POULTRY BOARD REVIEW

Infectious Bursal Dz

·         AKA Gumboro dz, Avian nephrosis

·         Caused by IBD virus; Birnaviridae family

·         Highly contagious viral infection

·         Special prediclection for bursa of Fabricuisu so causes immunosuppressive effect from bursal damage

·         Persistent in environment

·         Speedy onset w/ wet litter, sudden deaths over a short period

·         Signs:

a.     Cloacal bursa appears to be the primary target organ

b.     Bursa of febricius is inflamed and enlarged

c.      Renal changes probably due to dehydration

·         Virus isolation, serology ELISA

·         No specific tx

·         Eradication of more virulent stranins from infected sites is desirable b/c they can be increase in virulence w/ time

Spontaneous Cardiomyopathy in Turkeys; aka ‘Round heart dz’

·         Normal shape of heart is triangular

·         Unknown etiology

·         Causes mortality in turkeys between 1 and 4 wks old

·         Signs:

a.     Sudden death

b.     Ruffled feathers

c.      Dropping wings

d.     Labored gasping prior to death

·         Post mortem shows greatly enlarged ventricles and signs of congestive heart failure (anlarged liver, congested lungs)

·         DDx includes Furazolidone toxicity (looks identical to SCT)

Infectious bronchitis

·         Infectrious bronchitis virus

·         Chickens and pheasants

·         Signs:

a.     Severe respiratory dz

b.     Drop in egg prduction

c.      Loss of shell color

d.     Nephritis

·         Rising titer in paired serology or virus isoloation

·         Vaccinate

Nutritonal problems – feed mill errors

·         Vit E deficiency – encephalomalacia

·         Rickets – Vit D deficiency

·         Farmer should retain a sample of each batch of food delivered to the farm

Necrotic enteritis

·         Clostridium perfrigens

·         All poultry susceptible

·         2-8 weeks old

·         Necrotic enteritis is lesion

·         Tx is Penicillin; will rapidly stop

Marek’s Dz

·         Herpes virus

·         Floppy Chicken – in broilers

·         Paralysis of one or more legs or wings and or increased mortiality

·         Lymphoid tumors in ovary, lung, heart, liver, kidney, spleen, skin, muscle

·         Enlargement of peripheral nerves, mesentery, brachial and sciatic plexuses

·         Vaccination of day old chicks has controlled the dz

Coccidiosis

·         Eimeria spp

·         E. tenella –chickens             

·         Large, inflamed ceca                                         

·         Wt loss, reduced egg production, poor carcass quality

·         Histopath shows damage to villi & crypt, increased neutrophils and mononuclear cells             

·         Feed young chickens anticoccidial drugs (Clopidol)  during early rearing period

Malabsorption syndrome

·         AKA Runting syndrome, Infectious Stunting Syndrome

·         Transmissible agent – presumed to be a virus – imparis intestinal absorption

·         Mortatlity in 4-10 day old chicks

·         Signs:

a.     Thin

b.     Gizzards contain litter

c.      > 3 weeks old restricted growth and ‘helicopter wings’

·         Pancreatic atrophy and fibrosis

Coronaviral enteritis of Turkeys (Bluecomb dz)

·         Highly infectious dz affecting turkeys of all ages

·         Signs:

a.     inappetence, wt loss

b.     wet droppings

c.      Darkening of head and skin

d.     Drop in egg production and chalky eggshells

·         Infected birds may have increased numbers of secondary bacteria

·         Gross lesions seen in intestinal tract – watery and gaseous, gelatinous mucus

·         Corona effects entire villus

·         Abs (penicillin, tetracycline) in feed or drinking water may reduce mortality

·         Prevention and control is depopulate/repopulate, since feces from carrier birds remain the primary source of infection

·         No licensed vaccine is available

Histomoniasis – Turkey Blackhead

·         Histomonas meleagridis

·         Organism carried by ova of the worm Heterakis gallina which acts as a vector

