It's important to have your pet vaccinated against deadly diseases, like feline leukemia and canine parvovirus. Getting your pet vaccinated early on in their life can prevent them from ever acquiring awful diseases that can devastate their health. However, these vaccines can also cause some medical confusion if your pet is ever tested for diseases. Here's what you need to know about vaccine-induced diseases that can test false-positive.
Sometimes, veterinarians will test cats and dogs for various diseases to determine if a disease is at fault for any symptoms of illness they're having. While it won't happen to every vaccinated pet, sometimes a blood, fecal, or other determining test will come back with a result that says your pet has a disease when they actually don't. This result is referred to as a false-positive, meaning that the test came back with a positive result, but it's incorrect.
Why False Positives Occur
The way these tests work is by looking for the presence of antibodies in your pet's blood or other bodily fluids. When your pet's body fights off an illness or disease, they develop specific antibodies that the test looks for. However, your pet's body will also develop antibodies after being exposed to the vaccine for the disease, and those antibodies may be detected by the blood test. If the blood test detects those antibodies, the lab may send back a result indicating that your pet is infected with the disease in question, even though they don't actually have it. Some tests for diseases have a very small window of false-positives after a vaccination, like parvo, which may send back false-positives for 12 days. Others may cause false positives for many years, or a false positive may be more likely after each yearly vaccine booster is given.
If your vet knows that your pet has been previously vaccinated for a disease, they'll take this into consideration if a test comes back positive. However, if you have a new vet, make sure that you get the records of all the vaccinations and medical procedures your pet underwent previously so your vet knows that a false-positive may occur.
Test Before You Vaccinate
The only real way to avoid a false positive is to test your pet for a disease prior to vaccinating. It's possible for dogs and cats to acquire diseases at a young age, especially if they're feral, or they may inherit it from their mother. If you test your pet prior to having them vaccinated, you'll be able to know for sure whether they have any infectious diseases. If the test comes back clean, the vaccinations will protect them from ever getting those diseases, and any test that comes back positive afterwards will more likely than not be a false-positive.
If the test comes back positive prior to vaccinating, this is important information to have. If they're already infected, a vaccine won't help, but you can work with your vet to formulate a treatment plan to keep your pet as healthy as possible.
False-positives are a small problem that may pop up if your pet undergoes a blood test after a vaccination. However, the protection vaccinations provide to your pets are well worth a little confusion, and if your vet is aware of the vaccinations your pet has received, it will all work out. Contact a professional veterinarian service, like Edinburgh Animal Hospital, for more information on vaccinating your pet.