Mycotic diseases

Mycotic (fungal) diseases of animals and birds are of considerable importance both from public health and economic point of view. The fungi responsible for animal ringworm are zoonotic in nature and post problem to the people dealing with animals particularly pests. The loss of animal protein in the form of egg, meat and milk as a result of fatal aspergillosis in poultry and other birds, and mycotic mastitis and abortion in dairy animals directly affect the economy. In addition, the extensive damage caused to skin, hair, hide and wool by cutaneous mycoses also account for financial loss to the animal industry.

The aetiological agents of most of the mycoses exist and proliferate as saprophyte in the environmental material such as soil, avian excreta, bat dropping, bagasse, litter, straw, vegetable and other organic matter. These saprobic reservoirs act as a source of  infection to man, animals and birds. The infection is usually acquired by the inhalation of excessive number of fungal spores or other infectious particles through the respiratory tract. However, infection may also be established through the traumatic implantation of fungal cells into the subcutaneous tissues and mucous membranes of the eye, nose and mouth.

India being a vast country with considerable environmental diversity has not only cosmopolitan fungal pathogens such as Aspergillus fumigatus, Cryptococcus neoformans, Candida albicans, but also of those pathogenic species, which show preference for particular ecological habitats. Coccidiodes immitis and Paracoccidiodes brasiliensis have not been reported in India. Like many bacteria and viruses, fungi also produce sporadic as well as epidemic form of disease. Outbreaks of cryptococcal mastitis in Holstein-Friesian cows, aspergillosis in poultry and other birds, epizootic lymphangitis in horses, candidiasis in chicks, dermatophytosis in cow calves and buffalo calves, and mycotic dermatitis in sheep are reported in the literature. The introduction of antibodies and corticosteroids in the veterinary medicine has given an opportunity to the fungal organisms to become more prevalent.