03-08-2009, 08:22 AM
Dr. Prociv and Dr. Carlisle have responded to Menehune's question about rat lungworm in cats along with a couple of other questions I had for them. They write-
G’day Steven
Sorry I missed it earlier, but I’ve just come across your old e-mail; we’ve been having a few problems with e-mails lately, leading to our need to close down the old account and open a new one, hence the new address. We hope this has not caused you difficulties.
Anyway, to your questions . . .
In reply to Menehune's question "Really - can cats become infected, suffer - can they pass it on?"
Yes, that’s fascinating. It is something we have thought and talked about, but we’re not aware of any reports of Angio cantonensis infections in cats. You need to be careful with the term, “lungworm” as several different species fall into this category. However, as far as Angio goes, you’d think it should invade and migrate in cats, but nobody has ever done the studies (as far as we know), or reported natural infections in them. I’d be surprised to learn that cats are never exposed, i.e. never eat molluscs, either intentionally or accidentally. If people are finding cats to be affected, it’d be worth publishing (we know of lots of interesting cases in other animals that should have been, but never were, published).
Well, would you believe, I just saw website for lungworms in cats you provided in your letter (and checked it out), which reinforces what I said above. They’re ones that use cats as definitive hosts, i.e. complete their development in the cat, whereas Angio officially is not meant to do that outside of rats (although it gets pretty close in humans, judging by the few autopsy reports). I did find sexually mature Angios in a young child who died here, but there was no clear evidence of their copulating – while some of the females might have contained eggs, there was no evidence of eggs or L1s being released. There is no way a cat could transmit it (and if a cat somehow did, it could only be to a snail or other invertebrate!)
[In my letter, I asked: In your experimental work did you ever actually grow out L3 to adulthood in mice, as opposed to rats? I see in the literature where mice are used in nemacide trials against L3, but am not finding any records one way or another stating for documented fact whether or not sexually mature A. cantonesis have been dissected out of the pulmonary arteries of mice, as distinct from rats. Do you know if mice can carry Angio, or only rats?]
No, I never worked with Angio in mice, but I recall reading a paper that categorically stated Angio will not develop in mice. Those literature reports are concerned with drug effects against migrating L3s, which can be tricky to interpret, given the small size of mice, plus the short longevity (brevity?) of these L3 in them. My reading has always confirmed the idea that it’s highly specific for rats, although different rat species vary in their susceptibility (of course, there are several species of Angio, which prefer different host species). As far as I know the child here and a very similar case study from Melbourne about the same time were the first time Angio was found in human pulmonary arteries – although human lung changes (on chest X-ray) have been described many times in the past, in presumably heavy infections.
[Any comments on Angio in cats? Perhaps there is a role for ivermectin dosing prophylaxis in cats as well as dogs.]
Well, until there’s good evidence of feline infection, I wouldn’t advocate that – have there been suspicious cases? Of course, folks might be using ivermectin in cats for other reasons (just like in dogs), when its use could have an extra benefit (assuming them to be susceptible to angio).
[I am a bit worried that folks in Puna are going to flip out and start dosing their infants and children with ivermectin, anxious the tots will eat a heavily infected slug and die. The sense I am picking up is that ivermectin prohylaxis may be useful against low-level incidental infecton, but perhaps not so much against a massive dose of L3? I wonder what long-term exposure to ivermectin does to human physiology, particularly in developing children and in pregnant women (especially since many folks do not even know they are pregnant until week five or six).]
Good point – apart from the expense of such a strategy; it must cost quite a bit? I think if ivermectin is going to knock out a couple of L3s, it’ll do the same to a few thousand, so that’s not a problem. But you’d need to keep taking it periodically, forever. I’m only aware of its use in human strongyloidiasis, when only a few doses are given, apparently with no ill effects. For longer-term use, I have no idea – it would be best to ask the manufacturers, who should have big files of potential toxicity (but also who’ll probably have a fit, and tell you not to touch it! They’re very sensitive about legal liability, of course).
[Glad to hear you are located in Australia's sweet spot between the drought and flood zones!]
Yes, but now we’re expecting a cyclone (a.k.a. hurricane) to bear down on us in the next 1-2 days – winds are building up, and rain is on the way. It’s all fun’n’games as summer winds down.
Please let us know how you’re getting on, and sincere apologies again for having missed your e-mail for so long.
