Poultry Final

Risk factors of respiratory disease

stress, excessive dust, high ammonia

Infectious laryngotracheitis

chickens and pheasants, not turkeys

herpesvirus - life long shedding, destroyed by disinfectants and heat

horizontal transmission - direct and indirect, short-term survival on fomites

slow spreading, coughing blood

intranuclear inclusion bodies on histo

ddx - wet pox

MLV - spray, drinking water, eye-drop

recombinant virus-vectored vx - in ovo, wing web

can give live vaccine during outbreaks

REPORTABLE

Avian pox

strains specific to species

shed in high concentration

horizontal transmission - abrasions, cannibalism, insects, aerosolized

environmentally resistant

microscopic lesions - epithelium hyperplasia and hypertrophy, Bollinger bodies

pigeon pox vaccine - chickens in wing web

fowl pox vaccine - turkeys in leg

cull severely affected birds

Wet pox

diphtheritic form

plaques in mouth, esophagus, conjuncitva, larynx, trachea

slow spreading, respiratory disease

ddx - vitamin A deficiency, infectious laryngotracheitis

Dry pox

cutaneous form

proliferative lesions on featherless skin, papules to scabs

impaired wet gain, decreased egg production

ddx - pecking injuries, lymphoproliferative disease in turkeys

Avian influenza

orthomyxovirus - 16 H’s, 9 N’s

viral infection of respiratory and intestines

horizontal and vertical transmission

REPORTABLE

Low pathogen avian influenza (LPAI)

mild respiratory disease, low mortality, sick bird syndrome

acute onset of symptoms

ddx - infectious bronchitis, Newcastle, bordetella, infectious laryngotracheitis, myocplasmosis

prevent contact with waterfowl, vaccine not commonly used (except H1N1 for turkeys), quarantine and prolonged downtime

High pathogenic avian influenza (HPAI)

severe respiratory disease with viremic spread, high mortality

only H5 or H7 strains

clinical signs - acute or peracute onset, respiratory signs, diarrhea, swollen wattle and combs, neurologic signs

gross lesions - SQ hemorrhage of shanks, viscera petechia, misshapen eggs

ddx - velogenic Newcastle, fowl cholera

euthanasia and proper carcass disposal

Newcastle disease

Avian paramyxovirus 1

acute onset, sick bird syndrome, respiratory signs

adults - mild, low mortality

young - potentially severe disease, high mortality, CNS signs may occur

REPORTABLE

Mesogenic Newcastle

moderate disease, mainly respiratory signs but may have CNS signs

ddx - LPAI, infectious bronchitis, bordetella, infectious laryngotracheitis, mycoplasmosis

MLV - spray for 1do, drinking water

Killed and recombinant vx

Velogenic Newcastle

highly virulent, high mortality

acute to peracute onset, sick bird syndrome, severe respiratory disease, diarrhe, CNS signs

lesions - SQ swelling of head and neck, cyanotic comb and wattles, tissue hemorrhage

ddx - HPAI, fowl cholera

euthanasia and proper carcass disposal

Infectious bronchitis

coronavirus, multiple serotypes, readily destroyed by disinfectants

horizontal transmission - direct and indirect

almost 100% morbidity, high mortality with secondary infections

respiratory disease, decreased shell quality

pale and swollen kidney, false layer syndrome (enlarged and dysfunctional left oviduct)

ddx - NDV, LPAI, mycoplasmosis

live vx - spray, drinking water

killed vx - IM, SQ

Avian metapneumovirus

viral disease, readily destroyed by disinfectants and heat

mainly horizontal transmission (direct and indirect) but vertical possible

highly contagious, very fast disease course, high mortality with secondary infections, more severe in young birds

swollen head syndrome in chickens, rhinotracheitis in turkeys

ddx - infectious bronchitis, mNDV, LPAI, mycoplasmosis , infectious coryza

live vx - spray, drinking water

killed vx - IM, SQ

live vx early in life, boosting vx during production

REPORTABLE

Colibacillosis

avian pathogenic E. coli

can have local control of infection or sepsis

chronic and localized infections - coligranuloma (Hjarr'e’s disease), polyarthritis, osteomyelitis

can use antibiotics early in disease

Omphalitis/yolksacculitis

“mushy chick disease”, inflammation of navel

source - fecal contamination of eggs, in ovo infection from hens, AI

risk factors hatchery associated

Acute septicemia

colibacillosis

sudden deaths and increased mortality, non-specific lesions

ddx - acute systemic bacteria

Air sacculitis

infections secondary to poor air/ventilation, dust, ammonia, respiratory disease, immune suppression

