Slide Study Sets

Available on the AAAP Learning Management Site as pdf documents. $20 each

These Slide Study Sets are produced and distributed by the American Association of Avian Pathologist (AAAP). Reproduction is prohibited without permission. Images may be used for educational purposes as long as credit is given to AAAP. These Slide Sets have been produced and updated through the leadership of the AAAP Education Committee and the generous contributions of the slide study set authors.

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F. Merrill Ranck, Jr
Revised by A. M. Miles

Aspergillosis is the most common respiratory mycotic disease of poultry. Aspergillosis is defined as any disease condition caused by a member of the fungal genus Aspergillus.

Avian Cardiovascular System

R. J. Julian

The avian heart differs from the mammalian heart in that it is cone-shaped, has a thin right ventricle (RV) and thick left ventricular (LV) wall, with a thickness ratio of 1:4. A muscular flap, rather than a mammalian valve, separates the right atrium (RA)from the RV. This muscular flap is a continuation of muscle from the right ventricular wall. Other valves are similar to those found in the mammalian heart.

Avian Encephalomyelitis

O. J. Fletcher
T. Abdul-Aziz

Avian encephalomyelitis (AE) is an infectious viral disease of young (1 to 3 week old)chickens, turkeys, pheasants, and quail. The causative virus is a member of the Picornaviridae family. Older chickens may have cataracts as a consequence of AE infection.Susceptible laying hens can have reduction in egg production and hatchability. Because the virus can be transmitted through the egg, immunization of hens is critical for control of this disease.

Avian Infectious Bronchitis

B. S. Ladman
M. W. Jackwood

Infectious bronchitis is a highly contagious upper-respiratory tract disease caused by the avian coronavirus infectious bronchitis virus (IBV).

Avian Influenza

N. L. Tablante
H. L. Shivaprasad

AI is an infections, viral disease of birds caused by several subtypes of the type A strain of the influenza virus. The virus occurs natuarally among waterfowl and shorebirds which remain asymtomatic but may transmit the virus to domestic poultry such as chickens, turkeys, and ducks.

Avian Pox

D. N. Tripathy

Avian poxviruses--fowl, pigeon, turkey, canary, junco, quail, sparrow, and psittacine poxviruses--are members of the genus Avipoxvirus of the Poxviridae family. Fowl poxvirus is the type species of the genus. Because of similar clinical manifestation in different avian species, only fowl pox is described here.

Chicken Infectious Anemia

J. A. Smyth
H. L. Shivaprasad
K. A. Schat

Chicken infectious anemia (CIA) is a disease characterized by aplastic anemia, generalized lymphoid depletion, subcutaneous and intramuscular hemorrhages, and immunodepression. Because of the immunodepression, increased mortality due to secondary complications is often observed.

Clostridial Diseases

H. L. Shivaprasad
N. L. Tablante

Clostridia are spore-forming Gram positive bacilli that can cause various diseases with different clinical signs in poultry, ratites, psittacines, waterfowl, and wild birds. Many Clostridia can be found normally in the soil and in the gastrointestinal tract of many animals. All Clostridia produce a vast array of exotoxins.

Coccidiosis in Chickens and Turkeys

K. L. Watkins
K. Opengart

The coccidia are in the phylum Apicomplexa and may be grouped into numerousgenera consisting of more than a thousand species; however, this discussion will berestricted to the genus Eimeria, which infects chickens and turkeys.

Diseases of Malnutrition in Poultry

H. L. Shivaprasad

The slide set starts with an excellent definition of what is ‘nutrition’ followed by functions of 12 nutrients, effects of malnutrition on the body, factors that influence malnutrition, diagnoses, clinical signs and pathology of deficiency of various nutrients (vitamins A, B2, D3, E), minerals (Ca, P, selenium, manganese) and others such as choline, biotin, niacin, folic acid and iodine. The clinical signs and pathology of diseases are illustrated by excellent color pictures of gross and histopathology.  The written format is brief and concise and the slide set is user friendly.

