Exotics - Avian Dz 4

sihirlifil's version from 2017-04-06 13:16

Viral Dzs

Newcastle Dz

Question Answer
What is Newcastle's AKA? Zoonotic &/or reportable?Avian Pneumoencephalitis
What is the AKA for velogenic NCD? What are the 2 forms of velogenic dz?AKA: Exotic NCD
What virus czs Newcastle Dz?Newcastle Dz Virus (NDV) = Paramyxovirus Type 1 (PMV-1)
What spp. are susceptible to Newcastle Dz?All birds to varying degrees
How does xmission of Newcastle Dz occur?NDV is present in expired air, respiratory discharges, feces & eggs laid during clinical dz
Infxn can occur by ingestion or inhalation of contaminants
T/F: Vxd chickens may be a potential reservoir for shedding virus.TRUE
The live virus (lentogenic strain) Vx can be shed in the environment & may infect unvxd birds (but it rarely czs sig. dz)
What are the 2 1⁰ factors that determine the pathogenesis of Newcastle Dz?The virulence & tropism of the particular strain determine the pathogenesis of the dz
Immune status also plays a major role
Put these in order of most to least virulent: mesogenic, lentogenic, velogenic.Velogenic > Mesogenic > Lentogenic
Virulent       Medium         Low
What are the CS of Neurotropic Velogenic Newcastle Dz?Neurotropic NDV czs sudden death (50-90% mortality) w/:
Respiratory signs (gasping, coughing, sneezing, rales)
Neurological signs (drooping wings, dragging legs, torticollis, circling, depression)
What are the signs of Viscerotropic Newcastle Dz?Viscerotropic Velogenic NCVczs:
>90% mortality (peracute systemic dz)
Watery greenish diarrhea (Characteristic hemorrhagic lesions in intestine)
Respiratory signs
Swelling of the tissue of the head & neck
+/- Nero signs (if poultry survive beyond the acute phase)
What lesions are seen in the gastrointestinal tract, CNS, respiratory tract & skin & eyes?NDV czs hemorrhagic lesions especially in the:
Small intestine
- No gross lesions in the CNS
- Trachea may be inflamed & hemorrhagic & air sacs may be cloudy
- Face may be edematous w/ hemorrhage in conjunctivae
Describe the eggs & reproductive lesions of birds w/ Newcastle Dz.Degeneration & atresia of follicles may occur
Oviducts can be shrunken & edematous
Follicles are NOT pedunculated as they are in Pullorum Dz
(Other sources say NCD czs an alteration in the surface, shape & color of eggs)
How is preliminary Dx of Newcastle made?Newcastle is characterized by a very sudden onset & rapid spread of respiratory & nervous signs (or diarrhea depending on strain)
***What preventative measures should be taken to avoid Newcastle Dz?Live Vx (usually lentogenic strain) should be used during outbreaks at nearby farms
IMMEDIATE Quarantine of area w/in 5km
Depopulate affected flock (s)
Long term: Raise vaccinated birds. Effective vaccines are available
Control import of birds & poultry products

Infectious Laryngotracheitis

Question Answer
What spp. is particularly susceptible to Infectious Laryngotracheitis & at what age? What other spp. does the dz occur in?Older chickens
Pheasants & peafowl of any age
***What type of virus czs Infectious Laryngotracheitis?HERPES!
***How is Infectious Laryngotracheitis xmitted? How quickly does it spread?HORIZONTAL
What are the signs of mild pathogenic strains of Infectious Laryngotracheitis?Mild forms cz:
Oculonasal discharge
Swollen infraorbital sinuses (like Coryza)
↓ egg production
***What are the signs of Acute Infectious Laryngotracheitis?Acute form czs:
Coughing w/ bloody expectorant
Head shaking
Bloody beak, head, feathers
Morbidity & Mortality may be ↑
Describe the lesions czd by Infectious Laryngotracheitis.Inflammed tracheal epithelium +/- desquamation
Hemorrhage in the trachea/larynx in severe cases
***How is Dx of Infectious Laryngotracheitis made?Intranuclear inclusion bodies in the tracheal cells (its herpes!)
What are the methods of prevention & control of Infectious Laryngotracheitis?Contaminated premises should be:
Left vacant for 4-6 wks
T/F: All birds should be Vxd against Infectious Laryngotracheitis.FALSE
Vxn should only be done in endemic areas
Vxd birds may shed virus & be a source of infxn for new unvxd birds
Can Infectious Laryngotracheitis be Txed?Tx of Laryngotracheitis is of little value (its herpes... it's w/ you forever)