clinical signs - respiratory distress, depression, impaired weight gain

Cellulitis

source - fecal contamination of cutaneous wounds

gross lesions - yellow and thickening of skin, caseous material in subcutis

cause of condemnation at processing

Salpingitis

ascending infection of reproductive tract

chronic disease course with caseous material in oviduct

Avian mycoplasmosis

primarily vertical transmission, also horizontal transmission

severity MG > MS > MM, more severe in young birds

ddx - other bacterial infections, reovirus, infectious coryza, bordetellosis, cryptosporidiosis

treatment - quarantine, antibiotics often not effective, depopulation

control - get eggs or chicks from mycoplasma-free flocks

M. gallisepticum

chickens - chronic respiratory disease

turkeys - infectious sinusitis

nonspecific lesions - airsacculitis, fibrinous perihepatitis, fibrinous pericarditis

REPORTABLE

M. synoviae

chickens and turkeys

respiratory and locomotor issues, tenosynovitis

REPORTABLE

M. melargridis

respiratory in turkeys - mild conjunctivitis, airsacculitis in young turkeys

Infectious coryza

Avibacterium paragallinarum

older chickens, acute onset, sinusitis, septicemia

ddx - mycoplasma

treatment - antibiotics

Fowl cholera

pasteurella multocida

acute/peracute septicemic disease - high morbidity and mortality

chronic (localized) - follows acute disease, localized infections of comb, wattles, joints, or tendon sheaths

horizontal transmission, survivors become lifelong carriers

ddx - bacterial septicemia, HPAI, exotic or velogenic NCD

treatment - penicillin or tetracycline, cull severely affected birds and depopulation

Bordetllosis

turkey coryza, bordetella avium

horizontal transmission (direct and indirect), perisistent carriers

antibiotics not effective but may decrease secondary bacterial infections

MLV for poults - spray or in water

Chlamydiosis

chlamydia psittaci

classic - hepatomegaly and splenomegaly, turkeys - lacrimal gland

zoonotic potential

treatment - tetracyclien for 45 days

REPORTABLE

Aspergillosis

aspergillus fumigatus

respiratory and CNS signs

spores penetrate eggshells and infect birds

yellow or gray lesions in resp tract or liver

diagnosis - look for fungal hyphae, blood agar or Sabouraaud’s to culture

treatment long and expensive - antifungals (itraconazole, amphotericin B)

cull affected birds

Vitamin D deficiency

rickets and osteomalacia

complicated by imbalance of Ca:P

treatment - change or supplement ration to provide proper amounts of calcium, phosphorus, and vit D3

Rickets

vitamin D deficiency

disorder of young poultry (2-5wo), usually presents as lameness

long bones and beak soft and rubbery, beading of ribs, curving of ribs/keel/spine

excess vit A interferes with vit D3

Osteomalacia

vitamin D deficiency

cage layer fatigue - disorder of laying hens due to suboptimal nutrition

take Ca from bone for eggs, bones fracture easily

Vitamin E deficiency

Crazy chick disease - encephalomalacia

ataxia, paresis, paralysis

ddx - hypoglycaemia, vitamin B1 deficiency, meningitis/encephalitis

treatment - change feed, add synthetic antioxidants, add vit E in feed

prevention - ensure adequate vit E in diet, prevent excess vit A, prevent malabsorption/enteritis

Vitamin A deficiency

parents not fed enough Vit A → young birds have little vit A in eggs

clinical signs - poor growth and feathering, keratinized epithelium (cheesy exudate) in eye

lesions - inflamed and adhered eyelids, pustules in mouth/pharynx/esophagus

treatment - vit A in drinking water

prevention - ensure adequate vit A in feed, avoid prolonged storage to prevent rancidity

Visceral gout

acute urate deposition, vit A deficiency

like uremia in mammals, affects kidneys and other viscera

can be secondary to renal failure and not due to diet

usually fatal condition

prevention - reduce calcium, add vit A

Articular gout

chronic urate deposition, vit A deficiency

like gout in mammals, males > females, joint and synovium affected, granulomatous inflammation

due to genetics or high protein diet

treatment - correct ration and decrease protein

Marek’s disease

alpha-herpesvirus, ubiquitous disease

chickens younger than 16wo

transmission through feather follicle epithelium

CD4+ T cell interfollicular tumor, heterogenous population of cells, nonspecific clinical signs or neurological signs

causes early immunosuppresion

gross lesions - lymphoid infiltration (gray eye), corneal opacity, visceral tumors, enlarged nerves

