I'm going to PM you contact info for working through the HW. Every foster I deal with has HW. It's something we deal with in LA constantly. I'm used to it, and I've dealt with mild and severe cases, and I've only ever lost one dog....but I have
lost one dog (out of many treated), and we lost her despite emergency care by experts at the vet school...but she had a lot of underlying problems and very advanced disease.
The bottom line is that I'm so used to dealing with HW successfully that I don't even care when shelters tell me a dog is HW+. It doesn't even factor into my pull decision any more -- it's just something that's "normal" to us, and we're very comfortable with it. We've placed close to 200 dogs that survived HW, and they're happy, healthy, and recovered. Two of my three personal dogs are HW survivors. It's just something we deal with in rescue down here. I have a 12 y.o. HW survivor in my house right now -- he went through fast-kill injections at 6 y.o., and he's still strong and healthy as a senior!
That said, I want you to go into this with eyes open -- if I were in your shoes, I'd take the dog, but I know what I've dealing with.
There are no natural options to get rid of HWs. I've read and read and read looking...these are nasty, nasty parasites. I hate
that 3-shot treatment with a purple passion, so if there were a natural way to handle this, I'd be all over it. I follow the vet literature on HW research very closely. I have one of the most open-minded, creative, out-of-the box thinking evidence-based vets that I've ever known -- if there's a natural solution that works, she'll use it because she makes no distinction between camps or philosophies -- stuff either works or doesn't, and she wants what's safe, affordable and effective for her clients. She works with the best rescues in our region (including Villalobos, on Animal Planet)...we beg and plead to become her clients because she's SO good and SO smart. If there's a cheaper, less risky way to get a dog healthy, she's on it. We know of absolutely nothing to save HW+ dogs that's natural, unfortunately.
Not treating isn't an option. Dogs with advanced, untreated HW die a miserable, pain-filled death. So she needs a plan. Part of what you may have to wrestle with is whether you can make peace with heavy-duty pharmaceuticals to get her through this....and I know that's tough. And this particular drug is nasty -- you know I'm not dogmatic about pharma and I'll use anything that helps, but dang this one is rough.
There's lots of stuff to figure out -- HW+ should not have been transported up north, but now that it's happened, you've got to deal with it -- and you've got two things to worry about (1) this dog's long-term health, and (2) the community health:
1. Does she have circulating microfilariae? A vet or good vet tech needs to do a smear slide to look under the microscope-- not a regular HW test. They need to do this ASAP -- it's urgent.
If she has microfilariae, she's infectious, and it's summer, so every mosquito is an opportunity for her to transmit this to northern dogs that aren't on prevention. Keeping her away from mosquitoes is HUGELY important. Worse, Louisiana has confirmed that we have ivermectin-resistant HWs (they're still rare, but there's no way to know if the ones in them are this strain or not) -- so she could be introducing a bad, bad, bad form of HW into the community. We see a lot of break-through infections of dogs that are on Heartguard-type products now...so this is NOT something you want in Canada. Microfilariae need to be killed off immediately!
2. She needs to be on prevention, monthly with no winter break. Forget what you've read about that because we're not worrying about getting new worms in Canada: we're worrying about killing the baby ones she's already got in her, and not letting them reproduce. Prevention helps with the young ones that she traveled north with, as they're already growing inside her.
In LA, the best thing we're using is Advantage Multi. It's so effective for HW+ dogs that every HW+ in our rescue has to be on it, and not anything else. It is US FDA-approved to get rid of microfilariae, too. I know you won't like that kind of toxic pesticide, but it's the only one that has documented NO resistance. And....it's the best of some crappy options. It's topical, so we just don't see the bad reactions that sometimes pop up with other stuff (like Trifexis).
It is absorbed through the skin and builds up to steady state in the blood after 3-4 months, and once that happens, HWs start dying....just from the prevention product. So even if you don't do fast kill treatment, if you keep her on it til she tests negative, she will
test negative eventually.
3. The standard treatment requires Doxycycline for 30 days, at a pretty high dose (10mg/kg is optimal). You're not going to like that either. It's better tolerated than many other abx, but it's still a long-term abx course. It's necessary to kill a symbiotic bacteria that live in the HWs and cause lots of damage (including some of the things that make HW so deadly). This 30-day course is supposed to be repeated every 6 mo. if you do slow kill. It's expensive, but compounding pharmacies like Wedgewood can save you money.
4. She needs to be on prevention for at least 3 mo. to kill the baby HWs before you decide about fast-kill. If you do fast kill, I would wait for cool weather (fall/winter is ideal)--there's less risk of complication, though it's not clear why. The reason is that the immiticide doesn't kill the juveniles, and they could be outside the range of the prevention too -- if you do immiticide too soon, you could have to do it again when the juveniles grow up, and that's to be avoided at all costs.
5. Prednisone. The standard treatment with immiticide shots also puts them on a low-dose of pred for a long time to minimize the chance of life-threatening complications during fast-kill treatment. Yep, abx + pred is the gold-standard treatment recommended by the AHWS as part of this fast-kill treatment with the three-shot protocol.
