Arachnid antiparasitic medication

[schmiggle]

I suspect the answer is no, but figured I'd see if anyone knows anything. I've tried to google for this kind of thing before, but haven't come up with much.

A lot of imported inverts are bought stressed, and many likely have high parasite loads. I'm thinking most particularly of Damon medius, which many members have posted about losing due in large part to the way they were treated before importation, but I imagine it applies to a number of species. As far as I know, one of the first things to do with vertebrates in a similar situation is to take the animal to the vet and get it tested for a variety of common diseases. Then, when they inevitably turn out to be chock full of worms, they're given an antihelminthic to control what was probably an inconvenience in the wild but could become life-threatening after the animal has been weakened. Are there any such medications for invertebrates? I would think a lot of antibiotics have low toxicity, given that they target bacterial cell walls, but you never really know without experimental evidence.

 

[Edan bandoot]

Give it 10 years and someone with nepotistic government ties will get the funding for it. seems plausible on paper

 

[The Snark]

I suspect the answer is no,

I'm guessing you went light on pharmacology. As I understand it, whether antibiotics or other, it's pretty exacting how much load can be delivered into the blood stream over how long a period. Of course, we are also talking about the difference between a therapeutic dosage and a detrimental one which can be very close together. How long will the drug stay in the blood stream and how fast will it evacuate? Of course, this can change by hundreds or thousands of percentages from species to species. One dose, marginally effective, may need to be administered every hour, or once every 2 or 3 weeks.
Then when it comes to parasites, the drugs are, one and all, broad spectrum biocides, quite capable of killing any invertebrate. The precise loading must be maintained until it is distributed throughout the body to the undesireable organisms in the correct quantity while maintaining a threshold below lethal toxicity to the animal being treated. When you are talking the difference in micrograms between ineffective and lethal, which will alter drastically between animal species, you're probably going to find it easier to start a cactus farm in Greenland.

 

[schmiggle]

I'm guessing you went light on pharmacology. As I understand it, whether antibiotics or other, it's pretty exacting how much load can be delivered into the blood stream over how long a period. Of course, we are also talking about the difference between a therapeutic dosage and a detrimental one which can be very close together. How long will the drug stay in the blood stream and how fast will it evacuate? Of course, this can change by hundreds or thousands of percentages from species to species. One dose, marginally effective, may need to be administered every hour, or once every 2 or 3 weeks.
Then when it comes to parasites, the drugs are, one and all, broad spectrum biocides, quite capable of killing any invertebrate. The precise loading must be maintained until it is distributed throughout the body to the undesireable organisms in the correct quantity while maintaining a threshold below lethal toxicity to the animal being treated. When you are talking the difference in micrograms between ineffective and lethal, which will alter drastically between animal species, you're probably going to find it easier to start a cactus farm in Greenland.

I didn't mean that they don't exist as much as that they aren't for sale. I don't think there's been too much research, though I should check for silk worms.

 

[Malum Argenteum]

@schmiggle, there are indeed narrow spectrum antiparasitics (useful search term to get further leads) that MAY be useful -- though not as shotgun treatments, of course, since they are targeted to certain parasites. In aquaculture, praziquantel (for worms) and metronidazole (for parasitic protozoans) are routinely used -- with some pretty suspect dosing protocols, to boot -- with negligible effects on (most) non-target inverts, and are OTC in the US. I have no idea what the effects are on terrestrial arthropods, but I don't know that either are particulary toxic to marine arthropods, so that's encouraging.

There are other possible narrow spectrum drug options (Google; I'm not familiar with them) that would require an interested vet to be on board with, but my experience with exotics vets is that they are more willing than others to approve off label use for a trusted client who has put in the research.

 

[The Snark]

antihelminthic

Sorry for misunderstanding.
Entomologist: None that I know of. The only tests that we have heard of through channels is on mammals and certain animals grown and marketed specifically for food. The stand by for exportation appears to be quarantine with time duration appearing to be haphazard guesswork.
Of course, with parasites, quarantine is useless.

She went on to mention that I'm in the wrong country to get any first hand information. With illegal animal trafficking the order the day here and government information about as opaque as it can get, I went to web searches and got what you mentioned. There's shiploads of gossip and actual lab test results rarer than hens teeth.

 

[spideyspinneret78]

Finding anti-parasitic medications for invertebrates is a lot more difficult than you might think. A lot of the proven dewormers/ antiparasitics work on vertebrates because of the blood-brain barrier and the fact that they're designed to affect the nervous system of inverts while being unable to pass into the CNS of their vertebrate hosts. Many anthelminthics work because they paralyze the worm's nervous system. Ivermectin is another example...toxic to inverts, but doesn't affect most vertebrate hosts nearly as much. It'll require a lot of research to find a medication that's effective against oral nematodes, parasitic mites, etc. that won't also kill the tarantula/ scorpion. The nervous systems of some invertebrates tend to be similar in some regards, so it's complicated.