ddx - lymphoid leukosis, reticuloenotheliosis, other neoplasias

vx at day of age or intra-amniotic

MDV-1

gallid alphaherpesvirus 2

oncogenic virus in chickens

MDV-2

gallid alphaherpesvirus 3

non-oncogenic virus in chickens

MDV-3, HVT

meleagrid herpesvirus

non-oncogenic virus in turkeys

Avian lymphoid leukosis

retrovirus

vertical and horizontal transmission

chicken older than 16wo

infect bursa, B cell intrafollicular tumors, visceral tumors, bursal lesions, homogenous population of lymphoblasts

not just lymphoma, can have other kinds of tumors

ddx - Marek’s, reticuloendotheliosis

control - eradication at pedigree level, no vaccine

Erysipelas

erysipheothrix rhusiopathiae, resistant to environment and disinfectants

wide range of animal infected, zoonotic

diagnosis - bacterial culture or triple sugar iron test (will produce hydrogen sulfide)

ddx - fowl cholera, HPAI, vNDV, E. coli, ornithobacterium rhinotracheale, poison, trauma

treatment - penicillin, vx, oregano oil

Acute erysipelas

older birds, septicemia

birds found dead with minimal clinical signs, mild hepatomegaly and splenomegaly

Chronic erysipelas

localized infection

depression, respiratory signs, nasal exudate, diarrhea, swollen snoods, dark red skin lesion on face or head

Clostridial dermatitis

turkeys

cellulitis, gangrenous dermatitis, congestion and necrosis

treatment - antibiotics (bacitracin), probiotics, prebiotic, phytobiotics, organic acids

no vaccine

Mycobacteriosis

mycobacterium avium

older birds, zoonotic in immunosuppressed patients

chronic slow-spreading disease, gradual weight loss, death, granulomas in visceral organs

diagnosis - acid fast stain

ddx - yersiniosis, neoplasia

treatment not recommended, bacteria may become resistant

Dyschondroplasia

causes - fast growing birds, mycotoxins, chlorine imbalance acidosis, Ca:P imbalance, secondary to enteritis

clinical signs - reluctant to move, swollen joints, bowing legs

lesions - persistent cartilaginous plug

ddx - rickets

no treatment

prevention - slow growth, proper feeding and proper acid/base balance

Valgus and varus

valgus - knees point inward, varus - knees point outward

causes - genetics, growth rate

clinical signs - reluctant to move, bowing legs

ddx - rickets

no treatment

prevention - slow growth, better genetics, proper nutrition, improve environment

Spondylitis

Staph aureus, E. coli, Enterococcus decorum

trauma leading to bacterial localization in bone

diagnosis - lesions visible in vertebrae

ddx - spondylolisthesis or kinky back

poor response to antibiotics

prevention - minimize source of infection, vitamin D3 supplementation, reduce early growth

Osteomyelitis

Staph aureus, E. coli, Enterococcus decorum

trauma leading to bacterial localization in bone

diagnosis - lesion in bone

ddx - rickets, dyschondroplasia

poor response to antibiotics

Pododermatitis and bumble foot

cause - poor management, wet litter, increased ammonia

Staph spp most often

pododermatitis - footpad only

bumble foot - footpad and toes

treatment - cull if commercial poultry, antimicrobials/bandaging/surgery if individual or pet bird

control - environmental modifications

Mycotoxin

most common - alfatoxin, orchartoxins, Fusarium toxins

decreases innate, mucosal, humoral, and cellular immune response

pale liver and kidney, atophy or bursa of fabricius and thymus

Late stage Marek’s reactivation

occurs after very virulent Marek’s, not associated with lymphoid organ atrophy and/or tumors

no method to diagnose, no way to control

severe immunosuppression - cell-mediated and humoral immune response

Infectious anemia

only chickens

vertical and horizontal transmission

clinical disease after vertical infection or very early in horizontal infection

clinical signs in young chickens, resistant after 3 weeks

targets bone marrow and immature T lymphocytes

clinical signs - anemia, watery blood, necrotic dermatitis

lesions - bone marrow and thymus atrophy

vaccinate breeders

Infectious bursal disease

Gumboro disease, resistant to disinfectant and environment

serotype 1 - moderate, virulent, very virulent, classic, chickens natural host

serotype 2 - non-pathogenic

horizontal transmission, mosquitoes and rodents reservoirs

vaccinate breeders to prevent early infection and long-term immunosuppresion in progeny

vaccinate young chicks to prevent clinical disease

Subclinical infectious bursal disease

chickens <3wo

no clinical signs, no mortality

long-term immunosuppression, atrophy of bursa of Fabricius

Clinical infectious bursal disease

chickens >3wo

sick bird syndrome, diarrhea, mortality

max susceptibility 3-6 weeks

Reticuloendotheliosis

defective - can’t replicate but has oncogenic gene

non-defective - can replicate but no oncogenic gene

infection of defective and non-defective strain - can produce tumors very quickly

horizontal transmission, vertical transmission, biological contamination from vaccine

birds that don’t grow well, pale, Nakunke feathering

lesions - bursa and thymus atrophy, hypertrophy or peripheral nerves, proventriculitis and enteritis

