Exotics - Avian Dz 2

drraythe's version from 2016-05-06 22:16


Mycoplasma gallisepticum

Question Answer
What dz is czd by M. gallisepticum in chickens & pet birds?Chronic Respiratory Dz
What part of the world does this dz occur in?WORLDWIDE
Economic importance in the U.S.
***What is the other name for M. gallisepticum infxn in turkeys?Infectious Sinusitis
***What are complicated M. gallisepticum infxns called? Who gets this form?Complicated w/ other bacteria (usually E. coli) or viruses produce Air Saculitis
***2 methods of xmission of M. gallisepticum?The most common is thru **contamination as egg passes thru oviduct**
**Airborne xmission of M. gallisepticum (droplets)** or fecal contam. of eggs is also possible
NOTE: Ovarian xmission does NOT occur (unlike non-motile Salmonella & Paratyphoid in turkeys & S. enteritidis in chickens)
At what age do M. gallisepticum outbreaks occur in broilers?Btwn 4-8 wks
CS of M. gallisepticum infxns in broilers?Broilers have ↑ morbidity & ↓ mortality (except in complicated cases)
Downgrading of carcasses
Swollen nasal sinuses
CS of M. gallisepticum infxns in adult chickens?Adult chickens w/ Chronic Respiratory Dz have:
Mild tracheal rales
Nasal discharge
Reduced productivity (Low feed conversion)
What do turkeys w/ Infectious Sinusitis look like?Turkeys w/ M. gallisepticum have inflammation in the infraorbital sinus
Describe 3 gross lesions of complicated M. gallisepticum infxns (Air Saculitis).Air sacs have a thickened membrane & contain caseous pus
Fibrinopurulent Pericarditis
What is the 1⁰ gross lesion of uncomplicated M. gallisepticum?Catarrhal exudate (snot/thick mucus) present throughout respiratory tract
Pinpoint grayish beads of lymphofollicular aggregates seen microscopically in air sac membranes
DDx for M. gallisepticum in chickens?Often confused w/ Infectious Coryza
How do you Dx M. gallisepticum?CS
Lesions (Fibrinous/purulent discharge & perihepititis/carditis)
Serology (HI & ELISA)
3 DDxs for M. gallisepticum in turkeys.Fowl Cholera
Turkey Coryza
Are Vxs for M. gallisepticum available?Vxs available, but not very effective
You can also:
Medicate breeders
Egg dip
Have good management proceedures
***T/F: Egg fumigation is an effective method of preventing M. gallisepticum infxn.FALSE
Egg dipping = more effective than fumigation

Mycoplasma meleagridis

Question Answer
***What species are susceptible to M. meleagridis?Only turkeys get M. meleagridis, NOT chickens or anyone else!
***1⁰ method of xmission of M. meleagridis?**Mainly xmitted vertically (transovarian)**
Fecal contamination of eggs
Aerosol xmission
***At what age do turkeys w/ M. meleagridis show signs of air sacculitis? How does this differ from M. gallisepticum?M. meleagridis = Air Sacculitis in turkeys at **1 day** of age
Complicated M. gallisepticum = Air Sacculitis at 3-5 wks))
In addition to Air Sacculitis, what other lesions are czd by M. meleagridis?Skeletal lesions → twisting of the tarsometatarsus & swelling of the hock
(my only regret that I have.....BONEITIS)
M. meleagridis prevention?Avoid using infected semen
Dip eggs
Medicate breeders
Is there a Vx for M. meleagridis?Nope

Mycoplasma synoviae

Question Answer
What species are susceptible to Mycoplasma synoviae?Turkeys
Guinea fowl
2 different manifestations of M. synoviae infxns? Which is more common?Mycoplasma synoviae usually czs:
Sometimes sub-clinical URT infxns
What lesions are seen when M. synoviae is complicated by Newcastle or Infectious Bronchitis Virus?Air Sacculitis
Compare the xmission of M. synoviae to M. gallisepticum & M. meleagridis.Mycoplasma synoviae 1⁰ xmission = vertical (in oviduct), but can be horizontal (its similar to xmission of M. gallisepticum)
M. meleagridis = mostly egg xmission, some aerosol xmission
M. gallisepticum is readily xsmitted by either method
What is the incubation period for M. synoviae?2-3 wks
(Dz 1st appears at 2 wks in chicks infected by egg xmission & takes 2-3 wks to appear after exposure in adults)
At what age are CS & outbreaks of M. synoviae most common in chickens? In turkeys?4-16 wks in chickens
10-24 wks in turkeys
***What are the CS of M. synoviae? How is it differentiated from Pullorum Dz?M. synoviae (BONEITIS!) CS:
**Swelling of the hock joint & footpads**
Pale comb (anemia)
Retarded growth(anemia)

