Fungal diseases Few fungal species are common pathogens in avian species, and these belong to the grouping of Eumycota (mycelial forms), Mycoses are relatively uncommon diseases but are often devastating to the host supporting the fungal infection. The ability of fungi to infect animals is incidental to their maintenance. Aspergillosis is by far the most commonly encountered mycosis of birds and is an economically important respiratory disease of poultry. Candidiasis is the principal fungal infection of the digestive tract of poultry. Dermatophytosis affects the integument and is the only contagious and zoonotic mycosis.

ASPERGILLOSIS (BROODER PNEUMONIA) Affects most avian species. Important in poults, chicks, and quail. Usually a young bird disease Is a serious problem in penguins in zoos. Etiology Aspergillus fumigatus Spores from contaminated incubators, feed, and litter can penetrate broken shells. Large dose to infect. Probably not bird to bird. Incubation period 8 to 12 days in vivo, 48 hrs in vitro Course of Disease 2 to 3 weeks, may linger

Mortality Depends on age Up to 100% under brooder Other diseases aggravate Method of Spread Inhalation of spores 1- Contaminated eggs in incubator 2- Dusty litter and ranges. Spreads readily under brooder *If clinical signs occur after 7 days of age, consider farm rather than hatchery exposure.

Clinical Signs 1. Rapid gasping respiration (without rales) 2. "Starve outs", emaciated 3. Blepharo-conjunctivitis, yellow caseous pellet in eye 4. Encephalitis common in turkey poults but rare in chickens Post Mortem Findings 1. Round yellow caseous granulomas on air sac, throughout lungs. “Pearl disease” 2. Occlusion of trachea 3. Occasionally green mold growth on air sacs or in lungs

Diagnosis -Typical lesions -Culture on Sabouraud's dextrose agar /added chloramphenicol. -Identify and classify fungal growth (Light microscope). -Histopathology to demonstrate fungal hyphae in tissue. Hyphae brownish and have outgrowths in "y" branches. Treatment None specific Stress prevention

Prevention 1-Remove source of infection - Use high quality litter - Keep clean litter in nests - Collect eggs often to prevent cracks Do not set cracked eggs- - use automated eggs collection machine 2- Fumigate incubators and hatchers 3- Add antifungal agents to feed 4- General clean up - disinfection between grow out.

CROP MYCOSIS (THRUSH or CANDIDIASIS) Most common mycotic diseases of poultry Most important in young poults and occasionally cage layers Etiology Candida albicans Very ubiquitous in normal flora Follows debilitating condition Broad spectrum antibiotics favor development by disruption of normal flora balance. Incubation Period Experimentally about 30 days, but has been found in 7-14 day old poults

Course of Disease 3 to 4 weeks May become chronic, then several weeks Mortality Poults and chicks - up to 20 to 30% Older birds - after 4 weeks usually low Method of Spread 1. Drinking water - Associated with unsanitary, over-crowded condition - Slimy water founts, wet litter 2. Infected birds source of contamination 3. Cages due to decreased bacterial competition (No contact with feces).

Symptoms Poor growth "Sick chick attitude" In layers - decrease egg production 15 to 20% Birds vomit in feed trough Post Mortem Lesions Non-inflammatory - thickened crop and/or mouth White, circular, raised ulcer-like formation pseudomembrane Proventriculitis Gizzard erosion Can occasionally be cultured from the liver lesion. May cause splotchy hemorrhages in the digestive tract.

Diagnosis 1- Suggestive - typical lesion, non-inflammatory 2- Positive - isolation and identification 3- Special medias used: - Corn meal agar Bismuthglucose glycine yeast) Biggy agar ( - Brown colony with white halo Treatment - Mycostatin (nystatin) 100 gm/ton 7-10 days - CuSO 4 1:2000 in water - Chlorine in the drinking water at 5 ppm. - Clean up Prevention Maintain sanitation Avoid prolonged use of broad spectrum antibiotics Mycostatin (nystatin) in feed 50 gm/ton

DACTYLARIOSIS Encephalitis of turkeys and chickens Caused by the thermophilic (likes heat) fungus Causative Agent: Dactylaria gallopava Fungus contaminated hardwood litter and sawdust. The litter often has been stored in such a way as to generate heat which enhances fungal growth. Thermophile. Incubation Period Six to 10 days experimentally. In field outbreaks -- from 1 week to 6 weeks of age generally.

Course of Disease Acute to fatal. Can affect humans also but not by infection from bird. Humans get exposed same way as birds - by inhalation of spores from environment. No immunity. Mortality Due to encephalitis: Poults -- up to 30% Broilers % Method of Spread Spores in contaminated litter inhaled. Not communicable from bird to bird.

Clinical Signs CNS signs, incoordination followed by torticollis, leg paralysis. Down on sides Weak, ataxia, head tremors Post Mortem Lesions Lesions, granulomatous in character Cerebral, cerebellar or optic lobe Brains mushy with grayish walled-off lesions. Opacity in eye. No air sac problem Differential Diagnosis - Avian encephalomyelitis - Aspergillosis - Newcastle disease - Vitamin E deficiency

Diagnosis 1. Demonstration of hyphal elements in the brain. 2. Culture mold from lungs and brains. 3. Micromorphology of mold. Histopathology Granulomatous areas of brain and lung have massive inflammatory cellular infiltration. Centers - coagulative necrosis and giant cell formation. Small, delicate hyphal elements demonstrated.

Culture Techniques SDA with added chloramphenicol - 42 ° C thermophile. Warmer than normal incubation temperatures of ° C. Dark brown -- dematiaceous fungus with small oval two celled brown spores. NOTE Dactylaria sp. is also a human pathogen. Use extreme caution when handling diagnostic cultures in the laboratory. Treatment None, only supportive therapy

FAVUS Chronic dermatomycosis affecting chickens, turkeys and some other birds, animals and humans Etiology: Trichophyton megnini - Cultivation on sabouraud’s - Colonies’ round disks, white and velvety - A reddish pigment varying from rose or strawberry red to a deep raspberry diffuses through the medium

Clinical Signs and Lesions -White spots develop on surface of the comb and it may be appear as though sprinkled with flow -Wattles and unfeather portions of the head may be affected -As the disease progresses, scaly deposit become thicker and from a wrinkled crust. Feathers fall out in patches.- -Fungus spreads slowly from bird to bird by direct contact and by scales that become detached from affected bird.

Diagnosis -Characteristics of gross lesion -Microscopical checking of fungus -Culture of fungus Treatment - Iodine and glycerine (tinct.iodine : glycerine 1:6)