Abstract

Erysipelas has always been a threat to marine mammal collections and the strategies to address the situation have varied over the years. Vaccination was commonly used in the past, then stopped because of cases of anaphylactic reactions, then started again with different strategies and then adapted as knowledge evolved.

A first survey (covering the years 1989–2000), with 65% return answer and covering 1,373 animals in human care, reported 58 cases of erysipelas (4.22%) with 20 acute fatal septicaemia cases and 38 non-fatal cases (including 3 suspected non-fatal cases and 1 accidental isolation), all in non-vaccinated animals or animals vaccinated once long before. No case had occurred in regularly vaccinated animals. Those results had been presented at the first erysipelas conference in Chicago in 2000.

At the time of this abstract the preliminary results of a second survey (covering the years 2001–2020) are: 100+ facilities, 1600+ animals, over 10 different cetacean species, 37 fatal, 30 non-fatal and 8 suspected cases, all in non-vaccinated animals, and still expecting the questionnaire from facilities having had confirmed cases.

Fear of vaccination is still present because of the risk of local, general and/or former anaphylactic reaction, but the approach to the choice whether to vaccinate or not when faced with acute fatal cases is very different whether one is a small facility or one is part of a bigger group. Differences are also seen depending on the types of vaccine and more specifically their adjuvants (aluminum hydroxide vs. Amphigen® vs. alpha-tocopherol).

In 2019 we published the final results of our long-term study (20+ years) on vaccination in a dolphin population, where no anaphylactic reaction and no case of erysipelas infection were observed during the vaccination period, though the bacteria had been on the premises previously.^a

At least 3 vaccinations with a commercially available swine vaccine are necessary to reach antibody levels statistically higher than the level in naive and non-vaccinated animals. The recommended protocol is a primary vaccination, followed by 2 boosters, at one month and at 6 months. Yearly vaccination is recommended though it may be that after several years and/or in older animals a vaccination every two or three years may be sufficient. Determining what is a protective titer is impossible as it would imply infectious trials in dolphins which is ethically inacceptable.

*Presenting author

a. Corresponding author: Geraldine.lacave@icloud.com

Literature Cited

1.  Geraldine Lacave^a, Yi Cui, Ana Salbany, Carla Flanagan, Francesco Grande and Eric Cox. 2019. Erysipelas vaccination protocols in dolphins (Tursiops truncatus) evaluated by antibody responses over twenty continuous years. Dis Aquat org 134: 237–255.