the risk multiplies. Time is critical: both sets of toxins are already circulating, and delaying could mean treating seizures on top of heart issues.
The step-by-step response, from the first minute to the vet visit, is in our Azalea & Rhododendron emergency guide.