Spring is heartworm, flea and tick prevention season.  It’s time to see your veterinarian for your dog’s annual heartworm test, and to get your cat or dog’s parasite prevention for the season. To help you protect your pet, we have done a comparison of the main flea, tick parasites, and heartworm preventive products that are available.  Your vet can help you decide which one is best for your pet’s individual needs.
Tick Flea Heartworm parasiticides

K9 Advantix II:

Dose monthly, Topical for dogs 7 Weeks of Age and Older
Ingredients: Imidacloprid, Permethrin, and Pyriproxyfen
Mode of action:  Imidacloprid is a neo-nicotinoid insecticide which binds to nicotinergic receptors on post-synaptic neurons. Permethrin delays or prevents the inactivation of the sodium channels in insect nerves. Pyriproxyfen is an insect growth regulator.
Effectiveness: Kills and repels fleas and ticks, kills adult flea, flea eggs and larvae in 12 hours, also Kills adult ticks, mosquitoes and lice only. K9 Advantix II has repellent effect, reduces Biting from Mosquitoes and Stable Flies. K9 Advantix Kills and repels ticks, including the deer tick (Ixodes scapularis), the American dog tick (Dermacentor variabilis), the brown dog tick (Rhipicephalus sanguineus) and the Lone Star tick (Amblyomma americanum).
Read more about K9 Advantix II


Dose monthly, Chewable for dogs and puppies from 8 weeks of age, providing they weigh at least 2kg
Ingredients: Afoxolaner
Mode of action: Afoxolaner inhibits insect and acarine ligand-gated chloride channels, in particular those gated by the neurotransmitter gamma-aminobutyric acid (GABA), thereby blocking pre- and post-synaptic transfer of chloride ions across cell membranes.
Effectiveness: NexGard kills fleas before they can lay eggs in 8-12 hours, kill Ticks Dermacentor variabilis (American dog tick), >94% effectiveness against Ixodes scapularis (deer tick or black-legged tick), and >93% effectiveness against Rhipicephalus sanguineus (brown dog tick)
Adverse Reactions: On one study approximately 3-4% of treated dogs showed vomiting, Diarrhea and dry skin, lethargy and anorexia have been reported in approximately 1%
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Nexgard Spectra:

Dose monthly, Chewable
Ingredients: Afoxolaner & Milbemycin oxime
Mode of action: Afoxolaner inhibits insect and acarine ligand-gated chloride channels, in particular those gated by the neurotransmitter gamma-aminobutyric acid (GABA). Thereby blocking pre- and post-synaptic transfer of chloride ions across cell membranes. Milbemycin oxime acts as an endoparasiticide.
Effectiveness: same as Nexgard, in addition prevents canine heartworm (Dirofilaria immitis larvae). Treatment of infestations with adult roundworms (Toxocara canis and Toxascaris leonina), hookworms (Ancylostoma caninum, Ancylostoma braziliense and Ancylostoma ceylanicum) and whipworm (Trichuris vulpis). Treatment of demodicosis (caused by Demodex canis), sarcoptic mange (caused by Sarcoptes scabiei var. canis).
Adverse Reactions: same as Nexgard
Read more about Nexgard Spectra


Dose every 12 weeks, Chewable for dogs and puppies 6 months of age and older, and weighing 4.4 pounds or greater
Ingredients:  Fluralaner
Mode of action: Fluralaner belongs to the class of isoxazoline-substituted benzamide derivatives, an inhibitor of the arthropod nervous system, it is the antagonism of the ligand-gated chloride channels (gamma-aminobutyric acid (GABA)-receptor and glutamate-receptor).
Effectiveness: Bravecto Kills fleas and ticks, stats killing newly emerged adult fleas  (Ctenocephalides felis) within 2 hours before they can lay eggs, controls  4 species of ticks. Bravect treats and controls fleas and ticks Ixodes scapularis (black-legged tick), Dermacentor variabilis (American dog tick), and Rhipicephalus sanguineus (brown dog tick). Its effect last for 12 weeks, and only 8 weeks for Amblyomma americanum (lone star tick).
Adverse Reactions: In a well-controlled U.S. field study, which included 294 dogs, there were no serious adverse reactions. The most frequently reported adverse reaction in dogs was vomiting.
Read more about Bravecto


