Veterinary Health Surveillance

Weighing a great crested newt Most importantly this work is to prevent the introduction of alien parasites to native populations because exposure to novel parasites has been found to cause devastating epidemic disease. Health surveillance also ensures that captive bred animals are in good health and that their welfare is closely monitored, and elucidates threats to the health of wild populations by determining causes of morbidity and mortality.

Here are some examples of ZSL’s veterinary health surveillance work:

• Red kites found dead in the wild are examined to determine the cause of death. Such analysis has determined that toxicities, particularly those caused by anticoagulant rodenticides, are a significant threat to their survival. A large proportion of red kites’ diet is carrion and they will eat dead rodents killed with rodenticides. Such valuable information feeds into publicity campaigns to warn people of the dangers of such rodenticide use.

• Monitoring red squirrels found dead in the wild demonstrated the importance of disease in limiting populations of this species. A pox virus was identified which is lethal to red squirrels, but largely tolerated by grey squirrels, which probably act as carriers of the virus.

• All captive-bred animals reared for release at ZSL London Zoo and ZSL Whipsnade Zoo are health screened prior to release. One batch of captive-bred field crickets was not released into the wild because they had an alien potentially pathogenic parasite.

• Alien tapeworm parasites were identified in dormice prior to release, and animals were treated to eliminate these for the safety of wild populations.