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Animal Poisoning by pantherina and : A Commentary Michael Beug and Marilyn Shaw

WHEN DOGS get sick and poison- sured in terms of amount of per kg of body ing is suspected, it is often difficult to determine weight; thus a small dog that eats one mushroom whether or not were consumed, which winds up with a much, much higher concentration was the culprit, or how long it was between of toxin than a human who eats one mushroom. consumption and poisoning effects. When the Each species (and even different individuals mushroom is determined to be within a species) vary in susceptibility to . or Amanita muscaria, two additional challenges arise. Also, from work that I did years ago I know that The first problem is that some sources advise treat- the amount of toxins in Amanita pantherina (and ment with , a specific antidote for musca- Amanita muscaria) can be quite variable from one rine. However, levels are quite low in collection to the next. Similarly, it has been found these species in which the two most important that some collections of Amanita phalloides or of toxins are and . Atropine, Destroying Angels, like Amanita bisporigera, are far a powerful extracted from , more toxic than other collections. Furthermore, I stramonium, and other Solonaceae, exacerbates have also always been curious about the fact that the effects of ibotenic acid and muscimol. Nev- the poisonings that we see from Amanita pantherina ertheless, other symptoms at times indicate that in the Pacific Northwest sometimes seem more the use of some atropine might be beneficial. The severe than poisonings by Amanita muscaria. Nearly second problem is that the toxins ibotenic acid 30 years ago, on my first Sabbatical, I was work- and muscimol induce a deep comatose sleep. At ing with Dr. Scott Chilton on extracting a mystery this point, the vet will frequently consult with the toxin from Amanita pantherina that we do not see in owner, who will choose to euthanize the animal. Amanita muscaria. While we failed in our attempts But would the animal have recovered in a day or to identify this other toxin, we did observe that two? Some colleagues have long argued that with the dark-capped collections of Amanita pantherina patience, dogs will recover. But will dogs always had a lot more muscimol and ibotenic acid than recover? the light-capped collections of Amanita pantherina. It is clear that, barring exceptional complica- Had these puppies ingested particularly potent tions from other medical conditions, these toxins mushrooms? do not lead to death in humans from ingestion of Anne Leathem who lives in British Columbia, either Amanita muscaria or Amanita pantherina. In only a few hours from where the puppy incident two Amanita muscaria cases I was involved with in occurred reported: the 1970s, cat deaths occurred when the pet owner had saved a stash of dried mushrooms for hal- A few years ago we had a case of two seven- lucinogenic use. Are cats more susceptible to the week-old puppies eating Amanita pantherina. toxins than humans or dogs? We were contacted by a vet. At 1730 hours In 2008 one case of the death of two pup- one puppy was found with a decreased level pies from Amanita pantherina was presented to me of , increased tone in tail and in such clarity, that by the end, I was convinced jaw, muscle rigidity and tetanic spasms in the of the potential lethality of Amanita pantherina for back. Pupils and temperature were normal. At dogs. Some of what was going on was the fact that 1900 h the other puppy was found to have the these were puppies, with immune systems not yet same symptoms but greater CNS depression fully functioning and thus at greater susceptibility and less muscle rigidity. This second puppy to toxins. Another issue was size. Toxicity is mea- died suddenly at 2100 h, and on autopsy,

