Lecture 17 & 18 (Viral Diseases of Poultry)

Fowl Pox (Poxviridae)

-this virus is a poxvirus found in chickens and turkeys
-slow spread virus that requires direct contact with traumatized skin or oral mucosa
-can be transmitted by arthropod vectors (mosquitos) or by horizontal transmission

b) Fowlpox

The cutaneous form of ______________ results in proliferative lesions in featherless skin while the diphtheritic form results in plaques in the oral and UR mucosa. When particularly virulent, you can get lesions on internal organs

a) New Castle Disease
b) Fowlpox
c) Infectious Laryngotracheitis
d) Avian Influenza
e) Infectious Bronchitis

b) Fowlpox

a slow spreading infection characterized by proliferative lesions // environmental hygiene & quarantining infected animals will be important

a) New Castle Disease
b) Fowlpox
c) Infectious Laryngotracheitis
d) Avian Influenza
e) Infectious Bronchitis

Fowlpox

what virus?

Cutaneous (dry form) pox - papules, vesicles, pustules, crusts on unfeathered skin

Diphtheritic (wet form) - yellow raised lesions, mouth, pharynx, trachea - see difficulty swallowing/breathing, occasionally aspiration pneumonia

-vector elimination

-isolate birds with lesions

-environmental cleaning and disinfection

vaccination in the face of an outbreak as treatment or to prevent:

–chickens → wing-web (intradermal-needle stick)

-turkeys → inner thigh (intradermal-needle stick)

how do you control/treat a chicken or turkey with Fowlpox?

based on CS/LS ± histopathology // intracytoplasmic inclusions (Bollinger bodies)

how do you diagnose a chicken or turkey with Fowlpox?

non-enveloped viruses

[enveloped/non-enveloped] viruses are extremely resistant in the environment

a) Avian Paramyxovirus 1

Newcastle Disease is caused by:

a) Avian Paramyxovirus 1
b) Avian Orthomyxovirus 1
c) Avian Herpesvirus 1
d) Avian Adenovirus 1

Newcastle Disease

-this virus is seen worldwide in many bird species although has been eradicated from some countries like USA

-of particular importance in chickens and turkeys

-ZOONOTIC

-occasionally causes mild flu-like symptoms and conjunctivitis in humans

-rapid horizontal transmission primarily via aerosols, but also fecal-oral and fomites

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

Newcastle Disease:

may see peracute death or respiratory signs (swelling of head around eyes, oculonasal discharge, snick, cough) and acute drop in egg production followed by high mortality (>30-50%)

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

c) Mesogenic/Lentogenic forms (Paramyxovirus-1)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

Newcastle Disease:

in addition to respiratory signs, see CNS/PNS signs (torticollis, opisthotonus, leg and wing paralysis)

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

c) Mesogenic/Lentogenic forms (Paramyxovirus-1)

c) Mesogenic/Lentogenic forms (Paramyxovirus-1)

Newcastle Disease:

with this strain of Newcastle Disease, we see mild upper respiratory signs (sneezing aka “snicking” in birds) and occasionally a cough associated with airsacculitis (frothy airsacs) // infection with this strain is often followed by a secondary (opportunistic) bacterial infection like colibacillosis (E. coli)

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

c) Mesogenic/Lentogenic forms (Paramyxovirus-1)

-necropsy

-reverse transcriptase → Polymerase Chain Reaction (RT-PCR)

-serology performed on acute (taken at the time birds are sick) and convalescent (taken 2-3 weeks later, when birds are recovered) using Enzyme-linked Immunosorbent Assay (ELISA)

how do you diagnose a chicken or turkey with Newcastle Disease (VVND/NVND)?

true

t/f: suspected cases of VVND/NVND are reportable to the State Vet

-good biosecurity is critical to prevent spread

-Mesogenic (endemic PMV-1) infection is prevented using lentogenic (live) strains as vaccines in meat-type poultry (water-based) and prior to egg production

-killed vaccines (SQ/IM) are used as boosters after egg production has begun

how do you treat/prevent a chicken or turkey with Newcastle Disease (VVND/NVND)?

by testing, euthanasia, and disposal of infected animals

how is VVND/NVND eradicated in the USA?

a) New Castle Disease

clinical signs can include:

drop in egg production, numerous deaths in first day or two and ongoing for another 7-10 days with the whole flock sick and dying // greenish diarrhea, muscle tremors, drooping, paralysis, general malaise

a) New Castle Disease

b) Avian Pox

c) Infectious Laryngotracheitis

d) Avian Influenza

e) Infectious Bronchitis

c) Mild Conjunctivitis

Newcastle disease is zoonotic and it is associated with what in humans?

a) Large Bowel Diarrhea
b) Small Bowel Diarrhea
c) Mild Conjunctivitis
d) Mild Pneumonia

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

Newcastle Virus comes in various forms; which of the following is associated with high mortality and gut hemorrhagic lesions?

