There has been an increase in sightings of common earthball mushrooms due to the mild weather this autumn.
They are often found in shady wooded areas, and can kill over half of dogs who ingest them.
Symptoms to look out for include drooling, sickness and diarrhoea. Some species of fungi can cause neurotoxicity, which leads to 'drunken' behaviour such as erratic movements, hallucinations and seizures.
Vets advise that any dog that has eaten wild mushrooms should be taken for immediate assessment.
Owners should keep their dogs on leads in damp woodland areas, or use a basket muzzle to prevent them foraging.
The common earthball is also known as the pigskin poison puffball. It grows in autumn and winter in woods, heathland and short grass. They can also cause gastrointestinal illness in humans, as well as rhinitis and conjunctivitis.
This summer Leeds was hit by an outbreak of the canine disease parvovirus, which is transmitted via dog faeces and which can be fatal. It was thought to have been exacerbated by the hot, dry weather.