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medium-brown cap and white stem mush- the . It is also strongly rec- room fragments were found in the stomach. ommended that atropine be avoided, unless there The first puppy was then given gastric lavage, are unequivocal indications for its use. Because and mushroom fragments were retrieved. He of the species name of Amanita muscaria, a toxin still had increased muscle tone and worsening which was isolated in this mushroom was named CNS depression. We recommended giving “muscarine.” This toxin causes cholinergic symp- oral-activated charcoal and, if needed, IV di- toms (over stimulation of the parasympathetic azepam for . By the next morning this nervous system). These symptoms are rarely seen puppy had improved and was discharged the in muscimol/ibotenic acid poisonings (see “mus- following day. Both of the puppies had eaten carine” case below). Atropine is a specific antidote the mushrooms before 1630 h. for muscarine poisonings, but will typically increase the effects of muscimol/ibotenic acid. The symp- I think how much mushroom was consumed toms in these poisonings are very alarming and is likely different in these cases. Also, there are confusing. They typically eventually progress from individual variations in susceptibility and in toxin a hyperactive state, to staggering, collapse, and concentrations. Some puppies survive and others with muscle spasms. The supposition is that don’t. I think they are certainly more likely to die the dog is suffering, and this is the point at which than older dogs, but as you say the dose/body the decision to euthanize is generally made. How- weight is important. In human children, we don’t ever, if we can judge by what happens in human see this degree of CNS depression; breathing does cases (I’m not saying we necessarily can), there may not stop, but perhaps they consume less generally be fear but not physical suffering. It is recommend- than a gobbling puppy. The mysteries of fungi ed that euthanasia be avoided for several hours continue. since, in my experience, most dogs will survive if Marilyn Shaw has more experience with the poisoning is allowed to run its course. Close dogs that have eaten Amanita pantherina or Ama- observation should be given to avoid aspiration if nita muscaria than any other person in the country. vomiting should occur. It should be remembered Marilyn’s accounts follow: that these mushrooms are widely used intentionally by humans, and have been for thousands of years, I still wonder about the dog deaths from for their inebriating effects. They are, in fact, sold muscimol/ibotenic acid in general. As Michael on the internet for this purpose. knows, I have handled numerous cases going Marilyn also pointed out that cats can survive back 20 to 25 years, and had only two which eating Amanita muscaria. In the two cases I had dealt ended in death. One dog aspirated vomit with, death of the cat had been the outcome, so while comatose, during the 30 min. drive to I had concluded that cats always die from these the emergency vet clinic, and its lungs could mushrooms. Marilyn reported: not be cleared. The other, just a couple of years ago, involved a dog that was euthanized I had a case several years ago, which involved within three hours of onset of symptoms, three seven-week old kittens. Their owner said due to a comatose state and muscle spasms she had picked an Amanita muscaria, the day (“seizures”). The vet had proceeded without before, and was keeping it “to try to identify.” consultation with the PC. It was the owner The following day at 8:30 a.m. the kittens who called me later. In all of my other cases got hold of the mushroom and were eating (with one possible exception last year) all the it. They protested vehemently when it was dogs came out of it just fine, though recovery taken away. Soon they were tearing around the can take 10–12 hours or more. house as if possessed (hyper state). Finally, two abruptly fell fast asleep, remaining co- I always stress that over-treatment of the hy- matose (lethargic state) for several hours. The per state (“seizures”) must be avoided because of third was in much worse shape. He was vomit- the vacillations between hyper and lethargic (co- ing, having diarrhea, and was convulsed with matose) states. Tranquilizers can unduly suppress muscular spasms. The owner couldn’t afford a 38 McIlvainea Volume 18, Number 1, 2009 39

vet. I advised her to at least try to get one to Rocky Mountain Poison and Drug Cen- help. She called three, but none would agree ter is the largest and busiest of all the poison to see them without payment. I mentioned in centers in the country. It serves Colorado; passing that the treatment vets would give for Idaho; Montana; La Vegas and Reno, Nevada; the seizures would be some kind of tranquil- and Hawaii. I have had cases involving these izer. She described to me, in great distress, #3 from all of these areas with the pos- writhing at her feet. Later—about 4 p.m.— sible exception of Nevada, and often receive without my knowledge, she decided to give #3 calls from other parts of the country as well.” a quarter of a Valium she had on hand. (This is not recommended. I’m surprised it didn’t kill Dr. Denis Benjamin, MD and author of him.) That evening about 7:30 p.m. while she Mushrooms: Poisons and Panaceas (W. H. Freeman and was eating dinner with #3 on the sofa beside Company, New York 1995) on reading these ac- her, he/she raised his/her head briefly and counts emailed us these comments: meowed, but fell back into the coma-like sleep. In the middle of the night, about 12: I tend to agree with Marilyn’s comments 30 a.m., the owner heard loud crunching. She that over-treatment (of Amanita pantherina got up, thinking it was an older, overweight cat and Amanita muscaria poisonings) generally eating, but to her surprise, it was #3, fully re- causes far more problems in both humans covered and making up for the missed meals. and animals. The intense desire on the part of So I have to disagree that cats always die. physicians, vets, and pet owners to “don’t just These three tiny kittens made it even without stand there, do something” is always stronger veterinary care. than “don’t do something, just stand there.” Following recovery, everyone tends to believe Returning to the topic of dogs, Marilyn Shaw that the treatment did something useful. Most illustrated her feelings about the general non-le- often the recovery is in spite of the treatment. thality of Amanita pantherina and Amanita muscaria Managing the seizures may be reasonable, but in dogs with another one of her case reports: anticonvulsants can themselves cause consid- erable CNS depression, so doses have to be I am reminded of a call from a veterinarian carefully calculated. I would definitely avoid that was referred to me at 1:30 a..m. by RM- the use of atropine if the mushroom is identi- PDC several years ago. The vet said he had a fied as Amanita pantherina or A. muscaria. dog that had been poisoned by a muscarine Thank goodness for Marilyn’s extraor- mushroom. As I developed the facts about dinary memory, careful note-taking and symptoms, I was confused. They certainly did persistence in following up all her cases. I not sound like muscarine symptoms. Then ,as suspect that she has contributed more to our I got the description of the mushroom, it be- knowledge in the last few decades than the came clear that it was an Amanita muscaria case. medical/veterinary professions combined. I The dog was comatose with muscle spasms. have had no experience with cats, so I value “He’s dying,” the vet said. I advised that, given her observations. a few hours, I was sure the dog would survive. It did. There are no lasting effects from these poisonings.