Fungal diseases

P.O.C.

Aspergillosis
(Brooder pnemunia, Mycotic pnemunia, Pnemomycosis)

Candiasis
(Crop mycosis, Thrush, Sour crop, Moniliasis, Muguet, Stomatitis Oidica,
Oidiomycosis)

Favus
(White comb)

Definition

Mainly affects the respiratory system, but some infections spread to other visceral organs, affecting most domestic and wild birds.
Forms of Asperigillosis:
*Systemic Aspergillosis

*Dermatitis

*Mycotic Osteomyelitis & Arthritis

 *Ophthalmitis

*Encephalitis

 *Pulmonary Aspergillosis

Worldwide organism primarily affects the upper digestive tract of all birds and is characterized by whitish thickened areas of the crop and proventriculus, erosions in the gizzard, and inflammation of the vent area.

Chronic dermatomycosis, the comb is often affected, in severe cases the disease spreads to the feather portion of the body.

Etiology

There are many different kinds of:

 aspergillus (Aspergillus fumigatus and A. flavus are the two major agents while Aspergillus niger, Aspergillus candidus, Aspergillus glaucus, Aspergillus nidulans are among the species isolated as opportunistic pathogens.
found worldwide, especially in the autumn and winter >25 oC )

yeast-like fungus (Candida albicans) which is a dimorphic yeast appear as round or oval budding yeasts on surface epithelium or branching with pseudo-hyphae in deeper tissue

Trichophyton gallinae

  (Achorion gallinae).

Susceptibility

    in the brooder stage in domestic birds (chicks, Quails, pheasants, Turkey, Pigeon and ducks)

    in the form of an acute out-break in young chicks

    adult birds occasionally may be affected as sporadic cases.

    infect chicks and turkey poult at or below 10 days of age but may affect birds up to 10 weeks.

     Turkeys highly susceptible than chickens.

²  Chickens, turkeys, pigeons, pheasants, quail and grouse are species most commonly get affected as well as other domestic animals and humans.

²  Poultry of all ages are susceptible to the effects of this organism.

all ages under poor manage-mental conditions
Young birds with well-developed combs are most likely affected.

Mode of transmit-ssion

    The bird comes in contact with the organisms through contaminated feed, litter or premises.

 Egg borne disease: the fungi penetrate the egg shell due to contamination of egg shell with fungi during incubation and may lead to embryonic mortality or hatched infected chicks and infection to recently healthy hatched chicks by inhalation of spores this is called Hatchery borne disease.

    not contagious and does not spread from one bird to another. ( Most healthy birds can withstand repeated exposure to these organisms when there is count within the permissible limit).

    Inhalation of large amounts of the infectious form of the mold or reduced resistance of the bird apparently results in infection.
In adult turkeys, the disease more often affects the male.

    by ingestion of the causative organism in infected feed, water or environment.

    Unsanitary and unclean water troughs are an excellent reservoir of the Candida organism.

    The disease does not however, spread directly from bird to bird (not contagious).

    The organism grows especially well on corn, so infection can be introduced by feeding moldy feed.

Infection spreads from one bird to another by direct contacts.
(Contagious)

Clinical signs

The disease is observed in one of two forms:
 A-acute outbreaks with high morbidity and high mortality in young birds:
dyspnea, gasping, accelerated breathing, depression dullness, sleepiness, loss of appetite emaciation and sometimes convulsions and death. Serous excretion from nares and ocular mucosa could be observed usually unilateral in turkey poults characterized by yellow cheesy exudates beneath the nictating membrane causing bulging of the eyelids leads to blindness. In turkey eye affected resulted in inflammation and accumulation of cheesy material under the eyelids. Occasionally the organism invades the brain, causing paralysis or torticollis and or lack of equilibrium or other forms of nervous symptoms.

B- chronic condition affecting adult birds:
loss of appetite, gasping or coughing and a rapid loss of body weight. Mortality is usually low 1-2% in chicks and only a few birds are affected at one time. Mortality in duckling may exceed 50%.

    no specific symptoms
Young birds become listless, pale, show ruffled feathers and appear unthrifty.

