This review intends to provide veterinarians with key facts and information relevant to serological testing of individual dogs and cats in the clinical setting. Specifically, this paper addresses the role of antibody testing for the core, vaccine-preventable diseases canine distemper virus, canine and feline parvovirus, and canine adenovirus.
Did you ever wonder about the dose and frequency of vaccines recommended for your pet?
Can overvaccination occur and are there attendant risks?
Perhaps you are unaware that vaccines are not just made up of the intended vaccine antigen(s) but also contain a long list of other excipient materials:
- Adjuvants like aluminum salts and squalene to enhance the immune response (for killed inactivated vaccines).
- Preservatives added to prevent bacterial or other contamination (thimerosal = mercury salts).
- Stabilizers to keep the vaccine potent during transportation and storage (sugars or gelatin).
- Residual trace materials used during the manufacturing process and removed. These include: cell culture materials, used to grow the vaccine antigens (fetal calf serum, egg protein, culture media); inactivating ingredients, used to kill viruses or inactivate toxins (formaldehyde); antibiotics, used to prevent contamination by bacteria (neomycin, gentamicin).
Given this background, it is easy to imagine the potential adverse effects of overvaccination.
BUT, even today only about 40% of veterinarians are estimated to follow the current WSAVA, AVMA, AAHA and BVA vaccine policy guidelines. Further, there is no such thing as an ‘up to date’ or ‘due’ vaccination. Enlightened veterinarians now can offer separated vaccine components, rather than give them all together, since the published data show more adverse reactions when multiple vaccines are administered together.
Killed, inactivated vaccines containing adjuvants make up about 15% of veterinary biologicals used, but have been associated with 85% of the post-vaccination reactions. While adjuvants have been used safely in human and veterinary medicine for decades, but there is increasing worldwide concern about the safety of using thimerosal (mercury) and aluminum
How and Why do Adverse Events, called Vaccinosis, Occur?
- Millions of people, pets and livestock vaccinated annually.
- Reactions are relatively rare --- about 3-5 events per 100 vaccines given.
- Affects those genetically predisposed.
- Can be acute, sub-acute, and delayed for 30-45 days.
- New data links reactions to integrity and function of gut microbiome.
- Heavy metal exposure from vaccines is an emerging concern for humans, pets and livestock. Aluminum and mercury found in brains of autistic people, and from vaccine adjuvants that cross the blood –brain barrier after injection, and then persist life-long.
Vaccines containing aluminum are commonly used in sheep herd management and have been found to cause the ASIA syndrome (Autoimmune Inflammatory Syndrome Induced by Adjuvants). Studies from Spain evaluated sheep divided into 3 groups: control, aluminum adjuvant only and aluminum adjuvanted vaccine.:16 inoculations were given to the groups over an 11-month period. Results showed behavioral changes, aggression, stereotypic and excitatory responses, compulsive eating, and reduced sociability in both the adjuvant alone and adjuvanted vaccine groups but not in the controls. Changes were more pronounced in the vaccinated group; and some began after only 7 inoculations.
What About Vaccine Dosage in Relation to Age & Size?
Neonates & Infant Children
- Urgent need to remove heavy metals, like aluminum and mercury, from infant vaccines.
- Currently, neonates receive 17 times more aluminum from vaccines than allowed if doses were adjusted for body weight.
- Body weight is ignored in human vaccines, as they use these heavy metals to enhance immune efficacy.
- Experts now urge that aluminum and mercury not be given in vaccines until after brain maturation (6-7 months of age but preferably 12 months).
- Alternatives being considered are calcium phosphate and zinc.
Small Breed Dogs
- Small breed adult dogs, between 3-9 years of age, were studied.
- Dogs were healthy and had no vaccines for at least 3 years.
- Purpose was to determine if just half-dose of bivalent CDV and CPV vaccine elicited protective serum antibody titer responses.
- Titer levels compared 1- and 6-months later vs pre-vaccine titers.
- Half-dose vaccine resulted in sustained protective serum antibody titers for all dogs studied.
