Vicky Simon BVet Med Vet MF Hom. MRCVS
What is a Titre Test?
A titre test is a blood test which measures the antibody levels to various disease in your dogs' blood. If they have adequate antibody levels present, then this is the best evidence we can get showing proof of immunity. If they already have immunity present, demonstrated by the antibodies, the they do not need a booster vaccination that year. In fact, a titre test is better proof of immunity than vaccinating, as some dogs do not respond to vaccinations, although this is unusual. If you have a non-responder (more common in black & tan breeds) then you could give a vaccine every year and they may never produce antibodies or mount an adequate immune response, and so not be protected at all.
These antibody levels reflect humoral immunity, and allow us to measure this part of the immune system to a degree, although we still do not know how the body will respond in the face of actual disease. We are not able to measure cellular immunity, except by challenge – exposing the body to a disease and seeing if it responds by producing antibodies etc. Cellular immunity involves memory cells in the immune system, which can circulate for years, or a lifetime. These cells effectively ‘remember’ previous diseases that the body has been exposed to, so if they are encountered again, they can quickly ramp things up and get the humoral immune cells pumping out those antibodies again. If you encounter a disease your body has never met before, then the immune system has to start from scratch and so the response is much slower, allowing the disease to take a greater hold in the system.
What Diseases are Tested?
The titre tests we use in dogs measure antibody levels to Parvovirus, Distemper and Hepatits - the 3 core diseases dogs are vaccinated against.
You can titre test for Leptospirosis, but it is considered fairly pointless, as the antibodies for Lepto are known to be very short lived in the system, often no longer being present after as little as 6 months following vaccination. The absence of antibodies, as explained above, does not necessarily mean the absence of immunity.
Titre test are available for cats, but as cats tend to be much less amenable than dogs to having blood taken, they are less popular, and so less frequently stocked by veterinary practices. Bloods can be sent off for cats, for a titre test to be performed externally, if your vet does not stock the test. If sent to a specific lab, then the price does not differ hugely to the in-house test stocked by vets offering this option.
What will Happen on the Day?
All that will happen on the day of a titre test is that your vet will take a blood sample from your dog, and make note of their previous vaccine history. That's it! If the test is run in- house it can take as little as 20-30mins to have the results back, but this obviously depends on availability of staff to run the test. If it is sent off then timing may vary. In-house testing kits give you a score from 0-6. 0 is negative, and 1-6 is positive. The higher the score, the higher the antibody levels in your pets system, but any presence of antibodies gives evidence of immunity.
When Should I do a Titre Test?
Titre tests can be done at any time. However, the best time to do one is shortly before your dog is due their booster vaccination, so you know whether they need it or not. Booster vaccinations for Distemper, Hepatitis & Parvovirus are due every 3 years, after the 1 year booster.
Titres are especially important in young dogs, as if a puppy finishes their vaccine course before 16 weeks then the vaccines may not have been effective, due to maternal antibodies being present, which can block the action of the vaccine. This is why a 1 year booster is given, to catch any that were missed the 1st time around, but if your pups 1st vaccine worked perfectly well, then they shouldn’t be due a booster until 3 years later. A titre test can be performed any time from 1 month after a vaccination.
How Often Should I do a Titre Test?
Titre tests should be performed as often as needed. If you have a strong positive result then it is best to repeat the test every 3 years. If they have any borderline or very low results, then it may be worthwhile repeating the test the following year, especially if it is the Parvovirus result that is low, as this is the most prevalent of the tested diseases in the UK. Your results will be sent out to you by your vet shortly after the blood is taken, with recommendations for when a test will next be due.
Why Should I Titre Test?
Titre tests allow you to avoid over-vaccination of your pet. At each vaccination, there is always a risk of a vaccine reaction, either immediately, or a delayed reaction. There are also various immune mediated diseases that have been linked with vaccination, with evidence suggesting the vaccine can act as a trigger for the disease process. These include immune mediated haemolytic anaemia, immune mediated thrombocytopaenia & immune mediated skin diseases. It has also been observed that some chronic diseases, such as skin conditions, can aggravate following vaccination each time, even if only minimally.
In summary, a titre test is a great way of keeping your pets vaccinations to the minimum required, and so allowing them to be as healthy as possible.
More details of a practise near you that carries out titre testing can be obtained from https://www.vaccicheck.com