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

c) Mesogenic

d) Lentogenic

e) Asymptomatic enteric

a) New Castle Disease

clinical signs might include:

edema around the eyes, petechial hemorrhage of the nictitating membrane, hemorrhage and fibro-necrotic exudate in the tracheal/laryngeal mucosa, and numerous deaths within 1-2 days

a) New Castle Disease

b) Avian Pox

c) Infectious Laryngotracheitis

d) Avian Influenza

e) Infectious Bronchitis

b) Neurotrophic Velogenic Newcastle Disease (NVND)

Newcastle Virus comes in various forms; which of the following is associated with high mortality, respiratory & neurologic signs?

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

c) Mesogenic

d) Lentogenic

e) Asymptomatic enteric

c) Mesogenic

Newcastle Virus comes in various forms; which of the following is associated with acute respiratory & neurologic signs BUT lower mortality?

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

c) Mesogenic

d) Lentogenic

e) Asymptomatic enteric

d) Lentogenic

Newcastle Virus comes in various forms; which of the following is associated with Mild or inapparent, respiratory signs

a) Viscerotrophic Velogenic Newcastle Disease (VVND)

b) Neurotrophic Velogenic Newcastle Disease (NVND)

c) Mesogenic

d) Lentogenic

e) Asymptomatic enteric

true

t/f: H5 and H7 influenza strains are of greatest concern in poultry

migratory waterfowl and shore birds

which birds are considered the major natural reservoir for Avian Influenza and are typically asymptomatic (aclinical)

Avian Influenza

-this virus is transmitted horizontally via aerosols & fecal material
-fomites are also an important means of virus spreading
-new recombinant virus may emerge that can cause severe disease in humans
-potentially zoonotic (especially if it cycles between birds and susceptible mammals like pigs where human viruses may also cycle)

low strains

you usually see mild respiratory signs (snick, cough, rales, sinusitis), drop in egg production, and low mortality with [low/high] path strains H5 and H7

d) Avian Influenza

clinical signs:

-lesions include tracheitis ± hemorrhage

-SQ hemorrhages in comb, wattles, and legs

-sub-capsular hemorrhage in organs

-mild respiratory signs with low strains

-diarrhea/CNS problems with high strains

a) New Castle Disease

b) Avian Pox

c) Infectious Laryngotracheitis

d) Avian Influenza

e) Infectious Bronchitis

high strains

you usually see diarrhea, edema of head and face, CNS problems, acute drop in egg production, and high (>30-50%) mortality with [low/high] path strains H5 and H7

-necropsy
-RT-PCR
-confirmation of subtype by National Veterinary Services Lab (NVSL)

*H5 and H7 subtypes are REPORTABLE

how would you diagnose a bird with Avian Influenza?

-tight biosecurity

-surveillance to detect AI prior to moving birds to slaughter

-immediate quarantine of suspect flocks followed by euthanasia of H5/H7 flocks

-non-H5/H7 flocks may be held until shedding has decreased, then sent to market (aka controlled marketing)

-vaccines are rarely used in the USA because of surveillance programs and difficulty differentiating vaccinated and field challenged flocks

how do you treat/prevent a bird with Avian Influenza

d) Highly Pathogenic Avian Influenza

on a necropsy of a chicken, you find swollen sinuses, petechiae in the trachea, lungs, and proventriculus, and a swollen comb and wattle. these signs indicate the bird likely died from:

a) New Castle Disease
b) Avian Pox
c) Infectious Laryngotracheitis
d) Highly Pathogenic Avian Influenza
e) Infectious Bronchitis

false - found in chickens only

t/f: Infectious Bronchitis is found in chickens and turkeys

e) Infectious Bronchitis

clinical signs Include:

respiratory disease that becomes systemic causing hemorrhage in the trachea and hemorrhage in the oviducts

a) New Castle Disease

b) Avian Pox

c) Infectious Laryngotracheitis

d) Avian Influenza

e) Infectious Bronchitis

Infectious Bronchitis

clinically what virus is this?