    Affected caged layer hens become obese and anemic.

    Some birds exhibit a vent inflammation that resembles a diarrhea induced condition having whitish in crustations of the feathers and skin around the area.

    Feed consumption may decrease by ten to twenty percent.

     Lesions usually develop first on the comb, as the fungus spreads. white spots developed the surface of which scales off, and the comb may appear as through sprinkled with flour.

    The skin becomes thickened in the affected area and covered with scale and crusts especially around the feather follicles.

méningitis (a), dermatitis (b), uveitis (c) and arthritis (d)

PM

    hard nodular areas in the lungs and an infection of the air sacs.

    Sometimes the air sac lesions are similar to those produced by infectious sinusitis or CRD.

    In some birds, colonies of mold growth can be seen on the air sac membranes which appear as yellowish nodules and cloudy air sacs.

    Necrotic foci may be found on liver, spleen, kidneys, proventriculus and other organs.

 Sometimes fungus may invade blood stream reaching the brain  showing white to yellow necrotic foci.

    Ophthalmitis may occure and lead to blindness

    Are mostly confined to the crop, proventriculus and gizzard.

    The crop and proventriculus have whitish thickened areas that are often described as having a "turkish towel" appearance or pseudodiphtheritic membrane with necrotic batches with eroded mucosal surface.

    A moldy odor may be detected.
Lesion in feathered skin develop depression around follicles (Favus cups) few grey cup like spots which increase in size and coalesce to form wrinkled crusts.

Microscopic 

Aspergillosis

Candidiasis

Favus

Direct microscopic detection by taking small portion of the nodules in kOH 10% on a microscopic slide covering with cover slide then apply genital heating mixed with ink dye lactophenol to show

 blue stained separated branched hyphae

round cell and hyphae
-Stain with Gram stain, show gram positive stain.

branching fungal hyphae and

Arthrospores.

Lab. diagnosis

Sabouraud’s agar at 35 c antibacterial drugs as chlormephenicol could added to suppress any bacterial growth.

The flat colonies are initially white and turn blue green as conidia begin to mature.                
*Special stain:Periodic acid shaft & girocotts methenamine silver could used in histopathological  tissue smear.
*ELIZA could use in turkey for detection antibody

Colonies are whitish, creamy and highly convex with yeast odor after 1-2 days at 37c.
D.D: 
Wet form of pox,paratyphoid in pigeon,trichothecene mycotoxin,trichomoniasis in pigeon,vit A def.

slow-growing, flat-to-powdery white-to-cream colonies that often produce a characteristic pink-to-red diffusible pigment into the agar.

Prevention and control 

avoiding moldy litter, feed hoppers and watering places or premises are fertile area for fungal growth of moulds unless frequent moving of utensils.
3-Daily cleaning and disinfecting the equipment is often helpful.
4-Spraying the ground with Sod. Hydroxide or Cu Sulphate.
5- increase ventilation in poultry house.

The disease can usually be prevented by:
1- Eggs collected and stored away to prevent exposure to spores,
2- Hatchery equipment and brooding house must be cleaned and disinfected
Vaccines with (germinated conidia) from A. Fumigatus in turkey poults reduce mortality 50%

An inexpensive, yet effective, water treatment is the continuous addition of household chlorine bleach to the drinking water at the rate of 5 parts per million (ppm).

Treatment

Many broad-spectrum antibiotics will enhance this disease; therefore, they should not be used until after control of this condition is completed.

Tetracycline Sorbate at dose of 200 mg/L of drinking water for 5 days or Miconazole.
Dimethyldithiocarbamate injected SC was effective against infection in 5-10 weeks
Mycostatin, amphotericin B, crystal violet and brilliant green are effective in mild form of disease.

Addition of Nystatin (100 g/Ton) or copper sulfate (2-3 lb/Ton) to the feed for seven to ten days should control moniliasis beside an adequate amount of Vitamin A.Methyl violet choline chloride and vitamin K prevent crop mycosis.

 Remove the crust and apply topical antifungal