1. Avian pox

Etiology: Genus Avipoxvirus. Some viruses are adapted to a single avian species, others infect more than one species.

Species: Virtually all orders of birds including galliforms - turkeys, quail, grouse; passeriforms - songbirds; anseriforms - ducks and geese; falconiforms and strigiforms - raptors (J Wildlife Diseases 33:323-327, 1997); columbiforms - pigeons and doves.

Lesions: Multifocal to coalescing, proliferative and necrotizing dermatitis (epithelial hyperplasia with ballooning degeneration and large intracytoplasmic inclusions) in dry form; oral cavity and esophagus affected in wet form. Restricted to non-feathered portions of body (face and legs).

2. Duck plague, duck viral enteritis (DVE)

Etiology: Herpesvirus

Affected species: Ducks and geese. Seen in domestic and semi-wild ducks, occasionally in wild ducks.

Lesions: Acute, hemorrhagic, multifocal, fibrinonecrotic, ulcerative enteritis sometimes in characteristic annular bands at gut-associated lymphoid tissue. Multifocal necrotizing hepatitis, stomatitis, esophagitis, splenitis.

3. Herpesvirus of raptors

Etiology: Probably pigeon herpesvirus

Affected species: Pigeons. Raptors including hawks and owls may become infected via ingestion of prey species.

Lesions: Multifocal necrotizing hepatitis and splenitis as well as pharyngitis, esophagitis, and tracheitis.

4. Marble spleen disease, pheasant adenovirus

Etiology: Avian adenovirus (group II)

Affected species: Pen-raised pheasants (Avian Diseases 40:306-311, 1996; Avian Diseases 39:68-73, 1995). Also may occur in other farmed gamebirds, turkeys, chickens.

Lesions: Splenomegaly with multifocal necrotizing splenitis. Pulmonary hemorrhage also may occur.

Note: Quail bronchitis is caused by avian adenovirus (type 1); bobwhite quail (mostly pen-raised birds) have catarrhal conjunctivitis, tracheitis, bronchitis, and airsacculitis.

1. Avian cholera, fowl cholera, avian pasteurellosis

Etiology: Pasteurella multocida

Affected wild species: waterfowl, gulls, crows, recent reports in raptors (Avian Diseases 41:203-213, 1997; Avian Diseases 40:908-918, 1996)

Lesions are those of peracute septicemia: Multifocal hepatic necrosis is the classic lesion. Multifocal ecchymoses or petechiae in epicardium and catarrhal enteritis may occur. In raptors - septicemic lesions plus esophageal abscesses in Buteo hawks

2. New duck disease, duck septicemia

Etiology: Riemerella anatipestifer

Affected species: Very rare in wild waterfowl (more frequently reported in captive waterfowl and domestic birds)

Lesions: Fibrinous or exudative polyserositis - pericarditis, perihepatitis, airsacculitis. Meningitis and multiple thromboses may be observed microscopically.

3. Avian tuberculosis, mycobacteriosis

Etiology: Mycobacterium avium

Affected species: All avian species are susceptible. More frequently reported among wild species closely associated with domestic stock and in scavengers.

Lesions: Multifocal granulomas with central caseous necrosis (tubercles) - liver most commonly affected in waterfowl, also seen in spleen, lung, and intestines. Infrequent lesions in bones and marrow. Chronically affected birds are emaciated.

4. Avian salmonellosis

Etiology: Salmonella spp.

Affected species: Most avian orders from waterfowl to songbirds. Often seen as songbird epornitics at bird feeders in winter.

Lesions: Focally extensive or diffuse fibrinonecrotic esophagitis, ingluvitis. Multifocal caseonecrotic to granulomatous lesions may occur in skeletal muscle, heart, other tissues.

5. Mycoplasmal conjunctivitis, house finch conjunctivitis

Etiology: Mycoplasma gallisepticum (MG)

Affected species: Almost exclusively in house finches, occasionally in American goldfinches. First recognized in DC area in early 1994, disease now extends over entire eastern U.S. and Canada.

Lesions: Unilateral or bilateral exudative conjunctivitis often with mucopurulent nasal discharge, rarely with infraorbital sinusitis. Microscopic lesion is lymphoplasmacytic inflammation with epithelial hyperplasia in conjunctivae, cornea, nasal turbinates, and trachea (Avian Diseases 40:335-341, 1996; Vet Path 32:592, 1995, Abstract 186; J Wildlife Diseases 34:289-296, 1998).

