ProHeart 6 (Canada)

This page contains information on ProHeart 6 for veterinary use.
The information provided typically includes the following:
  • ProHeart 6 Indications
  • Warnings and cautions for ProHeart 6
  • Direction and dosage information for ProHeart 6

ProHeart 6

This treatment applies to the following species:
Manufacturer: Zoetis


Sustained Release Antiparasitic Injectable Suspension for Dogs


DIN 02245422


ProHeart 6 Indications

ProHeart 6 is indicated in dogs six months of age and older, for the prevention of canine cardiovascular dirofilariosis (Heartworm disease) caused by Dirofilaria immitis for six months after a single administration. It is also indicated for treatment of parasitic infections due to the adult and developing larval (L4) stages of hookworms, Ancylostoma caninum and Uncinaria stenocephala, in dogs.


The product consists of two separate vials. Vial 1 contains 10% w/w sterile moxidectin microspheres and Vial 2 contains a specifically formulated sterile vehicle for constitution with Vial 1. No other diluent should be used. The translucent appearance of the vehicle is normal. Each mL of constituted product contains 3.4 mg moxidectin, 3.1% glyceryl tristearate, 2.4% hydroxypropyl methylcellulose, 0.87% sodium chloride, 0.17% methylparaben, 0.02% propylparaben and 0.001% butylated hydroxytoluene.

ProHeart 6 Dosage And Administration

Swirl gently to uniformly resuspend microspheres in the constituted product before withdrawing 0.05 mL of the suspension/kg body weight into an appropriate size syringe fitted with a 18G or 20G hypodermic needle. Inject the product subcutaneously in the dorsum of the neck cranial to the scapula. The constituted suspension is for subcutaneous injection at the rate of 0.05 mL/kg body weight to provide 0.17 mg moxidectin/kg. ProHeart 6 can be administered to dogs 6 months of age and older. For growing dogs, dose to the average weight during the 6 month effective period. Administration may be repeated at 6 months intervals.


Dog weight (kg)

Dosage (mL/dog)

Dog weight (kg)

Dosage (mL/dog)

























Constitution Procedures

The two-part Sustained Release Injectable product must be mixed at least 30 minutes prior to the intended time of use.

Items needed to constitute Sustained Release Injectable Suspension:

- Microspheres (vial 1)

- Enclosed vent needle (25G)

- Sterile 20 mL syringe for transfer

- Vehicle (vial 2)

- Transfer needle (18G or 20G)

Constitution of the 17 mL vial product.

1. Shake microspheres vial to break up aggregates prior to constitution.

2. Using a 18G or 20G needle and sterile syringe, withdraw 17 mL of the unique vehicle from the vial. There is slightly more vehicle supplied than the 17 mL required.

3. Insert the enclosed 25G vent needle into the microsphere vial.

4. Transfer the vehicle into the microsphere vial through the stopper using the transfer needle and syringe.

5. Once the vehicle has been added, remove the vent and transfer needles from the microsphere vial. Discard unused vehicle and needles.

6. Shake the microsphere vial vigorously until a thoroughly mixed suspension is produced.

7. Allow suspension to stand for at least 30 minutes to allow large air bubbles to dissipate.

8. Record the date of mixing on the microsphere vial.

9. Before every use, gently swirl the mixture to achieve uniform suspension. The microspheres and vehicle will gradually separate on standing.

10. Use a 1 mL or 3 mL syringe and a 18G or 20G needle for dosing. Dose promptly after drawing into dosing syringe. If necessary when administration is delayed, gently roll the dosing syringe prior to injection to maintain a uniform suspension and accurate dosing.

11. Refrigerate the unused product. The constituted product remains stable for eight weeks in a refrigerator. Avoid direct sunlight.


Do not use in sick, debilitated or underweight dogs. ProHeart 6 should only be used in dogs testing negative for the presence of existing heartworm infection.

ProHeart 6 Cautions

All dogs 6 months of age and older should be tested for latent heartworm infections before beginning treatment with ProHeart 6. Infected dogs should be treated to remove adult heartworms and microfilariae prior to initiating treatment with ProHeart 6. Further re-testing before re-treatment with ProHeart 6 is at the discretion of the veterinarian.


*See Adverse Reactions section for complete information.


KEEP THIS AND ALL DRUGS OUT OF REACH OF CHILDREN. In case of human consumption, contact a Poison Control Center or a physician immediately.

Adverse Reactions

Adverse Drug Reaction Overview

Post-market experience with ProHeart 6 has identified a number of safety concerns associated with the use of this drug. The most frequently reported adverse events requiring clinical intervention have been allergic in nature. These reactions appear to be idiosyncratic, with no identifiable risk factors such as health status, age, sex, or breed. Anaphylaxis is the most clinically significant serious allergic event. The great majority of these adverse events have occurred at the labeled dose. Vomiting, lethargy and injection site reactions are other reported adverse events. Standard therapeutic intervention should be administered as appropriate. Consult a veterinarian immediately if any adverse reaction is suspected.

