Vaccines Cats Need: An Interview with Sarah Brandon, DVM

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Dr. Sarah Brandon is a practicing Veterinarian and CEO of Canna Companion, where she oversees the research, development, and manufacturing of hemp pet supplements.

Sarah Brandon DVM Canna Companion

Dr. Brandon also maintains a small feline only mobile practice in Washington state, focusing on a balanced, holistic approach for her patients which includes nutrition & herbal and essential oil supplementation.

It is her belief that the best healthcare plans incorporate the specific needs of the household, rather than only the patient. During the past two decades, researching herbal therapies in clinical practice became her passion, and the experience and data gained was used to launch a line of supplements designed to support a balanced cannabis receptor system.

Outside of her professional life, Dr. Brandon enjoys backpacking with her two rescued Belgian Malinois, playing fetch and laser tag with her three youngest cats, or curling up with a good book and one of four senior cats. Other hobbies include birdwatching, listening to Blues & Jazz, and making herbal teas from plants grown in her organic garden.

Check out our other interviews with Dr. Brandon:


Can you talk about vaccinations in general?

Yes, but let’s discuss the basics of feline immunity first. The feline immune system is comprised of 3 main areas: physical barriers (skin, gastrointestinal mucosa), nonspecific immunity (inflammatory response present at birth), and specific/adaptive immunity (acquired immunity to antigenic challenge via exposure or vaccination).

Physical: An intact, well-hydrated skin can keep out the vast majority of potential antigen. Add to that it will also produce a luxuriant and highly protective coat, and it’s no wonder cats spend most of their waking hours grooming. The gastrointestinal mucosa arguably is even more valuable to the feline immune system than skin.

Consider the opportunistic hunting nature of cats and the varied potential microbes which could cause serious harm if allowed into vascular circulation. We are quickly learning how vital this aspect of feline immune system is to systemic immune responses, particularly in relation to inflammation.

Nonspecific: This is the potentially life-saving immune response which helps protect us as feline physical and specific immunity develops. Cells involved here include neutrophils, macrophages, and eosinophils, all aimed at protecting the body right now from invaders.

Antigens antibody diagram
Source: https://en.wikipedia.org/wiki/Antibody

Specific: The last resort once exposure occurs — the antigen has bypassed skin and mucosal barriers and has triggered the inflammatory response which calls into action antibody production. Antibodies bind to antigens, helping nonspecific immune cells to correctly ID and effectively counter invaders.

Once the invasion has resolved, the antibodies are mostly disabled, their components used for other tasks. (Titers measure this process as they quantify circulating antibody numbers.)

From the body’s perspective, it is unnecessary to stay on high alert by constantly making antibodies for an antigen which is no longer present, or is now recognized as self.

Here’s where the specific immune response is also the first response when it comes to reexposure and mounting an effective, swift defense. Memory cells made during the initial exposure can fast track antibody production as soon as antigen is detected.

Vaccines are designed to present the body an antigen, stimulating the specific immune response. They do this in a variety of ways, each with their own set of pros/cons regarding effectiveness and adverse effects in cats.

As a general rule, adjuvanted vaccines are no longer recommended for cats due to how aggressive the feline immune system reacts to such compounds. In too many cats, adjuvants cause fibrosarcomas, a nastt type of cancer which is rarely responsive to therapy.

Ragdoll Cat Charlie Mission Veterinary Emergency and Specialty Visit July 25 2019 IMG_9994

Are there essential vaccinations for cats?

Yes. At this time, the American Association of Feline Practitioners (AAFP) recommends a set of core vaccines which includes FVRCP & Rabies. Non-core vaccines are recommended only when the cat in question has significant exposure.

These vaccines include FeLV, FIP, FIV, Chlamydia and Bordetella; Let’s talk about what disease processes the core vaccines cover.

Please note vaccinations do not prevent infection; they help the immune system counter viral infections so that serious illness is less likely to occur.

