At Grove Lodge Vets, we sometimes get enquiries from dog owners regarding their dog's vaccinations and the reasons for the annual booster. Set out below is an explanation of the reasoning behind this:
Dogs are vaccinated according to WSAVA guidelines against distemper, hepatitis, parvovirus, parainfluenza and leptospirosis.
Most of the components only need to be given every three years, but immunity to leptospirosis is less long-lasting, therefore it is recommended that this vaccine is given at least annually. This is not a 'core' vaccine but there is considered to be enough risk of disease in this area to justify vaccination. Therefore most dogs will receive a primary course of two full vaccines given 2-4 weeks apart, with the first given at no younger than 7 weeks of age, and the second at not less than 10 weeks of age. Onset of full immunity is 2 weeks after the second vaccination.
Dogs will then receive a full booster a year later and then every third year, with annual 'part' boosters (for leptospirosis) in between these times.
If a dog's vaccination is late, advice is to 'restart' the course with 2 vaccines given 2-4 weeks apart - this is again mainly to maintain immunity to the leptospirosis component.