-up to 100% morbidity

-oculonasal discharge in chicks

-adults → cough // severe egg production drops (> 50%) with soft shell and wrinkled eggs

-young → severe IB // impacted oviducts // ruptured ova

-renal failure if kidneys are affected

-necropsy
-RT-PCR
-ELISA on acute and convalescent sera
-histopathology to rule-out Infectious Laryngotracheitis

how do you diagnose a chicken with Infectious Bronchitis

vaccination:

-live (spray, water-based) and killed (SQ or IM)

-IB vaccine is given in conjunction with PMV-1 (Newcastle)

*strain(s) must match what is being detected locally

how do you treat/control a chicken with Infectious Bronchitis

e) Infectious Bronchitis

this coronavirus disease was mistaken for HPAI when first seen in North Dakota; it starts as a respiratory disease that becomes systemic. it is shed for days, spread by aerosols and fecal contamination, and vaccination is hard due to type-specific immunity

a) New Castle Disease
b) Avian Pox
c) Infectious Laryngotracheitis
d) Avian Influenza
e) Infectious Bronchitis

Infectious Bronchitis

-this virus is rapidly transmitted horizontally via aerosols, but also fecal-oral and fomites
-intermittent shedding for months
-all strains produce some respiratory disease
-some strains also target kidneys and oviduct

epithelial

Coronaviruses target __________ cells

Infectious Laryngotracheitis

-this virus is found worldwide in chickens
-horizontal transmission primarily via aerosols and fomites
-rate of spread is slow within a flock
-as with all herpesviruses, latency with stress shedding is a problem

Infectious Laryngotracheitis

clinically what virus is this?

-morbidity is high, but mortality is strain dependent

-milder strains produce conjunctivitis, oculonasal discharge, sinusitis, drop in egg production

-virulent strains also see coughing with expectoration of bloody mucus, dyspnea (open mouth gasping) with head/neck extension

-histopathology (intranuclear inclusion bodies seen in tracheal epithelial cells and conjunctival mucosa)
-PCR
-ELISA-serology

how do you diagnose a chicken with Infectious Laryngotracheitis

-because the virus moves slowly, you can vaccinate in the face of an outbreak to prevent spread w/in a flock

-Tissue Culture Origin (TCO) or Chick Embryo Origin (CEO) vaccine given by eye-drop method

-CEO can “roll-over” in flock and become virulent

how do you treat/control a chicken with Infectious Laryngotracheitis?

c) Neonatal Enteritis

-this virus occurs in young chickens (chicks) and turkeys (poults)
-horizontal transmission, fecal-oral
-infection is often complex and can include multiple viruses and other organisms associated with dysbiosis

a) Coronaviral Enteritis of Turkeys
b) Turkey Viral Hepatitis
c) Neonatal Enteritis
d) Marek's Disease

Neonatal Enteritis

clinically what virus is this?

-ill-thrift, shrill chirping, huddling, ruffled feathers, paleness, diarrhea, poor weight gain

-decreased feed and water intake // poor feed conversion

-un-even growth

-occasionally an acute spike in mortality, but usually slight to moderate increase mortality

-small intestines - mucosal hyperemia + watery, gaseous, intestinal contents, thin intestinal walls, litter material in gizzard

-necropsy
-RT-PCR
-histopathology (see villus blunting and coalescing)
-immunohistochemical staining

how do you diagnose a chicken or turkey with Neonatal Enteritis

Treatment (RX): Palliative - increase environmental temperature and ventilation rate

-to prevent the development of rickets (Malabsorption Syndrome) add Vitamin D to water and rouse birds to encourage them to eat and drink

-biosecurity

-no vaccines available

how do you treat/control a chicken or turkey with Neonatal Enteritis

rickets

what is a secondary disease that chickens or turkeys may develop with Neonatal Enteritis

a) Coronaviral Enteritis of Turkeys

-this virus affects turkeys at any age, but severity is worse in young birds
-horizontal transmission via feces
-shedding may continue for days-weeks after recovery (infection of enterocytes can still occur in the presence of antibodies, although clinical disease is diminished)
-older, recovered birds serve as a reservoir for young, naïve birds

a) Coronaviral Enteritis of Turkeys
b) Turkey Viral Hepatitis
c) Neonatal Enteritis
d) Marek's Disease

Coronaviral Enteritis of Turkeys

clinically what virus is this?

