Poultry Top Topics - Top 20 Poultry Diseases Part 2

Question 1

what is the classic case presentation of gumboro (infectious bursal disease) in young chicks under 3 weeks old? what about older chicks?

Answer 1

less than 3 weeks - usually subclinical but causes chronic immune suppression

older - watery diarrhea, dehydration, & prostration

Question 2

what is the etiology of gumboro?

Answer 2

birnavirus

Question 3

how is gumboro diagnosed?

Answer 3

reverse transcriptase PCR on bursal tissue is most common, virus isolation, & serological tests

Question 4

what is seen on necropsy of birds with infectious bursal disease?

Answer 4

swollen cloacal bursa of fabricius, usually yellowish but can be hemorrhagic (subclinical & recovered chickens have cloacal bursa atrophy)

Question 5

how is gumboro treated?

Answer 5

no treatment - depopulate & disinfect

Question 6

how is gumboro in chickens prevented?

Answer 6

vaccinate flocks to provide maternal antibodies & antibiotics provided to prevent secondary infections

Question 7

what is the bursa of fabricius?

Answer 7

lymphoid structure in birds that is an out-pouching of the cloaca

Question 8

T/F: gumboro, caused by birnavirus, has a worldwide distribution, is highly contagious, & is a reportable disease

Answer 8

true

Question 9

T/F: pullorum disease has a high mortality rate

Answer 9

true

Question 10

what is the classic case presentation of pullorum disease?

Answer 10

acute onset depression/death usually in chicks

death in adults with no preceding clinical signs

white diarrhea/pasting of the vent - may disseminate to other organs & cause grayish nodules

Question 11

what other birds can be affected by pullorum disease?

Answer 11

turkey poults

Question 12

what is the etiology of pullorum disease?

Answer 12

salmonella pullorum

Question 13

what necropsy lesions may be seen on a bird with pullorum disease?

Answer 13

gray nodules on the liver, spleen, lungs, intestines, gizzard, & heart

cecal cores - caseous material in the cecum

Question 14

how is pullorum disease diagnosed?

Answer 14

serology in adult birds

isolate & serotype from feces/fecal swabs or necropsy specimens

Question 15

what is the treatment for pullorum disease?

Answer 15

none - cull & disinfect

could use sulfas/fluoroquinolones in valuable birds

Question 16

how is pullorum disease prevented?

Answer 16

periodic serologic testing

Question 17

how is pullorum disease transmitted?

Answer 17

vertical or horizontal transmission - carried by some wild birds

Question 18

T/F: pullorum disease is rare in commercial poultry operations

Answer 18

true

Question 19

what animals are affected by infectious coryza?

Answer 19

only chickens - usually pullets & layers

Question 20

what is the classic case presentation of infectious coryza?

Answer 20

acute onset severe rhinitis/sinusitis, swollen heads, congested combs, conjunctivitis, nasal mucopurulent discharge, sneezing, open mouth breathing, rales, & chicken losses/drop in egg production

Question 21

what is the etiology of infectious coryza?

Answer 21

gram-negative non-motile catalase-negative avibacterium paragallinarum

Question 22

how is infectious coryza diagnosed?

Answer 22

culture from swabs of nasal, choanal, or sinus exudate - requires a nurse colony of staph aureus

PCR is superior to culture & can differentiate serotypes

Question 23

what is the benefit of having a negative coagulase test on a bird you think has infectious coryza?

Answer 23

negative catalase test distinguishes it from non-pathogenic organisms which are catalase positive

Question 24

how is infectious coryza treated?

Answer 24

susceptible to most abx - sulfas, quinolones, tetracyclines, & macrolides

vaccines for high risk areas

all-in & all-out implemented in commercial operations

Question 25

what may be seen on necropsy of a bird with infectious coryza?

Answer 25

tenacious, yellow-gray exudate in the infraorbital sinuses

Question 26

where are most cases of infectious coryza seen?

Answer 26

california, southeast US, & sometimes northeast US

Question 27

what is the prognosis for backyard chickens with infectious coryza?

Answer 27

good for them - difficult to fully eradicate from large commercial operations

Question 28

what animals serve as reservoirs for infectious coryza?

Answer 28

chronically infected chickens - horizontal transmission

Question 29

T/F: infectious coryza is a highly contagious disease

Answer 29

true

Question 30

what is the classic case presentation of fowl cholera?

Answer 30

fatal septicemia, peracute death, depressed/ruffled birds, anorexia, oral mucoid discharge, diarrhea, respiratory signs pneumonia in turkeys

Question 31

what clinical signs are seen in chronic cases of fowl cholera?

Answer 31

localized infections throughout the body

Question 32

what is the etiology of fowl cholera?

Answer 32

pasteurella multocida

Question 33

what is seen on necropsy of acute cases of fowl cholera? what about chronic cases?

Answer 33

acute - congestion of liver, spleen, & duodenum, & widespread hemorrhage chronic - caseous arthritis, widespread suppurative lesions, & necrotic lung lesions

Question 34

how is fowl cholera diagnosed?

Answer 34

bacterial isolation from clinical specimens or necropsy samples (harder to isolate from suppurative lesions from acute lesions) - blood agar & test for abx sensitivity/resistance blood smears or impression smears for bacteremia

Question 35

how is fowl cholera treated?

Answer 35

abx - TMS, amoxicillin, quinolones, & tetracyclines supportive care

Question 36

how is fowl cholera prevented?

Answer 36

commonly prevented with vaccines - bacterins & live

Question 37

what birds are especially susceptible to fowl cholera?

Answer 37

waterfowl

Question 38

what is the major reservoir of fowl cholera?

Answer 38

chronically infected birds

Question 39

T/F: fowl cholera is highly contagious

Answer 39

true

Question 40

what is the classic case presentation of coccidiosis?

Answer 40

chicks - diarrhea, sometimes bloody, dehydration, & may be fatal depressed/ruffled, anorexia, soiled vents mild cases can slow weight gain & decrease egg production

Question 41

what is the etiology of coccidiosis?

Answer 41

various eimeria species - vary in host, pathogenicity, & target different segments of the intestinal tract

Question 42

how is coccidiosis diagnosed?

Answer 42

fecal float

Question 43

how is coccidiosis diagnosed in necropsy?

Answer 43

scrapings of intestinal mucosa - may also see distributive lesions of the gi tract

Question 44

what are the 4 eimeria species & the different parts of the intestines they target?

Answer 44

1. e. tenella - cecum, highly pathogenic 2. e. nectrix - mid-small intestines, highly pathogenic 3. e. acervulina - upper small intestine, moderately pathogenic 4. e. mitis - lower small intestine, little pathology

Question 45

what is the prognosis of coccidiosis in chickens?

Answer 45

prognosis depends on the species of eimeria involved