Like all animals, cetaceans are exposed to diseases and biotoxins. However, the number of these diseases is increasing and the emergence of new diseases has been observed in cetaceans. Some can be transmitted by humans, others are the result of pollution,...

Recently it was found that cetaceans were victims of diseases earlier found only on land animals, and even diseases typical to livestock.

The rise and the appearance of these new diseases is even more problematic since the immune system of cetaceans can be weakened by (increasing) pollution of the marine environment. This problem is still not well known, but it is of concern because these diseases weaken the animals already faced with multiple threats.
The IWC has established a working group on emerging and resurging diseases of cetaceans: the CERD (Cetacean Emerging and Resurging Diseases).