Mycoplasmal conjunctivitis notes: Keratoconjunctivitis in chickens associated with MG (Vet Path 32:11-18, 1995). Conjunctivitis associated with Mycoplasma sturni in a European starling (J Wildlife Diseases 33:336-339, 1997) and in blue jays and northern mockingbirds (J Wildlife Diseases 34:403-406, 1998).

6. Infectious sinusitis, infraorbital sinusitis

Etiology: Mycoplasma gallisepticum

Affected species: Three reports in wild turkeys, all closely associated with domestic poultry.

Lesions: Serous to fibrinous infraorbital sinusitis.

7. Quail disease, ulcerative enteritis

Etiology: Clostridium colinum

Affected species: Pen-raised bobwhite quail, other captive gamebirds and domestic poultry

Lesions: Initially hemorrhagic enteritis in duodenum followed in survivors by multifocal to coalescing necrotizing, ulcerative enterocolitis and typhlitis. Acute, multifocal, necrotizing hepatitis may occur.

8. Chlamydiosis, psittacosis, ornithosis, parrot fever

Etiology: Chlamydia psittaci

Affected species: Waterfowl, herons, gulls, and pigeons are most commonly affected wild birds.

Lesions: Splenomegaly most common; less common - fibrinous polyserositis, hepatomegaly and focal hepatic necrosis, pulmonary edema, conjunctivitis, infraorbital sinusitis.

9. Coligranuloma

Etiology: Escherichia coli

Affected species: Infrequent in wild turkeys

Lesions: Multifocal to coalescing granulomatous hepatitis, enteritis, typhlitis

1. Histomoniasis, blackhead

Etiology: Histomonas meleagridis - protozoa within the ova of cecal worms (Heterakis gallinarum) are ingested by birds

Affected species: Wild turkey, grouse, quail, chukar partridge. Subclinical carriers include pheasant and chicken.

Lesions: Multifocal, necrotizing hepatitis (often with sunken, dark central area surrounded by a pale raised rim resulting in characteristic target or bullseye appearance); fibrinonecrotic, ulcerative typhlitis often with cecal cores or plugs

2. Trichomoniasis, crop canker

Etiology: Trichomonas gallinae

Affected species: Doves and pigeons, raptors ("frounce"), other wild birds

Lesions: Focally extensive caseous necrosis of oral cavity, esophagus, crop. May see multifocal granulomatous pneumonia, hepatitis, myocarditis. Emaciation in chronic cases.

3. Sarcocystosis, sarcosporidiosis, rice breast

Etiology: Sarcocystis spp. (S. rileyi most common in N.A. waterfowl)

Affected species: Wild ducks most frequently, also geese, swans, and songbirds as well as some mammals and reptiles.

Lesions: Multiple, cylindrical, off-white, protozoal cysts in pectoral and other skeletal muscles sometimes with mineralization.

4. Toxoplasmosis

Etiology: Toxoplasma gondii

Affected species: Recent reports in wild turkeys (J Wildlife Diseases 31:255-258, 1995) and barred owls (Avian Diseases 41:738-740, 1997), additional avian species

Lesions: Multifocal necrosis of liver, spleen, kidney, lung, etc. Microscopically the inflammatory infiltrates are predominated by macrophages with plasma cells, lymphocytes, and neutrophils.

1. Scaly leg mites

Etiology: Knemidokoptes mutants, K. jamaicensis

Affected species: Upland game birds such as wild turkeys and quail, passerine birds such as robins (J Wildlife Diseases 35:1-7, 1999) and grackles

Lesions: Hyperkeratotic dermatitis of legs with scaling and crusting

1. Crop worms, crop capillariasis

Etiology: Capillaria contorta, C. annulata

Affected species: Quail, turkeys, grouse, pheasants, partridges

Lesions: Severe infestations cause esophageal and ingluvial hypertrophy and hyperplasia with catarrhal to fibrinous inflammation.

