Dr. Tina Wismer, Senior Director of ASPCA Pet Poison Control Center joins Dr. Andy Roark to talk about a scary case. Vomiting, fever, muscle tremors, and a stiff gait…. what could be the cause??
Chlorfenapyr is a chemical used in some pest control sprays, and it can be a fatal toxin for pets. Dr. Wismer discusses the risks and how to treat these cases if/when we see them.
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LINKS
ASPCA Animal Poison Control: https://www.aspca.org/pet-care/animal-poison-control
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ABOUT OUR GUEST
Tina Wismer, DVM, MS, DABVT, DABT, is the Senior Director of the ASPCA Animal Poison Control Center. She earned her undergraduate degree from Ohio’s University of Findlay and received her DVM from Purdue University. Dr. Wismer worked in both small animal and emergency practice before joining the ASPCA Animal Poison Control Center in 1998. Dr. Wismer is a Diplomate of the American Board of Toxicology and the American Board of Veterinary Toxicology. She is an adjunct instructor at the University of Illinois, a visiting professor at St. Matthews University (Grand Cayman), a consultant for VIN (Veterinary Information Network) and a Master Gardener.
EPISODE TRANSCRIPT
This podcast transcript is made possible thanks to a generous gift from Banfield Pet Hospital, which is striving to increase accessibility and inclusivity across the veterinary profession. Click here to learn more about Equity, Inclusion & Diversity at Banfield.
Dr. Andrew Roark:
Welcome everybody to the Cone of Shame Veterinary Podcast. I am your host, Dr. Andrew Roark. Guys, I’ve got a fun toxicology case for you today. What’s going on with this trembling, shaking dog? Why did its two housemates die suddenly? What are we going to do about it? How concerned do we need to be in the future? Are we having good conversations with pet owners about what to do when they have the insect home protection guy come into their house? Let’s get into this episode.
Kelsey Beth Carpenter:
(Singing) This is your show we’re glad you’re here. We want to help you in your Veterinary Career. Welcome to the Cone of Shame, with Dr. Andy Roark
Dr. Andrew Roark:
Welcome to the podcast. Dr. Tina Wismer, thanks for being here.
Dr. Tina Wismer:
Thank you for inviting me.
Dr. Andrew Roark:
My absolute pleasure. I love having you on here. You’ve been on a number of times. You’re at my go to for toxicity questions that I have when I’m losing sleep about my patients eating things, you are the person that I reach out to. For those who do not know you, Dr. Tina Wismer is the senior director of the ASPCA Animal Poison Control Center. Thanks for being here.
Dr. Tina Wismer:
Thank you for inviting me.
Dr. Andrew Roark:
I think… Yeah. Sorry. I keep thanking you.
Dr. Tina Wismer:
I think we already did that. That’s okay.
Dr. Andrew Roark:
We did that already. Okay. I’m sorry. Let’s move on to the next session. I invited you here because I saw an article. It was actually in today’s Veterinary Nurse Magazine, which is a great magazine. They do good work. I enjoy a lot of stuff. They had a case that scared the willies out of me. I wanted to get some more information on it, and get your thoughts on, one, treatment of this thing. But then two, also, what are the risks and how likely am I to have to deal with it, and just get a more clear view of it. The case that they talk about, that I want to put to you presented like this, there is a pet owner and she went to school for the day. She came home and her three dogs were acting normally. She has a Labrador, she has a Chihuahua, and she has a Jack Russell, so big dog and two little dogs. They’re all acting normally.
Dr. Andrew Roark:
Then she takes them for a walk. When she comes back, it’s been about two hours since she got home. The big dog is acting normal, but the two small dogs are not. They are panting and they have both vomited multiple times. Then they had a stiff gait in their hind end, as they walked around. The vomitus was described as frothy fluid with a red tinge. Then about one hour after they started showing signs, both of the small dogs had died. The bigger dog was starting to show the same signs, the stiff gait, mostly it was the panting and appeared to be in distress. This dog was rushed into emergency care and was thankfully saved. The diagnosis that was given was chlorfenapyr poisoning. I just want to start to talk about that and what that means. Starting at the high level, what is chlorfenapyr?