Differential Diagnosis of Lymphoid and Myeloid Tumors

John R. Dunn
Isabel. M. Gimeno
Pat Wakenell
Yuko Sato

This slide set and associated text is to assist diagnosticians and veterinary pathologists in making accurate diagnoses of field cases in chickens where lymphoid or myeloid tumors are suspected. Lesions and other diagnostic features that distinguish Marek’s disease (MD), lymphoid leukosis (LL), myeloid leukosis (ML) and the bursal and nonbursal lymphomas associated with reticuloendotheliosis (RE) are discussed and illustrated. Differentiation of these neoplasms from nonneoplastic syndromes and assorted other tumors is also discussed. Emphasis is placed on diagnostic strategies rather than specific procedures.

Ectoparasitosis of Poultry

C. Gabriel Sentíes-Cué
Manuela Crispo
H.L. Shivaprasad

Ectoparasitosis are very common in commercial and backyard poultry operations all over the world. Ectoparasites can result in a significant reduction of flocks’ performance since they not only feed on birds, but also cause chronic stress, damage the skin and subcutaneous tissue and weaken the immune response against other diseases.

Emerging and Epidemic Diseases of Wild Birds

S. D. Fitzgerald
J. R. Fisher
N. L. Gottdenker

While most of the American Association of Avian Pathologists study sets are devoted to descriptions of disease conditions in domestic poultry, this study set will describe diseases of wild birds. Diseases of wild birds are important not only in their relation to the health of wild bird populations, but also because they represent important endemic infectious agents which pose threats to both poultry and in some cases human health.

Endoparasites of Poultry – Helminths

M. Crispo
H. L. Shivaprasad
G. C. Senties-Cue

Parasitic diseases play a significant role in backyard and commercial poultry flocks. Floor and free-range operations are more commonly affected, although caged flocks can also experience serious problems. The number and type of parasite species involved is greatly influenced by the epidemiological relationship between the parasite and its host/s. Overall, parasitic diseases can result in significant economic losses, in terms of poor birds’ performance, and negatively affect animal welfare.

Fowl Cholera

G. E. Onet
H. L. Shivaprasad

Fowl cholera is a septicemic disease caused by Pasteurella multocida which affects a variety of domesticated and wild birds. This highly contagious disease causes high morbidity and mortality resulting in great economic losses, especially in large industrial-type poultry complexes. It usually occurs as an acute disease, but chronic infections can also occur in some outbreaks.


T. Abdul-Aziz
H. J. Barnes
L. R. McDougald

Histomoniasis is a protozoan disease caused by the parasitic protozoan Histomonas meleagridis. The disease has a worldwide distribution.

Gross Lesions of Velogenic Viscerotropic Newcastle Disease

C. W. Beard

These slides show the lesions most commonly observed in chickens that die of velogenic viscerotropic Newcastle disease (VVND). Not all of the lesions described in this report are present in all or even a large percentage of chickens.

Infectious Bursal Disease

S. Rautenschlein
E. Mundt

Infectious bursal disease (IBD) is an acute viral infection of young chickens that affects the lymphoid tissue particularly the bursa of Fabricius.

Inclusion Body Hepatitis of Chickens

J. El-Atrache
P. Villegas

IBHC appears to be an emerging disease, this program was prepared as a summary of current knowledge which hopefully will provide useful guidelinesfor the diagnostician.

Infectious Coryza

P. J. Blackall
J. R. Blakey
H. L. Shivaprasad

Infectious coryza of chickens is an acute respiratory disease caused by Haemophilus paragallinarum. The disease occurs in poultry raising areas throughout the world.

Infectious Laryngotracheitis

T. Abdul-Aziz
J. S. Guy
H. J. Barnes

Laryngotracheitis (LT) is an acute viral respiratory disease primarily of chickens. Economic losses attributable to LT are increasingly important in many poultry producing areas throughout the United States and the world.

Marble Spleen Disease Ring-Necked Pheasants

S. D. Fitzgerald
W. M. Reed

Marble spleen disease (MSD) is a contagious disease of confinement-raised pheasants. It has been a significant cause of mortality in many areas of the United States, Canada, and Europe during the last 30 years. Marble spleen disease is caused by a type II avian adenovirus.

Marek's Disease

I. M. Gimeno

Marek’s disease virus (MDV) is able to induce a variety of syndromes and pathological manifestation in chickens. Because of its economic impact, the development of lymphomas in nerves and viscera is the pathological feature that has received the greatest attention. Nonetheless, there are other syndromes associated with the replication of MDV such as transient paralysis (TP), and lymphodegenerative syndromes, that occur independently of the development of lymphomas and are also addressed in this slide set.