FVRCP: Feline Viral Rhinotracheitis Calicivirus Panleukopenia

    • Feline Viral Rhinotracheitis refers to feline herpes viral infections. Most cats have a strain or two of FHV contracted from their mothers; the common kitten cold is due to this virus.
    • Calicivirus is a very difficult viral to protect against so vaccines focus on the most common strains which help the body fight off infection before they cause severe illness.
    • Feline panleukopenia is also called feline distemper and infections of pregnant queens or very young kittens can result in cerebellar hypoplasia.
    • Rabies: while it is not common in the feline population, it is zoonotic (transmissible to humans) and thus considered a core vaccine.

FeLV: Feline Leukemia Virus

    • Many consider FeLV vaccine a core kitten series, even those with 100% indoor only status. Adults over 3 yr have non-specific immunity against this virus but youngsters often need circulating antibodies upon exposure to prevent fulminant infection.
    • FeLV is a deadly virus which can lay dormant for years, and the years when cats are most vulnerable are also those in which they are most likely to escape the home.
    • I prefer to have a heart to heart with clients regarding the likelihood of possible exposure relative to that household’s needs. Does the house have young human children who might let the 18 mo kitten out? Is there a large population of outside cats, whether owned or stray, who like to visit your cat when she’s hanging out in her catio? What if your and your sister’s cats are from the same litter, remember each other, and love to play when visiting … but your sister’s cat, while vaccinated against FeLV, goes outside unsupervised? In all these cases, the risk is small for exposure but still higher than a kitten who lives in an adult human household, in a 3rd story apartment, and is introverted, preferring to remain home.

Blue Lynx Mitted Ragdoll Cat Trigg Chiggy at vet getting blood taken IMG_2780

Which vaccinations do I want to give a new kitten?

While most kittens have some immunity from their mothers, it is imperative to their immune system development, they also receive systemic vaccinations. This helps provide circulating antibodies during their vulnerable time, and perhaps more importantly, memory cells for future exposure needs.

The best method to achieve both with the least amount of risk is FVRCP canarypox vector series of 2-3 vaccinations given about 3 weeks apart, until the kitten is ~16 weeks of age. At the time of spay/neuter, usually 6-9 mo of age, a canarypox vector Rabies vaccine is administered.

Both injectable vaccines are administered as 1 year boosters. Intranasal FVRCP can be administered every 3 yr or as determined by titer count. Intranasal vaccines stimulate antibody production in the nasal mucosa, where these viral infections are primarily contracted. Rabies vaccine booster frequency is determined by county and state ordinances.

vet visit pet carrier IMG_7456

Which vaccines does a cat owner want to avoid?

FIP, Chlamydia and Bordetella are generally not recommended. I do not recommend them in cataries or other high-stress, close contact situations, preferring to reduce stress and clean the environment while placing a temporary hold on bringing in new cats (in the case of rescue facilities) and any breeding practices. Such a hold may be in place for up to 9-12 mo. As such it is usually ideal for cataries and rescue groups to pay close attention to the health of their charges and environment of their facilities.

FIV is also one I typically avoid, preferring to counsel clients on safer outside alternatives, like catios and fully enclosed outside cat runs. The goal is to prevent cat fights involving teeth, though it’s possible highly contagious cats may transfer the virus via other means. Once vaccinated, cats will test positive on standard testing procedures, putting them at risk if picked up by some local animal control agencies.

Ragdoll Cat at the Vet Veterinarian

How necessary is the rabies vaccine after a certain age?

My official answer is that it’s required by most states for all cats and dogs to have current vaccines or titers, without limitations like age or exposure. Some states allow veterinary medical authorization to discontinue vaccinations, giving doctors some flexibility in this matter, particularly where age and exposure are concerned. Consistent rabies vaccination has reduced viral load in all affected species, helping humans and domestic and wild critters.

It is my opinion that cats living 100% indoors, without any exposure to carrier species (e.g. bats, skunks, raccoons), who received at least two rabies vaccines 12-18 mo apart, should not have ongoing vaccinations.

Ragdoll Cat Charlie Mission Veterinary Emergency and Specialty Visit July 25 2019 IMG_5446

Due to memory cell production, if such a cat were exposed to rabies a decade later, they could still mount an immune response which is likely to protect them from serious or fatal effects. —- In such a case, you should immediately confine your cat to a quiet room away from people as the cat can still be contagious; contact your veterinarian as soon as possible for additional advice. Most states require immediate revaccination and observation of such a patient, either at home or the veterinary hospital.