Dr. Tina Wismer:
Chlorfenapyr is an insecticide. It is labeled for use on both agricultural products and for in the household.
Dr. Andrew Roark:
Okay. We most commonly see this where? I mean, I guess, how do companion animal vets tend see this? How is this used in our households? Is this something that people go down to Home Depot and pick up, and they’re just sort of spraying around the house? It sounds like this is sort of the next level up from that.
Dr. Tina Wismer:
Right. This can only be used by licensed pest control operators. This would be the company that you would pay to come in and spray your house for termites, or if you had a severe roach infestation. You’re not going to be able to go to Home Depot or Walmart and buy this yourself.
Dr. Andrew Roark:
Okay. How often does this happen? I mean, I get my house sprayed for termites, because I live in the woods. Is this a common occurrence? Is it fairly uncommon? How concerned about this type of toxicity should I be?
Dr. Tina Wismer:
Sure. Fortunately, it’s pretty rare. This product has been on the market since about 2001. We see the occasional animal that gets exposed and has problems, but it’s not very common.
Dr. Andrew Roark:
Well, why do we think it’s uncommon? Is this type of chemical not used really widely by the guys who are spraying? Is it dose dependent, and so most pets don’t reach a dose that is going to cause clinical signs? Were all three of these dogs just the weird cases that had a reaction? Yeah. What’s your take on why we don’t see this more commonly?
Dr. Tina Wismer:
Right. Number one, I don’t think it’s very commonly used as compared to our other like pyrethrin-based products, which we know are quite safe around mammals. I also think that most people remove their animals from the household when this person is coming over to spray. All of our cases have been animals that were inside the household when the spraying was occurring.
Dr. Andrew Roark:
Okay. Is there anything that, on the surface level, I could see or I could advise pet owners to see? If pet owners call me and they say, “Hey, I’m getting ready to get my house sprayed. Is there anything I should be looking for in the pest control guys?” Because I have gotten those questions a number of times, is there any red flags or anything that I should just put out to them and say, “Hey, here’s something to look out for.”
Dr. Tina Wismer:
Right. Most pest control operators will give you the name of the product that they’re using, things like EPA registration numbers. You can check and see how safe is this to use around pets. Also, the most important thing, remove them from the environment.
Dr. Andrew Roark:
Yeah, no matter what.
Dr. Tina Wismer:
Yeah. Don’t bring them back until you can’t smell the product anymore.
Dr. Andrew Roark:
Okay. That’s a good rule. If you can’t smell it, then it’s probably okay. Am I paraphrasing that appropriately?
Dr. Tina Wismer:
Yes, yes.
Dr. Andrew Roark:
Awesome. All right. Sweet. Okay. What do we tend to see on clinical presentation in these dogs? I told you, the pet owner said that she saw, what other signs do we see beyond that? Are there things that we’re going to find on admission to the hospital that maybe the pet owner would not have seen?
Dr. Tina Wismer:
Yeah. These guys tend to have pretty impressive tremors, muscle tremors. Then we get secondary hyperthermia, your body temperature goes up.
Dr. Andrew Roark:
Got it.
Dr. Tina Wismer:
Some of these guys will also develop pulmonary edema.
Dr. Andrew Roark:
What temperature levels are you talking about when you say the temperature goes up, because I see a lot of nervous dogs that come in at 102.5. Is that what we’re talking about? Are we talking about 104, 105?
Dr. Tina Wismer:
We’re talking, these guys can present at like 107 or 108.
Dr. Andrew Roark:
Okay.
Dr. Tina Wismer:
So badness. Bad.
Dr. Andrew Roark:
Yeah, badness. All right. That’s super helpful. Okay. That way I won’t be like, “Oh my God, he’s 103, is this [inaudible 00:07:28]. Have you had-
Dr. Tina Wismer:
No, not chlorfenapyr.
Dr. Andrew Roark:
What other presentations… Clearly we’ve got muscle fasciculation, stiff gait, vomiting, panting, things like that. This is going to look like a toxicity of some point. What else looks this way? What are my other differentials that I want to separate this from?
