Yorkshire dog next to mushroom

A dog may accidentally eat a mushroom while foraging.

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My dog ate mushrooms

By Dr. Katy Ellison MA VetMB MRCVS Veterinarian

Updated on the

Mushrooms come in all shapes and sizes, and unfortunately some are poisonous. Read on for what to do if you think your dog has eaten one.

Foraging for mushrooms is a popular hobby for some, but a dog’s foraging habits are a little less discerning, to say the least. So what do you do if you think your dog has been eating mushrooms? And is your dog likely to come to harm?

What are the symptoms of mushroom poisoning in dogs?

The symptoms depend on the variety of mushroom that has been eaten. There are approximately 4,500 species in the UK and fortunately the majority will do no harm. Of the mushrooms that are poisonous, there are a range of symptoms. The least toxic tend to cause vomiting and diarrhoea with associated nausea and abdominal pain, and the onset of these symptoms is fairly rapid often within a short time of eating them. Vomiting is actually a good thing, because it helps to rid the body of the offending mushrooms.  

Neurological symptoms (those connected with the brain and nervous system) are caused by “psychoactive” or hallucinogenic mushrooms. Affected dogs may appear poorly coordinated, almost as if they are drunk and this can progress to seizures and loss of consciousness.

The most deadly mushrooms cause liver and kidney failure, with typical signs of poor appetite, an increase in thirst, nausea and, in the case of liver disease, jaundice. Sadly, by the time the symptoms develop (sometimes several days after ingestion) the outlook is not very good and many affected dogs will die.

In general, if your dog starts to show signs of becoming unwell within three hours of eating mushrooms, the outlook is usually fairly good and it is likely that the mushrooms were one of the less toxic varieties. If signs start to develop six hours or more after ingestion, the consequences are likely to be very serious and life-threatening.

What are the causes of mushroom poisoning in dogs?

Of the 4,500 mushroom species that are native to the UK, the majority are edible and harmless. But a small number contain toxins that are harmful on ingestion, causing illnesses ranging from relatively mild gastrointestinal signs to organ failure and death. It can be very hard to accurately identify which category a mushroom falls into, even experts sometimes struggle with this task. As a general rule, any that are harmful to humans are likely to have the same effect on dogs. Dogs are frequent scavengers and may eat mushrooms on purpose or sometimes by mistake when eating other vegetation or grass.  

Mushrooms grow all year round, but thrive in warm, damp conditions, so they tend to grow more prolifically in the autumn months.

How do you test for possible mushroom poisoning in dogs?

There are no specific tests for mushroom poisoning, so your veterinary surgeon will rely initially on an accurate history from you, including what you think your dog has eaten, how much they ate and how long ago they ate it. It may be helpful to your vet if you bring in a photograph of the mushroom, if possible. Alternatively you could bring in a whole mushroom of the variety eaten, But you should wear gloves to do this and transport the mushroom in a sealed bag. A full clinical examination will aid with diagnosis and your vet is likely to advise full blood tests, checking liver and kidney function in particular.

What is the treatment for mushroom poisoning in dogs?

There are no antidotes to mushroom poisons, so treatment will focus on reducing absorption of the mushrooms and toxins from the intestines, and supportive care to treat any associated clinical signs. If your dog is seen by a veterinary surgeon within two hours of eating mushrooms, they are likely to give your dog an injection of a drug called apomorphine, which will make your dog vomit. After two hours, the stomach will have largely emptied and there will be little point in inducing vomiting. Charcoal may then be administered orally to reduce absorption of toxins from the intestines. Treatment will then be focused on supportive care, in other words treating and managing any symptoms that develop. Intravenous fluids are likely to be required in all cases.

In dogs showing gastrointestinal signs, gut protectants will be administered and medication to control nausea, if required. If there are neurological (nervous system) signs, medication may be given to control tremors and seizures, as well as pain relief to make sure your dog is as comfortable as possible. If liver or kidney failure has developed, the prognosis for recovery is not good, but treatment will focus on maintaining hydration with fluids and supporting kidney and liver function. Once organ failure has developed, urgent treatment is essential, if there is to be any hope of saving your dog.

What happens if my dog eats a mushroom?

The vast majority of mushrooms in the UK are harmless and edible. If a mushroom is safe for you to eat, then it is likely to be safe for your dog to eat. As such, if your dog steals a mushroom from the kitchen while you are cooking, do not panic. They will almost certainly be fine.

Having said that, of the 4,500 species of mushroom in the UK, about 50 are poisonous. Of these poisonous mushrooms, the majority cause fairly mild symptoms and will not result in death. Over 95% of mushroom-related fatalities are as a result of eating the death cap mushroom, Amanita phalloides. So in general, if your dog eats a mushroom, they are likely to be OK, but because of the small chance of serious illness or death, if they have eaten one of the more poisonous species, always seek veterinary advice.

How many mushrooms can kill a dog?

The number of mushrooms that can kill a dog depends on the species of mushroom that has been eaten. Mushrooms that are edible for humans will also be OK for dogs. At the other end of the spectrum are the highly poisonous mushrooms, such as the death cap mushroom, where as little as half a cap is enough to kill a person.  

