Although it is rare for your Chihuahua to have adverse effects from vaccines, it does happen. Because of the devastation canine diseases can cause, the chances of catching a deadly disease outweigh the risk of the vaccines. Most vaccines are multiple vaccines in a single shot. The more vaccines in one injection the greater the risk. Vaccinate your Chihuahua by all means, but just be aware there may be side effects.
When it comes to vaccines, size doesn't matter, if your Chi is only 36 ounces, the protocol is that your Chihuahua pup will get the same dose as a 20 pound puppy! Many vets and breeders only give the Chihuahua puppies a half dose of vaccine. The toy breeds and small breeds are more susceptible to adverse reactions, such as anaphylactic shock, even death.
Chihuahua Vaccination Schedule:
The standard practice for vaccinations is to give first vaccine at 6 weeks, the second vaccine at 9 or 10 weeks, the third vaccine at 12 to 14 weeks of age. Another words some vets give vaccines starting at 6 weeks then 3 week intervals, other vets starting at 6 weeks then 4 week intervals, some vets are now giving the toy breeds and smaller breeds their first vaccines at staring at 8 weeks. A lot of breeders give their own vaccines, except for rabies which must be given by a veterinarian. Their are some risks with giving the vaccines yourself. Your dog could go into anaphylactic shock. This could also happen at the vet's office also. If your going to try and give a vaccine yourself, you must know a few things. The vaccines are given under the skin not to or through the muscle. Although, given in the muscle is not fatal, it it very painful. Under the skin is called subcutaneous. You should have epinephrine on hand to counteract anaphylactic shock, but remember your vet is equipped to handle an emergency adverse reaction.
The reason for annual boosters is that the vaccination test procedures had only gone through duration of immunity for a twelve month period. The dog could have a 100% immunity against deadly diseases for 24 months or even 36 months, but because the testing had been done only for a 12 month period, the vaccinations could not be approved by the United States Department of Agriculture.
New vaccination protocols were arising from veterinary schools suggesting that a three year protocol should be used, but there wasn't any duration of immunity test for this time period (except for rabies) but if your veterinarian was to use the three year protocol, (boosters every three years) and the dog became ill with a disease, the vet could face some serious liability issues.
Since April of 2005, there is a combined canine vaccine for adenovirus, distemper, parvovirus, that carries a three year immunity duration approved by the USDA. The puppy schedule has changed with this, with only two vaccines given at 8 or 9 weeks and the second at 12 weeks.
Vaccinations are divided into core vaccines, The core vaccines (those underlined above) deemed absolutely necessary, are usually combined in one injection.
The non core vaccines are given when the dog may be exposed to the disease and may become ill, outweighs the risks that could come from the vaccine itself. Kennel cough is considered non core and can include distemper, adenovirus, parainfluenza, coronavirus, influenza A subtype H3NB.
Dogs can get Giardia (beaver fever), if exposed to water that contains this protozoan, standing water, puddles, rivers, lakes, streams. Often grown dogs can tolerate the bug, but puppies immune systems usually can not, it can be devastating. Most times it can only be observed in the pup's very fowl smelling diarrhea. They can seem fine except for the diarrhea, their appetites can be normal, they can have full bellies and still be very playful, but they are not getting the nutrition they need and they could suddenly fall dead. They need to be treated immediately. There was a vaccine for Giardia, but it was used to reduce the amount of cysts eliminated, not prevention and has been discontinued since 2009. There are treatments you can purchase for treating Giardia. They are broad spectrum dewormer, fenbendazole and Metronidazole are commonly used. Might be better to take them to a veterinarian.
Dogs do not have to be in the wild, hunting dogs, or running through the desert to get Lyme disease. Dogs have gotten it it cities also. Usually some tick repellent is enough when taking your little Chi out for a walk, with far less side effects than the Lyme disease vaccine.
The human measles virus shares some antigens with canine distemper, so if canine distemper is spreading in your neighborhood, your vet may want to vaccinate with the measles vaccine along with the distemper to give your Chi some cross protection.
Update on Vaccination Protocol!
Good news! After a visit to my vet last week, I learned the protocol for vaccinating your dog is changing! Your pet Chi will start the vaccination process at 8 weeks old. The only exception being is if the mother Chihuahua is not up to date on her vaccines, then the first vaccines will start at 6 weeks. Also the last vaccine will not be given along with the rabies, the rabies will be given separately. The vaccine itself will be safer, it will be a recombinant vaccine not the weaken or killed virus. And the dosage given will fit the breed. When and if your Veterinarian follows the new guidelines, you'll have to ask him or her.