Tommy Coyote Posted January 6, 2014 Report Share Posted January 6, 2014 Can someone put up the article out on Terrierman about heartworm? It goes against just about everything I've been told and it would be an interesting discussion. It's the Terrierman link that is highlighted on the near bottom of page two on Poop News. Would be interested in getting some of our scientist's views on this topic. Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 6, 2014 Report Share Posted January 6, 2014 The Billion Dollar Heartworm Scam What are your specific questions? Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 6, 2014 Report Share Posted January 6, 2014 Your questions may stem how the veterinary community has decided to improve protection of their animal patients from their human client's inattention to the details in the science. Quote Link to comment Share on other sites More sharing options...
Tommy Coyote Posted January 7, 2014 Author Report Share Posted January 7, 2014 I need to go back and read the article carefully. People around KC mostly spend a whole bunch of money for expensive heartworm drugs. I know that I do. It is just considered an absolute necessity for all dogs to be on heartworm meds. Is that all basically a big scam? Is the real risk much lower than has been presented to the public - and maybe to vets, too? Although I do think we are in a higher risk area because we sit on the river and the bugs carry the stuff up from the gulf. Personally, I wouldn't want to risk it in this area during the warmer months. And do we really need to keep the dogs on meds 12 months a year? In order for the little heartworm bugs to survive the outside temps have to be consistantly above 57 for 45 days? Here in KC that would probably only be June, July, Aug,,and maybe Sept. The other months would be safe to go w/o meds? I'm not considering needing to be on the meds for protection from whip and other sorts of intestinal parasites. I have generally stopped the HW meds in December when it is frozen solid here and then started again in May when I get their yearly HW check. Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 7, 2014 Report Share Posted January 7, 2014 I'm not sure I would call it a scam for the general public; I might call it a scam if we were only talking about well-educated and diligent owners. The way I view it the veterinary & animal welfare communities have decided it is easier to protect animals from failures of owners to dose properly if they promote dosing year round as opposed to dosing only as needed. It is easier to train people to do something every month than to train people to do something for a few specific months (depending upon location). Quote Link to comment Share on other sites More sharing options...
Tommy Coyote Posted January 7, 2014 Author Report Share Posted January 7, 2014 Just read in Veterinary Practice News that they are pushing for 12 month meds as well as a 1 year blood check. According to the article the incidence of HW is increasing. It's an article called Heartworm Horrors. I'm tring to find out how many actual cases of HW were recorded in Missouri last year. Quote Link to comment Share on other sites More sharing options...
Shetlander Posted January 7, 2014 Report Share Posted January 7, 2014 I don't know. I am not a statistics or science person, but just in my little corner of the world I have personally known of 4 dogs with heartworm (dogs that needed treatment) and that is just off the top of my head. I am sure I could come up with at least a few more if I prodded my sluggish memory. If the number of dogs with HW in Michigan over the past 7 years is only a bit over 500, it seems like I wouldn't have met a several dogs wit HW, not to mention reading about others on rescue sites. Back when I was doing holistic with Quinn, that vet lobbied hard for me not to do HW preventative but I just couldn't go along with that approach. It was the dogs I knew with the disease that made me say no. Quote Link to comment Share on other sites More sharing options...
Liz P Posted January 7, 2014 Report Share Posted January 7, 2014 New data suggests that mosquitoes survive "killing frosts" and can be found in areas much farther north than expected in the winter. I won't risk my dogs' lives to save a few bucks. Quote Link to comment Share on other sites More sharing options...
jvw Posted January 7, 2014 Report Share Posted January 7, 2014 I have had a mosquito or two pop up in my house in the dead of winter. Quote Link to comment Share on other sites More sharing options...
gcv-border Posted January 7, 2014 Report Share Posted January 7, 2014 Re: Liz P's post above (the quote function is STILL not working for me) I agree, but was wondering IF ivermectin does kill all the microfilaria stage of the heartworm (purportedly 3 months long), would a dose of ivermectin every other month work as well as a monthly dose. Assuming that the owner was rigorous in administering IV every 2 months, no exceptions. Also, any resistance to IV in heartworm populations? I have had to have a foster dog retested for HW because his last HW dose (at another vet) was given 45 days previously. The vet's policy was that they would not dispense HW meds without a test if the last dose was more than 45 days previous. Luckily I didn't pay for it. The rescue group did, but I thought it was a waste of money. Note: I do give Heartgard monthly. Quote Link to comment Share on other sites More sharing options...
