What Immunizations Do Pets Need? A Veterinarian’s Guide


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Vaccination is not just an issue for people and not just in the time of the coronavirus. The vaccination of animals actually began in the late 19th century when Louis Pasteur made a vaccine for chicken cholera in 1879. Two years later, the French chemist developed one for anthrax of sheep and cattle. Around the same time, the economic importance of livestock paired with enormous losses in the cattle and pork industries led to the establishment of the Bureau of Animal Industry (BAI) within the U.S. Department of Agriculture which spurred research in the veterinary sciences.

Today, veterinarians advise pet caregivers to vaccinate companion animals, like cats and dogs against common serious infectious diseases. The core vaccines for dogs are canine parvovirus, distemper, hepatitis, and rabies. For cats, they are panleukopenia (feline distemper), feline calicivirus, feline herpesvirus type I (rhinotracheitis), and rabies.

August is Pet Immunizations Awareness Month and what better time to benefit from the knowledge of a veterinary medical professional with over 50 years of experience. World-renowned veterinarian Dr. Jean Dodds graciously lent her expertise in the following interview on pet immunizations.

Interview with an Expert: Jean Dodds, DVM

Dr. Jean DoddsDr. Jean Dodds is a clinical research veterinarian and founder of Hemopet Holistic Care Veterinary Clinic, providing integrative animal care in Southern California. Established in 1986, the clinic was the first nonprofit national animal blood bank. Among the wide range of services offered, Hemopet has a diagnostic division dedicated to hematology and blood banking, immunology, endocrinology, nutrition, and holistic medicine.

Notably, in 2011, Dr. Dodds introduced a food sensitivity and intolerance diagnostic test for dogs, cats, and horses. NutriScan has now become a “gold standard” in the industry.

Dr. Dodds has more than 150 publications to her credit and 25 patents. The book she co-authored with Diana Laverdure, The Canine Thyroid Epidemic: Answers You Need for Your Dog, was awarded the “Best Care and Health Book for 2011” by the Dog Writers Association of America as well as the Eukanuba Maxwell Canine Health Award. She is a graduate of the Ontario Veterinary College.

Regarding what’s important to know about pet immunizations, Dr. Dodds shared,

Vaccines are carefully manufactured. They’re generally safe; you can have a rare adverse reaction, but we don’t need to over-vaccinate for diseases that are not prevalent in the area where the animal lives…As Dr. Ron Schultz, my good friend, used to say, ‘Be wise and immunize. But immunize wisely.’

VetTechColleges: What immunizations do you recommend?

Dr. Dodds: Having been involved in veterinary medical issues, especially in vaccination issues, for over 50 years, we have to reiterate that having the appropriate puppy and kitten vaccinations—including for avians, fowl, and livestock—in early life is essential to protect them against serious, potentially fatal infectious diseases.

For dogs, the critically important diseases everywhere are canine distemper virus and canine parvovirus. Veterinary medical associations also indicate that hepatitis can be a problem for the dog. Those three viruses are considered to be ‘core’ along with the rabies virus.

However, there have been no documented clinical cases of infectious canine hepatitis in North America for about 15 years now. Why does that matter? If you give young puppies distemper and parvo vaccines along with hepatitis vaccine together, it suppresses the tissue immunity of that puppy for 10 to 14 days, at a time when they’re going through a lot of other changes in their life: like a new home, new food, a new environment, and stressors that can change their immune systems’ recognition and function.

So, our view is, we would not give a vaccine-like hepatitis in the core for puppies when it’s currently not a clinically important disease…If it becomes a clinically important disease again, we’ll vaccinate because the risk of adverse reaction to the vaccine is minimal, in face of an outbreak of the virus.

Depending on where you live, you might need to use leptospirosis vaccines, although the current leptospirosis vaccines only protect against four strains, and most of the clinically important reportable forms of leptospirosis in North America today rarely include the four strains that are in the vaccine. So giving leptospirosis vaccine does not protect you against the common prevalent clinical strains in North America today.

So we need to think about where we live, what’s the high-risk exposure rate for certain infectious diseases, and vaccinate only for those.

