Many popular heartworm medications – like Heartgard and Tri-Heart Plus – include the medicine ivermectin. It’s one of the most important worm-killing drugs that’s used on both humans and animals to prevent infection.
While it’s effective, you might be curious to know exactly how the medication attacks parasites and stops them from spreading throughout the body.
According to The New York Times, ivermectin was extracted from soil fungus in the 1970s and was used in a range of treatments. For example, pharmaceutical manufacturer Merck began to use the drug to fight the effects of river blindness in 1987. Also called onchocerciasis, it’s caused by microscopic worms migrating into victims’ eyes via black fly bites. Today, it’s also used to combat lymphatic filariasis, a disease where worms transferred by mosquitoes infect the lymph nodes and cause severe swelling in extremities like the legs.
How does it work?
DermNet explained that ivermectin stimulates excessive release of neurotransmitters in the infectious worms’ nervous systems. It’s believed that this reaction paralyzes the parasites or inactivates their gut to prohibit nourishment. However, it’s important that doses be administered before the worms reach full maturity, as ivermectin doesn’t kill adult worms.
For dogs, Heartgard Plus is the proven choice for stopping and killing heartworms, hookworms, roundworms and other harmful parasites. The oral medication comes in a chewable tablet made with real beef that canines love, making administration an easy process. Heartgard works to stop heartworm disease by blocking its tissue stage, catching the infection before it can spread throughout the body.
When is it safe?
Although it’s beneficial to canines, pet parents have to be mindful of the recommended doses included with the medication. If exceeded, prescriptions that include ivermectin might cause tremors, disorientation, dilated pupils or loss of appetite. Dog owners should have their four-legged companions tested for heartworm infections before using Heartgard, as it might cause adverse reactions if administered too late.
Treatments that include ivermectin should be given once a month year-round or at least one month following the end of mosquito season. The tablets shouldn’t be swallowed whole, and can be broken up and dumped into meals to prevent this from happening. Dosages are determined based on weight, so dogs up to 25 pounds should be given 68 micrograms, while 26-50 pounds get 136 micrograms and 51-100 pounds receive 272 micrograms. Any canines over 100 pounds are typically administered a combination of tablets.