GentleLake Posted January 7, 2014 Report Share Posted January 7, 2014 New data suggests that mosquitoes survive "killing frosts" and can be found in areas much farther north than expected in the winter. AFAIK, the 57 F thing isn't about whether mosquitoes survive that temp, but whether the HW can survive in the mosquitoes below that temp. Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 7, 2014 Report Share Posted January 7, 2014 As far as I can tell from the last time I researched resistance in microfilaria, science has not been able to conclusively determine this in all except for a single sample collected from one dog from the Gulf States. I've wondered if the problem is not resistance but the laboratory determined effective minimum dose of preventative which was determined by infecting dogs with a specific dose of microfilaria (specific number of microfilaria) is no longer effective against the typical dose of microfilaria received from mosquitoes in the field. The laboratory dose was selected based upon the microfilaria level carried by mosquitoes decades ago when IV was being developed and I suspect the level carried in mosquitoes has increased over the years. Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 7, 2014 Report Share Posted January 7, 2014 AFAIK, the 57 F thing isn't about whether mosquitoes survive that temp, but whether the HW can survive in the mosquitoes below that temp. Actually I think it is the temp and time needed to mature from one stage to the next in the mosquito, not survival. Quote Link to comment Share on other sites More sharing options...
GentleLake Posted January 7, 2014 Report Share Posted January 7, 2014 OK, thanks, Mark. It does confirm, though, that it has nothing to do with whether or not the mosquito is able to survive low temps. Quote Link to comment Share on other sites More sharing options...
Liz P Posted January 7, 2014 Report Share Posted January 7, 2014 As far as timing on pills, you can only kill HW with the pills at certain life stages. They can mature past that point in less than 60 days, so I would not risk dosing every other month (especially since some months are longer than others). If you planned to dose every 45 days but forgot the pill, by the time you do remember it could be too late (as little as 52 days). Once a month just makes sense for people. Same date every month is easy to remember and more fool proof. Again, not worth risking your dog's life. I've not seen any data that proves they are developing resistance. We do know that resistance is a very real possibility with any parasite. I have seen data suggesting we may need a higher dose for prevention than what we have been using. This is especially true for the dogs that are on the high end of the weight for the dose range (the 48 lb dog taking the 25 to 50 lb dose). Quote Link to comment Share on other sites More sharing options...
cjohanna Posted January 8, 2014 Report Share Posted January 8, 2014 There is a good deal of discussion about whether the parasites are developing or have developed resistence to the drugs. Some mentions of that are here: http://www.2ndchance.info/heartwormMedResist.htmAnd more info, from the 2013 Western Veterinary Conference -- this is a PDF: http://tinyurl.com/kbts9ulI live in Chicago. I have not used chemical heartworm preventives since 2001; I have 6 dogs at present, and have had another 6 who passed away since 2001. (I don't have a high mortality rate, I adopt senior Shelties from rescue.) None of them ever tested positive for heartworm and I test every year. Some of them had been successfully treated for heartworm in the past, when they came into rescue. I use herbal preventives, and I feed a raw/natural diet and do not give annual vaccinations, so my heartworm protocol is part of a larger picture.I work with a local Sheltie rescue and we have quite a few h/w positive dogs that come in to rescue. Almost without exception, they have had very poor nutrition and general care before we got them -- many of them were strays or 'outside dogs'. Their resistence to parasites of all kinds is very low due to that. I don't think that well-fed dogs can't get heartworm, but I think the immune system does play a role in this. I found a reference to that in an article that I can't find now, but will post when/if I do. Interesting topic. Quote Link to comment Share on other sites More sharing options...
Shetlander Posted January 8, 2014 Report Share Posted January 8, 2014 I work with a local Sheltie rescue and we have quite a few h/w positive dogs that come in to rescue. Almost without exception, they have had very poor nutrition and general care before we got them -- many of them were strays or 'outside dogs'. Their resistence to parasites of all kinds is very low due to that. I don't think that well-fed dogs can't get heartworm, but I think the immune system does play a role in this. I found a reference to that in an article that I can't find now, but will post when/if I do. Interesting topic. Interesting. The holistic vet said that she felt a healthy dog wasn't likely to get heartworm. But since Quinn has a fairly weak immune system, that was all the more reason I thought to continue with preventative. Quote Link to comment Share on other sites More sharing options...
