Guidelines for the vaccination of dogs and cats

Vaccination has been used to protect our companion animals against infectious diseases for many years. Despite this success, vaccination of cats and dogs has become a contentious subject over recent years, with many clients suggesting that veterinary surgeons carry out too many vaccinations not only putting pets at risk from adverse reactions but also incurring unnecessary expense. Several groups have tried to address these issues and produce guidelines to assist in the decision as to whether or not to vaccinate an animal. One of the limitations with such guidelines is that a ‘one-size-fits-all’ approach will not be possible and so decisions will still have to be made by veterinary surgeons in practice with the individual animals’ circumstances being taken into account. The recent set of guidelines produced by the vaccination guidelines group (VGG) of the World Small Animal Veterinary Association (WSAVA) is published in this issue of the Journal of Small Animal Practice (Vaccination Guidelines Group 2007). The VGG has taken on the ambitious task of producing a set of guidelines applicable to veterinary surgeons vaccinating dogs and cats across the world. The prevalence of disease and infection may well be very different throughout the various countries and in addition animal management and vaccination uptake are likely to differ. Therefore, although these guidelines can give overall advice they will have to be adapted for use in individual countries and areas. An admirable task has been completed and this set of guidelines gives advice not only for the general dog and cat population but also specifically for rescue shelter situations. This is helpful as shelter premises often have a high prevalence of infection, may experience disease epidemics and have incoming animals that often have no vaccination history and therefore may be susceptible to infection and disease. The guidelines indicate core vaccines with which all dogs and cats should be vaccinated, as well as non-core vaccines which should only be used in specific individuals at particular risk. They also identify vaccines that are not recommended. This is often due to lack of scientific evidence to show a specific need for such a vaccine or may be due to other specific reasons associated with the vaccine (such as interference with diagnostic testing which occurs following the use of feline immunodeficiency virus vaccines). Veterinary surgeons will still have to make decisions based on a risk-benefit assessment for their individual patient. Knowledge of the prevalence of various infectious diseases in the local area would be helpful for this assessment but is usually unavailable. Indeed even countrywide prevalence data is not available for many companion animal infections and thus decisions have to be based on anecdotal evidence on the occurrence of disease. It is important to remember at this point that lack of disease may not mean lack of infection and so increasing the number of susceptible individuals in such a population (by reduced vaccination) may lead to disease epidemics. Perhaps the crux of the matter lies with client choice. Veterinary consultation is an important aspect of informed client choice. This is, of course, a time consuming exercise and some clients may have no interest in participating. So for these clients (perhaps the majority?) the ultimate decision will be given back to the vet to identify what he or she thinks is best for that animal. Where clients themselves make the choice some may prefer to have their pet vaccinated such that it has the best chance of protection against disease (especially if it is likely to come into contact with infection such as when going to a boarding cattery or kennel). For animals belonging to these clients use of some of the non-core vaccines, and perhaps booster vaccinations more frequently than recommended, would be an appropriate choice. Other clients may be more concerned about potential risks associated with vaccination and so be willing to accept the possibility of their pet developing mild diseases potentially associated with reduced vaccination regimens. Overall, vaccination has been successfully used for many years to protect our companion animals against infectious diseases. However, although successful in reducing clinical disease, the infections have not been eradicated and so animals must continue to be protected by vaccination. The VGG have encapsulated their fundamental concepts in the strap-line: ‘We should aim to vaccinate every animal, and to vaccinate each individual less frequently.’ Whilst as an ultimate aim this would be ideal (and would take us into the territory of population immunity more in line with our colleagues in the human vaccination field), for many veterinary surgeons in practice the vaccination of every cat and dog is a long way off. Veterinary surgeons in practice are at the frontline of achieving this aim but it will be impossible without the back-up of the pharmaceutical companies (in producing efficacious vaccines) and the licensing authorities (in ensuring the quality, safety and efficacy of the vaccines on the market). Perhaps this is our next challenge in small animal vaccination. Susan Dawson qualified from the University of Glasgow in 1983 and spent 6 years in general practice. Following this Susan moved to Liverpool and studied towards a PhD in feline calicivirus which she gained in 1991. Since this time Susan has continued working at Liverpool spending most of her time studying infectious diseases and she is currently Intervet Senior Lecturer in Small Animal Studies. Currently her main research interests are vaccination, zoonotic infections and antibacterial resistance.