Hemorrhagic enteritis

adenovirus, 6-12wo turkeys

horizontal transmission

acute - sudden death, droppings containing fresh blood

subclinical - immunosuppression, complications with E. coli

no treatment

vx at 3-4 weeks

Viral enteritis

clinical signs - diarrhea, noisy and hyperactive initially to sick bird syndrome

infection more severe in young birds, often mixed infections

difficult to isolate in lab

ddx - bacterial enteritis, parasites

Poult enteritis complex

turkey coronavirus, high morbidity

supportive care, depopulation in severe cases, control darkling beetles and flies

Transmissible viral proventriculitis

birnavirus

ddx - bornavirus (PDD in psittacines), PV dilation

Reovirus

starts enteric and then affects joints and tendon

broiler chickens

fecal-oral transmisison, vertical transmisison

swelling of digital flexor tendons, rupture of gastrocnemius tendon, swollen hock

ddx - bacterial arthritis

vaccinate breeders

Avian encephalomyelitis

picornavirus

starts enteric and then affects CNS

vertical transmission and then horizontal to susceptible age-mates

older birds - drop in egg production

young birds - encephalitis and neuro signs

encephalomyelitis, perivascular cuffing, neuronal degeneration

ddx - other CNS disease

Salmonella typhoid infecitons

S. pullorum - bacillary white diarrhea

S. gallinarum - fowl typhoid

chicks and poults 2-3wo, high morbidity and mortality

adults may be subclinical

eradication

REPORTABLE

Salmonella paratyphoid infections

live poultry reservoir for human Salmonella infection

acute or chronic septicemic bacterial disease in young poultry

can localize in ovary and shed in egg

risk management

Arizononosis

Salmonella arizonae

vertically transmitted

enteritis and septicemia in young turkeys

clinical signs - diarrhea, ataxia, tremors, torticollis

lesions - ocular opacity or turbidity, purulent exudate in meninges and brain

Necrotic enteritis

clostridium perfringens

predisposing factors - coccidiosis, rich in cereal grains, high protein diet, immunosuppression, stress

lesions - gas-filled and flaccid intestines, “Turkish towel” necrosis

treatment - antibiotics (bacitracin), probiotics, prebiotics, phytobiotics, organic acids

no effective vaccine yet

Coccidiosis

Eimeria in chickens and turkeys

fecal-oral transmission

asexual stage and sexual stage

diagnosis - gut scraping, fecal float

ddx - viral or bacterial enteritis, trauma or toxic if blood present

treatment - coccidostats (antimicrobials), coccidicidals (chemicals)

vaccine spray at hatchery

Chicken coccidia

broiler chickens - E. acervulina (upper half of small intestines), E. maxima (midgut), E. tenella (cecal cores)

breeders and layers - E. necatrix (anterior and middle small intestine), E. brunetti (lower small intestines)

Turkey coccidia

E. adenoeides (cecum), E. gallopavonis (lower ileum, ceca), E. meleagrimits (upper and midgut)

Coccidia prevention programs

straight program - one product throughout the year

rotation - different anticoccidials in summer and winter

bio-shuttle program - vaccine and anticoccidial in same flock

Histomoniasis

blackhead disease in turkeys, histomonas meleagridis

transmission - nematode heterakis gallinarum eggs → cloacal drinking, bird-to-bird

diarrhea, cyanosis, sick bird syndrome

ulcer-like target lesions on liver, caseous plug in ceca

ddx - HPAI, vNDV, fowl cholera, erysipelothrix, neopalsia, coccidia

prevention - prevent parasites (albendazole, fenbendazole), chemical coccidostats

Nematodes

hard to disinfect environment

mostly subclinical infections

ascaridia galli - brolier, commercial hens, free range adults

heterakis gallinarum - commercial hens, free range adults, turkeys

capillaria - commercial hens, free range adults

histomonas meleagridis - turkeys