Top 10 Poultry Part 2

What is the primary cause of infectious bursal disease in chickens?

Birnavirus.

What are the clinical signs of pullorum disease in chicks?

High mortality, acute onset depression, death, white diarrhea.

What is the key diagnostic test for infectious coryza?

Culture from swabs of nasal, choanal, or sinus exudate.

How is fowl cholera diagnosed?

Bacterial isolation from clinical specimens or necropsy samples.

What is the treatment for coccidiosis in chickens?

Toltrazuril, sulfonamides, amprolium.

What are the preventative measures for infectious bursal disease?

Vaccinate flocks to provide maternal immunity.

Which age group of chicks is typically affected by infectious bursal disease?

Chicks less than 3 weeks old.

What pathogen causes pullorum disease?

Salmonella Pullorum.

What are the common clinical signs of infectious coryza?

Acute rhinitis, swollen heads, nasal mucopurulent discharge.

What should be done in response to a fowl cholera outbreak in poultry?

Administer antibiotics and provide supportive care.

What is the significance of the Bursa of Fabricius in birds?

It is a lymphoid structure important for immune function.

How can coccidiosis be prevented?

Using coccidiostats in food/water and vaccines.

What condition is characterized by grayish nodules on internal organs in poultry?

Pullorum disease.

What is a classic symptom of coccidiosis in chickens?

Diarrhea (sometimes bloody) and dehydration.

What differentiates chronic fowl cholera from acute cases upon necropsy?

Localized infections in survivors vs. congestion and hemorrhage in acute cases.

What is a key feature of Avibacterium paragallinarum in infectious coryza?

It is a gram-negative, non-motile, catalase-negative bacterium.

Gumboro disease CS?

1. Chicks <3wks old: usually subclinical but causes chronic immune suppression

2. Older chicks: watery diarrhea, dehydration, prostration

Infectious bursal disease cause?

Birnavirus

Gumboro necropsy?

Swollen cloacal bursa of Fabricus, usually yellowish but can be hemorrhagic (subclinical and recovered chickens have cloacal bursa atrophy)

Infectious bursal disease Dx

1. RT PCR on bursal tissue most common

2. Virus isolation

3. Serologic tests are available

Gumboro disease Tx and prevention?

No Tx, depopulate and disinfect. Vaccinate flocks to provide maternal immunity. ABx for sec. inf.

What is bursa of Fabricius?

Its a lymphoid structure in birds that is an outpouching of the cloaca

Pullorum disease CS?

High mortality

1. Acute onset depression and death, usually in chicks

2. Usually death in adults with no preceding CS

3. White diarrhea/pasting of vent

4. Can also affect turkey poults

5. May disseminate to liver or other organs, cause greyish nodules

Pullorum disease cause?

Salmonella pullorum

Necropsy findings pullorum disease?

Usually no lesions, but may see gray nodules on liver, spleen, lungs, intestine, gizzard and heart. May also see cecal cores (caseous material in the cecum)

Pullorum disease Dx?

1. Serology in adults

2. Isolate and serotype from feces/fecal swabs or necropsy specimens

Pullorum disease Tx?

None, cull and disinfect. Prevent with periodic serologic testing. Could use ABx (sulfas, quinolones) in valuable birds.

Infectious coryza CS?

Only chickens, usually pullets and layers.

1. Acute onset of severe rhinitis and sinusitis

2. Swollen heads, congested combs, conjunctivitis

3. Nasal mucopurulent discharge, sneezing, open mouth breathing, rales

4. Chicken losses and drop in egg production

Infectious coryza etiology?

Gram -, non motile, catalase negative Avibacterium paragallinarum (formerly Haemophilus paragallinarum)

Infectious coryza Dx?

1. Culture of nasal, choanal swabs or sinus exudates

   • Requires nurse colony of Staphylococcus aureus

   • Negative catalase test distinguishes from nonpathogenic organisms (which are catalase +)

2. Necropsy

3. PCR

Acute coryza necropsy?

Tenacious yellow grey exudate in the infraorbital sinuses

Inf. coryza tx?

Susceptible to most ABx - sulfas, quinolones, tetracyclines, macrolides.

Vaccines - bacterin for high risk areas. All in/all out in commercial operations

Fowl cholera CS?

1. Fatal septicemia

2. Peracute death

3. Depressed and ruffled birds, anorexia

4. Oral mucoid discharge, diarrhea, resp. signs

5. Pneumonia in turkeys

6. Chronic - localized inf. throughout body

Fowl cholera etiology?

P. multocida

Necropsy fowl cholera?

Acute - congestion of liver, spleen, duodenum, hemorrhages

Chronic - caseous arthritis, widespread suppurative lesions, necrotic lung lesions

Dx fowl cholera?

• Bacterial isolation from clinical spec. or necropsy samples (harder to isolate from suppurative lesions than acute lesions)

  • Blood agar

  • Test for ABx sensitivity and resistance

• Blood smears or impression smears for bacteremia

Fowl cholera Tx?

ABx - TMS, amoxicillin, quinolones, tetracyclines

Supportive care

Prevented with vaccines (bacterins and live)

Fowl cholera reservoirs?

Chronically infected birds

Coccidiosis CS?

• In chicks - diarrhea (sometimes bloody) and dehydration ± fatal

• In older - depressed, ruffled, anorectic with soiled vents

• Milder coccidiosis can slow weight gain, decrease egg production

Coccidiosis etiology?

Various Eimeria species are found in chickens that vary in host, pathogenicity and target different segments of the IT:

1. E. tenella - cecum, highly pathogenic

2. E. nectrix - mid small intestine, highly pathogenic

3. E. acervulina - upper small intestine, moderately pathogenic

4. E. mitis - lower small intestine, little pathology

Coccidiosis Dx?

1. Fecal float

2. Necropsy - do scrapings of intestinal mucosa, also see lesions in GI tract

Coccidiosis Tx?

1. Tonazuril, sulfonamides, amprolium

2. Vit. A and K in feed or water

3. Prevent with coccidiostats in food/water and vaccines