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Heartworm Preventives

The American Heartworm Society recommends year-round administration of medications approved by the US Food and Drug Administration (FDA) to prevent heartworm infection. Currently available preventives are listed below; as new products become available, updates will be posted at heartwormsociety.org. Consult the appropriate manufacturer for minimum age/weight, use during breeding/lactation, or other health requirements for product usage.

Scroll down for feline and ferret preventives.

Preventives for Dogs

 Dirofilaria immitisOther Parasites Treated in Addition to Heartworm 
DrugTrade Name(s)Tissue Stages (Larvae)Circulating MicrofilariaeFleasTicksHookwormsRoundwormsWhipwormsTapewormsEar MitesSarcoptic Mange Mites

Minimum
Age/
Weight

Safe to
Use During
Breeding/
Lactation
Food
Allergen
Considerations
Oral Administration (monthly tablets and chews)
Ivermectin + pyrantel pamoate HEARTGARD® Plus (Boehringer Ingelheim)
Tri-Heart® Plus (Merck)
X       Xa Xb         6 weeks/
no
minimum
weight 
Yes 

Beef

Iverhart Plus® (Virbac) X       Xa Xb         Pork Liver 
Ivermectin + pyrantel pamoate + praziquantel Iverhart Max® (Virbac)
IMECTRO®
(Ceva)
X       Xa Xb   Xh      8 weeks/
6 lbs
  Not
Evaluated
 Pork liver
Artificial Beef
Milbemycin oxime Interceptor® (Elanco)
MilbeGuard® (Ceva)
Milbehart™ (Virbac)
X       Xc Xb Xd        4 weeks/
2 lbs
 Yes  Beef
Milbemycin oxime + praziquantel Interceptor® Plus (Elanco) X       Xc Xb Xd Xf     6 weeks/
2 lbs 
  Not
Evaluated
Chicken 
Milbemycin oxime + lufenuron Sentinel® Flavor Tabs (Merck) X   Xj   Xc Xb Xd       6 weeks/
2 lbs 
 Yes  Artificial beef
Pork/soy
Milbemycin oxime + lufenuron + praziquantel Sentinel® Spectrum® (Merck) X   Xj   Xc Xb Xd Xf    

6 weeks/
2 lbs 

  Not
Evaluated
 Beef
Milbemycin oxime + spinosad Trifexis® (Elanco) X   Xn   Xc Xb Xd       8 weeks/
5 lbs
 Use with
caution
 Artificial beef
Pork liver/
hydrolyzed soy
Moxidectin +

afoxolaner + pyrantel

NEXGARD® PLUS (Boehringer Ingelheim) X   Xn X6 Xa Xb          8 weeks/
4 lbs
  Not
Evaluated
 None
Moxidectin + sarolaner + pyrantel pamoate Simparica® Trio (Zoetis) X   Xk Xl Xm Xb         8 weeks/
2.8 lbs 
 Not
Evaluated
Pork 
Injectable Administration (every 6 or 12 months)
Moxidectin   ProHeart® 6 (Zoetis) X       Xo          

 6 months/
5 lbs

Yes
ProHeart® 12 (Zoetis) X       Xo           12 months/
5 lbs
Yes
Topical Administration (monthly spot-on)
Moxidectin + imidacloprid Advantage Multi® (Elanco)
IMOXI (Vetoquinol USA)
PARASEDGE Multi (Virbac)
Midamox (Norbrook)
X X Xn   Xp Xq Xd     Xr  7 weeks/
3 lbs
Not Evaluated 

Selamectin

Revolution®(Zoetis)
Paradyne®(Vethical)
Senergy (Virbac)
Selarid (Norbrook)
Revolt (Aurora)
X   Xz X1         Xu Xr  6 weeks/
no minimum
weight
 Yes

Preventives for Cats

 Dirofilaria immitisOther Parasites Treated in Addition to Heartworm 
DrugTrade Name(s)Tissue Stages (Larvae)Circulating MicrofilariaeFleasTicksHookwormsRoundwormsTapewormsEar MitesMinimum
Age/
Weight
Safe to
Use During
Breeding/
Lactation
Food
Allergen
Considerations
Oral Administration (monthly tablets and chews)
Milbemycin oxime Interceptor® (Elanco)
MilbeGuard® (Ceva)
Milbehart (Virbac)
X       Xc Xe      6 weeks/
1.5 lbs
Not
Evaluated 
 Beef
Topical Administration (monthly spot-on; Bravecto PLUS is every 2 months)
Moxidectin + imidacloprid Advantage Multi® (Elanco)
IMOXI (Vetoquinol USA)
PARASEDGE Multi (Virbac)
Midamox for Cats (Norbrook)
X   Xn   Xs Xt   Xu  9 weeks/
1.5 lbs
 Not
Evaluated
     