-in young poults, see depression, huddling, shrill chirping, drop in feed consumption, then water consumption, loss of body weight, watery or frothy droppings, variation in body size / unevenness

-intestines small, thin walled, lumens filled with watery or frothy gaseous contents

-in turkey breeder hens, see rapid drop in egg production, white egg shells

Poult Enteritis Mortality Syndrome (PEMS)

Coronavirus complicated by enteropathogenic E. coli, Salmonella, and protozoans – Cochlosoma, Trichomonas, Hexamita - is known as _________ ________ ________ syndrome

-necropsy
-CS/LS
-RT-PCR

how do you diagnose a turkey with Coronaviral Enteritis

RX: provide extra heat, increase ventilation, keep birds as dry as possible (watery droppings = wet litter) to reduce stress and chilling

-antibiotics for secondary bacterial infections

PX: biosecurity

-depopulation of premises followed by cleaning/disinfection of buildings and equipment

-if multiple ages on farm, switch to single age operation

-no vaccine available

how do you treat/control a turkey with Coronaviral Enteritis

b) Turkey Viral Hepatitis

this virus occurs by horizontal (fecal-oral) and vertical (hen to egg to poult) transmission in turkeys. ducks and geese serve as the natural reservoir for this virus

a) Coronaviral Enteritis of Turkeys
b) Turkey Viral Hepatitis
c) Neonatal Enteritis
d) Marek's Disease

Turkey Viral Hepatitis

clinically what virus is this?

-often subclinical unless another disease or stressor present

-see depression and sporadic deaths

-coalescing focal hepatic necrosis with congestion and hemorrhage

-focal pancreatic necrosis

-necropsy
-histopathology
-RT-PCR

how do you diagnose a turkey with Turkey Viral Hepatitis?

-do not continue to use eggs from breeders thought to be infected.
-no vaccine available

how do you treat/control a turkey with Turkey Viral Hepatitis?

Inclusion Body Hepatitis (IBH)/Hepatitis-Hydropericardium Syndrome (HHS)

-this virus occurs in chickens (broilers and layers) at 3-15 weeks of age
-older than 15 weeks likely have developed immunity
-serotype D appears to be the most problematic
-vertical and horizontal transmission // fecal-oral
-clinical disease tends not to occur unless there is some type of stressor or immunosuppressive event

Inclusion Body Hepatitis (IBH)/Hepatitis-Hydropericardium Syndrome (HHS)

clinically what virus is this?

-sudden peak in mortality, icterus, pallor, hepatomegaly, liver yellow-tan, mottled, and in some outbreaks, increased pericardial fluid

-areas of multifocal necrosis with intranuclear inclusion bodies may be found in liver, kidneys, heart

-will also see lesions associated w/predisposing disease

b) Hepatitis-Hydropericardium Syndrome (HHS)

___________________ is seen most commonly in young broiler chickens

a) Inclusion Body Hepatitis (IBH)
b) Hepatitis-Hydropericardium Syndrome (HHS)

-necropsy
-histopathology
-ELISA on acute and convalescent sera

how do you diagnose a chicken with IBH/HHS?

-vaccinate breeders
-do not use eggs from breeder flocks suspected of being infected

how do you treat/prevent a chicken with IBH/HHS?

nephritis (kidney inflammation/damage)

Chicken astrovirus (Neonatal Enteritis) may also cause _____________ leading to visceral/articular gout

gout

Nephrotrophic strains of Infectious Bronchitis Virus, G: Gammacoronavirus may cause nephritis leading to visceral/articular ___________

Infectious Bursal Disease (aka IBD, Gumboro Disease)

-this virus is seen in chickens, generally seen 3-6 weeks-of-age, but can occur in any chicken with a functional bursa of Fabricius
-horizontal transmission // fecal-oral

-B-lymphocytotrophic virus, replicates primarily in the bursa
-lesser mealworm (often found underneath feeders in poultry houses) may harbor virus for weeks

Infectious Bursal Disease

clinically what virus is this?

-acute onset, tremors, depression, anorexia, ruffled feathers, vent picking

-high morbidity, mortality may approach 30%

-bursa initially becomes edematous and congested, then completely atrophies in 78 days

-secondary bacterial infections occur as a result of immunosuppression

b) Infectious Bursal Disease

also known as "Gumboro Disease," this Birnavirus is very economically important as outbreaks result in depopulation and destruction of the animal products

a) Chicken Infectious Anemia
b) Infectious Bursal Disease
c) Pseudorabies
d) New Castle Disease
e) HPAI

b) Infectious Bursal Disease

targets Pre-B lymphocytes of the Bursa; occurs due to improper vaccination (a lapse) and causes sudden death. Occasionally birds recover but are then susceptible to other disease due to the immune suppression

a) Chicken Infectious Anemia
b) Infectious Bursal Disease
c) Pseudorabies
d) New Castle Disease
e) HPAI

-necropsy
-histopathology
-ELISA on acute and convalescent sera

how do you diagnose a chicken with Infectious Bursal Disease?

