Poultry Dz + Abortion

AMDUCA

• animal medicinal drug use clarification act

• describes what medications are not allowed to be used off-label for treatment of food/production animals

Veterinary Feed Directive

• bans the use of medically important (used in people) antibiotics as growth promoters

• restricts provision of antibiotics in feed to a prescribing veterinarian w/a valid VCPR

National Poultry Improvement Plan

• cooperative between government (state + federal) & industry

• voluntary participation

• developed screening for S. pulloum + fowl typhoid - successfully eradicated S. pullorum in commercial birds

Flock assessment

• food

• lighting

• air flow

• water

• space

• sanitation

• most common clinical signs at flock level: increased morbidity/mortality, decreased production, change in food/water consumption

Marek’s disease

• agent: gallid alphaherpesvirus (lymphoma of CD4+ T cells)

• spread: via feather dust, highly infective/ubiquitous

• clinical signs: persistent neuro Dz, transient paresis, ocular + skin lesions

• post-mortem lesions: tumors, enlarged nerves (sciatic)

• Dx: PCR on tumors

• treatment/mgmt: vaccinate, breed for resistance

Avian leukosis/sarcoma

• agent: alpharetrovirus (B cell sarcoma)

• spread: vertical transmission

• clinical signs: decreased egg production, anorexia, D+, dehydration (>14wks)

• post-mortem lesions: tumors (lymphoid neoplasia)

• Dx: p27 antigen detection (serology)

• treatment/mgmt: eradication from breeding stock (eliminated in commercial poultry)

Infectious bursal disease

• agent: immunosuppressive avibirnavirus

• spread: highly infectious/ubiquitous

• clinical signs: recumbent, bloody D+, dehydration, poor response to vaccination (3-6wks)

• post-mortem lesions: enlarged bursa ± hemorrhage, focal necrosis, & edema

• Dx: distinctive lesion

• treatment/mgmt: vaccinate chicks + laying hens

Infectious bronchitis

• agent: gammacoronavirus

• spread: direct contact/aerosols/feces/fomites, highly infectious/ubiquitous

• clinical signs: URI, wrinkled egg shells, watery droppings (nephrogenic strains) (chicks most severely affected)

• post-mortem lesions: resp exudate, swollen/pale kidneys, repro tract edema

• Dx: PCR

• treatment/mgmt: vaccinate, supportive care/abx for secondary infections, all-in/all-out system

Infectious laryngotracheitis

• agent: gallid herpesvirus

• spread: direct + indirect contact, lifelong carriers

• clinical signs: URI (rales), oculonasal discharge, bloody mucus

• post-mortem lesions: hemorrhage + congestion of larynx + trachea, mucoid casts in trachea

• Dx: histology of inclusion bodies in trachea

• treatment/mgmt: vaccinate to prevent spread

Mycoplasmosis (chronic respiratory disease + infectious sinusitis)

• agent: Mycoplasma gallisepticum

• spread: vertical + horizontal transmission, males & turkeys more susceptible, lifelong carriers

• clinical signs: URI, keratoconjunctivitis, airsacculitis

• post-mortem lesions: increased carcass condemnation

• Dx: PCR

• treatment/mgmt: vaccinate, abx can be used to reduce signs

• one of the costliest Dz of commercial poultry

Histomoniasis/Blackhead disease

• agent: Histomonas meleagridis (intermediate + paratenic host)

• spread: via cecal worm or cloacal drinking, high morbidity + mortality, worse in turkeys

• clinical signs: yellow D+, stilted gait, drooping wings

• post-mortem lesions: caseous cecal casts, multifocal hepatic necrosis

• Dx: gross or histologic lesions

• treatment/mgmt: keep chickens away from turkeys

Fowl pox

• agent: avipoxvirus

• spread: insect vectors/aerosol/fomites

• clinical signs:

  • cutaneous/dry: nodular scabbing lesions on non-feathered skin (predominant form)

