Heartworm Interval?

[cavNrott]

The recommendation to test every two years while only using intermittent heartworm prevention is not in line with the general heartworm guidelines. No amount of heartworm is desirable so it doesn't really make a lot of difference how big they are, if anything the number of worms is more significant because even one could cause an embolus once it dies.

A comment regarding heartworm prevention generally is that for most of the oral products at least, the doses are given at intervals rather than lasting for a full month ie. A dog receives 12 doses at 1 month intervals rather than 365 days of treatment. Same goes for oral intestinal workers, the ingredients in the tablets are not well absorbed systemically and kill intestinal parasites 'on the way past'. The dosing schedule is based on the life cycle, hence an increased frequency for example if you are trying to prevent hydatid tapeworm vs other intestinal parasites.

Rappie, thank you for that important information. It's good news for those of us who use monthly meds to keep our dogs worm and heartworm free.

[Rappie]

In the US, heartworm meds are prescription medicine and expensive, hence many of us simply buy Ivermectin for livestock and give it to our dogs monthly to bi-monthly. The dose most people use is 0.1 cc / 10 lbs . . . somewhat above the dosage in Heartguard tablets.

Can you buy Ivermectin over the counter in feedstores in Oz? It seems to be a good solution.

Note, I'm in Florida with a climate roughly equivalent to coastal QLD near the NSW border. We have a few mozzies year around, loads of 'em in spring, summer, and fall, and serious problems with heartworm in untreated dogs.

It is easily available but discussion of its use on the forum is inappropriate. Not only because giving a dose as a volume per kg without reference to be concentration of the liquid is meaningless if not potentially extremely dangerous, but also because the use of parasiticde treatments are covered by a legislated restraint which means that the instructions applied to them on the label cannot be altered unless authorised by legislation. An exemption applies to a registered veterinary surgeon to alter the instructions for well accepted uses where an acceptable registered alternative does not exist or is not practical - using ivermectin off label to treat demodectic mange - yes, using it to save money on heartworm prevention, no.

As an aside related to the commonly discussed 6 week interval, although it take several months for an adult heartworm to develop, juvenile worms can be present from as little as 52 days post infection. Yes, this is more than 42 days but it leaves only a small margin for error in dosing compared to the recommend monthly dosing.

[LisaCC]

In the US, heartworm meds are prescription medicine and expensive, hence many of us simply buy Ivermectin for livestock and give it to our dogs monthly to bi-monthly. The dose most people use is 0.1 cc / 10 lbs . . . somewhat above the dosage in Heartguard tablets.

Can you buy Ivermectin over the counter in feedstores in Oz? It seems to be a good solution.

Note, I'm in Florida with a climate roughly equivalent to coastal QLD near the NSW border. We have a few mozzies year around, loads of 'em in spring, summer, and fall, and serious problems with heartworm in untreated dogs.

It is easily available but discussion of its use on the forum is inappropriate. Not only because giving a dose as a volume per kg without reference to be concentration of the liquid is meaningless if not potentially extremely dangerous, but also because the use of parasiticde treatments are covered by a legislated restraint which means that the instructions applied to them on the label cannot be altered unless authorised by legislation. An exemption applies to a registered veterinary surgeon to alter the instructions for well accepted uses where an acceptable registered alternative does not exist or is not practical - using ivermectin off label to treat demodectic mange - yes, using it to save money on heartworm prevention, no.

As an aside related to the commonly discussed 6 week interval, although it take several months for an adult heartworm to develop, juvenile worms can be present from as little as 52 days post infection. Yes, this is more than 42 days but it leaves only a small margin for error in dosing compared to the recommend monthly dosing.

Rappie would you recommend heart worming all year round or just over the warmer months (when it start staying above the 14degrees at night)?

I've had vets tell me different things, even different things in uni lectures...

I lived in a cold climate with my last dog, so was told by vets then to not bother at all.

Edited December 19, 2014 by LisaCC

[Rappie]

If you are going to administer heartworm prevention I would do it year round.

[LisaCC]

If you are going to administer heartworm prevention I would do it year round.

Thanks :)

I did that over this winter, but have had some vets tell me it's a waste of money over winter. I will keep on going throughout the year.

