Using a preventive heartworm medicine is the only way to ensure your dog does not contract the life-threatening heartworm disease. But, how to choose which oral heartworm meds are best for you and your pet.
Most widely used are monthly oral heartworm pills as these are much
more reliable and easier to administer than the old fashioned daily
tablets. Although there are several brands to choose from all are
based on one of two active ingredients. In allheartworm pills either 'Ivermectin' or 'Milbemyclin
Oxine' will be used as the active ingredient. Both these ingredients
are able to kill any larval worms which have infested your pet's
bloodstream during the previous month. They also both discourage
reproduction in adult worms.
The ingredients, however are not identical. Ivermectin kills larvae
relatively slowly so the host animal should be able to absorb the dead
parasites with ease, even if in large volume. Milbemyclin oxine however kills much more rapidly. If this product were given to an animal already positive for heartworm
disease, the large volume of dead worms would be too much for the
animal to deal with and some form of shock reaction would be very
likely.
Ivermectin is much more effective at killing older larvae and adult heartworms than milbemyclin oxine. So, if a treatment is missed the ivermectin
based products are likely to still have a significant impact destroying
most worms in the animal's system. This ability can not be relied on
andheartworm pills should be given every 30 days as stated on the pack. But, if a treatment has been mistimed, ivermectin is the product most likely to be successful.
Because Ivermectin is so good at destroying adult worms and
discouraging female reproduction it is the most widely used active
ingredient used in the treatment of animals already infected withheartworm
disease. Used in larger dosages by vets to treat cases in infected
dogs, means this ingredient is the one coming under closest scrutiny on
a day to day basis. Any problems with the drug would be recognised by
animal health-care professionals rapidly.
So, why use the alternative Milbemyclin oxine based products, you
may ask. Well, the main reason is fear. Because some breeds (notably
collies) have a common genetic mutation which meansIvermectin is toxic too them. However, though that sounds alarming, the dosages in preventative heartworm pills is so tiny that even these breeds will receive no ill effect from the product. A reaction to Ivermectin
is only seen in those breeds when given the larger doses required to
treat the disease once established. However, understandably many
owners of the sensitive breeds choose aMibemyclin based product to ease their minds.
Also, Milbemyclin is able to destroy other parasites so a heartworm medicine containing it provides control for hookworms and roundworms too. Although Ivermectin is a strong insecticide the quantities contained in preventative heartworm pills are so low that it cannot destroy other intestinal worms without the addition of more active ingredients Pyrantel Pamoate and Praziquantel.
Another plus point for the Milbemyclin based products is that with an addition of Lufenuron they can also offer flea control too.
Although the heartworm medicines market is dominated by large
brands, there are a few generic products available too. These offer
exactly the same volume of active ingredients but usually in less
exciting packaging and for a significantly reduced price. There is no
reason not to buy generic petmeds as they come under the same rules and restrictions as the branded ones so you still get a safe and effective heartworm pill for your pet.
The key points when choosing oral heartworm meds are firstly that
your vet must check your pet for signs of the disease prior to
commencing preventative measures. Secondly, all heartworm pills must be given at the correct time interval and during the whole of the mosquito season. Thirdly always ensure your pet meds
are produced for your size and species of animal. Altering doses to
suit different types of animal is extremely dangerous and should be
left to the professionals.