Product details
Tri-Heart Plus (ivermectin/pyrantel) Chewable Tablets for Dogs are indicated for use in dogs to prevent canine heartworm disease by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) for a month (30 days) after infection and for the treatment and control of ascarids (Toxocara canis, Toxascaris leonina) and hookworms (Ancylostoma caninum, Uncinaria stenocephala, Ancylostoma braziliense) in dogs and puppies six weeks of age and older.
- Prevents heartworm disease, treats and controls roundworms and hookworms.
- Kills heartworm larvae before they reach your dog’s heart.
- Enjoy year-round protection for your dog with monthly treatments.
- Easy-to-give, beef-flavored, chewable tablet that your dog will enjoy.
- Safe for dogs with beef allergies.
Product sourced directly from the manufacturer or their approved distributor. Guaranteed genuine product backed by the manufacturer.
For
Dogs (6 weeks of age and older)
Active ingredient(s)
Ivermectin, Pyrantel pamoate
Inactive ingredients
Complete inactive ingredients list not provided by manufacturer.
Brand name
Tri-Heart Plus
Drug class
Avermectin antiparasitic, Tetrahydropyrimidine anthelmintic
Product flavoring
Tri-Heart Plus Chewable Tablets for Dogs are “beef” flavored.
*Contains pork, soy, milk (does not contain actual beef)
Manufacturer
Merck Animal Health
Product strength & size
| Weight Range | Ivermectin (per tablet) | Pyrantel (per tablet) | Color (blister card & carton) |
|---|---|---|---|
| Up to 25 lbs. | 68 mcg | 57 mg | Blue |
| 26 to 50 lbs. | 136 mcg | 114 mg | Green |
| 51 to 100 lbs. | 272 mcg | 227 mg | Brown |
*For dogs over 100 lbs., administer the appropriate combination of chewable tablets to cover your pet’s body weight.
Usage
*For complete product information, please review the full prescribing information in the manufacturer package insert.
Manufacturer Dosage and Administration:
Tri-Heart Plus (ivermectin/pyrantel) chewable tablets should be administered orally at monthly intervals at the recommended minimum dose level of 6 mcg of ivermectin per kilogram (2.72 mcg/lb) and 5 mg of pyrantel (as pamoate salt) per kg (2.27 mg/Ib) of body weight.
Remove only one chewable tablet at a time from the blister card. Because most dogs find Tri-Heart Plus chewable tablets palatable, the product can be offered to the dog by hand. Alternatively, it may be added intact to a small amount of dry food or placed in the back of the dog’s mouth for forced swallowing.
Care should be taken that the dog consumes the complete dose, and treated animals should be observed for a few minutes after administration to ensure that part of the dose is not lost or rejected. If it is suspected that any of the dose has been lost, redosing is recommended.
Tri-Heart Plus chewable tablets should be given at monthly intervals during the period of the year when mosquitoes (vectors), potentially carrying infective heartworm larvae, are active. The initial dose must be given within a month (30 days) after the dog’s first exposure to mosquitoes. The final dose must be given within a month (30 days) after the dog’s last exposure to mosquitoes.
When replacing another heartworm preventive product in a heartworm disease preventive program, the first dose of Tri-Heart Plus chewable tablets must be given within a month (30 days) of the last dose of the former medication.
If the interval between doses exceeds a month (30 days), the efficacy of ivermectin can be reduced. Therefore, for optimal performance, the chewable tablet must be given once a month on or about the same day of the month. If treatment is delayed, whether by a few days or many, immediate treatment with Tri-Heart Plus chewable tablets and resumption of the recommended dosing regimen minimizes the opportunity for the development of adult heartworms.
Monthly treatment with Tri-Heart Plus chewable tablets also provides effective treatment and control of ascarids (T. canis, T. leonina) and hookworms (A. caninum, U. stenocephala, A. braziliense). Clients should be advised of measures to be taken to prevent reinfection with intestinal parasites.
Missed doses
If a dose is missed: give Tri-Heart Plus immediately to resume monthly dosing and notify your veterinarian. Do not give two doses at once.