Dr. Tina Wismer:
Sure. The one thing this looks very common or very similar to is hops toxicosis. If you’re home brewing beer, dogs that get into the hop pellets or they get into the hops flowers that are in your compost pile will present the same way. They’ll be extremely hyperthermic, they’ll be panting.
Dr. Andrew Roark:
Okay. That’s a question I don’t have in my repertoire for pet owners. “Have you been brewing beer?”
Dr. Tina Wismer:
Perfect.
Dr. Andrew Roark:
No, yeah.
Dr. Tina Wismer:
It’s pretty popular now.
Dr. Andrew Roark:
I mean, yes in way, but if I… “Have you…” Okay. People, yeah. That’s going to get me some weird looks from people when I… “Quick,” as I race them the back, “have you brewed any beer? Tell me now.”
Dr. Tina Wismer:
“If so, can you bring me some?” Exactly.
Dr. Andrew Roark:
Exactly. “If not, that’s good. If yes, that’s all so good because I’m going to need one.” Okay. My main differential is hops from beer brewing. “Have you had any insecticide sprayed? You don’t brew beer, do ya?” Those are two good questions. Okay. Basically same muscle fasciculations, high body temperature, vomiting, things like that, I’m going to see in both of those cases.
Dr. Tina Wismer:
Yes.
Dr. Andrew Roark:
What am I going to see on my diagnostic tests? Is there anything I’m going to see on the blood work that’s going to tip me off, either that I’m looking at these two, either hops or chlorfenapyr, or that’s going to differentiate them? Am I going to see on radiographs? Walk me through my diagnostics, if you don’t mind.
Dr. Tina Wismer:
Yeah. On blood work, you’re really not going to see anything initially, everything’s going to be normal. As the process goes on, things like CK are going to rise because you’ve got a lot of muscle activity. Then we can potentially see coagulopathies because of high body temperature, DIC. But nothing initially, it’s going be completely normal. Radiographs, once again, also going to look pretty benign.
Dr. Andrew Roark:
The main way I’m hearing from you is clinical history is your guiding light.
Dr. Tina Wismer:
History.
Dr. Andrew Roark:
That’s going to make it or break it.
Dr. Tina Wismer:
Yes.
Dr. Andrew Roark:
When the pet owner says to you, “Yeah. We had the guy in to spray the house today while I was at work.” How big of a blaring siren is that for you? Is that a big, red flashing, “This is an emergency.” Or is that kind of a, “Hmm, we’re definitely going to need to look into… We’re going to need to take this seriously.” Yeah. How many alarm fire is this for you?
Dr. Tina Wismer:
Right. With most insecticides that are contacted by the inhalation route, we’re going to see signs within a couple of hours, so we’re going to also ask about timeframe. But if we’ve got clinical signs that fit, we’ve got tremors, we’ve got hypothermia, then, yes, this is your nine-alarm fire.
Dr. Andrew Roark:
Yeah. Okay. I wasn’t sure how many alarms we could have. I thought five was the most.
Dr. Tina Wismer:
I don’t know. I just make that up.
Dr. Andrew Roark:
But maybe nine, if it’s a nine-alarm, I’m like, “That’s bigger fire than I had even thought.” I love it. I got it.
Dr. Tina Wismer:
Infinity, I don’t know.
Dr. Andrew Roark:
Yeah, exactly. I’m just going to be honest, my knowledge of the alarm system that firemen used is very limited. When you said nine, I was like, “Holy crap.”
Dr. Tina Wismer:
Zero. Zero, I have no idea. Zero. Zero knowledge.
Dr. Andrew Roark:
Okay. Yeah, there’s got to be a better medical way of describing this than in a fire alarm categories. Okay. All right. Moving on. I get the point. I get the point. We’re not sleeping on this.
Dr. Tina Wismer:
No.
Dr. Andrew Roark:
We’re not going to sleep on this. How do we treat it? This dog presents and I need to take action, what are my main concerns as I do this? How am I going to treat this?
