Here's why:
* Disease Diversity: There are thousands of diseases, from viruses and bacteria to parasites and fungi. Each disease has a specific way it infects and damages an organism.
* Evolving Threats: New diseases are constantly emerging, and existing diseases can evolve to become resistant to treatments.
* Individual Variation: Even within a species, individuals have different immune systems and susceptibilities to disease.
While some animals might have a strong resistance to certain diseases, no creature is completely immune to all potential threats.