Vaccination May Not Equate to Immunization
But, vaccinated and truly immunized animals should be fully protected from disease. Immune memory cell immunity should persist life-long.
Giving boosters to immunized animals is unwise, as it will introduce unnecessary antigen, excipient adjuvants, preservatives and the other materials described above.
What is Sterilizing Immunity?
- An immune response that completely prevents and eliminates an infection.
- Animals properly immunized against the clinically important viral diseases have sterilizing immunity that not only prevents clinical disease but also prevents infection. Only the presence of antibody can prevent infection.
- An animal with a positive serum antibody test is protected from infection.
- Vaccinating that animal would not cause a significant increase in antibody titer, but hypersensitivity to vaccine components (e.g. fetal bovine serum) may develop.
- Furthermore, the animal doesn't need to be revaccinated and should not be revaccinated since the vaccine could cause an adverse reaction (hypersensitivity disorder).
- But, not all vaccines produce sterilizing immunity
- Those that do include: distemper virus, adenovirus, and parvovirus in the dog, and panleukopenia virus in the cat.
- Examples of vaccines that produce non-sterile immunity would be leptospirosis, bordetella, canine influenza, rabies virus, and herpesvirus and calicivirus --- the upper respiratory viruses of cats.
- While non-sterile immunity may not protect the animal from infection, it should keep the infection from progressing to severe clinical disease.
The bottom line here is to avoid overvaccination and, whenever possible, measure serum antibody titers instead.
- J Am Hol Vet Med Assoc. 41; 12-21, winter 2015.
- Ivanovski et al. J Trace Elements in Med and Biol. 51:138-140, 2019.
- Pinczowski, et al. Pharm Res, Nov 3, 2018; org/10/10.1016/ j. phrs.2018.10.019
- Weiler & Ricketson. J Trace Elements in Med and Biol. 48: 67-73, 2018.
Of the primasry fasctors that help control aging and memory, balanced nutrition and modest amounts of exercise are the most important for ourselves and the pets with whom we share our lives.
Functional foods are those that provide optimal nutrition and body function and improve the memory and cogniftive activity of aging. These include vitamins E and C, and resveratrol (acting as antioxidants) along with a mixture of fruits and vegetables to reduce free radical damage. Also important are alpha-lipoic acid and L-carnitine as they are cofactors of the mitochondria of all cells. Mitochondria are responsible within cells for providing for their respiration and energy production.
Exercise in modest amounts should be given along with tasks for the pet to learn and perform.
Omega-3 fatty acids are essential for dogs especially as they age because they help improve brain health and function and slow the loss of cognitive function associated with aging.
The requirement for essential nutrients increases not only during periods of rapid growth or reproduction but also in geriatrics, because immune function and bio-availability of nutrients generally wanes with aging.
Top 10 Great Foods for Brain Health and Memory
- Leafy greens (folate, vitamin B 9) - kale, spinach, collard and mustard greens
- Cruciferous vegetables (folate, carotenoids) - broccoli, cauliflower, bok choy, Brussel sprouts
- Beans/ legumes (choline)
- Whole grains (gluten-free = quinoa, millet, rice, soy, corn, flax, sorghum, TEFF, tapioca)
- Berries/cherries (anthocyanins, antioxidants, vitamins C and E)
- Omega 3 fatty acids (anti-oxidant, anti-inflammatory)
- Yellow Squash, asparagus, tomatoes, carrots, beets (folate, vitamin A, iron)
- Nuts (omega fatty acids, vitamins E and B 6, folate, magnesium) CAUTION macadamia, and walnuts are unsafe for pets
- Seeds (zinc, choline, vitamin E)
- Spices (anti-oxidant, anti-inflammatory)
Other Functional Superfoods
- Eggs - high in quality protein and choline for brain and memory
- Kiwis - antioxidant-rich, vitamins A, C and E, potassium, high in fiber
- Quinoa - high in protein and fiber, iron, zinc, vitamin. E, selenium
- Salmon - high omega-3 and iron, low calorie and low saturated fat
- Sweet Potatoes - high in vitamins A and C, calcium, potassium
- Mediterranean type diet - fish, nuts (for dogs: not macadamia, walnut or hickory nuts; brazil nuts and cashews are high in fat; pistachios, pecans, almonds can be moldy (aflatoxins); some dogs = peanut reactive); whole gluten-free grains; olive oil, fresh produce
