How do fungi cause disease?
Fungi can cause disease by invading tissue, producing toxins, or causing hypersensitization. Fungal infections are called mycoses but some veterinarians prefer the term “fungal disease”. Dermatophytes are those fungi that infect the skin and hair. As you look over Table 4-19 on pages 191-193 in Hendrix, you will notice that many of the mycoses in animals also infect humans. Fungi are ubiquitous, meaning they are commonly found everywhere in the environment and in normal flora. Fungi can cause disease in animals in the same way that bacteria do, but it is usually as an accidental opportunist. Fungi must invade tissue and colonize it first for infection to occur, and the animal must be susceptible in some way in order for disease to occur. Intact skin is an effective barrier as for bacteria, but small abrasions may allow entrance. Very small spores can be inhaled and gain access to the lower respiratory tract. Endogenous infections are caused by fungi that are present in the normal flora