Moxidectin + fluralaner Bravecto® PLUS (Merck) X   Xn Xv Xs Xt      6 months/
2.6 lbs
 Not
Evaluated
Esafoxolaner + eprinomectin + praziquantel NEXGARD® COMBO
(Boehringer Ingelheim)
X   Xn X4 Xg Xe X5   8 weeks/
1.8 lbs 
 Not
Evaluated
Selamectin

Revolution® (Zoetis)
Paradyne® (Vethical)
Revolt (Aurora)
Senergy (Virbac)
Selarid (Norbrook)

X   Xk   Xm Xe   Xu

 8 weeks/
no minimum
weight

 Yes
Selamectin + sarolaner Revolution® Plus (Zoetis) X   Xk X2 Xm Xe   Xu 8 weeks/
2.8 lbs 
Not
Evaluated 

Preventives for Ferrets

 Dirofilaria immitisOther Parasites Treated in Addition to Heartworm 
DrugTrade Name(s)Tissue Stages (Larvae)Circulating MicrofilariaeFleasTicksHookwormsRoundwormsTapewormsEar MitesMinimum
Age/
Weight
Safe to
Use During
Breeding/
Lactation
Topical Administration (monthly spot-on)
Moxidectin + imidacloprid

Advantage Multi® (Elanco)
Midamox™ for Cats (Norbrook)

X   Xn            2 lbs  Not
Evaluated

a - Ancylostoma caninum, Uncinaria stenocephala, A. braziliense; b - Ascarids (Toxocara canis, Toxascaris leonina); c - Adult Ancylostoma caninum; d - Trichuris vulpis; e- Toxocara cati; f - Taenia pisiformis, Echinococcus multilocularis, E. granulosus, Dipylidium caninum; g - Adult & immature hookworms (Ancylostoma tubaeforme, A. braziliense); h - D. caninum, T. pisiformis; i - Adult Ancylostoma tubaeforme; j - Prevention and control of flea populations (Ctenocephalides felis); k - Treatment of flea infestations (C. felis and C. canis); l - Treatment of tick infestations, with immediate & persistent tick killing activity for 5 weeks against Ixodes hexagonus, I. ricinus, Rhipicephalus sanguineus & for 4 weeks against Dermacentor reticulatus; m - A. caninum L4 larvae, immature adults (L5) and adults; U. stenocephala adults; n - Kills adult fleas; prevention & treatment of flea infestations (C. felis); o - Larval and adult A. caninum & U. stenocephala; p - Adult, immature adult, & fourth-stage larvae (L4) of A. caninum and U. stenocephala; q - Adult T. leonina & adult & L4 of T. canis; r - Sarcoptes scabiei var. canis; s - Adult, immature adult, & L4 of A. tubaeforme; t - Adult, immature adult, & L4 of T. cati; u - Otodectes cynotis; v - Control of tick infestations due to I. scapularis, D. variabilis, Haemaphysalis longicornis; w - Adult and L4 A. tubaeforme, adult A. braziliense; x - Adult and L4 T. cati; y - Adult D. caninum, E. multilocularis; z - Kills adult fleas & prevents flea eggs from hatching for 1 month; prevention & control of C. felis infestation; 1 - Control of tick infestations due to D. variabilis; 2 - Control of tick infestations due to I. scapularis, A. maculatum, D. variabilis; 3 - Adult D. caninum and E. multilocularis; 4 - Treatment and control of I. scapularis, R. sanguineus, D. variabilis, and A. americanum infestations for one month in dogs and puppies 8 weeks of age and older, weighing >4 pounds; 5 - D. caninum; 6 - Treatment and control of I. scapularis, R. sanguineous, D. variabilis, and A. americanum infestations for one month.

© 2024 American Heartworm Society | PO Box 1352 | Holly Springs, NC 27540 | E-mail: info@heartwormsociety.org                                                            REV 5/16/2024

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The colors are changing but your clients’ heartworm prevention programs shouldn’t. To help spice up your client outreach programs this fall, the AHS has created a new set of posters you can print or post on your social pages.

To keep this message front and center with your clients, we’re sharing a set of new posters you can print OR post on your Facebook or Instagram page.

  • To save or print a poster, just click on the image below, then click on the “download” button and save the PDF file.
  • To save a poster for use on your social pages, simply open the downloaded poster, then right click on the file and follow the menu instructions to save the file as a JPEG image.

For more client tools, be sure to visit the Resource Center. And if you don’t already, make sure you’re sharing our Facebook and Instagram posts!