Maralynn Posted January 8, 2014 Report Share Posted January 8, 2014 And what about dogs that spend a good deal of time outside in the summer? I live next to a swamp and mosquitoes can be thick during the summer. My dogs also spend about half of their time outdoors in the summer. Even though they're both quite healthy, I sure wouldn't be comfortable not giving them HW meds in this scenario. Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 8, 2014 Report Share Posted January 8, 2014 Everyone should note that the dogs used to establish the minimum effective dose of heartworm preventative were very closely monitored and controlled in terms of their diet and health. These dogs were purposely injected with microfilaria, monitored for the survival of the microfilaria after injection (100% infection of the injected dogs), growth of the microfilaria, and survival of the microfilaria after dosing with preventative. The pharmaceutical companies wanted to minimize any adverse reactions observed in the test dogs that could be attributed to their drug. This strongly refutes the notion that healthy dogs are unlikely to get heartworm; the keys are how likely is it for your dog to be bit by a mosquito and what is the likelihood that the mosquito is infected with L3 stage heartworms. This maturation process of the heartworm in the mosquito from the microfilaria to the L3 stage is extremely dependent on temperature. Laboratory studies have shown that this development requires a steady 24 hour daily temperature in excess of 64 F for 1 month. Even if the temperature drops below 57 F for just a few hours, development will be delayed. If the daily 24 hour temperature exceeds 80 F, only 10-14 days are required for development to the L3 stage. Source: Holistic Veterinary Center: THE REAL FACTS ABOUT HEARTWORM DISEASE (I purposely chose this source of info over one that readers may assume was inflenced by phamaceutical companies) One should be careful how they extrapolate the labratory data to the real world. These data do not say the outside air temp must meet the labratory temps but it says the mosquito must be at the labratory temps. This means mosquitos can keep warmer than air temps using radiative heating from solid objects that were warmed by the sun. Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 8, 2014 Report Share Posted January 8, 2014 This provides a very good overview on how the minimum effective doses were set for each preventative, possible means for the development of resistance in heartworms, overview of the current understanding of possible resistance in data from the field, and an overview of the ongoing studies into resistance. Heartworms, macrocyclic lactones, and the specter of resistance to prevention in the United States Quote Link to comment Share on other sites More sharing options...
cjohanna Posted January 8, 2014 Report Share Posted January 8, 2014 I think the injection is a key part of that finding, though, Mark. Consider that if ten dogs are injected with parvo, all ten will get parvo; but if ten dogs are exposed to parvo in the environment, not all ten dogs will get parvo. The immune system will be able to mount a response, if it can, when the virus enters the body through the dog's skin, nasal passages, etc. Direct injection into the bloodstream bypasses all the defense mechanisms that the body has to rebuff or respond to the disease or pest. This article in Dogs Naturally magazine makes some interesting points, one of which is that "Host immune responses affect the presence of circulating microfilariae." No, it's not correct to say that a healthy dog cannot get heartworm, I agree with that. It IS possible to say that a healthy dog has a lesser chance of contracting heartworm if it is exposed to it, because the immune response in a healthy dog will be very different from that of a weak dog in depleted health. http://www.dogsnaturallymagazine.com/protecting-your-dog-from-heartworm/ Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 8, 2014 Report Share Posted January 8, 2014 Your proposed hypothesis is not testible (controlled study) since the hypothesis requires a natural mode of infection. However, it is well accepted that healthy dogs are less likley to contract diseases than dogs with weekend immune systems. Quote Link to comment Share on other sites More sharing options...
Gideon's girl Posted January 8, 2014 Report Share Posted January 8, 2014 FWIW, I give heartworm prevention every 45 days and am well known for forgetting everything, so I put a reminder in my phone(or other calendar enabled device) and let it remind me when heartworm prevention is due. Quote Link to comment Share on other sites More sharing options...
Tommy Coyote Posted January 8, 2014 Author Report Share Posted January 8, 2014 When we had serious flooding here in Missouri I know that the cases of HW really increased. If you live near water - or a swamp - I would be extra careful about HW prevention. Didn't I read that even dogs on preventative can still get HW if the investation is bad enough? Would you have to increase the dosage just to be safer? Quote Link to comment Share on other sites More sharing options...
Mark Billadeau Posted January 8, 2014 Report Share Posted January 8, 2014 The linked article discusses reported cases of loss of effectiveness of preventative: In the area extending along the Mississippi River from Tennessee through Louisiana, there are many practitioners who contend that the heartworm preventives they have been using are no longer protecting dogs from infection. On the other hand, it has been reported that a very high percentage of these product failures are occurring in pets where compliance has not been as good as initially perceived by the claimant [16]. 16. Atkins C: Current controversies and dilemmas in heartworm disease: defining the issues by close examination. https://www.aahanet.org/Education/WebConference.aspx?key=428166ce-8c29-462d-ad51-f7b9bd3b1350 Quote Link to comment Share on other sites More sharing options...
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