ProHeart 6® Injection for Dogs

ProHeart 6® is a sustained-release veterinary injection that protects dogs against heartworm disease for six months per dose, with activity against certain hookworms. It is administered by a veterinarian as a single subcutaneous shot at the clinic. With US delivery from Canada and Canadian pricing, access is straightforward for clinics that prefer scheduled prevention over monthly dosing.

What ProHeart 6® Is and How It Works

ProHeart 6® contains moxidectin, a macrocyclic lactone that targets heartworm larvae transmitted by mosquitoes. After reconstitution and injection, the microsphere formulation releases moxidectin slowly, maintaining protective levels that prevent larvae from maturing into adult heartworms. Labeling also supports treatment of susceptible hookworm infections.

CanadianInsulin partners with licensed Canadian pharmacies and verifies prescriptions directly with your clinic before your medicine ships.

This product ships from Canada to the US once a valid prescription is confirmed. Families paying cash, including those without insurance, often prefer the predictability of a twice-yearly clinic-administered preventive over monthly home dosing. For a broader view of options, browse our Pet Medications.

Who ProHeart 6® Is For

Approved for dogs six months of age and older to prevent heartworm disease. Dogs should test negative for heartworm infection before starting or restarting injections. Safety considerations from the label include use in healthy dogs; caution is advised in dogs with a history of allergic disease, underweight dogs, or dogs with preexisting illness.

Not for use in cats. Dogs known to be hypersensitive to moxidectin or other macrocyclic lactones should avoid this product. Dogs that are heartworm-positive, or suspected of harboring microfilariae, require careful veterinary assessment before any macrocyclic lactone is given.

Dosage and Usage

ProHeart 6 is administered by a veterinarian as a single subcutaneous injection every six months. Dosing is weight-based. The clinic reconstitutes the microspheres with the supplied diluent and injects the sterile suspension according to label directions. Do not administer at home, and do not split or combine doses between pets.

Before the first dose, and when the interval between doses exceeds the recommended schedule, heartworm testing is typically performed. If the schedule lapses, the veterinarian may advise testing prior to re-dosing and may review interim preventive coverage during any gap.

Strengths and Forms

ProHeart 6 is supplied as a two-vial kit: one vial with sterile microspheres containing moxidectin and one vial of diluent. After reconstitution, the suspension is intended for subcutaneous injection. Kit sizes are designed so clinics can dose dogs across a wide range of body weights. Availability of specific pack sizes can vary by pharmacy and current stock.

Missed Dose and Timing

ProHeart 6 is designed for a six-month dosing interval. If a dose is delayed, clinics commonly reassess timing and may perform a heartworm test before giving the next injection. Maintaining consistent six-month protection limits gaps in coverage, especially in regions with year-round mosquito exposure.

Storage and Travel Basics

Clinics store ProHeart 6 refrigerated and follow the label for reconstitution and in-use handling. The product is not intended for home storage or self-administration. If long travel plans could overlap a scheduled dose, clinics often schedule the injection before departure or set a reminder for the next visit.

Temperature-sensitive items ship with cold‑chain handling and insulated packaging.

Benefits

• Six months of continuous heartworm prevention with one clinic-administered injection.
• Helps treat susceptible hookworm infections noted on the label.
• Improves adherence vs monthly preventives by removing the need for monthly dosing.
• Veterinary administration with observation after injection supports safe use.
• Useful for dogs that resist oral tablets or topical treatments.
• Predictable, twice-yearly scheduling simplifies preventive care planning.

Side Effects and Safety

Commonly reported effects include lethargy, vomiting, diarrhea, decreased appetite, drooling, cough, fever, itching, hives, facial swelling, and localized pain, swelling, or lumps at the injection site. Most events are mild and self-limited.

Serious but less common reactions can include anaphylaxis or anaphylactoid reactions, collapse, seizures, or severe gastrointestinal signs. Dogs with high microfilarial loads or existing heartworm disease may be at heightened risk of reaction when a macrocyclic lactone is administered. Immediate veterinary care is warranted for severe or rapidly worsening signs.