2. Proventriculus worms

Etiology/affected species: Eustrongylides in fish-eating birds such as herons, egrets, mergansers; Tetrameres spp. in ducks, quail

Lesions: Eustrongylides penetrates proventricular wall and incites marked fibrosis around nematode on serosal surface. Worms are bright red. Tetrameres spp. often subclinical, worms also are bright red.

3. Gizzard worms, stomach worms, ventricular nematodiasis

Etiology: Amidostomum spp and Epomidostomum spp.

Affected species: Geese, ducks, swans, coots

Lesions: Focal, hemorrhagic, ulcerative ventriculitis

4. Tracheal worms, gapeworms

Etiology: Syngamus trachea

Affected species: Wild turkey, grouse, quail, other wild and domestic galliformes, many passerines

Lesions: Catarrhal tracheitis to complete tracheal obstruction by nematodes

Etiology: Collyriclum faba

Affected species: Passerine birds such as grackles

Lesions: Pericloacal cysts with two flukes/cyst (trematodiasis), severe infestation may obstruct cloaca

1. Aspergillosis

Etiology: Aspergillus fumigatus most common

Affected species: Probably all avian species are susceptible; frequently seen in waterfowl and loons likely immunocompromised due to stress of migration, crowding, climate, etc.

Lesions: Multifocal granulomatous pneumonia; multifocal to coalescing granulomatous airsacculitis and serositis with intralesional fungi

1. Lead poisoning

Source: Spent shot in wetlands most common, fishing sinkers less common

Affected species: Ducks (J Wildlife Diseases 34:673-687, 1998), geese (Vet Path 30:522-528, 1993), swans, loons, and shorebirds; secondary poisoning of raptors (eagles and hawks) feeding on poisoned waterfowl or gunshot animals

Lesions: Impactions of esophagus, proventriculus, or gizzard due to vagal paralysis; emaciation in chronic cases; acute renal tubular necrosis; biliary stasis; gall bladder distention; bile staining of gizzard mucosa and liver; hydropericardium.

1. Visceral gout, visceral urate deposition

Etiology: Secondary to numerous processes

Affected species: All avian species

Lesions: Chalky, urate deposits in kidneys and on surfaces of heart, liver, mesentery, air sacs, muscles, etc.

2. Steatitis in herons

Etiology: Unknown, possible nutritional deficiency

Affected species: Great blue heron

Lesions: Severe multifocal steatitis, especially of abdominal fat

3. Amyloidosis

Etiology: Secondary to numerous disease processes

Affected species: All avian species

Lesions: Enlargement /pallor of tissues including spleen, liver, kidney due to amyloid deposition; splenic thrombosis

1. Canine distemper

Etiology: Canine morbillivirus.

Affected species: Raccoon (J Vet Diagn Invest 10:194-196, 1998); canids including gray fox, coyote; mustelids including black-footed ferret, skunk; large cats in Africa and in zoo collections (J Vet Diagn Invest 6:277-288, 1994).

Lesions: Interstitial pneumonia, mucopurulent conjunctivitis and rhinitis, diarrhea, hyperkeratosis of foot pads. Microscopic lesions as in domestic animals including pneumonia, encephalitis, lymphoid depletion, intranuclear and intracytoplasmic inclusion bodies. May be secondary toxoplasmosis or bacterial infections.

2. Parvoviral disease

Etiology/affected species: Canine parvovirus - coyotes, wolves (J Wildlife Diseases 33:321-322, 1997); feline panleukopenia parvovirus - bobcat; mink enteritis virus - farmed mink; raccoon parvovirus - raccoons (usually in captivity)

Lesions: Segmental, hemorrhagic, necrotizing enteritis with crypt depletion; lymphoid depletion (lymphadenopathy, thymic atrophy, etc.). Secondary infections may occur in these immunocompromised animals.

Aleutian disease of farmed mink: Characterized in adults by plasmacytosis, hypergammaglobulinemia, immune complex-mediated glomerulonephritis and arteritis. Lesions of immune complex disease - hepatosplenomegaly and lymphadenopathy due to lymphoplasmacytic/histiocytic infiltrates, glomerulonephritis. In young mink - acute interstitial pneumonia (Vet Path 31:216-218, 1994)

3. Woodchuck hepatitis

Etiology: Hepadnavirus

Affected species: Woodchucks

Lesions: Chronic-active, diffuse hepatitis with possible progression to hepatoma/hepatic carcinoma

4. Rabies

Etiology: Rhabdovirus

Affected species: All species susceptible. Primary terrestrial species varies with region - skunk, raccoon (J Vet Diagn Invest 10:194-196, 1998), gray fox, red fox, coyote. Bats - human cases in U.S. most frequently associated with silver-haired bat rabies strain.