6. Fast kill or slow kill? I've done both. AHWS recommends fast kill (immiticide), always -- that's what your rescue is offering you. It's worth about $1000 at retail, and if that's included in the adoption fee, it's a good deal.
I'm on the fence about immiticide -- like I said, I've had a dog die during fast-kill, and statistically about 10% of them have major complications. It's the gold standard, since it kills the worms faster so they have less time to do damage -- that's why the rec is so strong about doing it as the preferred treatment.
Even when there are no complications, I want to be honest that it's likely one of the hardest treatments you'll ever experience with a dog, and your dislike of Pharma will grow exponentially. It's rough.
It's a form of arsenic, big fat doses of arsenic administered deep in the muscle with a ginormous needle. It's so painful that they need an NSAID for a few days (yep, add that to your list of drugs in this cocktail...) -- some dogs are lame and unable to stand for a couple of days, and they moan in pain. They'll be incredibly lethargic for several days too. It's very hard to watch.
During immiticide treatment, you have to keep them on strict crate rest for 2 mo.--STRICT -- even going outside to potty has to be on leash. They can get NO exercise. The heartrate can't get elevated. The reason? As worms die, they embolize in the lungs, landing in the capillary beds. You want them to die and embolize slowly, one or two at a time. With a fast heartrate, a clump of dead worms can break off at once and clog a pulmonary artery. That can create a life-threatening emergency. If the emergency happens, they can die quickly, gushing blood out of their nose and mouth -- they have to be rushed to a vet ICU with an O2 tent and supportive care if there are any complications. When I have a dog going through this in rescue, I work with fosters to know the fastest route to the closest emergency vet, even in the middle of the night....because even though the chance is very low that they'll need it, you have to move fast if it happens.
So...assuming no complications, which is likely ... if all goes well, you've put the dog on abx for 30 days, on pred for 2-3 months, injected it with arsenic 3 times, and killed the adult HWs. As you well know, now you set about rebuilding health. It's a crappy, crappy situation, but death from HW is worse, so my HW dogs stay on probiotics, bovine colostrum and other goodies through treatment and beyond. There are other heart-supporting supplements we can talk about if you get her.
7. Slow kill as an option? The old way of doing slow kill was put them on a very low dose of ivermectin prevention that killed the worms in 2-3 years. During that time, they're in there doing major damage to the heart, lungs, and circulatory system. Some vets theorize that they'll have shorter lives if that happens.
Somehow, some way, vets in the trenches in LA (where more than half of big dogs are HW+ and most people can't afford immiticide treatment) figured out that you could use Advantage Multi for slow kill, with doxy. We've used it for several years. Other vets in other places thought it was nuts, until researchers associated with AHWS came out with published paper recently showing that we aren't nuts -- it does actually kill HWs. The fastest I've had a dog test negative with Doxy, Advantage Multi, and no other treatment is 9 mo. (compared to 5 mo. for fast kill -- 3 mo. of prevention, 2 mo. of shots). I've had a few take 18 mo. Lost and lots (big majority) of rescue dogs have tested negative at 12 mo. So I think of this as "intermediate kill" (not as slow as ivermectin, but not as fast as immiticide).
The kicker is we don't have to put them on strict crate rest during this. They can walk (but not jog). They can play and be normal dogs who just don't exercise hard. That's doable. We don't yet know if these dogs will have shorter lives, but we just haven't seen any serious complications doing this. We know that it's working really
well, esp. for dogs who have other issues that prevent them from going through immiticide treatment. So we do both -- some dogs who are good candidates for immiticide get it, others who aren't get Advantage Multi, and we do our best to just get as many of them cured one way or the other as we can.
8. How advanced is the disease? Are there any clinical signs yet (excercise intolerance, tiring easily, fluid retention, and esp. coughing)? Have they done a chest xray? That, too, is part of the AHWS gold-standard protocol. If not, if the dog doesn't have clinical signs, I probably would save the money. It never changes anything. It's nice to know how many worms there are, but so what? You still treat one way or the other. OTOH, if the dog has clinical signs and we're looking at advanced disease, I would do the chest x-ray.
Dogs with advanced disease go into Caval Syndrome fast, and without warning -- the key sign is their pee turns red like wine. The HWs then are moving inside the chest and killing the dog in the end-stage. At that point they need emergency surgery to pull the worms out of the dog manually -- it's super-high-risk surgery, and you may not even find anyone in Canada who's done much of it (it's something some southern vets have too much practice with, unfortunately). If this dog were to have advanced disease and might be at risk of Caval syndrome, I would think twice...but if she doesn't have a cough, isn't full of fluid in her chest and tummy (bloated-looking)...you're probably okay.
Note: Advantage Multi is marketed as Advocate in some markets outside the US. I'm not sure which one Bayer uses in Canada. It's a RX-only product.