Farm Animal Flashcards
What is the volume of the rumen?
180-200 litres
At what pH do the organisms digesting plant matter no longer function?
6.2 or below
What is the main volatile fatty acid produced by the rumen at normal pH?
Acetate - milk fat
Describe the process via which rumen acidosis occurs
Starch and sugar digestion causes a decrease in pH
Organisms tolerating this lower pH predominate
Propionate and butyrate are produced
At even lower pH lactate is produced leading to acidosis
What provides the buffering system within the rumen and how?
Saliva
- 100-150l produced a day
- Contains 3.5kg bicarbonate
- Produced by chewing and ruminating
What causes acute ruminal acidosis and is it serious?
Sudden ingestion of large amounts of fermentable carbohydrates
- Breaking into feed stores
- Overfeeding of concentrates
- Sudden lack of forage or straw bedding
Life threatening clinical emergency with a poor prognosis
What are the clinical signs presenting with acute ruminal acidosis?
Dull and recumbent
Ataxia
Anorexia
Blindness
Dehydration
Laminitis
Rumen stasis
Abdominal distension
Increased pulse
Sunken eyes
What is the treatment for acute ruminal acidosis?
5% Sodium Bicarbonate slow I/V - 5 litres per 450kg over 30 minutes
I/V fluids isotonic NaCl 150ml/kg over 6-12 hours
Oral Mg Hydroxide - 500g/450kg
Rumenotomy/Rumen lavage
What is SARA?
Sub-acute ruminal acidosis
Describe sub-acute ruminal acidosis
Ill defined herd syndrome
Low milk fat and depressed milk yields
Laminitis
Reduced appetite
Liver abscesses
Haemoptysis (coughing blood) and epistaxis caused by caudal vena cava thrombosis
High herd culling rate
What is almost diagnostic of chronic, sub-acute acidosis?
Repeated cases of epistaxis or haemoptysis within a herd
What changes with the clinical signs of LDA depending on severity?
Left flank distension changes
- More severe it gets the more the flank becomes distended
What clinical signs present with ruminal bloat?
Distension of left flank
May present as sudden death
May appear distressed - dyspnoea
May be recumbent
May be standing quietly
What are the two types of ruminal bloat?
Frothy bloat
Gaseous bloat
Describe frothy bloat
Stable foam forms in the rumen
Gas gets trapped preventing eructation
Usually cattle on pasture caused by soluble leaf proteins
- Legumes
- Clovers
- Alfalfa
- Cereal rich diets
Can be sudden and severe leading to sudden death
What is the treatment for frothy bloat?
Remove cattle from pasture/feed source
Do not use trocar or stomach tube
Antifoaming agent/surfactant to disperse foam
Sit in sternal recumbency if cow down
What can be used as an antifoaming agent/surfactant?
Poloxalene (Bloat Guard)
Mineral oil/corn oil
Simethicone (BIRP)
How can frothy bloat be prevented?
Careful pasture management
Care using lush pastures
Consider strip grazing/buffer feeding to prevent rapid intake of lush pasture
What can cause gaseous bloat?
Excessive carbohydrate intakes
Oesophageal obstruction
Milk fever
Lateral recumbency - blocks cardia
How should gaseous bloat be treated?
Relieve gas with stomach tube/rumen puncture
What is the proper name for hardware disease?
Traumatic reticulo-peritonitis
Describe hardware disease
Metal object is eaten
Remains in reticulum
Can stay for years
Penetrates wall of reticulum causing a variety of problems
What problems can be caused by hardware disease?
Local peritonitis
Diffuse peritonitis
Pericarditis
Liver abscess
What are some common causes of hardware disease?
Wire from tyres (silage clamps)
Wire from builders/bales
Nails, screws etc.
TMR - wires can be spread to many animals at once
What are the clinical signs that present with hardware disease?
Vague with numerous presentations
Milk yield drops with reduced appetite
Increased temperature
Arching of the back
Rumen contraction rate down
Reduced reticulo-rumen movements
Jugular pulse
Splashing sounds over heart
What are the three diagnostic tests used for hardware disease?
Withers pinch
Pole test
Eric Williams test
Describe the Eric Williams test
Pain just before the reticulum-rumen part of the rumen cycle starts
- Grunts
- Holds breath
- Shuffles feet
What is the treatment for hardwire disease?
Conservative - tie animal up with feet raised
Parentral antibiotics 5-7 days
Pain relief
Rumenotomy - remove wire
Slaughter
Which animals are left displaced abomasums more common in?
High producing dairy cows
Usually within 6 weeks of calving
What are some causes of left displaced abomasum?
Poor management over transition period
High concentrate diet
Insufficient fibre
Diet changes made too quickly
Other diseases
Genetic factors
What are the clinical signs presenting with left displaced abomasum?
Mild initially but highly variable
Drop in milk yield
Reduced or changed appetite
Cases will have raised ketone levels in blood and urine
Loss of body condition
Reduction of rumen contractions
How can left displaced abomasum be diagnosed?
Pings over the whole left flank
What is the treatment for left displaced abomasum?
Rolling
Roll and toggle
Right flank omentopexy
Left flank omentopexy
Right paramedian abomasopexy
What are some other rare causes of left side pings?