Rabies is the vaccine required legally everywhere. It is the one most likely to cause adverse reactions because all but two contain thimerosal, which is a mercury salt, and that can produce autoimmune, and other adverse reactions. Now, curiously, leptospirosis is the second most likely vaccine to cause adverse reactions because of hypersensitivity. So, again, things like the leptospirosis vaccine should be given only where it’s clinically needed and against the right strains.

So that’s the dog.

For the cat, the equivalent core vaccine is panleukopenia (FP), a parvovirus of cats that is considered a core vaccine.

The other upper respiratory vaccines of cats, like calici and herpes viruses, are recommended but optional in most cases.

Rabies is required now for cats in most places as well, the same as it is in the dog.

We have feline leukemia vaccine for this retrovirus infection which is a significant issue, particularly in kittens. Most kittens that have been exposed will become ill or immunocompromised, and the vaccine is not completely protective. It used to be 40 percent protective. Now it’s about 80 percent protective, but it doesn’t protect all kittens. Adult cats are usually relatively resistant to the clinical signs of feline leukemia virus.

We do not have a vaccine yet for the human HIV equivalent (FIV) Feline Immunodeficiency Virus in the cat, and the cat is actually in a better place with the rabies vaccines because there is a non-adjuvanted, mercury-free rabies vaccine licensed for cats. We do not have such a vaccine for the dog, but we desperately need it. We don’t want to give these heavy metals, along with the vaccines, to people or pets. So that’s basically, what we have for the cat.

The four viruses that are core—canine distemper, canine parvovirus, canine adenovirus (which is for hepatitis and kennel cough), and feline panleukopenia virus—all produce what’s called sterile immunity. When the animal has been vaccinated and actually immunized (just giving the vaccines doesn’t mean it took; you have to measure the serum antibody titer and show that they’ve been actually immunized), they cannot be reinfected. They basically are protected forever.

They can harbor the disease, but they can’t be infected. So they could pass it on to an unvaccinated or an unprotected dog or cat, but they themselves cannot get sick.

VetTechColleges: Could you speak about the timeline for immunizations?

Dr. Dodds: The biggest problem we have today in small animal medicine is that non-veterinarians (pet owners, pet guardians, pet breeders) can vaccinate their own animals for everything but rabies. Only rabies requires a veterinarian. So that means that if people are not understanding the immune system, they are vaccinating their puppies and their kittens when they’re way too young, like four weeks or five weeks. This is unwise for two reasons.

First of all, there are other things other than the vaccine viral or other antigens that you want in the vaccine. There’s fetal calf serum, or bovine and egg albumin. There are additives that release histamines and stimulate the immune cells to react because that’s the purpose of the vaccine. They’re called excipients, and the pets, when they’re very young, are going to be more reactive to them.

Secondly, unless those were orphaned puppies and kittens who never nursed on their mother, they’ve got colostrum, and in the first 36 hours of life, they get that orally from their mother, from drinking the mother’s milk.

The problem is that most of the adult animals that are well cared for today have been heavily vaccinated, and so the mother is going to have antibodies against that series of vaccines in her milk. And those antibodies can last now for 14 to 16 weeks. In fact, they’ve found kittens that still have maternal antibodies at 18 weeks.

So if you vaccinate them at four, five, six, seven, eight weeks of age, when they’re too young, it’s not going to effectively immunize them. It’s just going to be partially neutralized by the mother’s colostral antibodies. So residual maternal immunity is a huge issue in leaving puppies and kittens at risk if you vaccinate too early and then stop the vaccines too early. In other words, if you stop vaccinating at 12 weeks—which most of the vaccine labels will tell you is ok—it’s not going to work if the mothers still have antibodies. It’s going to neutralize it. Those puppies and kittens are only going to be partially immunized.

So knowing the pet’s history with nursing is vitally important.

And one of the ways that we can overcome this issue is to start the vaccines a little bit later, say at eight to ten weeks, and then we give two doses and we can give the second dose at 14 to 16 weeks. You then wait three weeks.

