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Friday, December 10, 2010

Heartworm Disease in San Diego

Heartworm disease- Myth or Reality for dogs in San Diego?  Well folks, unfortunately it is a reality now....

Here's a little history on this issue in San Diego....

For years San Diego County was blessed to be Heartworm Disease FREE. 

In the 1980's, I was a teenager working in a practice in North Park, and we rarely recommended heartworm prevention except for dogs that traveled to certain parts of the country or to military family dogs who were frequently moving to other parts of the country and world.  Those were the good old days.

Returning to San Diego in 1999, I was at first shocked to see how many veterinarians were recommending Heartworm Preventative.  My cardiology mentor from UC Davis was vehement that heartworm disease was too rare in Southern CA to merit preventative.  Very few cases, most INCORRECTLY diagnosed by mistaking the microfilaria of heartworm with a similar non pathogenic larvae produced in the blood stream by fleas, were truly being diagnosed. 

So were veterinarians who recommended heartworm preventative at that time doing the right thing or just looking for further income production for their practice?  My response at the time?  I was ok recommending Preventative because it also helped prevent other issues....

Look at what else Heartworm Preventative does...kills heartworm larvae (duh!)... but it also kills other larvae from the common roundworm, hookworm and whipworm.  Those diseases are actually zoonotic!!  That fancy words means that YOU can get it from the animal.  Most adult dogs are commonly exposed and can shed the L3-4 stages in their spit, even if they generally never get adult worms.  Wanna big wet kiss from your dog now?   THAT was a good enough reason for me to recommend preventative....especially to people with little kids.

Fast forward to 2010- what changed?  Why do we now need Heartworm Preventative for our dogs?  No one is completely sure why heartworm disease is now appearing in San Diego sporadically but at a HIGHER INCIDENCE.  Mosquitos, the vector for heartworm larva spreading, are more prevalent in our area now than 20 years ago.  We all keep hearing about West Nile Virus....well, guess how that bugger gets transmitted.  Yup, Mr. Buzzing Suckmeister.  Some authorities have speculated that the El Nino with wetter weather over the last few years is to blame for the 'squiters.  Others blame the economy and increase in foreclosures....standing water in pots, swimming pools in houses without occupants.  I think we can blame our friends in Louisiana just a bit as well.  Following Hurricane Katrina, over 300 dogs from Hurricane ravaged areas made their way to California.  Heartworm disease is like the common cold in Louisiana!  I'm convinced not every one of those dogs was free of larvae, even if they tested negative for adult heartworm.  (BTW- the Heartworm Antigen Test only detects pregnant females heartworms....use that on Trivial Pursuit!).

Bing bang boom....not matter what is to blame....we've NOW got an issue....

The final straw for us here at Pacific Beach Veterinary Clinic?  Reports that the County Veterinary Office of San Diego has seen adult heartworm in necropsied/autopsied coyotoes. one is giving the coyotes preventative!

So friends, the long answer opinion from this particular veterinary BLOGGER is that YES, your doggie should be on heartworm preventative here in San Diego.  It is cheap to prevent.  It is easy.  All you do is give them a once a month preventative treat nearly every dog loves to get.  Problem solved.

Did I mention it costs about $1200-1500 to treat a heartworm positive dog?  Did I mention many of their clinical signs are irreversible (pulmonary vessels NEVER are completely normal again after heartworm infestation!).  Did I mention we rarely diagnose it until they are sick? 

Veterinarians get it... prevention is best.  Not sure why those human insurance companies don't get that....another topic for another day!

More on which heartworm brands do what in a future posting!!!!

Take care my friends-

Yours in Blogging,

Dr. Hooli


  1. What about long term effects of a monthly poison in your dog? Isn't that a consideration? Couldn't it cause an autoimmune condition, chronic fatigue, skin problems or cancer over a dog's lifetime? What about quality of life considerations? Isn't this a toxic poison? Isn't that why it kills the larva? Not sure I want to take the risk of trusting the pharmaceutical companies on this one. Do you realize that the National Heartworm Society is actually a "non-profit" funded by large pharmaceutical companies? Maybe I'll just have my dog tested every 6 months instead. Especially since in San Diego the incidence is still really low. Also I have an indoor dog and I try to keep him away from mosquitos.

  2. I resisted heartworm drugs 10 years ago, but not anymore. If the local coyotes get it, all our local dogs are at risk.

    My dog was a rescue from St Francis AnimalSanctuary, Tylertown Mississippi, flown to Helen Woodward Animal Center as a 7 month old puppy in 2006. He had heartworm in Mississippi that seriously damaged his heart. The heartworm was eliminated in Mississippi before he was flown to San Diego but the damage to his right ventricle was visible in a cardiac sonogram.

    To this day, as a 10 year old, he doesn't have nearly the stamina you'd expect from a dog his size (60 lb) that is exercised as much as he is, about 7 miles daily plus dog park time.

    Heartworm is serious, it's here, and we owe it to our dogs to protect them.