caprine/ovine infectious dz

Caseous lymphadenitis: who

sheep

goats

horses

cattle

camelids

zebras

humans - ZOONOTIC

Caseous lymphadenitis: agent

Corynebacterium pseudotuberculosis

Caseous lymphadenitis: bacteria

Gram +, intracellular facultative anaerobe 

Caseous lymphadenitis: transmission

Contact with exudate between animals - inhaled, ingested or crosses skin via break in epidermis

sheep - shearing

goat: opening of abscesses in feed bunks, water, etc. 

Contaminated equipment: shearing tools, milking equipment 

Hardy in the environment and persists for several mos

Caseous lymphadenitis: pathophys

Facultative intracellular organism 

Virulence factors: cell wall withstands lysosomal degradation and phospholipase D exotoxin

Caseous lymphadenitis: forms

internal and external

Caseous lymphadenitis: c/s in goats

External abscesses mass +/- purulent drainage

HEAD AND CHEST

Location: mandibular, parotid, pre-formal, prescapular LN 

Caseous lymphadenitis: c/s in sheep

internal abscesses- HIND END

Weight loss >>

Locations affected: lungs, kidneys, mediastinal/bronchial/mesenteric/lumbar LNs

Caseous lymphadenitis: dx options

false positives in <6 mos due to passive transfer

Isolate bacteria from draining wounds or abscesses 

Clinically does not grow well on culture; textbook will say it does 

SHI(synergistic hemolysin inhibition test):

Able to monitor the prevalence or expo of incoming animals or to detect subclinical infections;

tests for antibodies

Serology 

Paired titers: collected at 2 weeks or more apart 

Result: 4 fold rise 

Single titer

Screening on herd or new incoming

Caseous lymphadenitis: tx

often not rewarding

culling is rec

Abxs not warranted because it is anaerobic and less effevtive

Caseous lymphadenitis: blood agar

It's fairly slow growing; it often takes 48 hours to grow in culture and has dry “hockey puck” colonies that can easily be moved around on agar.

Caseous lymphadenitis: incubation

8-9 days

detectable in 2-6 mos

Caseous lymphadenitis: horses

pigeon fever

Caseous lymphadenitis: other ddx

neoplasia

wattle cyst

caprine arthritis encephalitis virus: agent

non-oncogenic lentivirrus

caprine arthritis encephalitis virus: transmission

VERTICAL »»

horizontal: colostrum/milk

fomites, direct contact and resp droplets (RARE)

caprine arthritis encephalitis virus: incubation

mos to years

caprine arthritis encephalitis virus: syndromes

leukoencephalomyelitis

polysynovitis-arthritis

chronic interstitial lymphocytic pneumonia

caprine arthritis encephalitis virus: leukoencephalomyelitis

Young kids (2-6 ms)

Ascending paralysis starts in HLs  

caprine arthritis encephalitis virus: Polysynovitis-arthritis 

Mainly young adults - 2-6 y/o; can be any age

Joint enlargement, intermittent lameness 

Carpus >> stifle, hip, AO, hocks

Progress to walking on carpi to recumbency 
Inability to maintain weight 

large swollen knees with degenerative joint changes 

Symmetric firm swelling of mammary gland

Loss of production ability  

caprine arthritis encephalitis virus: Chronic interstitial lymphocytic pneumonia

Adults 

Progressive weight loss and dyspnea

caprine arthritis encephalitis virus: dx

Serology: ELISA looking for antibodies

Necropsy

caprine arthritis encephalitis virus: tx

None - CULL

Arthritis: initially - NSAIDS, analgesics but dz will progress and these will not be efficacious 

Interstitial pneumonia; steroids - disease will progress beyond what the steroids can help with; But will ultimately euthanize (DO NOT TAPER)

Encephalitis: euthanize

ovine progressive pneumonia: aka

Maedi-Visna (NAVLE name)

thin ewe syndrome!

ovine progressive pneumonia: transmission

colostrum or milk

direct contact

ovine progressive pneumonia: who

mature adult sheep »»

ovine progressive pneumonia: c/s

Weight loss despite good app - thin ewe syndrome 

Progressive respiratory insufficiency 

Indurative lymphocytic mastitis - poor milk production and lamb losses

+/- progressive posterior paresis

Arthritis 

Death in 6-12 mos from onset of C/S

ovine progressive pneumonia: dx

hx / c/s / lack of response to tc

serology: ELISA

ovine progressive pneumonia: necropsy

lungs are enlarged and heavy

thoracic LN enlarged

gray-brown color, gray spots

lymphoid infiltration of alveolar walls

ovine progressive pneumonia: tx

NONE - testing and culling 2x a year

pulmonary adenomatosis: name

ovine pulmonary carcinoma

sheep pulmonary carcinoma

ovine progressive pneumonia: agent

oncogenic retroviral infection of lungs

pulmonary adenomatosis: transmission

horizontal

pulmonary adenomatosis: c/s

Progressive weight loss 

Resp insufficiency 

Profuse nasal discharge - esp when rear legs are raised 

Death w/in few mos of C/S

pulmonary adenomatosis: dx

no antemortem tests

PCR or histology at necropsy 

Heavy, wet lungs 

Large, firm gray masses

pulmonary adenomatosis: tx

clinical suspicion cull!