Field Trial Adverse Drug Reactions

Because field trials are conducted under carefully controlled conditions, the adverse drug reaction rates observed in field trials may not reflect the rates observed in practice. In the four ProHeart 6 18-month long field trial studies, mild, transient swelling of injection sites for approximately 1-8 weeks have been observed further to the administration of the product per label recommendation. Other reactions observed at various times during the field testing program included diarrhea, vomiting, pruritus, weight loss, listlessness, seizures and increased body temperature.

The various adverse events reported during field trial studies with the recommended dose of ProHeart 6 are provided in the following table.

Percentage Of Dogs With Abnormal Health

Observations Reported in Field Trial Studies (n = 280)*


Percentage of ProHeart 6 Treated Dogs (# cases)


1.07 (3)

Injection Site Pruritus

1.07 (3)

Weight Loss

0.71 (2)


0.71 (2)


0.36 (1)

Elevated Body Temperature

0.36 (1)


0.36 (1)

*Data taken from the US FDA Center for Veterinary Medicine Freedom of Information Summary for ProHeart 6 (moxidectin) Sustained Release Injectable for Dogs, NADA 141-189.

Adverse reactions, other than injection site swellings, have not been observed in margin of safety studies in which dogs were administered ProHeart 6 at dosages up to five times the recommended dose level.

Post-approval Experience

Although all adverse reactions are not reported, the following adverse reaction information is based on voluntary post-approval adverse drug experience reporting. It is generally recognized that this method of reporting results in significant under-reporting of adverse drug reactions. In order of decreasing frequency, the adverse reactions reported to Health Canada through 2005 include, facial edema, anaphylaxis, vomiting, injection site reports, lethargy, urticaria, pruritus, diarrhea, anorexia, pain, liver disease and seizures. Allergic reactions represent the most common serious events reported. The post-approval experience in Europe is comparable to that of Canada in that reported events are similar in nature. The following adverse reaction reports are based on voluntary post-approval reporting to the Center for Veterinary Medicine in the United States*. For each body system, adverse reactions are listed in decreasing order of frequency.

Gastrointestinal: vomiting, diarrhea, anorexia, hypersalivation, dehydration, abdominal pain, elevated pancreatic enzymes, hematochezia, incontinence, gastrointestinal lesion, abdominal distension, pancreatitis, gastroenteritis, nausea, dysphagia, peritoneal effusion, tenesmus, gingivitis, polyphagia, tongue edema, constipation, pharyngitis, esophageal lesion, oral lesion, mesenteric lesion, tongue ulcer, gastrointestinal volvulus, borborygmi, esophageal obstruction, pica, prolapsed rectum, abnormal stool, esophageal dilatation, halitosis

Endocrine: hyperglycemia, hypercalcemia, hypoglycemia, hypothyroidism, hyperphosphatemia glucosuria, diabetes, hypoadrenocorticism, adrenal lesion, hyperadrenocorticism, parathyroid lesion

Hepatic: elevated liver enzymes, hypoalbuminemia, liver lesion, hypoproteinemia, icterus, hypercholesterolemia, abnormal hepatic ultrasound, low BUN, ascites, bilirubinuria, hepatomegaly, elevated lipids, hepatitis, liver failure, low fibrinogen

Neurologic: seizure, ataxia, paresis, nystagmus, proprioceptive deficit, blindness, head tilt, mydriasis, circling, neck pain, staring, vestibular disease, miosis, opisthotonos, pupillary areflexia, deafness, back pain, meningeal lesion, anisocoria, CSF abnormality, hyperesthesia, uveitis, hyphema, facial nerve paralysis, paralysis, brain lesion, paddling, encephalopathy, glaucoma, head pressing, retinal abnormality, strabismus, CNS infarct, dementia, head bobbing, inflammation of the iris, corneal opacity, prolapsed disc, prolapsed eyelid, neck torsion, corneal ulcer, blepharospasm, epiphora, Horner’s, keratoconjunctivitis, neuritis, photophobia, spinal cord lesion

Urinary: elevated BUN, elevated creatinine, hematuria, polydipsia, renal failure, proteinuria, adipsia, polyuria, hypokalemia, low specific gravity, hyponatremia, hypochloremia, UTI, bladder lesion, azotemia, crystalluria, abnormal kidney function test, electrolyte abnormalities, nephritis, stranguria, acidosis, casts, anuria, nephrotic calculi, cystitis, dysuria, oliguria

Behavioural: depression, lethargy, recumbency, trembling, nervousness, confusion, hyperactivity, vocalization, abnormal behaviour, aggression, unconsciousness, pacing, insomnia, fly biting, hallucination