RX: palliative

-treat secondary bacterial infections with antibiotics

PX: vaccinate breeders with killed vaccine → this typically provides sufficient immunity for broiler chickens to reach market age

-in areas where field challenge is heavy may need to vaccinate broilers/roaster chickens later in the production cycle

how do you treat/control a chicken with Infectious Bursal Disease?

Hemorrhagic Enteritis

-this virus primarily affects turkeys, 6-12 weeks-of- age
-also seen in pheasants and chickens
-horizontal transmission // fecal-oral
-replicates in/destroys B-cells and macrophages
-cytokine response leads to degranulation of GI mucosal mast cells

Hemorrhagic Enteritis

clinically what virus is this?

with virulent strains → high morbidity // acute increase in mortality (5-60%, avg 15%) // decrease in feed and water consumption // bloody feces (melena) // blood

with avirulent strains → see high morbidity // low mortality due to primary infection, but higher mortality due to secondary infection with E. coli or Salmonella ~10 days post-infection with HEV

with all pathotypes → see mottled spleens (hyperplasia of lymphoid germinal centers), but virulent pathotype also see necrosis of mucosa and luminal hemorrhage in duodenum

-necropsy
-histopathology → intranuclear inclusion bodies (spleen)
-agar gel immunodiffusion (AGID)
-PCR
-ELISA on acute and convalescent sera.

how do you diagnose a turkey with Hemorrhagic Enteritis?

RX: treat secondary bacterial infections with antibiotics

PX: for turkeys, live vaccine derived from pheasant strain or avirulent turkey strain, administered in the water at 5 weeks-of-age. virulent strain from turkeys is used to vaccinate pheasants.

how do you treat/diagnose a turkey with Hemorrhagic Enteritis?

c) Hemorrhagic Enteritis

associated with intranuclear inclusion bodies in the spleen and extensive hemorrhages seen on histopathology; can be confused with E. coli septicemia. recovered birds have lifelong immunity and there is also a vaccine that can be put in the water

a) New Castle Disease
b) Marek's Disease
c) Hemorrhagic Enteritis
d) Avian Influenza
e) Infectious Bronchitis

b) Lymphoid Leukosis

-this virus is found in chickens only
-horizontal and vertical transmission
-frequency of infected eggs is low but chicks hatched are permanently viremic and transmit horizontally

a) Hemorrhagic Enteritis
b) Lymphoid Leukosis
c) Marek's Disease
d) Chicken Infectious Anemia

Lymphoid Leukosis

clinically what virus is this?

-in older birds (>12 weeks) see enlargement of abdomen due to B-lymphoblastoid tumors and neoplastic infiltration in many organs, esp. liver (aka Big Liver Disease), bursa, kidney, ovary

-unlike Marek’s disease, do not see tumors in nervous system

-proventricular hyperplasia seen in young broiler chickens associated with J subgroup (ALV-J strain)

-history
-age
-necropsy
-RT-PCR
-histopathology → uniform lymphoblastoid cells, immunohistochemistry

how do you diagnose a chicken with Lymphoid Leukosis?

-no vaccine
-must get rid of infected breeders.

how do you treat/control a chicken with Lymphoid Leukosis?

d) Chicken Infectious Anemia

-this virus is found in chickens only
-vertical and horizontal transmission
-susceptibility to this viral infection rapidly decreases over the first 23 weeks-of-age (younger birds are more susceptible)

a) Hemorrhagic Enteritis
b) Lymphoid Leukosis
c) Marek's Disease
d) Chicken Infectious Anemia

Chicken Infectious Anemia

clinically what virus is this?

-failure to thrive // depressed

-bone marrow (watery, pale bone marrow), bursal, thymic and splenic atrophy

-aplastic anemia develops 1416 day-post-infection, PVC 627%, leukocytopenia, thrombocytopenia. Immunosuppression results in secondary bacterial and fungal infections.

-necropsy
-PCR
-ELISA on acute and convalescent sera

how do you diagnose a chicken with Chicken Infectious Anemia?