 

[schmiggle]

@schmiggle, there are indeed narrow spectrum antiparasitics (useful search term to get further leads) that MAY be useful -- though not as shotgun treatments, of course, since they are targeted to certain parasites. In aquaculture, praziquantel (for worms) and metronidazole (for parasitic protozoans) are routinely used -- with some pretty suspect dosing protocols, to boot -- with negligible effects on (most) non-target inverts, and are OTC in the US. I have no idea what the effects are on terrestrial arthropods, but I don't know that either are particulary toxic to marine arthropods, so that's encouraging.

There are other possible narrow spectrum drug options (Google; I'm not familiar with them) that would require an interested vet to be on board with, but my experience with exotics vets is that they are more willing than others to approve off label use for a trusted client who has put in the research.

Thanks, I'll look into these.

Finding anti-parasitic medications for invertebrates is a lot more difficult than you might think. A lot of the proven dewormers/ antiparasitics work on vertebrates because of the blood-brain barrier and the fact that they're designed to affect the nervous system of inverts while being unable to pass into the CNS of their vertebrate hosts. Many anthelminthics work because they paralyze the worm's nervous system. Ivermectin is another example...toxic to inverts, but doesn't affect most vertebrate hosts nearly as much. It'll require a lot of research to find a medication that's effective against oral nematodes, parasitic mites, etc. that won't also kill the tarantula/ scorpion. The nervous systems of some invertebrates tend to be similar in some regards, so it's complicated.

No, I know a lot of stuff that's toxic to parasites isn't toxic to us because of different metabolisms, though I wasn't aware the blood brain barrier was so critical in that regard (guess that's why we have it lol). I'm betting it's a lot easier to treat worms and protozoa than it is to treat mites, but you can also see mites with your naked eye, usually, so there's not as much reason to treat for them preemptively anyway.

I'll also look into antibiotics, since the bacterial metabolism they target is radically different from anything in metazoa. However, do any of you know anything more specific?

 

[The Snark]

All of the ...-azole antibiotics family should be suspect or avoided. Many affect or actively attack the central nervous system.

 

[spideyspinneret78]

All of the ...-azole antibiotics family should be suspect or avoided. Many affect or actively attack the central nervous system.

True. Metronidazole, for example can have neurological side effects.

 

[schmiggle]

I've been looking for stuff about silk worms to start, because they should have a more similar CNS to arachnids than any vertebrate and they don't have a blood brain barrier. For starters, I found this paper, which injected a range of antibiotic and antifungal medications after infection with human pathogens and found their effects to match those in humans, including which had to be administered by injection rather than orally. These meds seem like a good place to start, IMO. It does use fluconazole, and found that it worked, though not as well as the comparison medication, so might as well avoid anyway. I'll look into antihelminthics next.

 

[schmiggle]

I found this other paper looking at albendazole that found low toxicity in a couple of other lepidopteran larvae at levels effective to kill microsporidia. Albendazole is effective against a range of worms and protists in humans, as well, so this seems promising. Various papers have looked at albendazole, actually, so I think it's pretty safe, although it seems not to always be effective (particularly against microsporidia, ironically).

Moving on to praziquantel, this paper found low toxicity in dung beetle larvae--only 40% mortality at 1000mg/kg of dung dry weight, which is an absurdly high dose. I think that's rather promising as well.

Metronidazole was addressed here, where researchers found that it hurt cockroach gut flora but that there wasn't any direct toxicity. This was a bigger deal when cockroaches were fed metronidazole from hatching, which caused them to be stunted; when fed to adult cockroaches, there was no health effect. Also seems promising. @Malum Argenteum I'm quite impressed--you're two for two.

Seems like microsporidia are important arthropod parasites. Didn't really think about them, but might be important to find a medication that's effective against them for this kind of thing. There hasn't been too much success there, though, to be honest--lots of meds will work against one species of microsporidia, but not broadly. I haven't looked at those specifically, so that's maybe a next step.

Overall, it seems like there's actually a number of good options to try. My big concern is that drug interactions are well understood in vertebrates, but I haven't been able to find as much in inverts, and if you're actually trying to knock out parasites you can't easily test for, you probably want at least three meds--an antibiotic targeting bacteria, a traditional antifungal, and something like albendazole targeting assorted eukaryotes (including microsporidia--hence "traditional" antifungal). I don't think there's too much crossover in effectiveness.

 

[The Snark]

40% mortality

1000mg/kg of dung dry weight

........................................................................................ I'm going back to jackass fences. Will read those white papers when my masochism gene kicks in.