Unit 2 - Small Ruminant Respiratory + CNS? Flashcards
What type of breeders are sheep and goats?
Seasonally polyestrous - short day breeders
When does breeding of sheep and goats typically start?
In July
When is maximum fertility for sheep and goats approximately?
October
How long is gestation in sheep?
144-151 days
How long is gestation in goats?
150 days
What are the main small ruminant respiratory diseases?
Mannheimia haemolytica Bibersteinia trehalosi Pasteurella multocida Histophilus somni (goats) Mycoplasmas Corynebacterium pseudotuberculosis Trueperella pyogenes PI3 RSV Adenoviruses Reoviruses
What does Mannheimia haemolytica cause in lambs?
Neonatal lamb septicemia
What lesions will be found at post mortem in lambs with Mannheimia haemolytica infection?
Patchy or consolidated area in the lungs, hemorrhages on serosal surfaces, and areas of necrosis
What is the major predisposing factor to neonatal septicemia?
Poor ventilation
How is neonatal septicemia prevented?
Have good ventilation, bedding/cleanliness/moisture, and shearing ewes
How does shearing ewes aid in prevention of neonatal septicemia?
It reduces the moisture in the barn, makes teats more accessible, and allows for more ewes in lambing areas
How is neonatal septicemia treated?
Naxcel is approved for respiratory infections
Tilmicosin
LA200
What does Mannheimia haemolytica cause in feeder lambs?
Enzootic and sporadic pneumonia
What are the predisposing factors for feeder lamb pneumonia?
Crowding, processing, stress, and dust
What clinical signs are associated with feeder lamb pneumonia?
High fever, variable coughing, and rapid respiration
What will you find on necropsy in Mannheimia haemolytica pneumonia lambs?
Fibrino-hemorrhagic pneumonia, pleuritis, and pericarditis
Anterior and ventral areas in the lungs
How do you prevent respiratory disease in sheep and goats?
Decrease stress, crowding, dust, etc.
Improve air quality
Immunization for some agents
What antibiotics are approved in small ruminants?
Ceftiofur (Naxcel) - sheep and goat respiratory
Tilmicosin - sheep respiratory; kills goats
Procaine Pen-G- Sheep pneumonia
Aureomycin (doesn’t really work) - Campy abortion
Neomycin oral - enteritis in sheep and goats
Terramycin ophthalmic - sheep
What does Bibersteinia trehalosi cause in small ruminants?
Septicemia in feeder lambs
Respiratory disease in goats
What does Mycoplasma ovipneumoniae cause?
A chronic pneumonia/cough
What is M. ovipneumoniae often secondary to or vise-versa?
Mannheimia
What predisposes small ruminants to M. ovipneumoniae?
Poor ventilation
T/F: Persistent coughs can result in rectal prolapses in small ruminants.
True
How do you prevent and control M. ovipneumoniae?
Improve air quality
There is no immunization available
How is M. ovipneumoniae treated?
You can try antimicrobials, but the damage has already been done
What does M. capricolum subsp. capripneumoniae cause?
Contagious caprine pleuropneumonia (CCPP)
CCPP is a very ______ respiratory disease. Transmission is ______. CCPP is characterized by a severe __________ that is confined to the ______ cavity.
Aggressive
Rapid
Pleuropneumonia
Thoracic
What clinical signs are associated with peracute Mycoplasma mycoides subspecies mycoides LC infection in goats?
High fever, opisthotonus, death within 1-3 days, polysynovitis, and CNS signs in young kids
What clinical signs are associated with acute to subacute cases of M. mycoides subsp. mycoides LC in goats?
Polysynovitis and polyserositis
Fibrinous interstitial, broncho-or pleuropneumonia +/- mastitis
What differential should be considered with peractue forms of M. mycoides LC infection?
CAEV
What differential should be considered with acute to subacute forms of M. mycoides LC infection?
CCPP
What clinical disease has C. abortus been associated with in small ruminants?
Respiratory disease, conjunctivitis, and polyarthritis
Abortions as well, but we will get to that later
T/F: Ovine adenovirus causes severe respiratory disease in sheep
False - it produces a mild or inapparent disease in lambs that is most likely to predispose them to an infection with another agent
What does Parainfluenza 3 cause?
Acute respiratory disease in sheep
T/F: The bovine vaccine provides some protection against PI-3 in small ruminants
True
T/F: Respiratory syncytial virus is a serious respiratory pathogen where death is sudden and immunity is rare
False - Up to 50% of sheep have antibody
It may predispose small ruminants to respiratory disease
What does Respiratory syncytial virus do on a cellular level?
Syncytia in alveoar macrophages
What does Reovirus cause?
Experimental rhinitis, conjunctivitis, diarrhea with development of catarrhal or purulent pneumonia, pleuritis and pericarditis
What causes ovine progressive pneumonia (OPP)?
Non-onogenic lentivirus
What clinical signs are associated with OPP?
Progressive loss of condition, emaciation, and dyspnea
Fatal once they develop clinical signs
Hard bag
Encephalitic disease - slowly progressive ataxia, head tilt, and trembling of the lips
What lesions does OPP cause?
Massive lymphocytic infiltration of the lungs that may weigh 2-3x normal
How is OPP diagnosed?