Dose monthly, Chewable for  dogs 6 months of age or older and weighing 2.8 pounds or greater.
Ingredients:  Sarolaner
Mode of action: SIMPARICA, is insecticide belonging to the isoxazoline group. Sarolaner inhibits the function of the neurotransmitter gamma aminobutyric acid (GABA) receptor and glutamate receptor, and works at the neuromuscular junction in insects.
Effectiveness: SIMPARICA Kills adult fleas and ticks, effective against multiple species of ticks including Amblyomma americanum (lone star tick), Amblyomma maculatum (Gulf Coast tick), Dermacentor variabilis (American dog tick), Ixodes scapularis (black-legged tick), and Rhipicephalus sanguineus (brown dog tick) 48 hours post-administration and lasts for 30 days.
Adverse Reactions: lethargy, anorexia, ataxia, tremors, disorientation, hypersalivation, diminished proprioception.
Read more about Simparica


Dose monthly, Topical for dogs six weeks of age or older and cats eight weeks of age and older
Ingredients:  Selamectin
Mode of action: Revolution, is a macrocyclic lactone compound. These compounds effectively prevent the development of adult heartworm.
Effectiveness: Revolution Kills fleas and ticks, prevents development of flea eggs and larvae, treats ear mites and sarcoptic mange, also prevents heartworm. Revolution is effective against american dog tick (Dermacentor variabilis), NOT effective against Deer tick (Ixodes scapularis), it is also called Blacklegged ticks.
Adverse Reactions: alopecia with or without inflammation at or near the site of application was observed in approximately 1% of 691 treated cats. Other signs observed rarely (≤0.5% of 1743 treated cats and dogs) included vomiting, loose stool or diarrhea with or without blood, anorexia, lethargy, salivation, tachypnea, and muscle tremors.
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Heartgard plus:  

Dose monthly, Chewable for dogs 6 weeks and older. It treats and controls hookworms and roundworms
Ingredients: Ivermectin
Mode of action: It belongs to the family of avermectins. It binds to glutamate-gated chloride iron channels, which are present in invertebrate nerve and muscle cells, and causes the paralysis and death of the parasite.
Effectiveness: Heartgard treats and controls hookworms and roundworms. It is also prevents canine heartworm disease by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) for a month.
Adverse Reactions: In clinical field trials with HEARTGARD Plus, vomiting or diarrhea within 24 hours of dosing was rarely observed (1.1% of administered doses). NOT save for Collies and Shelties. Lethargy, anorexia, mydriasis, ataxia, and hypersalivation are reported.
Read more about Heartgard plus

Advantage Multi:  

Dose monthly, Topical for dogs and puppies that are at least 7 weeks of age and that weigh at least 3 lbs. For cats And Kittens 9 Weeks Of Age And Older And That Weigh At Least 2 Lbs
Ingredients: imidacloprid and moxidectin topical solution
Effectiveness: Kills fleas, treats hookworms, roundworms, whipworms, ear mites (Otodectes cynotis),  and sarcoptic mange (Sarcoptes scabiei var. canis), and aid in the treatment of generalized demodectic mange (Demodex canis). Advantage Multi also prevents canine heartworm larvae (Dirofilaria immitis) for a month.
Adverse Reactions: Advantage Multi rarely cause greasy fur, erythema and vomiting. These signs disappear without further treatment. In rare cases, it causes local hypersensitivity reactions. If the animal licks the application site after treatment, transient, self-limiting neurological signs such as ataxía and  generalized tremors. In addition to other side effects such as ocular signs (dilated pupils, little pupillary reflex, nystagmus), abnormal respiration, salivation and vomiting may occur infrequently.
Read more about Advantage Multi

Bravecto for Cats:  

Dose every 12 weeks, Topical. It kills fleas and ticks, kills flea eggs and larvae
Read more about Bravecto for Cats