Sudden Death in Growing Lambs Flashcards
List common causes of sudden death in growing lambs (general)
1) clostridial
2) pastuerellosis
3) acidosis (vs CCN)
4) acute liver fluke
5) others…
Name 5 diseases caused by clostridial infection (and causative clostridia)
1) pulpy kidney (Cl. perfringens type D)
2) Braxy (Cl. septicum)
3) Black disease (Cl. novyi type B)
4) Blackleg (Cl. chauvoei)
5) Abomasitis (Cl. sodellii)
CS pulpy kidney
enterotoxemia sudden death @ 4 weeks - 8 months (big/best lambs) If still alive: severe depression, abdominal pain, grinding teeth, neuro signs (seizures, opisthotonus)
Pathogenesis of pulpy kidney?
Cl. perfringens type D in gut @ birth - UNDIGESTED CARBOHYDRATES = organism reaches high # = (w/ trypsin present & no Ab), cleaved & creates toxin, gets into blood = increased vascular permeability (leads to hyperglycemia, glycosuria, nervous changes, death)
[more complex, just not enough space]
Pulpy kidney diagnosis?
Hx of move to rich feeding
PM
C. perfringens type D in smeras w/ Gram stain, by culture, and toxin gene by PCR,
e-toxin detectable by ELISA
Pulpy kidney pathology (PM findings)
carcass good condition
no gross lesions, clear fluid in body cavities
petechial hemorrhages on lungs & epicardium
pulpy kidneys
SI contents = fluid
CS of braxy
Rapid, fatal abomasitis
sudden death of young, non-immune sheep eating frosted forage
usually store lambs & ewe lambs
If alive: sudden onset of illness w/ weakness, anorexia, +/- pyrexia
Risk factor for braxy
eating frosted kale, grass, or other forages that could damage the abomasal wall
pathologenesis of braxy
Infection of wall by cl. sept. –> alpha toxin, local & systemic effects
alpha toxin = pore forming (into cells, lysis, release of cell K+ and hemoglobin)
Braxy diagnosis
Hx of frost and no vaccination
PM
Culture, gram stain of mucosal lesion & heart blood
IMHC
Demonstration of toxin in tissue or blood
PM findings for braxy
Abomasitis
thickened abomasal / duodenal walls
edematous, necrotic, hemorrhage
excess turbid peritoneal fluid
Describe Black’s disease
- caused by Cl. novyi, liver disease - (associated w/ migration of immature fluke)
- late autumn / winter
- sudden death
CS of tetanus
common following docking/castration
- stiffness, rigidity of limbs
- can’t swallow or eructate
- convulsions
CS of blackleg
sudden death
If alive: dullness, pyrexia, toxic MM, severe lameness w/ edema and emphysema
CS of Cl. sordellii
Sudden death + acute abomasitis @ 6-12 months
Treatment and prevention of Clostridial disease?
Penicillin (esp blackleg)
Fluke control (black disease)
Vaccination = ewes booster @ 4-6 weeks pre lambing (goes into colostrum, MDA last 10 weeks), lambs vx @ 10 weeks
[have combo vaccinations, multiple strains clostridia + pasteurella]
Prevention = introduce rich food gradually (pulpy kidney), remove affected groups to pasture, housing to prevent access to frosted grass (braxy)
Disease caused by Cl. perfringens Type B
Lamb dysentery
Cl. perfringens type A causes…
Malignant edema
Cl. perfringens type C causes…
Struck
Cl. perfringens type D causes…
Pulpy kidney
Cl. septicum causes…
Braxy
Cl. chauvei causes…
Blackleg
Cl. novyi causes…
Black disease
Cl. hemolyticum causes…
Bacilliary hemoglobinuria
Cl. sordellii causes…
Abomasitis
2 causes of pasteurellosis:
M. hemolytica, P. trehalosi
At what age do you see sudden death in lambs caused by pasteurellosis from M. hemolytica?
<12 weeks (pre-weaning)
At what age do you see sudden death in lambs caused by pasteurellosis from P. trehalosi?
recently weaned (>12-20 weeks)
Dx of pasteurellosis?
Hx, CS, PM
What do you see @ PM with a pasteurella infected lamb?
edematous and congested lungs enlarged, hemorrhagic LN widespread petechiae (serosal surfaces, epicardium, kidneys) Focal necrotizing hepatitis Upper alimentary tract erosions Pleurisy & Pericarditis
Tx of pasteurellosis
Oxytet?
Combo clostridia and pastuer. vaccination! (Ovivac & heptavac P plus)
What causes acidosis?
Sudden & unaccustomed intake of high quantities of rapidly fermentable carbohydrates (grain overload).
which breed is more prone to acidosis?
Scottish blackface
CS of acidosis?
sudden death (w/in 24 hours) anorexia & bruxism (teeth grinding) distended abdomen & ruminal stasis diarrhea dehydration & toxic MM Severe metabolic acidosis = tachypnoea, hypernoea
Dx of Acidosis?
Hx, CS, PM
Rumen contents - milky grey, foul odor, rumen epithelium sloughing off
rumen pH <5.5
Prevention of acidosis?
gradually introduce to grain concentrate (feeding over 3 weeks before ad lib)
feed good quality roughage
close the feed storage
Tx for acidosis?
If emergency consider rumenotomy
Na bicarb IV or PO
Encourage forage feeding
Rumen function stimulants