Musculoskeletal Disorders Chickens & Turkeys

R. J. Julian

Many peculiarities of the avian skeleton are related to flight. Other differences are related to egg production. Many avian bones are hollow and contain air sacs. Air sacs in bones make bones lighter but are of significance because air sacculitis can result in osteomyelitis, arthritis and synovitis.

Mycoplasma Gallisepticum Infection

S. H. Kleven
O. J. Fletcher

Mycoplasmas are very small bacteria that lack a cell wall and have a very small genome. They are therefore resistant to antibiotics that act by inhibiting cell wall synthesis, require a rich growth medium, and are more labile to inactivation by environmental factors than are the more resistant typical bacteria with cell walls, such as E. coli. Recent information, however, suggests that Mycoplasma gallisepticum (MG) cells survive longer outside the host than has been previously believed.

Mycoplasma Meleagridis Infection

R. Yamamoto
H. B. Ortmayer
Y. M. Saif

Mycoplasma meleagridis (MM) was first isolated in 1958 from turkey poults with air-sac lesions. Being antigenically distinct from M. gallisepticum, which was the mycoplasma of primary concern in turkeys at that time, the new serotype was named "Nstrain." Since then, the organism has been classified into the H-serotype and given the present species name.

Mycoplasma Synoviae Infection

Z. Raviv
D. H. Ley

Mycoplasma synoviae(MS) is a pathogen of chickens and turkeys, causing significant economic losses to poultry producers worldwide. Infection can be associated with upper respiratory disease, airsacculitis, synovitis, tenosynovitis, and bursitis. Disease severity has been influenced by other respiratory pathogens (e.g., Newcastle disease virus, infectious bronchitis virus), more virulent MS strains, and host species predilection (turkeys more susceptible than chickens).

Necrotic Enteritis

T. Abdul-Aziz
H. J. Barnes

Necrotic enteritis (NE) is an enteric bacterial disease of chickens, turkeys, and a few other avian species caused by Clostridium perfringens. The disease is characterized by damage to the intestinal mucosa by toxins produced by the causative bacteria. It occurs worldwide and causes considerable financial losses to broiler producers due to mortality, treatment cost, and, in its milder subclinical form, poor growth and feed utilization. The disease was first reported in chickens in 1961.

Pullorum Disease and Fowl Typhoid

H. L. Shivaprasad
R. P. Chin

Pullorum disease (PD) and fowl typhoid (FT) are highly infectious and contagious diseases of poultry first described in 1900 and 1888, respectively. Losses from PD and FT were so severe that they once impaired the expansion of the poultry industry. Currently, reports of FT in the U.S. are rare.

An Overview of Exotic Newcastle Disease

H. L. Shivaprasad
R. Crespo

Exotic Newcastle disease is a highly contagious acute viral disease of most (if not all) species of birds. Often called "Exotic ND" or "END" in the USA because virulent strains are not endemic in USA poultry.

RNA Tumor Viruses

G. Zavala

Avian tumor viruses include Marek’s disease virus (MDV), reticuloendotheliosis virus (REV) and the avian leukosis sarcoma group of retroviruses (ALSV). MDV is a herpesvirus, and REV and ALSV are retroviruses unrelated to each other. All avian retroviruses of economic significance are classified within the family Retroviridae, subfamily Orthoretrovirinae.


K. Roza-Sutherland

Serology is an accurate and inexpensive indicator of a flock having contact with a specific pathogen of interest or of the presence of maternal antibodies to a specific pathogen in young chicks.

Systemic Viral Diseases of Pet Birds

S. D. Fitzgerald
W. M. Reed

The purpose of this slide study set is to review several of the important systemic viral diseases which are unique to pet birds. Three important systemic viruses which are unique to pet birds will be described: herpesvirus (Pacheco's disease), circovirus (psittacine beak and feather disease), and polyomavirus (budgerigar fledgling disease).

Systematic Diseases of Waterfowl

T. Stoute
P. R. Woolcock

The waterfowl disease slide study set gives an overview of the most common diseases affecting waterfowl. The term waterfowl encompass members of the family Anatidae and includes ducks, geese and swans.

Viral Arthritis

H. S. Sellers

Viral arthritis is an infectious disease of chickens and turkeys, affecting primarily the synovial membrane and tendon sheaths, caused by a reovirus.