·         Causes dullness, D+ w/ yellow dropping

·         Cecum is enlarged filled w/ caseous necrotic material

·         Liver – Cream circular lesions on the liver w/ a center that is dark and hemorrhagic

Lymphoid leukosis

·         14-30 wks of age chicks

·         Signs:

a.     Non specific – pale, shriveled comb

b.     Anappetence, emaciation, weakness

c.      Enlarged abdomen

d.     Spotted feathers

e.     Hepatomegally

·         Tumors:

a.     PM – visible tumors in liver

b.     Some tumors may be in spleen, bursa of Fabricius

c.      Tumors are soft, smooth and glistening

d.     Consist of aggregates of large lymphoid cells that are primitive develomental stage (poorly defined cytoplasmic membrane, much basophilic cytoplasm, vesicular nucleus)

e.     Cytoplasm of most tumor cells contain a large amount of RNA, which stains red (indicating cells are immature and rapidly dividing)

f.        Predominant cell is lymphoblast

·         There is no change in circulating blood!!

Lymphoproliferative Disease of Turkeys

·         Retrovirus infection

·         Leukocytosis – usually mature

·         Splenomegaly

Internal parasites

·         Ascaridiasis – Ascaridia galli, hermaphrodita, columba, platycerci;VLM (visceral larval migrans of CNS)

·         Gizzard and Intestinal Worms – Porrocecum; L found under horny lining of gizzard; may cause tumors in serosal surface of intestine (eggs look like ascarids only bigger and thick-walled)

·         Proventricular and Gizzard worms – Microtetrameres, Hatertia, Dispharynx, Spiroptera; Cockroach int host;

·         Eyeworms – Thelazia; nicitating membrane

·         Gizzard worms of ducks and geese – Amidostonum anseris;

·         Capillariasis – Threadworms, Hairworms; Capillaria spp; Earthworm; Bipolar plugged eggs

·         Cecal worms – Heterakis gallinarum carries Histomonas (see above)

·         Proventricular worm – Acuaria; Water flea is intermediate host; very high mortality

·         Trichostrongyles – Trichostrongylus tenuis;cecum

·         Syngamiasis – Gapes; Earthworms, slugs, snails and beetles; in trachea; causes dysnpnea

·         Cyanthostomiasis – Cyanthostoma spp;Earthworm; orbit and nasal cavity

·         Filiariasis – Serratospiculum;biting arthropods; L in blood stream (lung, intestine, SQ, metatarsal, eye); CNS signs

·         Thorny headed worm – Acanthocephalis; mucosa of intestine causing enteritis

·         Tapeworms – Cestoda; fish secondary host; not often pathogenic

·         Flukes – Anemia; signs depend on location in body

Infectious laryngotracheitis

·         Herpes virus – latency and carrier state

·         Found in ‘back yard’ flocks

·         Signs:

a.     Conjunctivitis

b.     Upper tracheal obstruction

c.      Gasping

d.     Back yard flocks have sporadic deaths w/ tracheal plugs

·         Inflamed tracheal epithelium

·         Vaccination of young stock w/ eye drop

External parasites

·         Red mite – Dermanyssus gallina;Anemia and death; lives in buildings

·         Northern Fowl Mite – Ornythonyssus sylviarum;

·         Cnemidocoptes mutans – scaly leg, very common in backyard chickens;

Mycoplasmosis

·         Mycoplasma gallisepticum synovae, - chickens and turkeys

·         M.  meleagridis - turkey

·         M iowae – turkey, infertility

·         Can cause sinusitis, resp dz, conjunctivitis, synovitis and lameness

·         Lesions in infraorbital sinus, respiratory trac, air sacs, lungs, sternal bursa, joints and tendon sheaths, embryos and impaired growth

Hemorrhagic enteritis

·         Adenovirus

·         Related to Marble Spleen Dz of pheasants and Avian Adenovirus Splenomegaly of chickens

·         Acute dz of > 4 wk old turkeys

·         Replicates intranuclearly in cells of reticuloendothelial system (spleen)

·         Transmitted oral – fecal

·         Signs:

a.     rapid onset

b.     Depression

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