For dogs prone to allergic disease or with prior vaccine or drug reactions, veterinarians may observe longer post-injection or tailor timing relative to other procedures. For context on managing canine skin symptoms that sometimes coexist with allergies, see Apoquel For Dogs.

Drug Interactions and Cautions

• Use caution with other macrocyclic lactones or drugs that affect P‑glycoprotein transport; sensitive breeds or dogs with ABCB1 gene variants may be more susceptible to neurologic signs at excessive exposures.
• Concurrent use with routine vaccines, anesthetics, or common preventives is often compatible under veterinary supervision, but the clinic will determine timing.
• Dogs that are ill, underweight, or recovering from major disease may require stabilization before receiving ProHeart 6.
• Always disclose all medicines, supplements, preventives, and recent treatments so the clinic can review potential interactions.

What to Expect Over Time

After injection, clinics typically observe dogs briefly. Most dogs resume normal activity the same day. Protective levels persist for the intended six-month period, helping prevent heartworm larvae from maturing. Periodic wellness checks, heartworm testing per local risk, and on-time redosing help maintain continuous coverage year-round.

Compare With Alternatives

Monthly topical selamectin products such as Revolution For Dog provide heartworm prevention along with flea and mite control when used on schedule. For intestinal parasites only, veterinarians may use dewormers like Panacur Suspension or Strongid P depending on the species identified. Multi-pet households that include cats sometimes prefer broad-spectrum feline options such as Revolution Plus or Nexgard Combo for comprehensive parasite control tailored to cats.

Pricing and Access

Canadian pricing and US delivery from Canada can offer meaningful savings versus typical clinic cash prices. After the clinic confirms a valid prescription, the order is dispensed by a licensed Canadian pharmacy. To view current pricing and place an order for clinic delivery, add the item to cart and follow checkout. For seasonal offers, see Buy Pet Medications Online and check our promotions page.

Availability and Substitutions

Supply can vary. If ProHeart 6 is temporarily unavailable, a prescriber may recommend an appropriate alternative preventive or an interim monthly therapy until stock returns. Substitution choices depend on the dog’s age, weight, local parasite pressures, and medical history.

Patient Suitability and Cost‑Saving Tips

Good candidates include healthy, heartworm‑negative dogs six months and older whose families prefer clinic-administered prevention or who struggle with monthly dosing. Dogs with a history of severe allergic reactions, those that are underweight or systemically ill, or dogs that test positive for heartworm require individualized planning and may not be candidates until stabilized.

• Schedule the next six‑month dose at the time of the current injection to avoid gaps.
• Consider ordering multiple kits for clinic use per the prescription if the veterinarian plans doses for the coming year.
• Set digital reminders tied to the dog’s birth month or wellness visits.
• Keep written records of dose dates, lot numbers, and any observed reactions.

Questions to Ask Your Clinician

• Is my dog an appropriate candidate for ProHeart 6, and is heartworm testing up to date?
• What side effects should be monitored at home after the injection?
• How should we time this injection with vaccinations, surgery, or dental procedures?
• What is our plan if a dose is delayed or we plan extended travel?
• Are there any medicines or preventives we should avoid around injection day?
• Should we add deworming for other intestinal parasites based on fecal results?
• What records should I keep for future reference and refills?

Authoritative Sources

• Zoetis ProHeart 6 Product Page
• FDA FOI Summary: Moxidectin Injection
• ProHeart 6 Prescribing Information

Ready to streamline clinic supply with Canadian pricing and prompt, express, cold‑chain shipping? Add ProHeart 6 to cart and select clinic delivery at checkout.

Disclaimer: This information is educational and not a substitute for veterinary advice. Use only as prescribed by a licensed veterinarian. Refer to the official label for complete directions, contraindications, and safety information.