If multiple doses have been missed, consult your veterinarian prior to restarting the monthly dosing schedule.
Storage
Store in a cool, dry place at a controlled room temperature between 59 and 86°F. Protect product from light. Keep out of the reach of children and pets. Tablets should remain sealed in their original packaging and should only be taken out of the blister pack at the time of dosing. Store away from heat and direct sunlight.
Do not store in the bathroom, near the kitchen sink, or in damp places. The medicine may break down if exposed to heat or moisture.
Side effects
Tri-Heart Plus is generally well tolerated, and side effects are considered uncommon when given at the recommended dosage. The most common side effects of this medication are vomiting and diarrhea.
Other reported side effects include (but may not be limited to) decreased appetite, depression/lethargy, hypersalivation (drooling), and pupil dilation.
Contact your veterinarian immediately if your pet experiences severe/excessive drooling, seizures or tremors, or exhibits decreased coordination (e.g., staggering, stumbling, difficulty walking).
Notify your veterinarian if your pet experiences any of the effects described above, or if you notice any other side effects that are persistent or troublesome.
If you notice anything unusual, please consult your veterinarian.
Precautions
*For complete product information including warnings and precautions, please refer to the manufacturer package insert.
For oral use in dogs only- not for use in humans. Keep this and all drugs out of the reach of children. In case of ingestion by humans, consult a physician immediately.
All dogs should be tested for existing heartworm infection before starting treatment with Tri-Heart Plus chewable tablets which are not effective against adult D. immitis. Infected dogs must be treated to remove adult heartworms and microfilariae before initiating a program with Tri-Heart Plus chewable tablets.
While some microfilariae may be killed by the ivermectin in Tri-Heart Plus chewable tablets at the recommended dose level, Tri-Heart Plus chewable tablets are not effective for microfilariae clearance. A mild hypersensitivity-type reaction, presumably due to dead or dying microfilariae and particularly involving a transient diarrhea has been observed in clinical trials with ivermectin alone after treatment of some dogs that have circulating microfilariae.
Do not administer to animals with a known history or suspected allergy/hypersensitivity to any avermectin or tetrahydropyrimidine drug, including this medication or any of its ingredients. Allergic reactions to medications may occur. Be sure to inform Vetsource and your veterinarian if your pet has any known drug sensitivities or allergies.
If your pet displays symptoms of an allergic reaction, discontinue therapy and call your veterinarian immediately or seek emergency veterinary attention. Symptoms may include (but are not limited to): swollen lips, tongue, face, or airways; difficulty breathing; agitation; profuse salivation; and widespread hives or itching.
Drug and food interactions
There are no documented drug or food interactions with this medication when given at the recommended dosage.
*NOTE: this may not be a comprehensive list. Contact your veterinarian if your pet experiences any unusual reactions when different medications are given together.
Please ensure your veterinarian is aware of all medications and supplements that your pet is currently receiving. Your veterinarian may prescribe multiple medications, even if a potential drug interaction may occur. In these instances, your veterinarian may adjust the dosages or monitor your pet more closely.
Adverse reactions
If you are concerned that your pet has experienced an adverse reaction to this medication, please contact the manufacturer Merck Animal Health at 1-800-224-5318 or Vetsource Pet Owner Care at 877-738-4443.
Overdose
If you have any reason to suspect an overdose, call your doctor/veterinarian or the appropriate poison control resource immediately.
For humans:
The national toll-free Poison Help line, 1-800-222-1222, will connect you to your local poison center in case of emergency. This service is available nationwide and in most U.S. territories.
For animals:
The ASPCA Animal Poison Control Center is available 24 hours a day, 365 days a year at 888-426-4435.
Pet Poison Helpline® also provides a 24/7 animal poison control service at 855-764-7661.
*Please note: this information is for third-party services and is provided for convenience in case of potential poison-related emergencies. There may be consultation fee for these services.
Disclaimer
The content provided on this page is NOT medical advice.
All content, including the images and product description above, is intended for general informational purposes only and should not be considered a substitute for professional veterinary consultation, diagnosis, or treatment.