Pullorum Dz CS:
Swelling in the hock, but footpads will not be involved
There are usually other CS like diarrhea
Describe the changes in synovial fluid as dz progressesNormally synovial fluid is clear & watery, but M. synoviae = more viscous & cloudy. As the dz progresses the exudates becomes creamy/gray & caseous
What are the less common gross lesions of M. synoviae?Liver & spleen may become enlarged, mottled & greenish to dark red
Kidneys are swollen & pale
Caseous exudates may extend over the skull, along the neck & into air sacs
***Key features used to make a presumptive Dx of M. synoviae? What method is used to provide a more conclusive Dx?Swollen footpads & hocks
Pale comb (anemia)

- Serology to confirm Dx
T/F: Viral Arthritis is a DDx for turkeys w/ swollen joints.FALSE
Turkeys do not get Viral Arthritis, only chickens do!!
Is there a Vx for M. synoviae?Yes, Oil Emulsion Bacterin (not very effective)
M. synoviae be prevention?Egg dipping & continuous low dose Chlortetracycline

Escherichia coli Infxns

Question Answer
How do eggs become infected w/ E. coli & what is the outcome? What if E. coli is xmitted thru the resp route?Fecal contamination of eggs is the most important source
Eggs can also become infected directly thru ovary
If egg is infected embryonic chick mortality is common
Respiratory infxn (from contaminated environment) czs colisepticemia or air sac dz
Mortality may continue up to what age (generally)? Lesions?Mortality usually w/in the 1st 3 wks
Lesions = Omphalitis & Peritonitis
In cases where chick mortality does not occur, what evidence of dz can be seen?Retained yolk sac & poor growth may be the only signs
T/F Unlike Salmonellosis, E. coli does not cz liver or spleen involvement in very young chicks.TRUE
E. coli does produce pinpoint necrosis & swelling in the liver, but only in colisepticemia, not egg xmission
Colisepticemia occurs in broilers of what age, when is the peak?Btwn 3- 12 wks
Peak incidence at 6-9 wks
What are the 1⁰ CS & gross lesions of acute colisepticemia?Mortality (over 20%)
Swollen Liver, +/- pinpoint necrotic foci
+/- Pericarditis
Main lesions of Air Sac Dz czd by E. coli?Air Sac Dz = less mortality than colisepticemia
Swollen, dark liver may be covered thick, white, false membrane
Chronic Pericarditis
How is E. coli Dx made? How is pathogenicity determined?Must be isolation & identification w/ pathogenicity determined by inoculation of embryos
E. coli prevention?Difficult to control
Good husbandry, cleaning, disinfxn & fumigating eggs may help

Fowl Cholera

Question Answer
What organism czs Fowl Cholera?Fowl Cholera is czd by Pasteurella multocida
How is Pasteurella multocida xmitted?Horizontally thru feed & water contam. w/ excretions
What avian species are susceptible to Pasteurella multocida? Especially which?Most avian species are susceptible to P. multocida
Especially turkeys
T/F Pasteurella multocida isolates of pigs are pathogenic to fowl.TRUE. Pigs should not be raised near birds
T/F Younger birds are more susceptible to P. multocida than older birds.FALSE. Older birds (over 3 mo) are more susceptible
Birds w/ acute Fowl Cholera may die w/in (26-48hrs) post exposure
CS of Acute Fowl Cholera?Death w/in 26-48 hrs
Often w/o any CS
4 major CS of Subacute Fowl Cholera? Other signs?Subacute Fowl Cholera CS:

Watery oral discharge
Where does Chronic Fowl Cholera usually localize? What are the CS?CS are related to the area of localization
Usually in the:
Leg or wing joints
What gross lesions are seen w/ Chronic Fowl Cholera?Fluid or caseous exudate in affected:
Conjunctival sac
Middle ear
Tendon sheath(s)
Infraorbital sinuses
(wherever it has localized)
**Gross lesions seen w/ Acute & Subacute forms of P. multocida?Lesions are related to vascular disturbances
Sub-epicardial & subserosal hemorrhages = most common
Petechial & ecchymotic hemorrhages may be widespread
Enlarged, congested, friable liver w/ necrotic foci
Ovarian follicles may be flaccid or reuptured
In turkeys - pneumonia usually w/ unilateral consolidation of lungs & fibrinous pleuritis
**Pneumonia is more common in what species? What are the lesions related to Pneumonia?**More common in turkeys**, but can occur in chickens
Unilateral consolidation of lungs w/ Fibrinous Pleuritis
+/- Pericarditis & Perihepatitis
What is the best way to Dx Fowl Cholera? Tentative Dx?Final Dx = Isolation & identification of the organism
Tentative Dx: (Acute/Subacute) Staining of liver impression smear w/ GIEMSA & presence of bipolar organisms
What is the best way to prevent Fowl Cholera?Fowl Cholera can be prevented by good sanitation & management practices
*T/F Fowl Cholera is not a dz of the hatchery.TRUE
Eggs are not directly infected
It occurs primarily in older birds
When should Vxn be done?In endemic areas, vx at 6-8 wks

Yersinia pseudotuberculosis (Not included in his final review)

Question Answer
What spp. are susceptible to Yersinia pseudotuberculosis?Numerous avian spp. are susceptible
Many mammalian spp. are also susceptible
Why is Y. pseudotuberculosis of such significance?Its ZOONOTIC & may affect pet birds
T/F: The CS of Y. pseudotuberculosis are highly variable.TRUE
CS vary widely:
Sudden death w/o signs
Chronic cases of weakness
Respiratory difficulty
Severe hemorrhagic enteritis may be prominent
Lesions will be seen in psittacines w/ Y. pseudotuberculosis?Granulomatous lesions in the liver

Campylobacter Infxns

Question Answer
What is the predominant spp. of Campylobacter in poultry?C. jejuni is the predominant spp. in poultry
**Can humans get Campy?YES! ZOONOTIC
How is Campy xmitted?Probably by fecal contam. from the environment
Egg xmission in the hen or in hatchery is strongly suspected
What gross lesions & CS of broilers?Broilers do not show gross lesions or CS
**What does Campy cz to humans?Gastroenteritis in man
Major source of food poisoning
What dz is Campy associated w/ in pullets?Hepatitis
CS of Campylobacter in layers?Tends to run a chronic course in layers
Weight loss, anemia & diarrhea
Low mortality
What gross lesions are seen in layers?Layers = Hepatosplenomegaly w/ small irregular necrotic foci & cirrhosis of the liver
Is there a Vx for Campy?No


Question Answer
What bacteria cz Spirochetosis?Borrelia anserina
T/F: Birds are susceptible to Borrelia burgdorferi.TRUE
Mallards & Bobwhite quail along w/ many mammals, inclding humans
In what spp. & in what parts of the US is Spirochetosis most common?Reported most often in turkeys, chickens & pheasants in California, New Mexico, Texas & Arizona
How is Borrelia anserina usually xmitted? What other methods are there?Soft tick Argas persicus is the 1⁰ vector
Also ingestion of infected bird blood/feces/tissue & contaminated needles
CS of Spirochetosis?3-8 days of incubation, then Non-specific CS:
Ruffled feathers
Green diarrhea
Sometimes paralysis
What gross lesions of Spirochetosis?Splenomegaly w/ ecchymotic hemorrhages
Hepatomegaly w/ small necrotic areas
Kidneys may show nephritic changes
How is Spirochetosis Dxd?Stain blood smears w/ Giemsa to look for spirochetes
T/F: Borrelia anserine is Vxd for in the US.FALSE. Effective Vxs are available, but not in the US

Avian Intestinal Spirochetosis (AIS)

Question Answer
T/F: Avian spp. can xmit Brachyspira hyodysenteriae to pigs.FALSE
The strain of B. hyodysenteriae that affects RHEAS/Chickens is different than pig strain
***Naturally occurring dz w/ intestinal spirochetes affects what spp.?Rheas
Rank these spp. in order of severity of dz they produce: B. pilosicoli, B. hyodysenteriae, B. intermedius.B. hyodysenteriae > B. intermedius (moderate dz) > B. pilosicoli (apathogenic)
What lesions are seen in Rheas w/ Intestinal Spirochetosis?Necrotizing Typhlitis:
Ceca = Dilated, ulcerated & necrotic
What are the CS of B. hyodysenteriae?Watery diarrhea, or may die suddenly w/o CS
Dz is more common in what age rheas?Rheas >6 mo
4 DDx that also cz Necrotizing Typhlitis (inflamed ceca) in Rheas?Clostridia
Histomonas meleagridis
How do you Tx AIS?Dimetridozole
Xmission of AIS?Fecal-Oral

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