Now, those puppies don’t go anywhere; they don’t go to the dog park or cat park; they don’t walk around the whole neighborhood. They stay in their home, in their backyard, or with friends that have healthy pets. You wait until three weeks after the last vaccination and you measure the serum antibody level to see if the animals developed immunity. It’s called a titer test.

VetTechColleges: And then using the information from the titer will tell you how to proceed?

Dr. Dodds: Correct. Some people used to run a test on the dam called a normograph—and it’s still offered, but it’s expensive. Near the end of her pregnancy, you have blood drawn from the mother and measure her serum antibody levels for the core infectious viruses (other than rabies).

And then, you do serial dilutions until the antibody titer disappears from a protective level. That will give you an estimate of when the puppies and kittens need to start their vaccinations, in order to be protected. The trouble is that it takes a while, and it’s expensive and many people don’t like to take their heavily pregnant pets to the veterinarian to have blood drawn because of the stress and also potential exposure risks.

VetTechColleges: Would you say these are things that the veterinarian directs for their clients or that a pet owner really needs to research and know so that they can advocate for their pet?

Dr. Dodds: The fact of the matter is veterinarians are marketed heavily by Big Pharma. They tell people all the time that their pets need to be vaccinated over and over even when they’re 20 years old—every year. There’s plenty of data to show that the current vaccines last at least three years and that if the animal is properly vaccinated, like I mentioned earlier, and has sterile immunity, it doesn’t need to be vaccinated ever again.

What you can do for ‘nervous Nellie’ pet guardians is recommend that every three years as adults, you can measure their [pet’s] serum antibody levels, just to reaffirm that they have immunity.

Now, remember, when you’re measuring the serum antibody level, it’s not just the residual vaccine effects that you’re measuring but also the exposure that that animal has had out in the real world. The reason for vaccinations is to effect protection upon exposure. Viruses like parvovirus and panleukopenia are everywhere. They’re ubiquitous. When you take the animal out into the real world, it’s going to be exposed, and the purpose of that is to boost its own internal immunity. So, it goes up.

People say, “I’ve been doing titers on my adult dog every three years, and he’s now 11. How can the titer have gone up when I haven’t vaccinated since when the animal was a puppy?” It’s because the dog was exposed and the exposure creates another boost to the immunity.

That doesn’t mean we want to deliberately expose them, of course.

Some people have even suggested that. That you vaccinate all the puppies in the litter except for the runt because it’s not strong enough, and the shed vaccine virus will vaccinate the runt when it runs around with its littermates.

First of all, if there is a shed virus, the level is not as high as the actual vaccine, and you certainly don’t want to take a runty puppy that’s not strong and expose it to anything that the other puppies are shedding.

VetTechColleges: So, in that case, would you need to isolate the puppy for a certain amount of time?

You keep the puppy separated from the others. You help it get strong, hopefully grow, and then if necessary, except for rabies, you can give a half dose to a small dog. We’ve published research studies to show that in a tiny dog, where they’re less than 12 pounds as adults, half a dose will fully immunize against distemper and parvovirus, for example.

In fact, many toy breeders now only give a half dose of distemper and parvovirus vaccine because if it’s designed in the vaccine production facilities to protect the average dog—and they usually use beagles for their studies—it’s either not enough for the Saint Bernard or too much for the Chihuahua. If it protects the Saint Bernard, it’s obviously got a lot more antigen than is needed for the Chihuahua.

You can’t do that for rabies, not because it wouldn’t work, but because the law doesn’t allow that.

VetTechColleges: Are there immunizations that you advise against?

Dr. Dodds: I don’t give leptospirosis unless it’s a particular problem in the area with the strains that are in the vaccine. And we give rabies only without mercury (thimerosal).

Other vaccines like ringworm…rattlesnake, we don’t recommend. We have coronavirus vaccines, which are basically useless. Giving a coronavirus vaccine does not protect the pet against coronavirus disease because the protection lies in the gastrointestinal tract. So having antibodies in the blood does nothing for the coronaviruses living in the gut.

We don’t do hepatitis in the dog for the reasons mentioned above. Some people are really concerned about that and so when the animals are going out in the real world, you know, grooming and whatever, we can give them the kennel cough vaccine. Just not the injectable one—that doesn’t give good respiratory virus cross-protection—so we use the oral Bordetella.

