Giant Hogweed – Can It Hurt Your Dog?

giant-hogweed1-1024x655 Giant Hogweed - Can It Hurt Your Dog?


We have all heard stories about giant hogweed, and how dangerous it can be, but just what exactly is it, how hazardous is it, what are the threats from giant hogweed to our dogs., nd how can it be identified so we can keep ourselves and our pups at a safe distance?

What is Giant Hogweed?

To give it its botanical name, Heracleum Maximum, sometimes known as cow parsnip, Giant Hogweed is a member of the carrot family and a relative of cow parsley. It can grow up to 6 metres tall, is a hairy biennial plant which has white umbrella-like, flower clusters and dark green leaves, sometimes 1-3 feet in diameter. It’s mostly found growing along riverbanks and footpaths, but can also be found in cemeteries and parks and along common routes for dog walkers. It has a reputation for being the most dangerous plant in Britain.

Although the entire plant is poisonous, the seeds are especially dangerous to almost anything that comes in contact with the species, especially livestock, companion animals such as dogs, and even humans. Photosensitisation is what makes giant hogweed such a threat to dogs, and is a clinical condition in which areas exposed to light that is lacking protection, become hyperactive to sunlight because of the photodynamic agents that are present.

The injury occurs not only when ingested, but when the plant’s sap comes into contact with skin or fur. Symptoms include extreme blistering and burning that is extremely painful, as well as wrinkling, cracking and discolouration of the skin. More extreme conditions caused by giant hogweed include extensive scarring and even blindness, with animals specifically being at risk for suffering from permanent scarring of the eyes and cloudiness of the corneas, both of which can result in permanent blindness.

After Exposure with Giant Hogweed

The hairy coat of your dog should provide some protection, but areas such as the ears, muzzle and nose can be worst affected.

However, if the pet owner is lucky enough to know for sure their dog has eaten giant hogweed the can react quickly and ideally take steps immediately to reduce the effects of the plant. Start by ensuring there is no remaining plant matter in the mouth, and by thoroughly washing the skin and fur to make sure no sap lingers. Now cover the area affected and keep out of the sunlight. The sap is phototoxic and if exposed to sunlight will cause blisters and burns. Ensure that you wear protective gloves and immediately wash your hands after handling your dog. Take your dog for immediate medical attention from the Vet.

Your vet will provide any necessary treatments, such as activated charcoal, gastric lavage, wound treatments and corticosteroids as needed.

The prognosis for dogs that receive treatment is good and the majority will recover in days, although any scarring on the nose and ears could well remain, and of course, in some cases, damage to the eyes and lasting blindness may result.

There are several plants that dog owners will already know to be on the lookout for, such as lilies, bulbs and foxgloves, but giant hogweed could be pretty low on some people’s radar. It is important to be able to identify this toxic plant when out walking in the countryside.



Article by Finchley Dog walker for all your bespoke dog walking needs.  Edited  by Sue of Tip Dog School – positive dog training finchleyPositive training