In senior patients (7 yr or older) continuing vaccination may be detrimental to their health, particularly if they are in the early stages of any disease process. That said, canarypox vector vaccines are relatively safe, and if we presume vaccinations are appropriate to discontinue once a cat is 7 yr old, that cat may only receive 3 rabies vaccines in its lifetime: ~9 mo old, ~2 yr old, ~5 yr old.

How can I talk my vet into doing a titer and not giving my cat the vaccine?

First look up your local ordinances. Your doctor may be limited in what she can recommend in this area. If your state allows some flexibility, they will usually offer solutions like titers, or provide examples of medical necessity to discontinue vaccinations. Once you have legal information, make sure your cat is already protected (2 vaccines 12-18 mo apart) and 100% indoor only.

Then schedule a phone call with your veterinarian to discuss this topic as it applies to your cat. Be prepared to pay a consultation fee for her time. Sometimes phone calls appear less confrontational and both parties feel heard. Bottom line, though, is that if you firmly disagree with the recommended care for your cat, you need to seek another doctor who is more in line with your preferences. We know only when pet parents and medical professionals work together, will our cats receive the best care.

Charlie and Trigg at the vet

She likes to scare me that the state could put my cat to sleep if I don’t vaccinate it and it bites someone.

This is very antiquated verbiage, and while I heard it myself when young, it has morphed into something less horrific. In this case, the confinement period mentioned above is much longer and usually required to be at a veterinary hospital or other approved facility. From there, each state has different requirements regarding release, prevention, etc. If during that quarantine period, a patient exhibits rabies viral symptoms, euthanasia and viral identification at a state-approved lab is usually required.

Do house cats need to be vaccinated?

Yes when kittens, plus a 1 yr booster for both FVRCP & Rabies. Rabies vaccine should be given per legal requirements thereafter. FVRCP is recommended every 3 yr until a senior, or ongoing if exposure is also ongoing. For example, if you travel and board your cat, then exposure is higher than if she remained at home with a cat sitter.

Pet carrier at vet cat carrier at vet IMG_7631

When should cats be vaccinated?

Kittens at 9, 12, & 15 wks; boosters 12-18 mo later; every 3 yr until senior cats (or lifelong if legally required or exposure warrants). This presumes core vaccines FVRCP/Rabies +/- FeLV. If kittens receive FeLV, then it becomes tricky balancing trips to the doctor vs number of vaccines/visit. The more vaccines at once, the more the immune system responds systemically, often causing fevers, poor appetite, and tenderness at injection site. No more than 2 vaccines should be given at one time if at all possible to reduce that risk.

Can cats die from vaccinations?

Yes, anaphylaxis can occur. There is often a warning sign first in the form of significant fever, sore joints, GI upset, and/or low appetite following a single vaccine.

In such cases, the doctor must evaluate risk/benefit regarding ongoing vaccinations, and make the determination whether antihistamines should be administered prior to the next booster vs discontinue that/all vaccines.

While it is possible for a first time vaccine to cause death, that is thankfully extremely rare with non-adjuvanted vaccines.

Blue Lynx Mitted Ragdoll Cat Trigg Chiggy at vet IMG_2779

Reader Questions

“Linda Rupp: Which vaccinations are absolutely essential for your cat’s health and which are not? I’ve read so much inconsistent information about which vaccinations ragdolls should and shouldn’t have.”

In my opinion, FVRCP & Rabies up to 3-4 yr of age, then as determined based on exposure. FeLV should be added if the youngster has an increased risk of exposure. I generally do not continue vaccinations in indoor only cats thereafter. I stick with recombinant vaccines.

“Anne Grove: I recently had a nightmare of an experience with a blood panel on one of my older cats coming back positive for FELV. We all went into panic mode. It seemed to be an impossible diagnosis for an older, indoor cat that had not been exposed to the virus. The question arose as to whether all of my indoor cats should be vaccinated for FELV. After much expense, more tests and finally another blood draw, it was determined that the first blood sample was tainted. I have since read that these tests are not always reliable. I would appreciate an opinion on these vaccinations and blood tests for indoor cats, both young and older.”

