Vaccines play a critical role in protecting our pets from serious diseases — but how do we know when they actually need a booster?

That’s where titre testing comes in. This simple blood test helps answer one of the most important questions in preventative care:

Is your pet already protected?

What Is a Titre Test?

A titre (pronounced “tight-er”) is a measurement of the antibodies your pet has developed against a specific virus — most often from prior vaccination. These antibodies are a marker of immune memory and indicate that the body is ready to defend itself if re-exposed.

In pets, titre testing most commonly applies to the core diseases:

• Dogs: Canine Parvovirus, Distemper Virus, and Adenovirus (Hepatitis)
• Cats: Feline Panleukopenia Virus (also called feline parvovirus)

A positive titre confirms your pet is still protected and likely does not need a booster at that time.

Does a Titre Replace the Full C5 Vaccination?

Not entirely. In Australia, the C5 vaccine includes:

• C3 core components: Parvovirus, Distemper, Adenovirus
• • Kennel cough components: Bordetella bronchiseptica and Parainfluenza virus

Titre testing covers the C3 portion only — the serious, potentially fatal viral infections that generate strong, lasting antibody responses.

However, kennel cough vaccines do not create long-lasting immunity, and no titre test currently exists for them. Immunity to Bordetella and Parainfluenza is short-lived and primarily local (mucosal), not reliably reflected in blood antibody levels.

So while titres are a gold standard for C3 immunity, they don’t cover kennel cough, and a C5 vaccine may still be required for boarding or daycare.

Will Kennels Accept Titre Results?

Not always — and this can be frustrating. Despite growing awareness and support from veterinary bodies, many boarding facilities and councils still require proof of annual C5 vaccination as a blanket policy.

This is usually due to:

• Insurance requirements
• Risk management policies
• Limited understanding of titre testing

However, many progressive facilities will accept lab-verified titre results, especially when accompanied by a vet-stamped certificate and covering letter. It’s always worth checking well in advance and advocating for your pet’s individual care.

How Reliable Are Titre Tests?

In dogs, a positive titre for parvovirus, distemper, or adenovirus strongly correlates with immune protection.

In challenge studies, dogs with protective titres remained healthy even when directly exposed to these viruses years after vaccination.¹

Because these are systemic viral diseases, circulating antibodies play a major role in defence. If antibodies are present, the immune system almost certainly retains strong memory.

So in dogs:

• ✅ Positive titre = protected
• ❓ Negative titre = may still be protected, but a booster is often advised

In cats, it’s a bit more complex:

• Panleukopenia titres are reliable indicators of protection
• But Herpesvirus and Calicivirus immunity is less well-reflected by blood titres, as protection relies more on mucosal and cell-mediated immunity
• Because of this, titre testing is less commonly used in cats — and often limited to panleukopenia

Why Not Just Vaccinate Again?

If vaccines are safe, why bother testing?

Because the goal of vaccination is to build immune memory, not to repeatedly trigger the immune system once memory is established.

While most healthy pets tolerate vaccines well, unnecessary immune stimulation may not be ideal — especially for:

• Pets with chronic disease or allergies
• Animals with autoimmune conditions
• Pets with a history of vaccine reactions
• Seniors or integratively managed pets

Is There Evidence That Over-Vaccinating Can Be Harmful?

Yes — though much of the concern remains theoretical or observational, particularly in pets. We do know:

• In humans and lab animals, repeated immune stimulation is linked to chronic inflammation and immune dysregulation
• In veterinary medicine, over-vaccination has been associated with:
• Autoimmune thyroiditis
• Haemolytic anaemia
• Skin flares, behavioural changes, and general inflammation in sensitive individuals

That’s why the World Small Animal Veterinary Association (WSAVA) recommends vaccinating “no more often than necessary”, and supports titre testing as a valid alternative.

What a Titre Test Can (and Can’t) Tell You

Can do:

• Confirm your pet’s protective immunity for core viruses
• Help avoid unnecessary boosters
• Support exemption requests (in some cases)
• Offer peace of mind for immunocompromised or reactive pets

Can’t do:

• Assess kennel cough immunity
• Measure T-cell or mucosal immunity
• Predict future vaccine response

When to Consider Titre Testing

Titre testing is ideal for:

• Adult dogs due for a C3 booster
• Senior pets or those with chronic conditions
• Dogs with previous vaccine reactions
• Puppies, 2–4 weeks post-final vaccine, to confirm immunity
• Breeding animals
• Pet parents seeking a minimal, tailored approach to vaccination

How Is It Done?

Titre testing involves a simple blood draw, analysed by a veterinary laboratory. At iScreenPets, our Prevention Screen – Titres uses accredited lab-based testing for:

• Parvovirus
• Distemper
• Adenovirus

Results are clear, quantitative, and include a downloadable PDF to share with your vet, kennel, or council.

Final Thoughts

Titre testing isn’t anti-vaccine — it’s pro-informed care.

It empowers pet parents to protect their dogs from deadly disease without over-vaccinating. It respects immune memory. And it opens the door to more individualised, evidence-based veterinary medicine — the kind that sees the animal, not just the calendar.

At this stage, we recommend annual titre testing, as there isn’t enough data to reliably determine how long a high antibody level persists in every individual. Some dogs may retain protective titres for years, while others drop off more quickly. Annual monitoring provides confidence and documentation — especially if required for daycare, boarding, or council compliance.

That said, some guardians — in consultation with their vet — may choose to test less frequently if results have remained consistently high.

Because when it comes to immunity, more isn’t always better — but smarter always is.