Consult your veterinarian for complete information about this product and how it fits into your pet's individual treatment plan.
Last revised: 8/07/2025
-
Description
Product detailsTri-Heart Plus (ivermectin/pyrantel) Chewable Tablets for Dogs are indicated for use in dogs to prevent canine heartworm disease by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) for a month (30 days) after infection and for the treatment and control of ascarids (Toxocara canis, Toxascaris leonina) and hookworms (Ancylostoma caninum, Uncinaria stenocephala, Ancylostoma braziliense) in dogs and puppies six weeks of age and older.- Prevents heartworm disease, treats and controls roundworms and hookworms.
- Kills heartworm larvae before they reach your dog’s heart.
- Enjoy year-round protection for your dog with monthly treatments.
- Easy-to-give, beef-flavored, chewable tablet that your dog will enjoy.
- Safe for dogs with beef allergies.
Product sourced directly from the manufacturer or their approved distributor. Guaranteed genuine product backed by the manufacturer.ForDogs (6 weeks of age and older)Active ingredient(s)Ivermectin, Pyrantel pamoateInactive ingredientsComplete inactive ingredients list not provided by manufacturer.Brand nameTri-Heart PlusDrug classAvermectin antiparasitic, Tetrahydropyrimidine anthelminticProduct flavoringTri-Heart Plus Chewable Tablets for Dogs are “beef” flavored.*Contains pork, soy, milk (does not contain actual beef)ManufacturerMerck Animal HealthProduct strength & sizeWeight Range Ivermectin (per tablet) Pyrantel (per tablet) Color (blister card & carton) Up to 25 lbs. 68 mcg 57 mg Blue 26 to 50 lbs. 136 mcg 114 mg Green 51 to 100 lbs. 272 mcg 227 mg Brown *For dogs over 100 lbs., administer the appropriate combination of chewable tablets to cover your pet’s body weight.Usage*For complete product information, please review the full prescribing information in the manufacturer package insert.Manufacturer Dosage and Administration:Tri-Heart Plus (ivermectin/pyrantel) chewable tablets should be administered orally at monthly intervals at the recommended minimum dose level of 6 mcg of ivermectin per kilogram (2.72 mcg/lb) and 5 mg of pyrantel (as pamoate salt) per kg (2.27 mg/Ib) of body weight.Remove only one chewable tablet at a time from the blister card. Because most dogs find Tri-Heart Plus chewable tablets palatable, the product can be offered to the dog by hand. Alternatively, it may be added intact to a small amount of dry food or placed in the back of the dog’s mouth for forced swallowing.Care should be taken that the dog consumes the complete dose, and treated animals should be observed for a few minutes after administration to ensure that part of the dose is not lost or rejected. If it is suspected that any of the dose has been lost, redosing is recommended.Tri-Heart Plus chewable tablets should be given at monthly intervals during the period of the year when mosquitoes (vectors), potentially carrying infective heartworm larvae, are active. The initial dose must be given within a month (30 days) after the dog’s first exposure to mosquitoes. The final dose must be given within a month (30 days) after the dog’s last exposure to mosquitoes.When replacing another heartworm preventive product in a heartworm disease preventive program, the first dose of Tri-Heart Plus chewable tablets must be given within a month (30 days) of the last dose of the former medication.If the interval between doses exceeds a month (30 days), the efficacy of ivermectin can be reduced. Therefore, for optimal performance, the chewable tablet must be given once a month on or about the same day of the month. If treatment is delayed, whether by a few days or many, immediate treatment with Tri-Heart Plus chewable tablets and resumption of the recommended dosing regimen minimizes the opportunity for the development of adult heartworms.Monthly treatment with Tri-Heart Plus chewable tablets also provides effective treatment and control of ascarids (T. canis, T. leonina) and hookworms (A. caninum, U. stenocephala, A. braziliense). Clients should be advised of measures to be taken to prevent reinfection with intestinal parasites.Missed dosesIf a dose is missed: give Tri-Heart Plus immediately to resume monthly dosing and notify your veterinarian. Do not give two doses at once.If multiple doses have been missed, consult your veterinarian prior to restarting the monthly dosing schedule.StorageStore in a cool, dry place at a controlled room temperature between 59 and 86°F. Protect product from light. Keep out of the reach of children and pets. Tablets should remain sealed in their original packaging and should only be taken out of the blister pack at the time of dosing. Store