Infectious Bronchitis

Question Answer
What czs Infectious Bronchitis?Coronavirus
***What spp. are susceptible to Infectious Bronchitis Virus?Only Chickens
(All ages, but more severe in chicks <6 wks)
How is Infectious Bronchitis xmitted? Morbidity is (↓, ↑).Horizontal
Inhalation of virus-containing droplets expelled coughing
Morbidity is very ↑
Under what circumstances does Infectious Bronchitis cz mortality? Which strain czs greater mortality?Generally mortality occurs only in young chicks
Mortality in all ages is higher w/ the 'Australian T' strain
What is the difference btwn CS of Infectious Bronchitis in young chicks compared to older chicks (over 6 wks)?Chicks >6wks have mild resp signs
Chicks <6 wks have severe resp signs inclding:
Tracheal rales
Nasal discharge
Wet eyes
Swollen sinuses
***What are the signs of Infectious Bronchitis in layers? What do the eggs look like?Transient respiratory signs
Reduced egg production (degree depends on if infxn occurs during the early part of the laying period (only a slight drop) or during the latter half (severe drop in egg production))
Eggs will be misshapen, discolored, rough, thin-soft-shelled w/ watery albumin
Describe the gross lesions of Infectious Bronchitis. What happens in complicated cases?Lesions in the URT, inclding:
Serous or catarrhal exudates in the trachea, nasal passages & sinuses
Complicated cases cz lesions of Air Sac Dz
T/F: The reduction in length & weight of the oviduct is only temporary.TRUE
What happens to female chicks that are infected early in life?Permanent dmg to the oviduct may occur in chicks infected in early development
Name 5 other dz that cz respiratory signs similar to Infectious Bronchitis. How are they differentiated?Newcastle Dz (more severe, w/ mortality in all ages; nervous signs in young chicks)
Infectious Laryngotracheitis (does NOT usually affect young birds; hemorrhage in trachea)
Infectious Coryza (severe swelling of the face; foul odor)
Avian Influenza & Mycoplasmosis (Respiratory signs similar to Infectious Bronchitis)

Egg Drop Syndrome

Question Answer
Label the dz w/ the Group of Adenovirus that czs it (Group 1, 2 or 3)
(1) Marble spleen dz (pheasants)
(2) Quail bronchitis
(3) Egg Drop Syndrome
(4) CELO
(5) Inclusion Body Hepatitis
(6) Hemorrhagic enteritis (turkeys)
(1) Marble spleen dz (pheasants) = Group 2
(2) Quail bronchitis = Group 1
(3) Egg Drop Syndrome = Group 3
(4) CELO = Group 1
(5) Inclusion Body Hepatitis = Group 1
(6) Hemorrhagic enteritis (turkeys) = Group 2
***Egg Drop Syndrome is czd by what type of Adenovirus from what group?Group 3 Atadenovirus
***T/F: Egg Drop Syndrome has not been documented in the US.TRUE
Egg Drop Syndrome occurs in what spp.? Who is the only host?Chickens = only host
(Virus has been isolated from ducks & other waterfowl)
What type of xmission occurs w/ Egg Drop Syndrome?Vertical & horizontal xmission (contact w/ infected feces)
What do eggs look like from a chicken w/ Egg Drop Syndrome?Egg shells are very thin, misshapen & lose coloration of pigment
Some are Shell-less
***What differentiates Egg Drop Syndrome from Infectious Bronchitis & Newcastle Dz?Unlike Infectious Bronchitis & Newcastle Dz, Egg Drop Syndrome spreads slowly
What gross lesions are czd by Group 3 Atadenovirus?No gross lesions except for ugly, thin-shelled eggs
How is Egg Drop Syndrome Dxd?Virus isolation is a good method for Dx
When should Vxs for Egg Drop Syndrome be used?Vx breeders at 14-16 wks

Viral Arthritis

Question Answer
What are the other names for Viral Arthritis?AKA: Tenosynovitis
AKA: Ruptured gastrocnemius tendon
AKA: Reovirus infxn
What czs Viral Arthritis?Orthoreovirus in the Reoviridae family
What spp. is affected & at what age?Chickens (usually broilers) at 4-16 wks
How is Viral Arthritis transmitted?Mostly xmitted by the fecal-oral route or fecal contamination of eggs
[but vertical xmission also occurs]
What are the CS of Viral Arthritis?Signs may be unilateral or bilateral & incld:
Inflammation above the hock joint (other dzs cz swelling below the hock)
Rupture of the gastrocnemius (stilted gait)
Lameness results, birds sit on their hocks but remain active
Describe the gross lesions in affected joints.Lemon yellow-brownish blood tinged or purulent exudates in affected joint
+/- Hemorrhage into the tendon sheath
+/- Erosions on the synovial membranes
Chronic cases cz fibrosis & adhesions of affected tendons
What is the Vxn protocol for Viral Arthritis?Broiler breeders should be Vxd at 10-15 wks. If they are not, the chicks should be Vxd at 1 day old
Serology should be preformed \at 30 days intervals to monitor/detect dz