Edited December 19, 2014 by LisaCC

[seregil]

Erny, its my understanding that these drugs do not stay in the system for 365 days of the year. When a monthly dose of heartworm prevention is given, it gets rid of any HW larvae (microfilaria) that MAY be in the body at that time, ie you are treating for the month just gone, not protecting for the month ahead. I think these drugs are out of the body in 24 hours.

Same as when you give intestinal worm treatment every 3 months (or whatever), you are getting rid of any worms that MAY be there, it does not stop worms for the three months ahead.

[Dame Aussie]

We seem to have a lot of mosquitoes all year round. This is probably due to the neighbours at the back of me having a spa with stagnant water most of the year. The only time they attend to their spa is if they want to use it. Then they empty it and fill with fresh water that they again allow to stagnate until they want to use the spa again. They use their spa only a couple of times a year.

In view of the above I medicate the dogs with a heartworm preventative every month, all year round. Are the mosquitoes getting bigger? We have some huge ones here.

I swear they have tripled in size this year I give every 6 weeks. Not worth the risk, we have sooooo many mozzies. After rappies advice I'll make it monthly.

Edited December 20, 2014 by Dame Aussie

[VizslaMomma]

That's an interesting approach Airedaler, I wonder how much it would cost to add in a heartworm test when my dogs are being titre tested every year?

The cost for this test was about $100 in NSW 3 years ago.

This was for a dog being adopted by a family member via the grapevine .(Friend of a friend knew of a dog needing to be rehoused).

[sandgrubber]

In the US, heartworm meds are prescription medicine and expensive, hence many of us simply buy Ivermectin for livestock and give it to our dogs monthly to bi-monthly. The dose most people use is 0.1 cc / 10 lbs . . . somewhat above the dosage in Heartguard tablets.

Can you buy Ivermectin over the counter in feedstores in Oz? It seems to be a good solution.

Note, I'm in Florida with a climate roughly equivalent to coastal QLD near the NSW border. We have a few mozzies year around, loads of 'em in spring, summer, and fall, and serious problems with heartworm in untreated dogs.

It is easily available but discussion of its use on the forum is inappropriate. Not only because giving a dose as a volume per kg without reference to be concentration of the liquid is meaningless if not potentially extremely dangerous, but also because the use of parasiticde treatments are covered by a legislated restraint which means that the instructions applied to them on the label cannot be altered unless authorised by legislation. An exemption applies to a registered veterinary surgeon to alter the instructions for well accepted uses where an acceptable registered alternative does not exist or is not practical - using ivermectin off label to treat demodectic mange - yes, using it to save money on heartworm prevention, no.

As an aside related to the commonly discussed 6 week interval, although it take several months for an adult heartworm to develop, juvenile worms can be present from as little as 52 days post infection. Yes, this is more than 42 days but it leaves only a small margin for error in dosing compared to the recommend monthly dosing.

Oops! I thought I specified 1% solution. You're correct, it's wrong to specify a dosage without specifying the concentration. I'm correcting my post. There is lots of discussion and documentation available about tolerances. I like using the liquid because unlike tablets, where the same dosage is used for a 75 lb dog and a 150 lb dog, you can dose precisely by weight.

Heartworm meds are a prescription medicine in the US and you must test annually to get your prescription renewed. Strange, cause you can buy all sorts of vaccines over the counter.

Heartworm prevention can get quite expensive. People on limited income often loose their dogs to heartworm cause they can't easily afford the medication.

[Jemmy]

I don't do HW prevention at all, on the advice of my vet due to our climate. If I ever move back to the mainland or to a warmer climate I'm going to have to be very strict with my calendar! Interesting to read about though :)

[OSoSwift]

Yep Ivermectin is available but I wouldn't risk t I know of a few dogs that have died horrible deaths due to accidental over dosing. No way I would risk mine.

I ahve seen dogs affected bya nd treated for HW infestation, wouldn't be risking that either...........

I believe TAS is very low risk for HW.

We are in a low risk but not a no risk area. I treat mine all year round - well they have sentinel so they do get treated monthly.

Edited December 20, 2014 by OSoSwift

[Dame Aussie]

We use sentinel too.