What is a drawback of using serology for pathogen detection in immunodeficient animals?

Using serology for pathogen detection in immunodeficient animals primarily relies on the host's immune response to identify the presence of pathogens through the detection of antibodies. In immunodeficient animals, this immune response is often compromised or absent, which greatly limits the effectiveness of serological testing. Since such tests depend on the ability of the host to produce antibodies against the pathogens, the lack of a robust immune response in these animals can lead to false negatives or an inability to detect infections altogether.

This characteristic restricts serology's utility in these specific cases, as other pathogen detection methods that do not rely on the immune system—such as PCR (polymerase chain reaction) or culture techniques—may be more suitable for identifying infections in immunodeficient hosts. These alternative methods can detect the pathogen's genetic material or live organisms directly, independent of the immune response, which is often absent or ineffective in immunodeficient animals.