Fowl Pox

Question Answer
What spp. are susceptible to Fowl Pox?Nearly every avian spp. has its own strain of pox virus
It's common in Chickens, Turkeys, Pigeons, Canaries, Psittacines & wild birds
**2 ways that Fowl Pox is xmitted?Fowl Pox can be xmitted when scabs fall off & contaminates litter
Mosquitoes may also xmit the virus w/in the flock & from farm to farm
Describe the CS of the cutaneous form of Fowl Pox [also called dry pox].Cutaneous Fowl Pox czs:
Nodular lesions on the unfeathered areas (head comb, wattle)
Nodules may turn into vesicles, ulcerate & form scabs
What CS are associated w/ the diphtheritic form of Fowl Pox [a.k.a. wet pox]?Diphtheritic Fowl Pox czs dyspnea or inappetence (depending on the location of the lesions)
Lesions can be inside the mouth, nares, trachea & esophagous
Mortality is usually ↓ (except in canaries where its fatal)
The diphtheritic form of Fowl Pox is fatal in what spp.?Fatal in Canaries
Describe the gross lesions czd by diphtheritic Fowl Pox?Diphtheritic lesions are:
Epithelial hyperplasia
Necrotic raised yellow plaques on mucus membranes, especially in the mouth

but also in other parts of the upper respiratory tract or esophagus
What are the gross lesions of diphtheritic Fowl Pox specific to finches & canaries?Finches & canaries have hepatosplenomegaly czd by infiltration of immature lymphoid cells
There are also lesions in the oral cavity & respiratory tract
How is Fowl Pox Dxd?Intracytoplasmic inclusion bodies (Bollinger bodies) (eosinophilic)
***What is the only suitable method for prevention & control of Fowl Pox?VACCINATE!
What Vx is used in chickens & turkeys for 1⁰ Vxn & boosters?The Pigeon Pox Vx is usually used for 1⁰ Vxn of chickens & turkeys & then they get boostered w/ Fowl Pox
What Vx is used in pet birds?Pet birds should be Vxd w/ the Pigeon Pox Vx
What does a 'take' indicate?A 'take' is a small lesion at the site of infxn. It indicates that the Vx worked
If there is no 'take', the bird should be revxd

Infectious Bursal Dz

Question Answer
Infectious Bursal Dz is AKA?Gumboro Dz
T/F: IBD is no longer a problem in the U.S. bc of effective Vxn programs.FALSE. Infectious Bursal Dz is still a problem in the U.S., despite vxing
***Clinical Gumboro Dz is only seen in what spp.?Only chickens get clinical IBD, but ducks & turkeys may be infected
Infectious Bursal Dz virus is in what family?IBDV is in the Birnaviridae family
Which serotype of IBDV is more virulent, 1 or 2?IBDV serotype 1 contains virulent strains. Serotype 2 is nonpathogenic
How is Infectious Bursal Dz xmitted?Horizontally, by the fecal oral route
CS of IBD are usually seen at (< 1wk, 1-3 wks, 3-7 wks, > 10wks).CS of IBD are seen at 3-7 wks
Classical Infectious Bursal Dz has a (gradual, sudden) onset w/ (↓, ↑) morbidity, spiking morbidity & recovery is (non-existent, slow, rapid).Classical Infectious Bursal Dz has a sudden onset, ↑ morbidity, spiking mortality & rapid recovery (w/in 4 days)
***What are the CS of IBD?CS of IBD incld:
Ruffled feathers
***What is the most important aspect of Infectious Bursal Dz & at what age does it occur?Immunosuppression
However, bursal dmg in chickens >3 wks only marginally affects immune competence
Describe the progressive changes in the bursa of fabricius after IBD infxn. (What color changes & size changes & at how many days?)Bursal changes post infxn:
Day 2-3 = Gelatinous yellowish transudate w/ cream colored bursa
Day 3 = Dark red bursa starting to enlarge
Day 4 = Bursa double it’s normal weight
Day 5-7 = Gray bursa returns to normal weight & starts to atrophy
Day 8 = Bursa is 1/3 normal weight
What is the main method for controlling Infectious Bursal Dz?Vxn is the 1⁰ method of controlling IBD, but once an outbreak occurs, depopulation & disinfxn are required
Give the IBD Vxn protocol (what type of Vx & at what ages) for chicks & breeders.Chicks w/o maternal antibody should be given an attenuated Vx at day 1
Chicks w/ maternal antibody can be given an intermediate strain Vx at 2-3 wks
Breeders should be Vxd the same as chicks, but get a live virulent Vx booster at 10-14 wks
Then an oil emulsion killed Vx at 16-18 wks