Lesions: No gross lesions. Microscopic encephalomyelitis with neuronal cytoplasmic inclusions, especially hippocampus in carnivores, Purkinje cells in herbivores

5. Shope fibroma

Etiology: Leporipoxvirus

Affected species: Cottontail rabbit

Lesions: Single to multifocal, cutaneous, fibromatous masses

6. Squirrel fibroma

Etiology: Leporipoxvirus

Affected species: Gray squirrels, woodchucks

Lesions: Multifocal and sometimes coalescing, cutaneous, fibromatous masses

7. Deer fibroma, infectious cutaneous fibroma

Etiology: Papovavirus

Affected species: White-tailed deer; other wild ruminants probably are infected by species-specific papovaviruses

Lesions: Multiple proliferative cutaneous masses, sessile to pendulous, most often on head or hindquarters. Superficial necrosis with secondary bacterial infection may occur. Microscopic lesion consists of cutaneous fibroproliferative mass with epithelial hyperplasia.

8. Hemorrhagic disease of deer

Etiology: Bluetongue and Epizootic Hemorrhagic Disease orbiviruses (several serotypes)

Affected species: Primarily white-tailed deer with other deer and wild ruminant species also affected (J Wildlife Diseases 31:30-36, 1995)

Lesions: Pathogenesis characterized by viral infection and damage of vascular endothelium with loss of vascular integrity.

Peracute form - subcutaneous edema of head and neck, pulmonary edema, hydropericardium, hydrothorax, hydroperitoneum;

Acute form - peracute lesions plus multifocal hemorrhages of heart (pulmonary artery) and gastrointestinal tract, erosive and ulcerative glossitis, stomatitis, rumenitis, and omasitis;

Chronic form - ulcerative glossitis and rumenitis with rumen papillae atrophy and mucosal scarring, interruptions in hoof wall.

NOTE: A newly recognized adenoviral disease with similar lesions was reported in deer in 1996 in California. Intranuclear inclusion bodies were present in addition to the above-described lesions (J Wildlife Diseases 33:801-811, 1997; Vet Path 33:125-132, 1996).

9. Malignant catarrhal fever

Etiology: Gammaherpesviruses - "Ovine herpesvirus-2" in sheep-associated form (most common in captive wild ruminants); Alcelaphine herpesvirus-1 in wildebeest-associated form seen in zoo collections of ruminants

Affected species: Captive white-tailed deer and bison - very rarely reported in free-ranging wild ruminants

Lesions: Multifocal fibrinonecrotic, erosive to ulcerative inflammation of epithelial surfaces - conjunctivitis, nasal dermatitis, rhinitis, stomatitis, esophagitis, rumenitis, abomasitis, enteritis; corneal edema/opacity; multifocal whitish, nodular masses consisting of extensive perivascular proliferations of lymphoblastic/lymphocytic cells. Fibrinoid vascular necrosis also is observed microscopically. Chronic form of disease in cattle characterized by obliterative arteriopathy (J Vet Diag Invest 7:108-121, 1995) also observed in bison (J Vet Diagn Invest 10:255-262, 1998).

10. Additional viral diseases of domestic animals that may occur in wild animals, captive animals, or under experimental conditions

Lesions are similar or identical to those of domestic animals

Infectious canine hepatitis: Adenovirus - affected species include canids (coyote, wolf, fox), skunks

Bovine viral diarrhea (pestivirus), infectious bovine rhinotracheitis (herpesvirus), vesicular diseases - foot and mouth disease (picornavirus), rinderpest and peste des petits ruminants (morbillivirus). Natural and experimental disease in white-tailed deer and other ruminants

11. Additional viral infections without gross lesions in wild animals

Hantavirus (Sin Nombre and Blackwater canal viruses) - inapparent infections in wild rodent reservoirs including the deer mouse (Peromyscus maniculatus) and cotton rat (Sigmodon hispidus)