Vaccination of dogs and cats: no longer so controversial?
VACCINATION practice continues to cause confusion for UK practitioners who are often perplexed by the apparently conflicting information that they receive from various sources. As little as 10 years ago, the vaccination of adult dogs and cats was perceived to be a relatively straightforward process whereby every animal enrolled with a practice received a particular combination of vaccine components every year. This practice was legally sound as all vaccines were licensed with a minimum duration of immunity (DOI) of one year. The administration of the ‘annual booster vaccine’ was regarded as the principle reason for an annual veterinary visit and it was commonplace to issue reminder cards for the ‘annual booster’.

So why has this procedure changed? As the widespread and remarkably successful use of vaccines over the past few decades has resulted in a drastic reduction in the incidence of those serious infectious diseases against which we commonly vaccinate, attention has inevitably shifted to the small risk of vaccine-associated adverse reactions. Over the past 20 years, concerns have been raised over the safety of repeated administration of vaccines in both human and veterinary medicine. Although licensed vaccines have an extremely high safety profile, no product can be guaranteed safe in every patient and there is evidence that occasional adverse reactions to vaccines occur. Such reported suspected adverse reactions form a spectrum from mild and transient pyrexia and lethargy, through to allergic or autoimmune diseases, life-threatening neoplasia (the feline injection site sarcoma), or rarely death of the animal. Recent UK pharmacovigilance data suggest that the overall prevalence of canine adverse reactions is very low (18.5 per 100,000 doses of vaccine sold [VMD 2010]), while epidemiological analyses of a US corporate practice database provides figures of 30 to 50 reactions per 10,000 dogs or cats vaccinated (Moore and others …