away from heat and direct sunlight.Do not store in the bathroom, near the kitchen sink, or in damp places. The medicine may break down if exposed to heat or moisture.Side effectsTri-Heart Plus is generally well tolerated, and side effects are considered uncommon when given at the recommended dosage. The most common side effects of this medication are vomiting and diarrhea.Other reported side effects include (but may not be limited to) decreased appetite, depression/lethargy, hypersalivation (drooling), and pupil dilation.Contact your veterinarian immediately if your pet experiences severe/excessive drooling, seizures or tremors, or exhibits decreased coordination (e.g., staggering, stumbling, difficulty walking).Notify your veterinarian if your pet experiences any of the effects described above, or if you notice any other side effects that are persistent or troublesome.If you notice anything unusual, please consult your veterinarian.Precautions*For complete product information including warnings and precautions, please refer to the manufacturer package insert.For oral use in dogs only- not for use in humans. Keep this and all drugs out of the reach of children. In case of ingestion by humans, consult a physician immediately.All dogs should be tested for existing heartworm infection before starting treatment with Tri-Heart Plus chewable tablets which are not effective against adult D. immitis. Infected dogs must be treated to remove adult heartworms and microfilariae before initiating a program with Tri-Heart Plus chewable tablets.While some microfilariae may be killed by the ivermectin in Tri-Heart Plus chewable tablets at the recommended dose level, Tri-Heart Plus chewable tablets are not effective for microfilariae clearance. A mild hypersensitivity-type reaction, presumably due to dead or dying microfilariae and particularly involving a transient diarrhea has been observed in clinical trials with ivermectin alone after treatment of some dogs that have circulating microfilariae.Do not administer to animals with a known history or suspected allergy/hypersensitivity to any avermectin or tetrahydropyrimidine drug, including this medication or any of its ingredients. Allergic reactions to medications may occur. Be sure to inform Vetsource and your veterinarian if your pet has any known drug sensitivities or allergies.If your pet displays symptoms of an allergic reaction, discontinue therapy and call your veterinarian immediately or seek emergency veterinary attention. Symptoms may include (but are not limited to): swollen lips, tongue, face, or airways; difficulty breathing; agitation; profuse salivation; and widespread hives or itching.Drug and food interactionsThere are no documented drug or food interactions with this medication when given at the recommended dosage.*NOTE: this may not be a comprehensive list. Contact your veterinarian if your pet experiences any unusual reactions when different medications are given together.Please ensure your veterinarian is aware of all medications and supplements that your pet is currently receiving. Your veterinarian may prescribe multiple medications, even if a potential drug interaction may occur. In these instances, your veterinarian may adjust the dosages or monitor your pet more closely.Adverse reactionsIf you are concerned that your pet has experienced an adverse reaction to this medication, please contact the manufacturer Merck Animal Health at 1-800-224-5318 or Vetsource Pet Owner Care at 877-738-4443.OverdoseIf you have any reason to suspect an overdose, call your doctor/veterinarian or the appropriate poison control resource immediately.For humans:The national toll-free Poison Help line, 1-800-222-1222, will connect you to your local poison center in case of emergency. This service is available nationwide and in most U.S. territories.For animals:The ASPCA Animal Poison Control Center is available 24 hours a day, 365 days a year at 888-426-4435.Pet Poison Helpline® also provides a 24/7 animal poison control service at 855-764-7661.*Please note: this information is for third-party services and is provided for convenience in case of potential poison-related emergencies. There may be consultation fee for these services.DisclaimerThe content provided on this page is NOT medical advice.All content, including the images and product description above, is intended for general informational purposes only and should not be considered a substitute for professional veterinary consultation, diagnosis, or treatment.Consult your veterinarian for complete information about this product and how it fits into your pet's individual treatment plan.Last revised: 8/07/2025 -
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