- Avoid Trans Fats & Saturated Fats - less dairy, red meat, fried foods
- Heart-Healthy diet - also good for the brain
- Plenty of Omega-3 Fatty Acids – causes 26% less brain lesions
- Smaller meals throughout the day – helps digestion
- Eat Fruits, Vegetables, and Berries - of various colors
- Green Tea - enhances memory and alertness; anti-inflammatory; put on body sores, in foods
Canine Cognitive Dysfunction
Clinical Signs of Cognitive Dysfunction
- Confusion/disorientation in familiar surroundings
- Increased sleeping/insomnia
- Loss of interest in people and events
- Forgetfulness of housetraining habits
- Failure to recognize familiar people and animals
- Wandering aimlessly/pacing
- Loss of appetite/forgetting to eat
- Staring into space
- Decreased activity level
- Lack of response to name/commands
- Failure to pay attention
Nutrients of Genera Benefit for Cognitive Dysfunction
- Milk thistle and SAMe (S-adenosylmethionine)
- Medium-chain triglycerides (MCTs)
- DHA and EPA omega-3 fatty acids
- Avoid glutens
- Avoid carbohydrates with high glycemic index
Silibinin (milk thistle extract) prevents impairment of both short-term and recognition memory
- prevention for cancer as well
- works as antioxidant, protects brain from oxidative damage
SAMe (S-adenosyl methionine) improves neuron membrane fluidity
- increases serotonin and dopamine metabolites
- reduces effects of depression in people
- may help human Alzheimer’s patients
Phospholipid choline is critical for cell membrane structure and function
- increases production of acetylcholine
- helps reverse signs of cognitive and other neurological disorders of aging pets
Medium -Chain Triglycerides, like coconut oil, break down and absorb rapidly, unlike fats; quick source of non-carbohydrate energy
- readily cross blood-brain barrier, supplying 20% of brain energy requirement
- important for ketone production
- help body use omega-3 fatty acids more efficiently
- helps age-related cognitive decline by providing alternative source of brain energy
- give berries their rich pigment; antioxidants; also benefit cognitive health of senior dogs
- most potent is aronia, the chokeberry. Greater antioxidant than all other berries; anti-cancer; anti-bacterial, anti-viral and even anti-diabetic; and anti-inflammatory
- protect brain function in geriatrics and those with gluten intolerance by avoiding wheat, barley, rye, oats unless labeled gluten-free, kamut, spelt, farro, and couscous
- linked with impairment of brain function, including learning disabilities, attention-deficit-hyperactivity disorder, and memory problems
- gluten sensitivity may manifest exclusively as a neurological disease
Avoid Carbohydrates with a high glycemic index (GI)
- impaired glucose metabolism caused by sugary foods can promote brain starvation, leading to memory problems, like canine cognitive dysfunction
- foods with high GI can also lead to hunger-related behavioral problems
- simple carbohydrates digest and absorb quickly (hence rapid rise and fall in blood sugar concentrations), so pets feel hungry again quickly
There are four decisions no dog owner can avoid. You will be making these lifestyle choices for your dog regardless of whether you spend time researching the available information to ensure they are well-considered and informed decisions or whether they are simply choices of omission - we are certainly all prone to taking the easy road of doing things the way we always have.
A few months ago, I wrote about the comprehensive changes in our approach to vaccinating dogs that have led to a situation where routine vaccines will in most cases now be for puppies only as the adult 'boosters' of the past are replaced with titre tests.
Today, I want to touch upon another area where changes are currently sweeping across the veterinary community, namely the issue of neutering.
Cultural differences play a big role when new dog owners decide whether to have their dog neutered or to leave him or her intact. In some parts of the world, neutering of healthy dogs is considered unethical. In Norway routine neutering is downright illegal meaning that around 99% of all dogs in Norway are left intact. At the same time, there are parts of the world where neutering has historically been strongly encouraged and perhaps even regarded as a prerequisite for responsible dog ownership.
