Bovine surgery 3 - abomasum Flashcards
what animals are abomasal displacement syndromes most common in?
- Most common in high production dairy cows
types of abomasal displacements
- Left displacement of the abomasusm (LDA) (most common)
- Right displacement of the abomasum (RDA)*
- Right side volvulus of the abomasum (RVA)*
> *may be 2 stages of progression of the same syndrome
abomasal displacement - changes and issues with this anatomic malpositioning
- Stretching of lesser omentum & attached structures
- Abomasum is suspended by lesser omentum
- Partial outflow obstruction occurs because duodenum is compressed by stretching
- In case of LDA also occurs due to compression under rumen
LDA costs
- Economic loss
- Decreased milk production
- Cost of treatment
- Premature culling
- Increased mild of complicated ketosis and metritis
Predisposing factors: LDA? common time of occurence?
Predisposing factors well established in dairy cattle: reduction in abomasal motility and accumulation of gas are prerequisites
- Lactation stage
> Occurs early in lactation (first 2-4 weeks)
* Anatomy
* Genetics
* Nutrition
* Metabolism
* Management/environment
LDA - predisposing anatomy factors, esp around late pregnancy?
- In late pregnancy, abomasum pushed in cranial & transverse position by large
uterus - Combination of decreased feed intake & expanding uterus pushes rumen dorsally
- Sudden reduction in uterus following calving leaves void for abomasum to slide into void
LDA - predisposing genetic factors
Breed based predisposition
> Research into whether genes associated with motility are implicated
LDA - predisposing nutrition factors
- High concentrate low fibre rations implicated in many studies
- Negative energy balance in periparturient period: decrease in appetite, and increased milk production – fat mobilized from adipose tissue resulting in high blood concentration of non-esterified FA and lipid accumulation in liver. More likely to develop DA if high concentration
- Low postpartum calcium levels: goal is to prevent or reduce metabolic alkalosis, which alters parathyroid hormone receptor and reduces ability of body to mobilize and retain calcium
LDA - predisposing metabolic factors
- Increased insulin resistance
- Stress & age
LDA - predisposing management / environment factors
Housing at high density is complex systems and overconditioning in dry period implicated
LDA diagnosis
- History
> Decreased milk production and/or appetite
> May be depression, scant feces - clinical signs
> Auscultation and percussion of left sided tympanic ping
> Centred over last few ribs on a line from elbow to tuber coxae
> Often ping is transient as gas enters or leave abomasum – ‘floating DA’
> If remains in same place consistently, suspect adhesions from abomasal ulceration - Further steps for diagnosis if necessary
> Pass tube into rumen and blow air, listen to paralumbar fossa – is rumbling
sound from rumen close or distant?
> Collection of fluid from rumen – elevated rumen chloride (normal is less than 30 mEq/L)
DDX for left sided ping:
DDX for left sided ping: combine information from nature of ping and rectal examination
* LDA
* Ruminal tympany
* Pnuemoperitoneum
* Rumen void
LDA - transient vs consistent ping meaning
- Often ping is transient as gas enters or leave abomasum – ‘floating DA’
- If remains in same place consistently, suspect adhesions from abomasal ulceration
RDA lab data
- similar to LDA, may have down Cl-, down K+, metabolic alkalosis
- hemoconcentration
RVA lab data
- sequestration of HCL in abomasum > more severe down Cl-, down K+, metabolic alkalosis, hypocalcemia ?
- eventually get overriding metabolic acidosis from dehydration, shock & lactic acid production