Dr. Tina Wismer:
Sure. We want to get our body temperature down. You’re going to use things like IV fluids, wet the fur, a cool fan. Then for vomiting, pick your favorite antiemetic. For tremors, you’re going to use methocarbamol. You’re great. Muscle relaxant. Then, these guys actually respond pretty well to lipids.
Dr. Andrew Roark:
Okay. Tell me more about that. They respond pretty well to lipids.
Dr. Tina Wismer:
Sure.
Dr. Andrew Roark:
Walk me through that. That’s not something I reach for a whole lot.
Dr. Tina Wismer:
Sure. When we’re talking about lipids, we’re talking about the 20% solution that you use for partial parenteral nutrition, right?
Dr. Andrew Roark:
Okay.
Dr. Tina Wismer:
You’re feeding them through the vein. The thought is that we have certain toxins, including chlorfenapyr, that are highly lipid soluble. The thought is, if we give dogs lipids, we’re going to bind the toxin within the bloodstream and therefore it can’t get out and it can’t affect the receptors and cause clinical signs.
Dr. Andrew Roark:
Okay. Talk to me about a dosing regime and a timeframe for this, if you don’t mind.
Dr. Tina Wismer:
Sure. We start out with a bolus of about one and a half mils per kilo. You can give that over about 20 to 30 minutes. Then we drop down to a constant rate infusion of 0.5 mils per kilo per minute, and we’re going to do that for another 30 to 60 minutes. Right?
Dr. Andrew Roark:
Okay.
Dr. Tina Wismer:
The big thing is, if you’ve got a small dog we don’t want to volume overload, so make sure you go on the low end. Then we’re going to stop our constant rate infusion for about four hours. We’re going to then check and see if we’re lipemic. If we’re lipemic, we’re going to hold off. But if we’re no longer lipemic and our animal is still symptomatic, then they get another dose of lipids.
Dr. Andrew Roark:
What kind of timeframe am I looking for to see a change, or ideally, a resolution of symptoms? If I’m seeing muscle fasciculations and things like that, and I start to give some lipids and things, is this a 30 minutes in and I start to see improvements? Is this a longer play? Is this magic where you start to… It’s like deworming… or blood transfusion in a hookworm puppy where they just open their eyes and feel better? What are we talking about?
Dr. Tina Wismer:
Sure. With something like chlorfenapyr, typically it just takes like one dose of lipids. Usually by the time we finish that one to two hour timeframe, they’re much better. If we’re using lipids to treat something like marijuana or avermectins, things like ivermectin or Moxidectin, then you may need to give multiple doses of lipids before we see an improvement.
Dr. Andrew Roark:
Okay. Then what is the ultimate official cause of death in these cases?
Dr. Tina Wismer:
They can either die from severe hypothermia, or they can die from pulmonary edema.
Dr. Andrew Roark:
Okay. I’m assuming I’m going to pay special attention to lung sounds, things like that, as we’re treating and just try to manage to that.
Dr. Tina Wismer:
Exactly, yes.
Dr. Andrew Roark:
Okay. All right. Any other pearls of wisdom for me? Any words of advice as I would wade into something like this? Any mistakes I really want to avoid making?
Dr. Tina Wismer:
I think the important thing is to keep a pretty close eye on these guys for the first couple of hours that you have them. If they’re going to die, they tend to die pretty quickly.
Dr. Andrew Roark:
Okay.
Dr. Tina Wismer:
If we can get that temperature back down quickly, then they do well. Otherwise, then we have to manage DIC, and no one wants to do that. Just, let’s take-
Dr. Andrew Roark:
No, yeah. Let’s not do that. Awesome. Dr. Wismer, thank you so much for being here. Tina, I appreciate you so much. I really appreciate your time.
Dr. Tina Wismer:
Thanks for inviting me.
Dr. Andrew Roark:
That is our episode. Guys, I hope you enjoyed it. I hope you got something out of it. If you’re watching on YouTube, hit that Like and Subscribe button. If you’re checking out the podcast, the nicest thing you can do is leave an honest review wherever you get your podcast, it’s how people find the show. Means the world to me. Guys, thank you so much for being here. I hope you learned something. I hope you enjoyed your time with me. I hope see you again soon. Take care of yourselves, all right? Be well. Bye.
