Seasonal Advice - Keep your dogs away from Acorns (from the Oak Tree) & Conkers (from the Horse Chestnut Tree)
Conkers: Signs of poisoning usually appear within one to six hours. Clinical signs are drooling, excessive drinking, vomiting, diarrhoea and abdominal pain, difficulty breathing. Seek immediate veterinary advice should you have any worries.
Acorns: Acorns are highly toxic for pets and can easily be eaten. They are most dangerous before they ripen, when they are still green. Signs include vomiting, diarrhoea, abdominal pain, loss of appetite and lethargy.
Seek immediate veterinary advice should you have any worries.
From The Good Vet Guide.