Clinical signs, AGID test, cELISA, and PCR
What OPP diagnostic method is good for screening whole flocks?
AGID
What OPP diagnostic method may miss early infections?
cELISA
What OPP diagnostic method detects viral RNA and is expensive?
PCR
How is OPP prevented/controlled?
Test and cull
Prevent colostral transmission from positive ewes to lambs
How is caprine arthritis-encephalitis (CAEV) spread?
Colostrum and milk
What population of goats gets the encephalitic form of CAEV?
Young kids - you first see clinical signs 1-4 months of age
What lesions does the encephalitic form of CAEV cause?
Loss of white matter architecture and replacement with gitter cells, lymphocytes, and debris
What clinical signs does the encephalitic form CAEV cause?
Ataxia, posterior paresis, tremors, abnormal posture, tetraparesis or paralysis
They may be stunted and have interstitial pneumonia
What population of goats get the arthritic form of CAEV?
Adults > 1 year of age
What lesions does the arthritic form of CAEV cause?
Proliferative synovitis - villous hypertrophy, synovial cell hyperplasia, and infiltration by mononuclear cells
Less severe CNS
How is CAEV diagnosed?
Characteristic lesions cELISA IHC AGID PCR
How do you treat the CNS form of CAEV? Arthritic form?
CNS - not very successful
Arthritic - supportive care and good nutrition
How do you control CAEV?
Test and cull
Prevent colostral transmission
What is the etiologic agent of pulmonary adenomatosis?
Type D Retrovirus
What population of small ruminants is affected by pulmonary adenomatosis?
Sheep of all ages - slow onset, CS of all ages are susceptible
Rare in goats
How is pulmonary adenomatosis transmitted?
Via virus in nasal secretions
What clinical signs are associated with pulmonary adenomatosis?
Progressive respiratory signs with fatal secondary pneumonia
What lesions are associated with pulmonary adenomatosis?
Lungs that are extensively infiltrated with tumors
How is pulmonary adenomatosis diagnosed?
Clinical signs
Histopath - adenocarcinomas from type 2 alveolar epithelial cells
How do you treat pulmonary adenomatosis?
There is no treatment
How is pulmonary adenomatosis controlled?
Slaughter
What causes enzootic nasal adenocarcinoma in sheep? Goats?
Sheep - ENTV1
Goats - ENTV2`
How are enzootic nasal tumor viruses spread?
By contact with nasal secretions of infected animals
T/F: Enzootic nasal adenocarcinomas tend not to metastasize, but are routinely fatal.
True
How are enzootic nasal adenocarcinomas diagnosed?
Radiograph or endoscopic exam
PCR
IHC
What codons determine the susceptibility of a sheep to developing the most common strains of Scrapie?
Codon 136 and 171
What genotypes for codon 136 are susceptible to Scrapie? Not susceptible?
AV and VV
AA is not susceptible
What genotypes for codon 171 are susceptible to scrapie? Not susceptible?
QQ, QH, and HH are susceptible
RR, RQ, and RH are not susceptible
In what population of sheep are variant scrapie strains found?
In sheep with ‘resistant’ genotypes
How may variant scrapie strains arise?
From spontaneous mutation
Goats with serine at codon ______ and lysine at ______ have been recognized as more resistant or immune to scrapie.
146, 222
Those w/o are highly susceptible
How is scrapie transmitted?
Transplacental
Contact with fetal membranes is considered to be the highest risk factor
What disease is similar to Scrapie, transmits easier, and can be transmitted via the fecal-oral route, urine, saliva, carcass decomposition, and possibly semen transmission?
Chronic Wasting Disease of Deer and Elk
Why are extensive decontamination methods required to control CWD?
Because prions can build up in confinement facilities
What clinical signs are associated with Scrapie?
Insidious onset of subtle behavior changes Rubbing wool off behind elbows and base of tail Nibbling of the legs Ataxia/unsteadiness Hopping gait Wasting Unable to rise Blindness
How is Scrapie prevented and controlled?
Use RR rams and S146/K122 bucks
Do not add ewes to a flock unless genotyped
Slaughter and proper disposal of positive sheep
Trace-back
What initiates the scrapie flock certification program?
Sheep producers
Who controls the scrapie eradication program?
State-federal cooperative program
What are the basic rules for scrapie animal ID tags?
An ID is required for the following:
When sheep leave a farm
All sheep over 18 months of age
All ewe lambs not sold directly to slaughter
All breeding animals except low-risk commercial goats
Goats in contact with sheep
Sheep and goats going to exhibitions/fairs except wethers
When in doubt - tag
How is scrapie diagnosed?
Clinical signs
Histopath on the brain stem and spinal cord
Blood test
IHC on rectal biopsy
How does the Protein Misfolding Cyclic Amplification (PMCA) work?
The sample is mixed with normal brain tissue
If present, prion protein acts as a template and chains of abnormal protein form
Sample is exposed to ultrasound to break up protein chains
Sample has many more templates and is allowed to form new chains (amplification)
What sampling programs are available for Scrapie?
Regulatory Scrapie Slaughter Surveillance
Vets and owners can submit samples for testing
Scrapie Flock Certification program
Is the US scrapie free?
Not according to OIE