Until five years ago many vets certainly considered routine neutering as being in the general interest of the dog. The most serious side effect was believed to be the risk of urinary incontinence ('spay incontinence') in bitches. Then, in 2013, a bombshell was dropped in the form of a major study from the UC Davis school of veterinary medicine. The study revealed what no one had previously suspected, that neutered dogs of both sexes have a much greater risk of developing joint disease as well as several different types of cancer compared to intact dogs. In the frenzy of studies that have followed, increased risks of allergies, autoimmune disorders and thyroid disease have been added to the list of side effects and though research is ongoing, it is certainly safe to say that this startling new evidence should make anyone think twice before neutering.
For now, here's what we know:
Health benefits and risks
Health benefits of castration
- A castrated dog will have a reduced risk of benign prostate hyperplasia in old age and, of course, no risk of testicular cancer. There are, however, no overriding health-based arguments for routine castration.
Health ill effects of castration
- Increased risk of joint disease (cruciate ligament disease, hip dysplasia and elbow dysplasia)
- Increased risk of several types of cancer (lymphoma, hemangiosarcoma, osteosarcoma, mast cell tumours)
- increased risk of a range of immune-mediated diseases, such as allergies and auto-immune disease
Health benefits and risks
Health benefits of spaying
- No risk of pyometra (womb infections)
- Reduced risk of mammary tumours (breast cancer)
Health ill effects of spaying
- Risk of urinary incontinence and increased risk of cystitis
- Increased risk of joint disease (cruciate ligament disease, hip dysplasia and elbow dysplasia)
- Increased risk of several types of cancer (lymphoma, hemangiosarcoma, osteosarcoma, mast cell tumours)
- Increased risk of a range of immune-mediated diseases, such as allergies and auto-immune disease
Please note that the above information relates to routine neutering of healthy dogs only. If your dog has an illness (such as testicular cancer or a womb infection) this may tip the scale in favour of neutering. In the case of healthy dogs, however, it is now clear that neutering will have an overall detrimental effect on the health of male dogs. It also looks like bitches are healthier when left intact, though this requires the carers to look out for signs of mammary tumours and pyometra.
Research is very much ongoing. One aspect, for instance, that it turns out we don't understand as well as we thought we did prior to 2013 is the relevance of the age of neutering. Whatever new evidence surfaces in the future, there can be no doubt that the way we look out for our dogs is changing fast.
Over 50 years ago now, my friend and colleague, Prof. Ron Schultz, and I were the only two people saying we were over-vaccinating pets. I was called irresponsible in public at a large veterinary conference because others were unwilling to consider the idea that vaccines might not always be needed or safe. Since then, people aren’t shooting arrows at us now because our backs are full of them! Joking aside, despite the criticism, we were and remain determined to continue to educate about this topic.
Even today, estimates are that only about 40% of veterinarians are following the current WSAVA, AVMA, AAHA and BVA vaccine policy guidelines. * There is no such thing as an ‘up to date’ or ‘due’ vaccination. Enlightened veterinarians now can offer a package of separated vaccine components, when available, rather than give them all together, since the published data show more adverse reactions when multiple vaccines are administered at the same time.
Summary on Vaccine Policy
AAHA 2003 – Current knowledge supports the statement that
- No vaccine is always safe, no vaccine is always protective and no vaccine is always indicated
- Misunderstanding, misinformation and the conservative nature of our profession have largely slowed adoption of protocols advocating decreased frequency of vaccination
From Prof. Michael J. Day
- Vaccination should be just one part of a holistic preventive healthcare program for pets that is most simply delivered within the framework of an annual health check consultation
- Vaccination is an act of veterinary science that should be considered as individualized medicine, tailored for the needs of the individual pet, and delivered as one part of a preventive medicine program in an annual health check visit
Importantly, pet caregivers should understand that the act of giving a vaccine may not equate to immunization of that animal. Vaccines may not always produce the needed or desired immune protective response, not only if the vaccine itself was inadequately prepared (very rare) but also if the pet is a genetic low or non-responder to that vaccine (quite common in certain breeds of dogs and their families). In the latter case, that pet will be susceptible lifelong to the disease of concern and revaccination will not help and could even be harmful.