I am sorry to hear of such a scare; not a pleasant experience for sure. Most FeLV tests are antigen-based Elisa Snap tests, which can show equivocal and false positive results, though it’s not common.

In such cases, it is recommended for a second blood sample to be sent to a local lab for antigen testing. If positive on both, then exposure has occurred. If the second result is negative, retesting via antibody and/or antigen in 3-6 mo often confirms clearance or contraction of infection.

While most cats who contract the disease exhibit symptoms within that time frame, subclinical infections are possible putting other young cats at risk. Vaccinating those cats is recommended.

If exposure to the virus did not lead to infection, then vaccinating those cats is not necessary.

“Jeanne Ganiere Rasmussen: I think cats are over vaccinated. Which vaccinations can we get a titer on? I’ve heard some vaccinations provide immunity for many years. My cats are indoor only and there is zero chance of contact with another cat or even a vector like a mouse.”

I agree. While vaccines have greatly reduced infections in the US feline population, we certainly shouldn’t administer them for that reason alone. All vaccines provide some type of immunity for years, but perhaps not in measurable forms.

Titers are usually available for FVRCP, FeLV & Rabies viruses and provide quantification of circulating antibodies, not circulating memory cell levels. It is the latter which provides long term (lifelong in many cases) protection against severe infection if exposed to those viruses years after their last vaccine.

Bottom line: indoor only cats >3-4 yr likely do not need ongoing vaccination for their health. Schedule a call with their doctor to discuss their specific risks.

“Tami Zale: I have heard of many cats developing FIP after vaccination. Any recommendations to minimize risk?”

FIP is generally not a vaccine we recommend as is not very effective even at preventing the symptom of peritonitis, inflammation of the abdominal wall lining.

In most cases where FIP vaccine was administered, the FCoV (Feline Coronavirus) has already infected the patient, and the development of symptoms may be related to the infection itself or immune boost from the vaccine (not the vaccine itself). In cases where FCoV is endemic, environmental cleaning is warranted and far more effective than vaccination.

If FIP shows up after non-FIP vaccines were administered, then FCoV infection had also already occurred and we still cannot determine if the virus caused the FIP symptoms or the non-FIP vaccine related immune boost is to blame.

How to avoid this as best as possible? Skip vaccines if your kitten/cat isn’t apparently healthy. It’s better to wait and restart a series than to risk taxing the immune system. Give only 1-2 vaccines at one time.

“Clair Squires: I understand UK and US vaccines and veterinary practices differ but I wondered about booster vaccines?

My 2 had their full kitten vaccines for FIP/FeLV/Cat Flu (we don’t need the rabies vaccine in the UK) and their first boosters but haven’t had any since, they are now 7, happy and healthy indoor floppies.

Since it’s 5 years + since the vaccines would:

1. A booster be recommended?

No, provided nothing changes with their husbandry practices.

2. Would a booster even work after 5 years gap?

Yes, though some argue a mini-series of 2 injections is required. In theory, 1 booster after 5 yr gap will boost antibody levels and reinforce cellular/memory immunity. If you were going to travel this summer, boarding the cats, I would consider FVRCP IN 6-8 wk prior to your trip.

3. Would a full vaccine now be required to give maximum protection?”

I think they are adequately protected for everything except rabies, given their vaccine history and exposure. Yes, they are missing their 1 yr booster for FVRCP & FeLV, which may limit some memory cell production; overall they are well protected. At their age, even 1 Rabies vaccine now, will provide proper exposure.

“Brittany Oesterreich: One of our ragdoll mixes had a bad reaction to his 2nd distemper vaccination as a kitten and as a result we waited until he was over a year before giving the next distemper. This time he had no reaction and was fine. Should we still be more worried about another reaction in the future being a greater risk for him than his littermate who had no reaction?

Yes, though a full evaluation of the circumstances should precede another vaccine. Did he receive more than 1 vaccine at that time? Was he recovering from typical kitten upper respiratory infections or GI upset?