  • diphtheritic/wet: yellow cankers on MM, dyspnea

• Dx: histopath

• treatment/mgmt: vaccinate (prevention & treatment), abx for secondary infection

Infertility

• inability to produce (any or the expected amount) off offspring, often with no clinical signs

• failure of any single functional event in males or females

3 components of infertility

• early embryonic death: loss prior to organogenesis (some normal occurrence in a herd)

• abortion: loss after organogenesis but before full-term (goal <5%)

• stillbirth: loss at or after full-term (within 24 hours of birth) due to dystocia or late-stage fetal death

Signs of infertility

• females: no/irregular cycles, lack of estrus signs, failure to conceive/pregnancy loss

• males: failure to breed/ejaculate, poor semen quality, decreased libido, conformation issues (ex: persistent frenulum)

Heat detection rate

• # of animals detected as coming into heat & inseminated in 1 estrous cycle / # of eligible animals

• influenced by overcrowding, temp, housing, time, & high production

Conception rate

• # of animals confirmed pregnant / # of animals bred

• defined both for all services & service #

• measure of fertility

• influenced by genetics, nutrition, high production, health, heat stress, & breeder

Pregnancy rate

• # of animals confirmed pregnant / # of eligible animals (within 1 estrous cycle peiod)

• heat detection rate * conception rate

• measure of repro efficiency at herd level

Average days open

• determined by voluntary waiting period (~110 days), heat detection rate, & conception rate

Non-infectious causes of pregnancy loss

• incidental: mastitis/systemic illness, twins, fighting

• toxins: fescue, cottonseed, mycotoxin

  • Zearalenone (mycotoxin) in swine

• iatrogenic: re-insemination, vaccination, prostaglandin or glucocorticoid admin

Infectious causes of abortion

• primarily bacterial, followed by viral (often systemic Dz)

• protozoal & fungal less common

Abortive pathogens in cattle

• Salmonella - culture

• BVDV - ear notch testing

• infectious bovine rhinotracheitis - antibody or genetic testing

• Leptospira - mid-stream urine testing

• Tritrichomonas fetus - TF pouch PCR

(the trick is bills)

Abortive pathogens in swine

• parvovirus: stillbirths, mummies, EED, infertility

• PRRS

• swine flu

• Leptospira - mid-stream urine testing

all can be tested via PCR

(P-PSL)

Abortive pathogens in SR

• chlamydiosis (enzootic abortion of ewes/placentitis)

• Campylobacteriosis

• Toxoplasmosis: mummies

• Cache Valley abortion - serum neutralization testing

all but Cache Valley can be tested via PCR

(chlamydia camping in the toxic Cache Valley)

Fertility reducing agents of poultry

• Mycoplasma gallisepticum - ELISA/PCR

• Infectious bronchitis virus - ELISA/PCR

• Salmonella pullorum - serum

• Salmonella - culture

(MISSing eggs)

Abortive pathogens of horses

• EHV-1 - serum neutralization, PCR

• EIA - Coggins

• Strep. equi zooepidemcus

• placentitis (ascending infection of Strep, Staph, or E. coli): premature udder development & milk production - US, SAA, culture

• Potomac Horse fever - PCR

• Rhodococcus

(rhode a horse to the Potomac zoo where there’s an epidemic of placentitis)

Abortive pathogens of SA

• parvovirus - ELISA snap

• canine herpes - PCR

• FIV/FeLV - ELISA snap

Zoonotic causes of abortion

• Neospora caninum + Toxoplasma gondii (SA definitive host, infect ruminants + people)

• chlamydiosis/EAE

• Salmonella

• Q fever (Coxiella burnettii)

• Brucellosis

• Listeria

Testing for infectious causes of abortion

• submit placenta, deceased fetuses, & dam serum (for titer serology)

• early submission + proper storage critical

  • formalin + fresh placenta, liver, kidney, & lesions

  • sterile fetal stomach contents + heart blood

  • do not touch fetal samples w/gloves

• measure & record fetus’ weight + estimated age (crown-rump length)