In response to issues raised above, vaccine experts recently have recommended new protocols for dogs and cats. These include: 1) giving the puppy or kitten vaccine series later (starting not before 8 weeks of age, except in the cases of outbreaks of virulent viral disease or in orphans or those that never received colostrum from their dams) followed by a booster at one year of age; 2) administering further boosters in a combination vaccine every three years or as split components alternating every other year until; 3) the pet reaches geriatric age, at which time booster vaccination is likely to be unnecessary and can be unsafe for those with aging-related or immunologic disorders.
In the intervening years between booster vaccinations, and in the case of geriatric pets, circulating humoral immunity can be evaluated by measuring serum vaccine antibody titers as an indication of the presence of immune memory (e.g. VacciCheck). Titers do not distinguish between immunity generated by vaccination and/or exposure to the disease, although the magnitude of immunity produced just by vaccination is usually lower.
When to Vaccinate Puppies & Kittens? Which Vaccines are Needed? What About Socialization?
- Should receive MLV or recombinant “Core” vaccines (canine distemper, parvovirus and hepatitis/adenovirus) preferably either at 9-10 and 14-16 weeks of age (minimum protocol), or, at 9, 12 and 16-18 weeks of age
- Rabies vaccines are all adjuvanted killed products and are given as required by law, preferably always given separately from other vaccines, and as late as legally allowed – e.g. 20-24 weeks of age. Thimerosal (mercury) - free rabies vaccines are preferred and safer
- Other vaccines are optional, and depend upon circumstances and disease risk in the area
- For the optional Bordetella or kennel cough vaccines, the oral version is preferred over the intranasal although both offer better protection than the injectable version
- Leptospirosis vaccines protect against only 4 serovars of the organism and are second to rabies vaccines in risk of hypersensitivity and other adverse effects. Use if endemic in the area of concern
- While canine influenza viruses (2 strains; H3N2 and H3N8) are highly contagious, most infected dogs have mild to no clinical issues, unless they develop a high fever and are at risk for secondary pneumonia. Vaccination, while being widely promoted, is still optional
- Three or more days after the last round of puppy vaccines, they can be out and about to be socialized. In the interim period, between 10-14 weeks of age, socialization can take place in the back yard or at puppy training classes with known friends and healthy dogs
- Until fully vaccinated, puppies should not walk on unfamiliar or public grounds; they can be carried about, when needed to travel
- If Titer testing is desired, instead of giving another vaccine after 12 weeks of age, wait until at least 16 weeks of age to avoid measuring residual maternal immunity
- Core vaccines (feline panleukopenia, feline calicivirus, feline rhinotracheitis/herpes) given as MLV or killed, inactivated or intranasal products are started in a 2 or three-dose series beginning for example at 7-9 weeks of age and 12-16 weeks, or at 7, 11 and 16 weeks
- Rabies vaccines if legally required are recommended as for puppies, although cats can receive a recombinant non-adjuvanted rabies vaccine which is preferred over the adjuvanted killed rabies vaccines given to dogs. This non-adjuvanted rabies vaccine is not yet available for dogs
- Some people consider feline leukemia virus (FeLV) vaccine as important for cats, especially those that live outdoors or are indoor/outdoor. Options are a recombinant non-adjuvanted or a killed adjuvanted vaccine
- Feline immune deficiency virus (FIV) vaccine is available in an adjuvanted killed virus vaccine for those cats at similar exposure risk to FeLV.
- Other vaccines (Chlamydia, FIP) are generally not recommended or are optional, and depend upon circumstances and disease risk in the area
- Socialization and Vaccine Titer testing options are as for puppies
*WSAVA-World Small Animal Veterinary Association; AVM A- American Veterinary Medical Association; AAHA-, American Animal Hospital Association; BVA- British Veterinary Association