Hematologic: elevated WBC, anemia, thrombocytopenia, autoimmune hemolytic anemia, neutrophilia, polycythemia, low WBC, petechia, monocytosis, lymphopenia, epistaxis, eosinophilia, DIC, bone marrow lesion, aplastic anemia, monocytopenia, reticulocytosis, basophilia, eosinopenia, pancytopenia, hemaglobinuria, clotting problem

Dermatologic/musculoskeletal: injection site swelling, pain on injection, alopecia, lameness, pain, skin lesion, abscess, twitching, stiffness, ecchymosis, dermatitis, conjunctivitis, locomotary disorder, otitis, arthritis, seborrhea, shedding, skin necrosis/ulceration, scleral injection, granuloma, hyperpigmentation, cellulitus, dermal mass, hyperkeratosis, erythema multiforme, myositis, bone lesion, muscle lesion, leukoderm, tail disorder, tetany

Immunologic: anaphylaxis, urticaria, facial edema, edema, pruritus, lymphadenopathy, hyperglobulinemia, splenic lesion, Coomb’s positive, splenomegaly, ANA positive, purpura, thymic lesion

Cardiopulmonary: dyspnea, polypnea, pallor, coughing, bradycardia, cardiac arrest, weak pulse, cyanosis, heart murmur, cardiopulmonary lesion, pulmonary congestion, exercise intolerance, apnea, nasal discharge, pleural effusion, ECG abnormality, syncope, arrhythmia, cardiomegaly, hypertension, sneezing, pericardial effusion, pneumonia, bronchitis, emphysema, tachycardia

Generalized: fever, weight loss, hypothermia, muscle atrophy, hyperemia, sepsis, weight gain

Neoplastic: neoplasm, injection site neoplasm, lymphoma, skin neoplasia, abdominal mass, liver neoplasm, brain neoplasia, bone neoplasm, multiple organ neoplasm, pancreatic neoplasm, splenic neoplasm

Reproductive: vaginal bleeding, prostatomegaly, birth defect, abortion, vulvular discharge, vulvular edema, abnormal estrus, scrotal erythema/edema, metritis, prepucial edema, testicular edema

In rare situations, death has been associated with some of the adverse reactions listed above.

*Taken from the US FDA Center for Veterinary Medicine’s July, 2004 Cumulative ADE Summary.


Moxidectin is a semi-synthetic methoxime derivative of nemadectin which is a fermentation product of Streptomyces cyaneogriseus subsp noncyanogenus. Moxidectin is a pentacyclic 16-membered lactone macrolide. Moxidectin has activity resulting in paralysis and death of affected parasites. The stage of the canine heartworm affected at the recommended dose rate of 0.17 mg/kg body weight is the tissue larval stage. There is no measurable effect against the adult heartworm at this dose rate. Both larval and adult stages of hookworms are susceptible.

Animal Safety

ProHeart 6 has been safely administered to a wide variety of dog breeds. The target animal safety testing program for ProHeart 6 included field tests at the recommended dose level, a margin of safety study, tests with ivermectin-sensitive collie dogs, tests with dogs known to have patent heartworm infections, and reproductive studies with breeding bitches and stud dogs. The results of these studies showed that ProHeart 6 was safe at all doses tested in target animals six months of age and older, including administration at five times the recommended dose level.

As part of the field-testing program, ProHeart 6 was safely used in conjunction with a variety of veterinary products commonly used in dogs. These products included vaccines, vitamins and nutritional supplements, steroid and antibiotic medications, anesthesia, tranquilizers, sedatives, nonsteroidal anti-inflammatory products, shampoos, dips, and other ectoparasite treatments.


Store the unconstituted product at 25°C or lower. Do not expose to light for extended periods of time. After constitution, the product is stable for 8 weeks stored under refrigeration at 2 to 8°C.

How Supplied

ProHeart 6 (moxidectin) Sustained Release Injectable Suspension for Dogs comes in a pack.

Single pack contains:

1 vial of moxidectin microspheres [10% w/w] (598 mg)

1 vial of constitution vehicle (17 mL)

1 vent needle

Each 5 - Pack contains:

5 vials of moxidectin microspheres [10% w/w] (598 mg/vial)

5 vials of constitution vehicle (17 mL/vial)

5 vent needles

® Wyeth LLC

Pfizer Canada Inc., Licensee

Pfizer Animal Health, Pfizer Canada Inc, Kirkland QC H9J 2M5




NAC No.: 11984212

Order Desk:   800-663-8888
Technical Services Canada:   800-461-0917
Technical Services USA:   800-366-5288
Every effort has been made to ensure the accuracy of the ProHeart 6 information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the Canadian product label or package insert.

Copyright © 2014 North American Compendiums. Updated: 2014-07-28