-biosecurity
-vaccination of breeder hens with live vaccine (9-15 weeks-of-age, since clinical disease is only a problem in chicks)
-monitor antibody levels in breeders to ensure levels are high

*never vaccinate while in egg production because of vertical transmission

how do you treat/control a chicken with Chicken Infectious Anemia?

c) Marek's Disease

-this virus occurs in chickens, 27 months of age
-late disease occurs after onset of production because birds are not well vaccinated
-immunosuppressed at time of vaccination or exposure to highly virulent field strain
-horizontal transmission
-latent virus chronically shed by infected chickens in feather follicle dander (inhalation and ingestion)
-virus is extremely resistant while in dried cells

a) Hemorrhagic Enteritis
b) Lymphoid Leukosis
c) Marek's Disease
d) Chicken Infectious Anemia

Marek's Disease

clinically what virus is this?

-T-lymphoblastoid tumors and inflammation acting as space occupying masses

-unique propensity to develop in nervous tissue

-associated with partial paralysis // blindness

-graying of iris // loss of sharp pupillary border definition

-gross enlargement of peripheral nerves

-also see reddening/swelling of feather follicles especially on legs

-tumors in liver, heart, spleen, gonad, kidney, proventriculus

-history // age
-necropsy
-location (nervous system) of neoplastic lesions
-histopathology → pleomorphic lymphoblastoid cells
-PCR
-immunohistochemistry

how would you diagnose a chicken with Marek's Disease?

-vaccination in ovo (in the egg) or at 1 day of age

-good cleaning and disinfection to decrease heavy exposure that might overwhelm protection

how would you treat/control a chicken with Marek's Disease?

b) Egg Drop Syndrome

-clinical disease only in chickens, but can recover virus from Anseriformes (ducks and geese)
-horizontal and vertical transmission
-virus remains latent until birds approach peak egg production (stress associated with high physiologic demand)

a) Hemorrhagic Enteritis
b) Egg Drop Syndrome
c) Marek's Disease
d) Chicken Infectious Anemia

Egg Drop Syndrome

clinically what virus is this?

-loss of color in pigmented eggs

-thin shelled and shell-less eggs

-failure to reach projected peak egg production levels

-ovaries and oviduct may atrophy (become inactive)

-relative to eggs that are laid → internal egg quality, fertility and hatchability are unaffected

-vaccinate pullets (young chickens prior to lay)
-use killed vaccine because of latency and vertical transmission problems

how do you control/treat a chicken with Egg Drop Syndrome

Reoviral Arthritis/Tenosynovitis

clinically what virus is this?

-arthritis/tenosynovitis

-see lameness → foot pads, hock joints, and digital flexor/extensor tendons swollen

-often see rupture of tendons

-hock joint contains small amount of straw colored or blood tinged fluid

-erosions in articular cartilage

-may also see petechial hemorrhages in heart and diarrhea

-sanitation
-broiler chicken most susceptible at 1d of age
-vaccinate breeders to boost maternal/passive immunity

how do you treat/control a chicken with Reoviral Arthritis/Tenosynovitis

Osteoporosis (Boot Shanks)

clinically what virus is this?

-long bones of legs thickened

-periosteum

-underlying bone often spongy but can become dense over time

-bone is essentially hyperplastic and prolific

-no vaccine
-eliminate breeders due to vertical transmission

how do you treat/control a chicken with Osteoporosis (Boot Shanks)?

Avian Encephalomyelitis

clinically what virus is this?

-may see slight drop in egg production in adult birds

-in young → dull expression, ataxia, "buzzing," tremors of head and neck and legs, paresis progressing to paralysis and prostration

-recovered birds may develop cataracts in eyes as the get older

-if turn affected chicks and poults upside-down, will exacerbate tremors

-necropsy → white spots in muscle of gizzard and proventriculus

-vaccinate breeders

-attenuated live vaccine administered by wing web inoculation or in water (per os)

-killed vaccine may be used if breeders are in egg production due to concern over vertical transmission.

how do you treat a chicken or turkey with Avian Encephalomyelitis

Equine Encephalitis

clinically what virus is this?

-birds are usually aclinical, but occasionally will see: depression, somnolence, incoordination, ataxia, circling, paresis, paralysis

-no gross lesions visible, microscopic lesions only

-neuronal degeneration, focal meningitis, perivascular lymphocytic infiltrate

-horizontally transmitted through mosquitos