Should little dogs get the same amount of vaccine as a big dog?

A common question we get asked is: “Why does my little 2 pound yorkie get the same amount of vaccine as a 90 pound rottie?”  Seems like a reasonable question since their flea and heartworm medications are different sizes, their deworming doses or antibiotics are different sizes, heck, even their dog beds are different sizes.

The first thing I would ask is, what drives this question?  Is it fear that your little dog will have a reaction to the vaccine because they are so small?  Or is it the thought that they may not need as much vaccine to give them the same level of protection as a big dog?

Well, here are the answers.

More often than not, people choose not to vaccinate their pets out of fear.  Not the fear of their pets contracting a deadly disease like Parvo but more the fear that their pet will have a serious reaction to the vaccine.  Let’s talk about vaccine reactions.  According to a recent study¹, only 0.2% of dogs had an owner-reported vaccine reaction that ranged from lethargy and injection site sensitivity (minor reaction) to major anaphylactic reactions.  The more serious reactions (major anaphylactic reaction) accounted for 85 of the 343 reactions reported (so only 25% of the 0.2% which equals an overall risk of serious reaction of 0.05%).  So vaccine reactions are pretty rare.  Be that as it may, what if your dog is that unlucky one?  If your dog is the unlucky reactor, it means that his or her immune system is responding inappropriately to something in that vaccine.  By reducing the vaccine by ½ does not change the fact that his or her immune system is going to inappropriately respond to it any more than a person with a peanut allergy will have less chance of a reaction if they only eat ½ a peanut.

So why do they need the same amount of vaccine as a big dog to get the same immunity?  This question stems from the idea that a small dog will need less antibiotics to treat infection, less flea medication to prevent infestation, less hair dye to make them completely pink (do not try at home), etc.  Well, the immune system does not work like that.  The vaccine is a biologic that is designed to create an immune system response that will ultimately provide protection by creating antibodies.  We know that there is a “critical mass” of antigen (the bad thing we are vaccinating against) to get the process started and that critical mass is roughly the same for all dogs (a super tiny amount).  It’s like rolling a snowball down a hill.  You need a big enough snowball to start with to end up with a bigger ball at the bottom of the hill.  If you start with too small a snowball, it may not get rolling at all, and even if it does, the ball you end up with at the bottom of the hill will be smaller than you had wanted.

And finally, the legal disclaimer.  The American Veterinary Medical Association’s official position statement is: “Failure to administer a vaccine in the method deemed appropriate by the manufacturer (e.g. allowable concurrent treatments, route of administration, full dose) may result in suboptimal protection and/or adversely alter the established safety profile of the product. All manufacturer cautionary warnings on vaccines should be followed. Veterinarians should recognize that failure to use vaccines according to manufacturer-labeled directions may result in potential liability to the veterinarian in the case of an adverse event or lack of efficacy.”

Here at Coastal, we have taken every measure we can to ensure that your pets are getting the safest vaccines available on the market and getting them at the appropriate time intervals to provide protection for as long as possible.  Please see the other blogs, Puppy Vaccines: What if we already gave 3? And DAP v. DHLPPC and why more is not better.

Any questions about your pet’s vaccines? Give us a call and we can get you in to have our team evaluate your pet and get you our best recommendations.

Dr. Tedder