Bestandsimpfung beim Pferd: 44 Jahre Impfungen im Haupt- und Landgestüt Marbach a. d. Lauter (1972–2015) – Infektionsmedizinische Aspekte

Abstract

The whole horsestock of the Governmental Main Stud Marbach/Lauter had been vaccinated between 1972 and 2015, accompanied and controlled by virological, bacteriological and serological investigations. In total 1.332 horses of different breeds had been treated thus by using 23.860 vaccinations. The different vaccines used during the observation period from 1972 until autumn 1976 were a killed Influenza vaccine (Prevaccun (R)) and a modified live EHV1-vaccine (Prevaccinol (R)). These vaccines had been used once a year only for breeding mares, stallions and riding horses. Later on a killed combination vaccine (Influenza H7/N/7, H3/N8, EHV1-killed, Reovirus types 1 and 3 killed) had been used for the whole stock with booster vaccinations every 9 months, followed by the succesive products (different Resequin (R) vaccines). The Fluvaccine Prequenza (R) and the killed EHV1/4 vaccine Duvaxyn EUV1/4 (R) were implemented, when Resequin (R) was no longer on the market. The booster vaccinations with this two vaccines had been performed every six months independent of the stage of pregnancy of the breeding mares. Foals weren't vaccinated before the 9th month of age, basic immunizations were performed 8 weeks apart. Tetanus revaccinations were performed according to the product descriptions independent of other vaccinations. The strict management and hygienic system used at the stud, seperating the different horse generations, seperating stabling of the stallion- and mare foals after weaning, are described as well as the hygienic measurements, the microbiological and serological investigations. Every single case of abortion had been investigated virologically, bacteriologically and patho-histologically. The EHV1- abortion rate (13 virologically confirmed EHV1-abortions) during the documented 44 years of investigation was 0,65% despite the twice year vaccination with killed EHV1/4 vaccines of the 2.012 pregnant mares. The comparable percentage of EHV1-abortions in the German Throroughbred with a totally different EHV-vaccination regime (3 vaccinations during the pregnancies within the last trimester) was 0,37%, on the basis of 29.116 foalings between 1992 and 2014. Beside EHV1-isolates from abortions, EHV1 were isolated from nasal swabs of weaned vaccinated foals. More over EHV3 (Coitalexanthema) from diseased mares was isolated for the first time between 1975 and 1976. The carrier was found in a stallion. In an influenza H3/N8-challenge trial (endobronchial challenge infection) four regularly vaccinated 2,5 year old stallions were infected. After their release into the stallion herd no clinical signs of influenza in the contact horses or virus isolation occurred. There was no outbreak of Equine Influenza in the Marbach stud for 44 years. No metaphylactic treatment for tetanus had been nescessary despite multiple injuries especially in the young horse herds. Immunity of the whole stock against tetanus could be demonstrated by serological tests (ELISA, Fassisi Teta check (R)) including the influence of maternally derived antibodies on the basic immunization of foals. The elected, described vaccination regime together with the hygienic measurements and the management program for young and adult horses have demonstrated its effectiveness at the Marbach stud. The data obtained and the vaccination program are discussed in relation to an existing German "Impfleitlinie fur Pferde" with a given "OFF LABEL USE" for EHV1 vaccines and false recommendations for the tetanus vaccination. Existing directions for the use of vaccines on the basis of product descriptions are discussed.