We used to use the intranasal version, but it can spray around the eyes and anybody standing nearby, so that’s not a good idea. When you give oral Bordetella vaccine, you cross-protect against the kennel cough complex, and part of that is adenovirus A2, which is the kennel cough complex and also protects against adenovirus A1, which is infectious canine hepatitis virus.

We don’t have a specific canine hepatitis vaccine anymore because the ones that were originally created caused blue eye where [the dogs] got a blue deposit, and the eyes looked like they had cataracts, and the animals couldn’t see. So we don’t use the adenovirus A1 vaccine anymore. We use adenovirus A2 to protect against canine hepatitis.

So if you give oral Bordetella anywhere from eight months to a year, you’re going to protect against the kennel cough complex and hepatitis.

All of the vaccines that we give, whether they be distemper and parvovirus or panleukopenia or rabies, we detox the molecular energy of the vaccine viruses with oral homeopathics. All vaccines get detoxed with the homeopathic Thuja, given once a day for five days, starting the evening of the vaccination, and we use the potency of the remedy at 30c.

For rabies, you give Thuja, but you also add the particular rabies molecular energy homeopathic which is called Lyssin. That stands for the Lyssavirus. Rabies is part of the Lyssa family of viruses. We give that with the Thuja, once a day, starting on the day of the vaccination, for five to seven days at 30c potency. We do that to help the body say, “Hey, I’ve seen this antigen before. I don’t have a problem with it.” That’s the concept behind this homeopathic use.

Thuja was first recognized by Sir Malcolm Burnett who got the Nobel Prize decades ago for it.

VetTechColleges: What factors should pet owners consider when making decisions about immunizations?

Dr. Dodds: The first thing that pet owners should do is read carefully. You can read on Dr. Google, but remember that there is [information] that’s not valid on those websites and [information] that is. So you need to be sure that what you’re reading is from people that are considered to be experts in the profession.

Then, find out, are we using canine influenza vaccines? Canine influenza is ubiquitous. It’s everywhere. So all animals are exposed to the flu, just like all people are exposed to their flu. The question is, do you use the flu vaccines that are developed for dogs? There are two strains. They cause very few reactions. Most cases of canine influenza are mild, and they get over it. If the pet harbors streptococcal bacteria in the lungs, and that’s not common, those animals that get the flu virus can be very sick, and some of them can die.

So the question is, do you automatically give the flu vaccine along with everything else in puppies? No, we don’t. In fact, we don’t use it at all. However, there may be certain exposure circumstances. Maybe they’re herding dogs. They’re out in the field a lot. They’re doing the kinds of activities where they may have exposure to things that most pets wouldn’t. And in that case, they may need to be vaccinated for the two canine influenza strains.

So people need to think about that. They need to read about it. They need to find out what the risk of exposure is for the pet. The same thing is true of using heartworm or a flea and tick preventive with all of the reactions we’re getting these days. Why would you do that if your pet is not exposed or has low exposure risk? If you’re going to an area where there’s an exposure risk, you can give a preventive, just one, and it’ll be done with when you come back to your own area where there is low exposure. The same thing would apply to vaccine-related situations.

The Bottom Line: Pet Immunizations

When researching information about pet vaccinations:
1) Read carefully. Be sure you’re reading expert opinions.
2) Evaluate the animal’s risk of exposure taking into consideration region and lifestyle.
3) When administering a vaccine, adjust the volume according to the size of the animal, except in the case of the rabies vaccine, which is administered uniformly as required by law.

For more information, find vaccine guidelines published by the following organizations:

Cevia Yellin (Writer)

Cevia Yellin is a freelance writer based in Eugene, Oregon. She studied English and French literature as an undergraduate. After serving two years as an AmeriCorps volunteer, she earned her master of arts in teaching English to speakers of other languages. Cevia's travels and experiences working with students of diverse linguistic and cultural backgrounds have contributed to her interest in the forces that shape identity. She grew up on the edge of Philadelphia, where her mom still lives in her childhood home.