Just to dispel some “myths” on this thread:
The yearly SNAP test screens for antibodies for ehrlichiosis. As long as there are antibodies in your pet the test will be positive. Antibodies do not always correlate with actual illness. A second blood test called a PCR test screens for DNA material of the Ehrlichia bacteria proper and can be performed to confirm actual disease carrier state. However, often if we have antibodies and clinical signs consistent with tick borne illness we will treat. It is true that once positive a pet may remain “positive” for years as antibodies can be persistently elevated. Alternately if a pet is positive for years there is also the possibility of re-exposure through new tick bites.
NO, I repeat NO, tick preventative is a panacea of prevention of tick borne illness. ALL, I repeat ALL, tick preventatives can take up to 12-24 hours for a tick to die. Disease transmission can happen in as few as 8 hours of feeding time. However, disease transmission increases significantly with length of feeding time.
Ehrlichiosis is a dangerous tick borne illness. Common symptoms are low platelets, low RBC (anemia), joint pain, fever, swollen lymph nodes, neurological signs, kidney failure. We have dogs dies annually from tick borne illness, even with aggressive appropriate therapy. Tick preventatives should be applied monthly to help greatly reduce the chances of illness.
The fact that one poster here had dogs not on HW prevention and lived in an area that has it was pure luck, nothing more nothing less. The fact that she had a dog die from HW treatment with Immiticide could have been prevented had that dog been on a preventative (or at least 99% prevented as that is how effective HW prevention is). NO dog, or at least 99% of dogs, should die of HW disease as it is an easily prevented disease.
I am quite certain pesticides have long term health effects on us all. You have more contact with pesticides in your daily life than you do via monthly preventative application on your pet(s). Additionally, pesticide side effects are usually cumulative over long periods of time. IMO, our pets do not have a natural life span long enough to really see those effects. We do as we live 60,70,80+ years. Our pets live 10,12,14 years. If we shorten their lifespan by 6 months but have made their lives better through being flea, tick and heartworm free I see that as a win, win.