The AHS believes weather patterns are influencing mosquito populations.
"AHS recommends that veterinarians be vigilant about recommending annual heartworm testing and year-round use of heartworm protection. Without such vigilance, heartworm incidence numbers could climb higher than ever before," the association says.
Right around this time a year ago, the Companion Animal Parasite Council (CAPC) weighed in regarding reports of increasing resistance to heartworm prevention drugs in dogs:
"There is a growing body of anecdotal reports and experimental evidence that currently available heartworm preventives (macrocyclic lactones) may not be completely efficacious in preventing heartworm infection in dogs. Reports of resistance for dogs in the region have resulted in confusion about how best to prevent infection in veterinary patients," CAPC reports.
"At this time, reports of resistance appear to be confined to dogs from the south-central United States where dogs have become infected while on preventives or remain infected following treatments.
"Veterinarians should also continue to emphasize the need for heartworm diagnostic tests at recommended intervals and appropriate times," the statement says.
According to dvm360:
Since the vast majority of heartworm cases are the result of failed product compliance, CAPC wants veterinarians to continue recommending year-round heartworm prevention.
The organization says it will continue to monitor ongoing research and make updated recommendations on best preventive strategies as additional information becomes available.
'Failed product compliance' is a fancy way of saying pet owners aren't giving their dogs heartworm drugs as often as necessary to prevent disease.
Heartworm Resistance – A Growing Concern
Recently I saw my first dog patient with both heartworm disease and an active Lyme infection. She acquired these illnesses while taking a monthly, year-round chemical heartworm preventive AND a spot-on flea/tick preventive – both prescribed by her regular vet. Ironically, I also identified heartworm and Lyme disease in a patient that was not on any tick prevention and only uses heartworm prevention 6 months out of the year.
An increase in the number of canine heartworm cases isn't a problem of pet owner compliance with drug dosing instructions. It's a problem with the drugs themselves -- parasites are becoming resistant to them because they're overprescribed and overused.
In fact, according to a recent Dogfiles.com article, a scientist who worked for Merial LLC, maker of Heartgard™ heartworm products, has filed suit against the pharmaceutical giant in federal court claiming she was ‘extortionately fired.’ The scientist says Merial knew of problems with ineffectiveness of its Heartgard Plus product as early as 2002, but refused to update package labeling, despite warnings from the FDA.
According to the fired scientist, Merial’s internal studies to support claims of Heartgard Plus effectiveness were unscientific. Her suit also maintains the company is aware of growing heartworm resistance to its product and is in the process of reformulating it.
As you read this, major sponsors of both the American Heartworm Society and the Companion Animal Parasite Council – pharmaceutical giants including Bayer, Pfizer, Novartis, and yes, Merial – are hard at work developing a new generation of toxic chemicals.
These new heartworm drugs will replace the current generation of overprescribed and overused drugs to which parasites are growing immune. And it’s a sure bet these new drugs, like their predecessors, will be associated with autoimmune disease and cancer in companion animals.And in a matter of years, it’s also a sure bet parasites will develop resistance to the new generation of drugs as well.
Eye-Opening Facts about Heartworm Disease and 'Preventives'
There are a few important things to keep in mind as you consider heartworm protection for your own dog:
- The incidence of life-threatening heartworm disease is considerably less than the scary warnings, gruesome pictures and drug company marketing campaigns would have you believe. Heartworm disease can only occur under a precise set of circumstances.
- According to heartworm preventive dosing maps, there are only a few areas of the U.S. where dosing your dog with 9 months to year-round heartworm medicine might be advisable. Those locations are in Texas and Florida, and a few other spots along the Gulf coast. The rest of the country runs high exposure risk at from 3 to 7 months. The majority of states are at 6 months or less.
- Preventives don't actually prevent your dog from getting heartworms. What these chemicals do is kill off the worm larvae at the microfilaria stage. These products are insecticides designed to kill heartworm larvae inside your pet. As such, they have the potential for short and long-term side effects damaging to your canine companion's health.
- There are less toxic ways to protect your pet than administering a lifelong course of monthly, year-round chemical heartworm preventives.
Preparing for Mosquito Season
Consult with a holistic vet to assess your dog's true risk of exposure to infected mosquitoes. A holistic or integrative vet should be knowledgeable about:
- Risk of exposure to heartworm disease in your area
- Potential side effects of preventive drugs
- Drug alternatives
- Methods of detoxifying your dog's body after a course of drug treatment
Build a strong foundation of vibrant health in your dog by feeding a balanced, species-appropriate diet. The healthier your dog is, the less attractive she'll be to all types of pests and parasites, and the better able her immune system will be to fight off invaders.
- Use a non-toxic insect barrier in your yard and around the outside of your home.
- Don't take your dog around standing water. Eliminate as much standing water as possible around your home and yard by cleaning your rain gutters regularly and aerating ornamental ponds and decorative water gardens.
- Stay out of wet marshes and thickly wooded areas.
- Keep your pet indoors during early morning and early evening hours when mosquitoes are thickest.
- Make liberal use of a safe, effective pet pest repellent like my Natural Flea and Tick Defense.
Less is More When It Comes to Chemical Heartworm Preventives
If you live in an area of the U.S. where mosquitoes are common and you know your dog's risk of exposure to heartworm disease is significant, here are my recommendations for protecting your precious furry family member:
- With guidance from a holistic vet, try using natural preventives like heartworm nosodes rather than chemicals. Make sure to do heartworm testing every 3 to 4 months (not annually) as natural heartworm preventives can't guarantee your pet will never acquire the disease. Remember, heartworms live in your pet's bloodstream, so natural GI (gastrointestinal) dewormers, such as diatomaceous earth, and anti-parasitic herbs (such as wormwood) are not effective at killing larvae in your pet's bloodstream.
- If your dog's kidneys and liver are healthy, try using a chemical preventive at the lowest effective dosage. This could mean having the drug compounded if necessary for dogs weighing in at the low end of dosing instructions. Give the treatment at 6-week intervals rather than at 4 weeks, for the minimum number of months required during mosquito season.
- Avoid all-in-one chemical products claiming to get rid of every possible GI worm and external parasites as well. Remember – less is more. The goal is to use the least amount of chemical necessary that successfully treats heartworm. Adding other chemicals to the mix adds to the toxic load your dog's body must contend with. Also avoid giving your pet a chemical flea/tick preventive during the same week.
- Follow up a course of treatment with natural liver detox agents like milk thistle and SAMe, in consultation with your holistic vet.
- Always have your vet do a heartworm test before beginning any preventive treatment. A protocol I put in place in my clinic last month is to run a 4Dx blood test every 6 months on dogs that spend a lot of time outdoors during warmer weather. The 4Dx tests for heartworm, Lyme disease, anaplasmosis and e. canis.
This is a change from my prior recommendation for annual heartworm testing. Because parasites are becoming resistant to heartworm, flea and tick chemicals, the sooner you can identify infection in your pets, the sooner a protocol can be instituted to safely treat the infection with fewer long-term side effects.