Was the vaccine an injectable; which type? What is his subsequent exposure risk? Depending on those questions and other circumstances, he may need another vaccine but 60 min after antihistamines are administered.

Conversely, his exposure risk may be far less than another vaccine-related fever risk; no vaccines may be warranted. He may indeed be at greater risk than his littermate for another reaction.

Also i’m curious about the vet side of this: our vet said if he had any kind of reaction he would write an exemption so he wouldn’t need any more. Is this as simple as writing it out with the reasoning or is there a process behind it that a vet has to go through to make that exemption legal? (which I know may differ from state to state, but just in general I guess)”

I love that your veterinarian is thinking along these lines! If your state allows it for rabies, then a waiver may be the most appropriate option. FVRCP exemptions apply to his medical record only and are not regulated by state law. Some states allow a simple statement; others require a specific form be filled out.

“Bonnie Byrne Sharkey: 1 yr rabies or 3 year or even at all if indoor cat. Also I like the question about real need for any shots after the kitten shots. Is a titer tests a good idea”

Here’s what I did with my cats who are 100% indoor only but who are exposed to strays off/on throughout their life: FVRCP & Rabies (canarypox vector vaccines) as kittens + 1 year booster for both.

They have not received FeLV vaccines nor any vaccine since ~2 yr of age. For my group, this protocol balances protection and proper immune response with risk of exposure. It may change with another household, just depends on individual risk.

“Cathy Williams: Ask at what age are vaccinations no longer needed?”

Most doctors agree if the cat is >12 yr old (geriatric), no vaccines are needed unless ongoing exposure is present. Some drop that age down to 7 yr (senior), and others stop at 2-3 yr of age (if no exposure is present). Ongoing exposure generally means a cat allowed outside without direct adult supervision.

“Anne Grove: My Ragdoll Bach is now 11 years ago. When he had his last kitten vaccination, he had a terrible reaction and went into shock…seizure, foaming at the mouth, violent shaking. I rushed him and his brother back to the vet where they were waiting and they immediately administered a shot to counteract the vaccine. Thankfully he survived but it was frightening for everyone.

How terrifying! I am glad he survived without ill effects.

My vet said that the vaccination contained a “new” antibody and they had not yet seen this reaction. He never used the new vaccine again.

This reaction can happen with any vaccine and is thankfully quite rare.

Since mine are indoor cats and not exposed to typical viruses, I stopped vaccinations after that experience. I would appreciate an opinion on the kitten vaccines and others typically recommended annually.”

I would not vaccinate Batch either! Annual vaccines are not something I recommend as a general rule, and prefer to assess the household and individual patient to strict 1 or 3 yr vaccine administration.

“Judith Gagnon: I would love to know her opinion on life vaccines versus kill vaccines …..”

This article details vaccines and various studies. In general, MLV (modified live vaccines) often provide the most complete immune response as you are presenting the body with viral antigen, just not the portion which causes disease. As a result of that immune response, reactions like fevers are slightly more common.

Actual infections are also possible, though usually not severe. For example, a MLV FVRCP may cause an upper respiratory tract infection. Killed vaccines are less likely to cause adverse reactions but may not stimulate the immune system enough, which is why adjuvants were created.

One cannot give a MLV of rabies for risk of actually giving the animal rabies; adjuvants incite the immune system to respond aggressively towards whatever antigen the vaccine is presenting. That aggression can cause fibrosarcoma, which is why alternative vaccinations were developed. Recombinant (canarypox) is thus far the safest vaccine for cats and is neither MLV nor killed.

It uses a virus whose natural host range is restricted to birds; canarypox is capable of infecting mammalian cells, resulting in a nonproductive infection … and appropriate immune response. The body thinks it’s being invaded, responds in kind, but doesn’t contract actual disease nor reacts so strongly that it creates tumors.


Check out our other interviews with Dr. Brandon:

Comments (3)

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  1. As always, LURVE these SUPER PAWESOME & FABULOUS Interview posts with Dr. Brandon, Jenny honey! A GREAT BIG PURRY THANK YOU SOOOOO VERY MUCH to you both! Such great & very valuable info to know!

    Big hugs & lots of love & purrs!

    Patti & Miss Pink Sugarbelle

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