Tri-Heart Plus Chewable Tablets is a once-a-month oral heartworm preventive 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).
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/lb) of body weight. The recommended dosing schedule for
prevention of canine heartworm disease and for the treatment and control of
ascarids and hookworms is as follows:
Chewable Tablets per Month
Color Coding on
Blister Card and Carton
Up to 25 lbs
26 to 50 lbs
51 to 100 lbs
Tri-Heart Plus ivermectin/pyrantel chewable tablets are
recommended for dogs 6 weeks of age and older. For dogs over 100 lbs, use
the appropriate combination of these tablets.
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
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.
Federal (U.S.A.) law restricts
this drug to use by or on the order of a licensed veterinarian
Plus chewable tablets given orally using the recommended dose and regimen,
are effective against the tissue larval stage of D.
immitis for a month (30 days) after infection and, as a result, prevent
the development of the adult stage. Tri-Heart Plus chewable tablets are also
effective against canine ascarids (T. canis, T. leonina)
and hookworms (A. caninum. U. stenocephala, A.
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.Adverse Reactions:
In clinical field
trials with ivermectin/pyrantel, vomiting or diarrhea within 24 hours of
dosing was rarely observed (1.1% of administered doses). The following
adverse reactions have been reported following the use of ivermectin at the
recommended dose: depression/lethargy, vomiting, anorexia, diarrhea,
mydriasis, ataxia, staggering, convulsions and hypersalivation.
Studies with ivermectin indicate
that certain dogs of the Collie breed are more sensitive to the effects of
ivermectin administered at elevated dose levels (more than 16 times the
target use level of 6 mcg/kg) than dogs of other breeds. At elevated doses,
sensitive dogs showed adverse reactions which included mydriasis,
depression, ataxia, tremors, drooling, paresis, recumbency, excitability,
stupor, coma and death. Ivermectin demonstrated no signs of toxicity at 10
times the recommended dose (60 mcg/kg) in sensitive Collies. Results of
these trials and bioequivalency studies support the safety of ivermectin
products in dogs, including Collies, when used as recommended.
Ivermectin/pyrantel has shown a wide margin of safety at the
recommended dose level in dogs, including pregnant or breeding bitches, stud
dogs and puppies aged 6 or more weeks. In clinical trials, many commonly
used flea collars, dips, shampoos, anthelmintics, antibiotics, vaccines and
steroid preparations have been administered with ivermectin/pyrantel in a
heartworm disease preventive program.
Keep this and all drugs out of the reach of
Store at controlled room temperature of 59-86° F (15-30° C).
Protect product from light.