What kinds of mushrooms are poisonous to dogs?

If a mushroom is poisonous for you, it will almost certainly be poisonous to dogs. The mushroom responsible for the most fatalities worldwide is the death cap. Other mushrooms that are highly poisonous have names that allude to their deadly nature, such as deadly webcap, funeral bell and destroying angel, among others. The deadly webcap is particularly dangerous because it looks like the edible chanterelle mushroom.

Should I induce vomiting if my dog ate a mushroom?

If you a certain that your dog has eaten an edible mushroom, for example they have raided your shopping or snaffled a mushroom from the kitchen floor, there is no need to induce vomiting because your dog will be OK.

But if your dog has eaten a mushroom while you are out walking with them and you are in any doubt as to whether the mushroom is edible, vomiting should be induced. This should only be done by a veterinary surgeon. Usually the vet will administer an injection of a drug called apomorphine, which will make your dog vomit within 15 minutes or so. It is not recommended to try to induce vomiting yourself because not only may you cause your dog direct harm, but in addition if you are unsuccessful you will have lost valuable minutes. The longer the mushroom sit in your dog’s stomach, the more will be absorbed and the worse the effects.

What do I do if my dog ate a mushroom in our backyard?

Most mushrooms growing in a backyard will be harmless to your dog, but unless you can positively identify the mushroom as safe to eat, seek urgent veterinary advice.

How long does it take for a dog to die from poisoning?

It can take several days for a dog to die from mushroom poisoning. Contrary to what might be expected, the cases where symptoms develop very quickly after ingestion are almost always relatively mild and the prognosis for a full recovery is good. Where there is a delay before symptoms developing, the prognosis is usually far worse and death from liver or kidney failure ensues over the course of a few days.

What do I do if my dog ate a mushroom in the grass?

Many dogs are scavengers and will always be on the look-out for a tasty morsel. Or they may accidentally eat a mushroom while foraging about in long grass. Reassuringly over 99% of mushrooms in the UK are non-toxic, so in the vast majority of cases no harm will come to your dog. Having said that, if your dog has been unlucky enough to eat a toxic variety, once symptoms develop it may be too late to save them. Always err on the side of caution and unless you are very confident with your mushroom identification, seek veterinary advice.

What do I do if my dog ate a white mushroom outside?

The recommendation to people who forage for mushrooms is that you should never eat a mushroom unless you can positively identify it and the same rule should apply to dogs. Just because a mushroom is white and looks fairly innocuous does not meant that it is. If you have seen your dog eat a white mushroom, unless you can positively identify it as safe to eat (and even experts can sometimes find this task tricky) seek urgent veterinary advice.

What do I do if my dog ate a mushroom and is throwing up?

If your dog ate a mushroom and is vomiting within three hours of eating it, the effects are generally what is known as self-limiting (i.e. they will resolve with little or no treatment) and not life-threatening. If your dog starts vomiting after a longer time interval, they may be vomiting as a result of kidney or liver failure and the prognosis for your dog is not good.

How long does it take for a mushroom to poison a dog?

The length of time that mushroom poisoning takes to develop in dogs depends on the species of mushroom that has been ingested. Signs of mushroom poisoning tend to develop quickly with the less toxic varieties, with vomiting and diarrhoea starting in as little as 10 minutes after ingestion and up to two or three hours after. The more toxic the mushroom, the longer the signs take to develop and it can be several days before signs of liver and kidney failure develop.

Can dogs eat button mushrooms?

Button mushrooms are safe for dogs to eat. A good rule is that if a mushroom is safe for us to eat, they are safe for dogs.

Should I try to identify mushrooms that are toxic to dogs?

Mushroom identification is a job that should be left to experts. Do not waste time trying to identify a mushroom that your dog has eaten out on a walk. It is better to operate under the assumption that it is toxic and treat accordingly.  

Are death cap mushrooms lethal for dogs?

The death cap mushroom, Amanita phalloides, is the most deadly fungus known, causing 95% of mushroom fatalities. It is found relatively commonly in the UK, particularly in woodland areas in the autumn months. It ranges from pale yellow to olive in appearance and measures 5 to 15cm across. A lethal dose is thought to be in the region of 0.1mg/kg, so in a 30 kilogram Labrador this would equate to as little as 3mg. Half a cap is known to cause fatality in people. Emergency veterinary care is required, if you think your dog may have eaten a death cap mushroom.

How to keep dogs from eating mushrooms

When out on walks try to keep your dog under control and stop them from scavenging. Wooded areas in the autumn are frequently alive with mushrooms, but they can be found all year round, so always pay attention.

Mushrooms will frequently grow on lawns as well. Fortunately the majority of these will be totally harmless, but it is wise to remove them from your garden, disposing of them carefully so that you do not spread the fungal spores.

When should I see a vet?

If you think that your dog may have eaten a mushroom, unless it is a variety that you would eat yourself, seek immediate veterinary care. 

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