google-site-verification: googlef65cde1d8f5ab5fe.htmlHeartworm disease

Linwood Animal Hospital

504 Linwood Drive
Paragould, AR 72450



In the Mississippi Delta Heartworms are one of the most prevalent parasites our companion animals will encounter.  In this section, aimed at educating you about the disease and the preventions I recommend, I'll start with a couple "Vetnotes" articles that are on the topic.  Following the article you'll find additional information regarding specific heartworm preventatives that are available.

Article #1 (March 2010)

For most pet owners this month's column may be the single most important topic that I'll ever write about.  I'd like to thank Laura Wood for her recent e-mail that paved the way for this article.

Laura writes: "Dr Reddick,  Could you please discuss the importance of heartworm prevention in your next column.  So many people don't realize how prevalent the disease is in our area and they don't understand that it is often fatal.  They are also surprised at how costly the treatment for heartworms can be.  What about the winter months?  So many people think heartworms can't be spread during the cold season."

Laura your comments are so important, and you're right, it's unfortunate that many people learn about heartworms when it's too late.  Heartworms are something that I see or discuss every day that I practice.

First off lets answer the question of what are heartworms?  The name can be taken literally in that they are parasitic "roundworms" (20-30cm long) that take up residence in your pet's heart.  They most often affect dogs, but cats and many wild animals can also contract and spread the disease.  Heartworms have a lifespan of several years and can do severe damage to the animals heart and lungs during that lifespan.  Heartworms are spread by the mosquito.  Basically, a mosquito will bite an infected animal and then transmit the disease by biting another animal. 

If the claim hasn't already been made I'll promise that we are living in the heartworm capital of the world!  It's not coincidental that within the past couple of years the world's most known veterinary parisitologists have been right here in northeast Arkansas conducting studies on the disease.

The good news is that there are good preventatives available for heartworm disease.  For many years there were multiple preventatives that each provided excellent protection.  Over the last 2-3 years I've noticed that several of those preventatives have become much less effective at preventing the disease.  This is based on my own personal observations and not on science. Most preventatives are either given orally or applied topically(on the skin) once a month.  I would strongly encourage you to ask your veterinarian which preventatives are available and the pros and cons of each.

Diagnosing heartworms in dogs is done by testing a small blood sample for an antigen that female heartworms produce.  The testing is very accurate and can be done in just a few minutes.  One important thing to remember is that the test is looking for a substance that ADULT heartworms produce.  It takes around 6 months for a heartworm to reach "adulthood" after  the pet is initially infected.  This means that testing may not identify infections that occurred within the past few months.  I personally recommend heartworm testing at 6 month intervals for my canine patients due to the high prevalence in our area.

Laura is right in saying that the treatment can be costly.  The treatment typically requires a full diagnostic work-up, including blood work and x-rays, to determine the current health status prior to treatment, since the drugs themself may cause sickness.  The special drugs used to treat are also very expensive.  At most veterinary clinics a full treatment, including diagnostics, may cost anywhere from $400 to well over $800 depending on the size of the dog.

Although the disease is spread much more commonly in the warmer months it can certainly be spread year round.  A short warm spell where a few mosquitoes start stirring is all that is needed.

Heartworm disease is a serious problem that you should be aware of.  Please let us know if you have any questions about the prevention or treatment of this potentially deadly disease.

Article #2 (March 2011)

Spring is definitely in the air!  If you're like me you can't wait for green grass and those long sunny days!  Unfortunately for our four legged companions it's also a time of the year when mosquitoes are in higher numbers and the risk of contracting heartworm disease is at its peak.  This month I'd like to share with you some exciting news relative to the fight against this deadly disease.

For over 4 years I've been a strong advocate for the heartworm preventative Advantage Multiâ„¢.  It has its pros and cons with the most important consideration being that it prevents heartworms… Very well I might add.  It is also a flea preventative that works fairly well for most pets.  On the downside it's applied topically and needs to be applied monthly.  Topical medications in general can be a little messy and leave that undesirable "oily spot" for a day or so.  Other than that it's still a well accepted and highly recommended product.  

The exciting news is the re-introduction of a heartworm preventative called Proheart6â„¢.  This heartworm preventative originally came on the market in 2001 and grew in popularity very quickly.  Unfortunately in 2004 it was voluntarily recalled due to concerns about adverse reactions.  Since the recall it has been researched and modified into a newer form that was re-introduced in 2008.  At the end of 2010 several restrictions on the drug were lifted that once again made it advantageous and feasible to use for our canine patients. 

The obvious benefit of this prevention is that it is a single slow release injection administered once every 6 months.  It also contains the same active drug, moxidectin, which is in Advantage Multiâ„¢.  The prevention does, however, still have several restrictions mainly dealing with age and overall health.  Although current studies show the newer form of Proheart6â„¢ to be much safer than the original drug, there will always be some risk of having an adverse reaction.

Proheart6â„¢ will certainly not replace the use of Advantage Multiâ„¢ which has worked so well for us over the past few years.  It will, however, be another option that may be a better fit for you and your pet.  Please call with any questions about heartworms and which preventative may be best for your pet!

God Bless!

Brent Reddick, DVM

Linwood Animal Hospital Recommends Either Advantage Multiâ„¢ or Proheart6â„¢ for the prevention of heartworm disease.