Dog owners are being advised to beware the dangers posed by conkers and acorns to their snuffle-searching canines. While heralding the arrival of autumn with their distinct green shells and hard brown shells, conkers can make our four-legged friends seriously unwell if eaten or chewed due to causing a toxin called aesculin, Dogs Trust said. Symptoms include vomiting, diarrhoea, stomach pain, restlessness, a rash, swelling around the eyes and mouth, and not being able to move. Dogs can also choke on conkers and acorns, or suffer blockages in the gut. Victoria Phillips, Veterinary Surgeon Manager at Dogs Trust, said: "Conkers might be a sign that autumn is here, but it is vital that dog owners understand that conkers and acorns can be toxic to dogs and, in some cases, can even be deadly. “Bigger dogs might swallow them, and smaller pooches might give them a chew, both of which can have some nasty side effects.” She added: "To keep your dog safe this autumn, walk your dogs on a lead where there are lots of conkers on the floor, and keep your eyes peeled for your pooch playing with them. "They may look relatively harmless, but they can cause serious issues." Dogs Trust advises any owner who is concerned their dog has chewed or consumed conkers or acorns, or is showing signs of illness, to contact a vet immediately. For more information, visit Dogs Trust (opens new tab).