mycoplasma spp: which

bovis

mycoides subsp capri

ovinpneumoniae

capricolum capripneumoniae

polyarthritis

keratoconjunctivitis

mycoplasma spp: who

limited to goats

mycoplasma spp: bovis

resp disease

chronic pneumonia

polyarthritis

otitis

conjunctivitis

mycoplasma mycoides: forms

mastitis

polyarthritis

keratoconjunctivitis

mycoplasma mycoides: clinical syndromes in kids

Peracute illness with high fevers (105-108) + death w/in 12-24 hours 

CNS syndrome with opisthotonos + death within 24-72 hours 

Acute to subacute syndrome of high fevers, multiple joint effusions or pneumonia

80-90% fatality rate

mycoplasma ovinpneumoniae: where

upper resp tract in goats and sheep

mycoplasma ovinpneumoniae: transmissiion

Asymptomatic  Mild resp dz  Severe pneumonia and death  Others  Lethargy  Fever  Decreased app  Cough  Nasal discharge  Decreased milk production

Mycoplasma carpicolum capripneumoniae: where

africa, asia, and middle east

Mycoplasma carpicolum capripneumoniae: who

goats »

exotic ungulates

Mycoplasma carpicolum capripneumoniae: transmission

close contact and resp droplets

Mycoplasma carpicolum capripneumoniae: syndromes

peracute: die w/in 1-3 days with minimal signs

acute: fever, labored breathing and generally diet in 7-10 days

chronic: chronic cough, nasal discharge, debilitation

Mycoplasma carpicolum capripneumoniae: death and sickness

100% morbidity

70-100% mortality

contagious ecythma: aka

sore mouth

scabby mouth

contagious ecythma: agent

parapoxvirus

contagious ecythma: incubation

2-14 days

contagious ecythma: transmission

direct contact or fomites

contagious ecythma: who

sheep

goats

young, immunocompromised

camelids

wild ruminants

contagious ecythma: c/s

Crusting  usually around the commissures of the lips Proliferative lesions in skin of lips  Nostrils  Oral mucosa  Teats  Occ - vulva

contagious ecythma: dx

typical lesions

definitive: electron microscopy, PCR or IHC of crusts

contagious ecythma: tx

none - self-limiting

tube feed if affecting intake and tx secondary infections

bluetongue: agents

orbivirus

bluetongue virus

bluetongue: vector

culicoides midges

bluetongue: who

sheep, and wild rums (deer and bison)

bluetongue: zoonotic?

no

bluetongue: syndromes

repro

systemic hemorrhagic vial fever

bluetongue: c/s

Reproductive 

Abortions, weak lambs, teratogenic effects  

Systemic viral hemorrhagic fever 

GI, lung, skin 

Vascular endothelial damage = hemorrhage, petechiae

Fever 

Facial edema 

Hyperemia 

Cyanotic tongue  CLASSIC

Coronary band lesions 

Offspring will have hydranencephaly

bluetongue: DX

ELISA - core VP7 protein of BTV 

Quantitative PCR

bluetongue: tx

supportive

peste de peti: who

goats and sheep

peste de petits: agent

morbilivirus in paramyxoviridae

peste de petits: where

not US

africa. asia and reported in Euproe

peste de petits: transmission

close contact with infected animals

peste de petits: c/s

fever

necrotic stomatitis

gastroenteritis

pneumonia

nasal dischatrge

d+

dehydration

epizootic hemorrhagic disease: what

closely related to bluetongue

epizootic hemorrhagic disease: who

deer

reported in sheep, cattle and camelids

epizootic hemorrhagic disease: c/s

sore muzzle, hyperemia of oral membranes

epizootic hemorrhagic disease: transmission

culicoides midges - like bluetongue

scrapie: what

transmissible spongiform encephalopathy

scrapie: agent

prion

scrapie: incubation

2-7 years

scrapie: transmission

birthing season »

placenta and fluids

oral uptake

scrapie: who

sheep »

1-5 years

scrapie: c/s

clinical course slow over several months

•Early behavioral changes + weight loss

•Separate from herd, nervous, restless

•Pruritus of increasing intensity

•Head, withers, flanks, back, rump, base of tail, lower limbs

•Can cause ocular lesions or aural hematoma from scratching

•Reflex nibbling

•Tremors, cerebellar ataxia, apathy, exercise intolerance --> stupor, collapse, convulsions

•Death from convulsions or starvation

scrapie: dx

Biopsy of the lymphoid tissues inside of the third eyelid or the tonsils. Alternatively, histology of the brain for characteristic changes of bilaterally symmetric intracytoplasmic vacuolation of neurons.

Can confirm with immunohistochemistry for prion protein fibrils

scrapie: tx

none - cull