Vaccination

There is little doubt that widespread and regular vaccination of pets has had significant benefits in the control of major infectious diseases. We have seen the practical eradication of canine distemper and hepatitis from some urban dog populations and a significant impact on the severity and extent of parvovirus infection due to widespread use of vaccination in dogs in Australia. The AHV fully supports the AVA vaccination guidelines.

It is essential that all owners consult their own veterinary practitioner about a proper vaccination program for their animals. Such factors as species, breed, age, disease status,presence of inter-current diseases, vaccination history of in-contact animals, and life style all are important in determining the appropriate vaccination strategy for individual animals.

Whilst vaccination has unquestionable benefits, the subject of annual revaccination is being increasingly examined.  Recently published laboratory studies have shown that some vaccinations in dogs and cats may provide significant serological titres lasting for at least 3 years and longer. Whether the current low levels of these diseases in cats and dogs will remain after introduction of less frequent vaccination strategies will only be known after many years.

In some diseases, immunity is short-lived and so not all vaccinations can be administered on a less frequent basis and still confer preventative immunity. In such cases there still needs to be an annual vaccination schedule. The best advice on these diseases can be determined in a consultation with the veterinary practitioner.

Side effects may occur after vaccination with all vaccines; these side effects are uncommon, short lived and cause little discomfort in healthy animals. However, vaccinating animals which are immune compromised or suffering disease states goes against manufacturers’ recommendations, and can cause more severe acute or long term side effects.

In these cases the vaccinating veterinarians weigh the risk of side effects against the animals’ illnesses and likelihood of catching the disease against which they wish to vaccinate. In such cases the use of antibody titres to determine the need for vaccination becomes important.
 

Antibody Titre Tests

In the poultry and pig industries assessment of the serological titres of animals is well established as a valuable management tool. Analysis of the titres provides a quantifiable assessment of the vaccination status of the animals and thereby a measure of their susceptibility to disease and a rational indication for any requirement for revaccination.

Titre tests are readily available and affordable within Australia, for assessing the need to revaccinate dogs and cats.

Vetpath in WA has an affordable and easily accessed system of titre testing for parvovirus and distemper, and the Vetpath website shows a wide range of other diseases for which it is possible to determine serum antibody concentrations.

Jean Dodds from Hemopet in the USA has details on her website of a series of titre tests which cover the complexity of parvovirus, hepatitis, distemper, skin disease, and immune mediated thyroiditis which can be connected with inappropriate vaccination. Sending serum to the USA si not restricted, and the results are returned within one to two weeks of postage.

IDEXX and other major pathology laboratories also offer tests. There are also in house testing kits advertised on the internet. Companies selling these products give glowing reports of their accuracy. In purchasing these it is wise to check that they can accurately estimate the lower titres where results may be equivocal.

It is also wise to remember the significance of the titres, some viruses such as distemper may cause low titres and the animal still be immune, whereas parvovirus titres more accurately reflect immune status. Different types of viruses have different relationship of titre to protection status, diseases such as Kennel cough in dogs, or Fowlpox in hens may have a multiple viral causality.

Veterinary assessment of vaccine usage and the use of titre testing is underway.

1. Canine Parvovirus serology titre results

The University of Syndey's Centre for Veterinary Education (CVE) proudly announced the launch of a new impartial central data collection point for Canine Parvovirus serology titre results in April 2011. This unique repository is a world first opportunity for veterinarians to collate facts on which evidence based medicine (EBM) can be practised. Situated within a secure section of the main CVE website it will provide statistical evidence for duration of immunity conferred by particular vaccines and regimes real time comparison of titre tests, and mapping of the titre levels by postcode. The data ultimately will be available for a review paper. The Parvo Survey is easy to access and use. Contributors can review, edit, delete records at any time available to both CVE members and non members: a free repository to all just create an account which will provide access maintained as long the need is perceived and data continues to be added.

To log on and start entering data, or just to have a browse, please visit http://www.cve.edu.au/parvosurvey

Or access via the links at AVA eLine

2.Titre Testing Webinar

Follow the link Saving Lives With Antibody Titer Tests also see below for further info. You need to register and then you can listen to the whole recorded broadcast, it goes for about an hour and a half. The webinar was co-ordinated by the US Maddie's Fund/Institute, and refers to titre testing in shelters - (see this the link for info re Maddie's Institute: http://www.maddiesfund.org/Resource_Library/Maddies_Institute.html ), but the titre testing information is relevant across the board for all dogs. Schultz talks about repeated titre testing instead of revaccination (i.e. titre testing every three years, then every year after the age of 10).


References:

Dodds WJ. Advocate for serologic testing after vaccination. J Am Vet Med Assoc 2003;222:149-150; author reply 150-141.

Gill M, Srinivas J, Morozov I, et al. Three-Year Duration of Immunity for Canine Distemper, Adenovirus,and Parvovirus After Vaccination with a Multivalent Canine Vaccine Intern J Appl Res Vet Med 2004;2:227-234.

Hoelzer K, Parrish CR, Esteban D, Colin RP, John JH. Evolution and Variation of the Parvoviruses. Origin and Evolution of Viruses (Second Edition). Academic Press, London, 2008:393-416

Kennedy LJ, Quarmby S, Happ GM, et al. Association of canine hypothyroidism with a common major histocompatibility complex DLA class II allele. Tissue Antigens 2006;68:82-86.

Patel JR, Heldens JGM. Review of companion animal viral diseases and immunoprophylaxis. Vaccine 2009;27:491-504

Schultze AE, Frank LA, Hahn KA. Repeated physical and cytologic characterizations of subcutaneous postvaccinal reactions in cats. Am J Vet Res 1997;58:719-724.

Twark L, Dodds WJ. Clinical use of serum parvovirus and distemper virus antibody titers for determining revaccination strategies in healthy dogs. J Am Vet 0Med Assoc 2000;217:1021-1024.