Vaccinating Senior Dogs

[yellow dog]

not saying there wouldn't be any value in the test, but if money is tight (again this and having a complete couch potato are the only reasons not to vaccinate a dog IMHO) the test is one thing I would start thinking about it.
the reason (and that is my very personal opinion and there will be many that disagree) is that for a dog that has been treated continuously during the summer months are
a) heartworm is not (yet) as prevalent here as in the southern USA
b) the antigen test will only detect adult female particulates in the blood
c) there is a 5-7 month migration time after infection
d) most vets will end up not prescribe milbemycin due to cost, because the owner is often not willing to pay for it...
e) they might use ivermecin (same as what is used in preventative drugs, which will kill larvae and microfilaria, but only sterilize the adult worms) instead.
this might work if it is given over a very long period in sufficient doses. the problem is that this way we will eventually end up with invermecin resistant heartworms (think of penicillin resistance, because we abused it for so long)

Again, I'm not recommending to take any shortcuts (regardless of the age of the dog), but if you think about not doing what your vet recommends, you better start looking into a lot of details.
Most likely you'll start to agree with your vet's recommendation or at the very least you will be able to have an educated discussion with them thereafter.

Ivermectin is used mainly by large kennel owners due to low cost . A kennel of 10 to 60 dogs cannot afford to do the blood test on every Young or Senior dog in a mushing kennel. Ivermectin is the main preferred drug used. In all my years being around these huge kennels not one died of heartworm living in mosquito infested parts of the country. Vets opinions can really vary depending on experience and when I say experience I don't necessarily mean years of experience. Find yourself a vet that is involved in dog sports such as hunting, mushing, skijoring, agility etc. These vets seem and are more in tune with what vaccinations, wormers are really needed because they are around huge numbers of dogs because of these dog sport events. Many famous dog vets involved in dog sports over the years that have made big contributions to the care and health . I searched for a new vet since moving to Sarnia and personally met with four of them before I found the right one for my dogs and my future breeding plans. Not all vets are equal and have walked out on a few over the years because of lack of knowledge or trying to talk me into test or test's that were not necessary.