Mushrooms on Walks: Dog Safety Guide

Thousands of mushroom species grow in the wild, and only a small proportion are dangerous. But those few can be deadly, and many look similar to harmless ones. Some, such as the death cap and certain webcaps, can cause liver or kidney failure. Others, such as fly agaric, affect the nervous system. Since the risk cannot be judged by a casual look, all wild mushrooms should be treated with caution.

Dogs are drawn to mushrooms by smell, and some find them tasty. The signs of poisoning can appear within minutes or be delayed by many hours, and a dog who seems well initially can become seriously ill later.

The signs depend on the type of mushroom, and can be broad. Seek veterinary help if you see any of the following, or if you know your dog has eaten a mushroom.

• Vomiting, diarrhea, drooling, and abdominal pain.
• Lethargy, weakness, and a wobbly walk.
• Tremors, seizures, or agitation.
• Excessive thirst and urination, or the absence of urine.
• Yellowing of the gums or eyes (jaundice).
• Collapse or unresponsiveness.

Note: Some of the most dangerous mushrooms cause a delay of 6 to 24 hours or more before signs appear, followed by apparent improvement, and then organ failure. Do not wait.

Treat any ingestion as an emergency. Quick action improves the outlook.

1. Stop your dog from eating more, and remove remaining pieces from the mouth, if safe.
2. Take a photo of the mushroom, and collect a sample, in a paper bag (not plastic), if you can do so safely.
3. Note the time, the amount, and the location.
4. Call your veterinarian or an emergency clinic straight away. In the US, the ASPCA Animal Poison Control Center is 888-426-4435 and the Pet Poison Helpline is 855-764-7661; a fee may apply.
5. Go to the clinic if advised, and take the sample and photos.
6. Do not try to make your dog vomit unless a vet tells you to.

Most mushroom incidents happen when dogs forage off the path. Keep your dog on a leash in woods and fields during damp autumn weather, and watch where they sniff. Choose cleared paths, and avoid areas with lots of mushrooms. Teach a strong leave-it, and reward your dog for ignoring things on the ground. In a high-risk area, consider a basket muzzle, after training your dog to wear one.

Pay attention to unusual behavior when your dog sniffs and chews. If you see your dog eating something, stop them immediately, and check their mouth.

Mushrooms often appear on lawns after rain. Check your yard daily in damp weather, and remove mushrooms promptly, wearing gloves, and dispose of them in a sealed bag. Keep leaf piles, mulch, and wood chips tidy, since they can encourage growth. Do not assume that a mushroom is safe because you have seen it before. Fungus can appear suddenly.

If you cannot control the growth, supervise your dog in the yard, particularly in autumn and after rain.

Never rely on folk tests, such as whether a mushroom is eaten by animals, or turns silver. They do not work. Do not trust phone apps to identify mushrooms for medical decisions. Contact your vet, give as much information as you can, and let the professionals decide. It is always better to call and learn that it was harmless, than to wait and learn that it was not.

A sample helps your vet and a poison specialist to identify the mushroom. Collect it only if it is safe to do so.

1. Wear gloves, or use a plastic bag over your hand.
2. Take a clear photo of the mushroom where it grew, including the cap, gills, stem, and base.
3. Gently dig out the whole mushroom, including the base.
4. Place it in a paper bag, or wrap it in paper, not plastic, which causes it to rot.
5. Keep it cool, and take it with you to the vet.
6. Wash your hands afterward.

Some species are well known for causing serious illness. The death cap and related Amanita species can cause liver failure, and some small brown mushrooms contain toxins that damage the kidneys. Fly agaric causes neurological signs. But many harmless species look similar, and identification needs expert examination. Do not rely on photos from the internet, folklore, or your own judgment. Treat every wild mushroom as possibly dangerous.

Train a solid leave-it, using real objects and a high-value treat. Reward your dog for sniffing and then looking away. For dogs who eat everything, consider a basket muzzle for walks in mushroom-rich places, introduced gradually with treats. Keep your dog on a leash in the woods, and avoid damp, shaded areas in autumn. Ask your vet for advice about risk in your area.