Bloat
Rumen collapse
Vagal indigestion
Pneumoperitoneum
Why can right displaced abomasum be a problem?
Twist to become abomasal torsion or volvulus leading to:
- Acute intestinal obstruction
- Blood supply compromised
- Ischaemic necrosis
What are the clinical signs of right displaced abomasum?
Cow sick
Shocked
Dehyrated
Pain
What should be done to treat right displaced abomasum?
Surgery within hours
Slaughter on humane grounds
Describe caecal dilation
Similar predisposing factors to LDA
Clinical signs similar to LDA
How can caecal dilation be diagnosed?
Rectal examination
- Caecal apex palpable coming into pelvic inlet
Ping right paralumbar fossa
What is the treatment for caecal dilation?
Medical fluids and high fibre diet
Surgery if problem persists
What is the treatment for volvulus?
Drain surgically
Exteriorise
Pack abdomen
Incise apex and drain
What can cause a ping in the right paralumbar fossa?
Gas in spiral colon
- Not clinically significant
What can cause pings on the left and right side of a cow?
Left side
- LDA
- Can be other causes
Right side
- RDA
- Abomasal volvulus
- Caecal dilation
- Volvulus and gas in spiral colon
Describe rumen collapse
Clinical sign rather than a disease
Occurs in cattle suffering severe inflammatory disease
Results in anorexia and shrinkage in rumen size
Large dull ping over dorsal left abdomen
Rectal examination confirms presence
What is the treatment for rumen collapse?
Not surgical!
Treat primary disease
Consider fluid via stomach tube
Ensure diagnosis is correct
- Make sure ping has been heard correctly
What is the most common abdominal disorder of cattle in the UK?
Left displacement of the abomasum
What differs between left and right displaced abomasum?
Left has ingesta continuing to pass through at a slower rate
Right the organ can become completely occluded
What are some factors that may reduce abomasal motility?
High concentrate/low fibre rations
- Flow of VFA increased into abomasum
- Gives a higher risk of displacement
Periparturient disease
- Hypocalcaemia and insulin may play a role
Genetic selection
- Channel Island breeds
- Deep chested Holsteins
What are the two most common presentations of LDA?
High yielding cow
- Fed too much concentrate too soon after calving
Heifer
- Metritis following dystocia
- Results in reduced dry matter intake
- Exacerbated by illness and bullying
What are the signs of left displaced abomasum?
Recently calved cow/heifer
Sudden onset inappetence/anorexia
Milk drop (30-50% reduction)
Scour
Rapid loss of condition
Ketosis
Depressed ruminal activity
Temperature may be normal or slightly raised
How can left displaced abomasum be diagnosed?
Auscultate over upper part of last intercostal space
Listen for a ping
Once ping located always tinkle (push flank with fist or knee)
Usually develop hypochloraemic, hypokalaemic metabolic alkalosis
Severe ketosis (Rothera’s test)
Paradoxical aciduria
How can left displaced abomasum be treated conservatively?
Rolling
- Cast cow onto right side
- Slowly roll onto back and keep for 10 minutes
- Gradually bring her over to lie on left side
- Allow to stand
- Auscultate for ping and listen for emptying noises
Combine with medical treatment
- Buscopan Compositum
- Metoclopramide
- Instant Coffee
- Potassium chloride
What are the signs for right displaced abomasum?
Dilation and displacement:
- Sudden onset anorexia
- Milk drop
- No rumination
- Sprung last rib on right side
- Initial scour followed by past faeces
Following volvulus:
- Cessation of faecal output
- Normal/low temperature
- Heart rate varies
- Dehydration
- Normal/reduced respiratory rate
- Cool extremities or death
How can right sided abomasal displacement be diagnosed?
Ping on right hand side extending cranially to 9th intercostal space
Distended organ palpable at arm’s length on right side
Sever hypochloremic, hypokalaemic metabolic alkalosis
Ketosis and hypocalcaemia also present
What are medical treatments for right displaced abomasum and when should it be used?
Metoclopramide and Buscopan Compositum
Only used if animals value does not warrant surgery costs
Which animals does caecal dilation and volvulus commonly present in?
Cows with early lactation on a high concentrate diet or on lush pasture
How does caecal dilatation and volvulus occur?
Fermentation occurs
Gas dilates the caecum
Free distal end is not suspended by mesentery
Free to rotate producing volvulus
What are the signs of caecal dilatation and volvulus?
Rapid onset anorexia and milk drop
Decreased faecal output
TPR normal
Right paralumbar fossa filling
Absence of rumination
Colic
Dehydration
Elevated heart rate
How can caecal dilatation and volvulus be diagnosed?
Ping in right caudal abdomen
No further foward than first three caudal rib spaces
Large distended gas filled sausage palpated filling the pelvic cavity on rectal examination
Mild metabolic alkalosis
What is the medical treatment for caecal dilatation and volvulus?
Buscopan 30ml IV two doses at 12 hour intervals
Take off concentrate feed for 5-7 days
What needs to apply for medical treatment of caecal dilatation and volvulus?
Normal heart rate
Anorexia with some faeces being passed
Dehydration is absent or mild
What needs to apply for surgical treatment of caecal dilatation and volvulus?
Raised heart rate
Total anorexia with no faecal output
Dehydration and colic