)'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'(
A pleasant slideshow: http://www.thejoymovie.com
)'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'(
G’day Steven
Sorry I missed it earlier, but I’ve just come across your old e-mail; we’ve been having a few problems with e-mails lately, leading to our need to close down the old account and open a new one, hence the new address. We hope this has not caused you difficulties.
Anyway, to your questions . . .
In reply to Menehune's question "Really - can cats become infected, suffer - can they pass it on?"
Yes, that’s fascinating. It is something we have thought and talked about, but we’re not aware of any reports of Angio cantonensis infections in cats. You need to be careful with the term, “lungworm” as several different species fall into this category. However, as far as Angio goes, you’d think it should invade and migrate in cats, but nobody has ever done the studies (as far as we know), or reported natural infections in them. I’d be surprised to learn that cats are never exposed, i.e. never eat molluscs, either intentionally or accidentally. If people are finding cats to be affected, it’d be worth publishing (we know of lots of interesting cases in other animals that should have been, but never were, published).
Well, would you believe, I just saw website for lungworms in cats you provided in your letter (and checked it out), which reinforces what I said above. They’re ones that use cats as definitive hosts, i.e. complete their development in the cat, whereas Angio officially is not meant to do that outside of rats (although it gets pretty close in humans, judging by the few autopsy reports). I did find sexually mature Angios in a young child who died here, but there was no clear evidence of their copulating – while some of the females might have contained eggs, there was no evidence of eggs or L1s being released. There is no way a cat could transmit it (and if a cat somehow did, it could only be to a snail or other invertebrate!)
[In my letter, I asked: In your experimental work did you ever actually grow out L3 to adulthood in mice, as opposed to rats? I see in the literature where mice are used in nemacide trials against L3, but am not finding any records one way or another stating for documented fact whether or not sexually mature A. cantonesis have been dissected out of the pulmonary arteries of mice, as distinct from rats. Do you know if mice can carry Angio, or only rats?]
No, I never worked with Angio in mice, but I recall reading a paper that categorically stated Angio will not develop in mice. Those literature reports are concerned with drug effects against migrating L3s, which can be tricky to interpret, given the small size of mice, plus the short longevity (brevity?) of these L3 in them. My reading has always confirmed the idea that it’s highly specific for rats, although different rat species vary in their susceptibility (of course, there are several species of Angio, which prefer different host species). As far as I know the child here and a very similar case study from Melbourne about the same time were the first time Angio was found in human pulmonary arteries – although human lung changes (on chest X-ray) have been described many times in the past, in presumably heavy infections.
[Any comments on Angio in cats? Perhaps there is a role for ivermectin dosing prophylaxis in cats as well as dogs.]
Well, until there’s good evidence of feline infection, I wouldn’t advocate that – have there been suspicious cases? Of course, folks might be using ivermectin in cats for other reasons (just like in dogs), when its use could have an extra benefit (assuming them to be susceptible to angio).
[I am a bit worried that folks in Puna are going to flip out and start dosing their infants and children with ivermectin, anxious the tots will eat a heavily infected slug and die. The sense I am picking up is that ivermectin prohylaxis may be useful against low-level incidental infecton, but perhaps not so much against a massive dose of L3? I wonder what long-term exposure to ivermectin does to human physiology, particularly in developing children and in pregnant women (especially since many folks do not even know they are pregnant until week five or six).]
Good point – apart from the expense of such a strategy; it must cost quite a bit? I think if ivermectin is going to knock out a couple of L3s, it’ll do the same to a few thousand, so that’s not a problem. But you’d need to keep taking it periodically, forever. I’m only aware of its use in human strongyloidiasis, when only a few doses are given, apparently with no ill effects. For longer-term use, I have no idea – it would be best to ask the manufacturers, who should have big files of potential toxicity (but also who’ll probably have a fit, and tell you not to touch it! They’re very sensitive about legal liability, of course).
[Glad to hear you are located in Australia's sweet spot between the drought and flood zones!]
Yes, but now we’re expecting a cyclone (a.k.a. hurricane) to bear down on us in the next 1-2 days – winds are building up, and rain is on the way. It’s all fun’n’games as summer winds down.
Please let us know how you’re getting on, and sincere apologies again for having missed your e-mail for so long.
)'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'(
A pleasant slideshow: http://www.thejoymovie.com
)'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'(
)'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'(
Astonishing skill! This archer is a real-life Legolas and then some!
http://geekologie.com/2013/11/real-life-...rs-anc.php
)'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'(
Astonishing skill! This archer is a real-life Legolas and then some!
http://geekologie.com/2013/11/real-life-...rs-anc.php
)'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'( )'(