Cattle 2 Flashcards
RDA what is it, 2 main types with typical history
Abomasal dilation and torsion - generally dilation then torsion
- “RDA” = right displaced abomasum
- “RTA” = right torsion of the abomasum
- Many vets use them synonymously because dilations become torsed, and then the cow is sick
○ Blood supply to abomasum is occluded
- Typical History
○ A recently calved cow that is suddenly “off her milk” - pathognomonic
○ Looks sick, abdominal pain
What are the typical clinical signs and duration of onset for right displaced abomasum
- Typical Clinical Signs
○ Vary with severity – the blood supply is compromised
○ A high-pitch ping, high up on the right side
○ Little or no milk in udder
○ Sometimes palpate abomasum per rectum
○ Sometimes melena (bad prognosis) - BAD
○ Sometimes heart rate high heart rate - over 120-150bpm - BAD
PROGNOSTIC - a very acute condition
○ the heart rate rapidly increasing up to 160 per minute.
○ peripheral circulatory failure ‐ the animal feels cold, mucus membranes pale.
Right displaced abomasum cause and prognosis
- Cause
○ Probably similar to that of LDA (but it’s less common)
○ Abomasal atony results in a distended abomasum.
○ The distended abomasum can become displaced in a dorsal direction
○ The displaced abomasum and attached structures may rotate – compromising the blood supply - Prognosis -> uncomplicated displacement surgically is good if volvulus prognosis is guarded at best
Right displaced abomasum correction what are the steps within
a. Assess prognosis - >melena and HR >100 are bad signs when corrected - euthanasia
b. IV fluids if very shock
c. If fairly early, can correct torsion by “rocking” ‐ sweeping action
§ if very distended, may need to drain via large needle with rubber tube attached - need to be careful
§ Know when fixed, when untwist then gas leaves and disappears
d. Standard closure
e. Antibiotics and NSAIDS
Dietary abomasal impaction typical history and clinical signs
- Typical History:
○ Cows fed large amounts of poor quality roughage
○ complete anorexia
○ very scant faeces
○ and a distended abdomen - Typical Clinical Signs:
○ heart rate, respiratory rate commonly rise
○ expiratory grunt due to abdominal distension.
○ the impacted abomasum palpated in the right lower quadrant of the abdomen
Dietary abomasal impaction treatment and prognosis
○ move impacted material with paraffin oil
○ surgery right paramediam approach
○ results often poor
Physical obstruction of the pylorus what generally due to and typical history
- Due to intestinal phytobezoars from plants such as onion weed
- Typical History:
○ cattle which are grazing on country which contains large amounts of onion weed
○ sudden depression in milk yield
○ Mild distended abdomen
Physical obstruction of the pylorus typical clinical signs and treatment
- Typical clinical signs
○ a gradual distension of the abdomen
○ fluid splashing detected in the lower right flank
○ in many cases a solid lump can be detected on ballottement on the lower right abdomen ‐ this is usually a phytobezoar.
○ faeces scant and pasty. - treatment
○ surgical approach ‐ low right flank incision
○ standing or cast
○ open over phytobezoar and remove
○ suture mucous membrane lining of abomasum separately from muscle layer
Intestinal phytobezoars what size, what can result in, where harder to find
- smaller phytobezoars pass into the small intestine.
- may cause obstruction at any site along the small intestine
- Harder to find as hidden within omentum
- Less severe unless cause volvulus or intussusception
Intestinal phytobezoars common physical examination findings
○ sudden severe depression in milk yield.
○ dehydration.
○ commonly a very small amount of greenish rumen discharge observed at nares of affected animals
§ GREEN NASAL DISCHARGE INDICATION FOR LAPORAOTOMY -> intestinal blockage
○ ballottement/auscultation right abdomen ‐ may detect fluid splashing sounds.
○ rectal examination ‐
§ early stages the amount of faeces is reduced and somewhat pasty
§ Later, grey yellow faeces ‐ extremely pasty, very foul smell ‐ pathognomonic
○ as condition progresses
§ dehydration increases
§ heart rate increases
Intestinal phytobezoars treatment and prognosis
- Treatment - removal
○ Right paralumbar approach as cranial as possible
○ Careful search of intestines - palpation
§ duodenum a common site, but can be anywhere.
○ Incise over phytobezoar, remove and close intestine ‐ double layer inturning suture using O Dexon. - Prognosis -> good in early case but worsen the longer the condition is left untreated
Intussusception signs and findings
- signs with an intussusception more severe and more acute in onset than those seen with a phytobezoar.
- Findings
○ initially, colic may be observed by farmer
○ completely off milk, complete anorexia.
○ the pulse becomes increasingly fast and weak.
○ as condition progresses, dehydration increases.
○ faeces reduced in amount ‐
§ animals start to pass blood and mucus with the faeces - MELENA
§ soon only small quantities of tenacious blood stained faeces
on rectal examination may be possible (20% of cases) to palpate lesion per rectum ‐ banana shaped
Intussusception diagnosis and surgery what involved
- Diagnosis -> presence of pings in the right caudal abdomen and the presence of distended loops of bowel on rectal palpation
- Surgery
○ Usually need fluid and supportive therapy
○ right paralumbar approach, paravertebral
a. identify intussusception
b. try and gently pull it apart
c. alternatively, resect affected area
d. end to end anastomosis, using simple interrupted
e. crushing sutures 0 Dexon (long acting absorbable) -> longer functional life than catgut
Intestinal torsion what generally involve and findings
- Generally involved volvulus of the small intestines (+ large intestine) around the root of the mesentery
- Finding
○ abdominal pain ‐ the colic soon disappears
○ the heart rate becomes elevated, respiration is laboured and the mucus membranes are pale.
○ auscultation ballottement right abdomen elicits splashing sounds
○ distended loops of bowel may be detected on a rectal examination.
Intestinal torsion diagnosis/treatment and prognosis
- Diagnosis/treatment -> exploratory laparotomy
○ identify twist at root of mesentery, or may involve only part of intestine. attempt to correct twist - Prognosis
○ Good if no dying tissue and catch early, generally by the time they are presented it is poor
Dilation, volvulus and torsion of the caecum what occurs and what can look like
- dilation of the caecum usually precedes caecal torsion.
○ simple caecal dilation is not a surgical problem. - In volvulus, the apex of the cecum is rotated cranially and caecal body becomes distended
- Rotation of the caecum along its long axis is caecal torsion – which may occur around the base of the caecum and may involve the distal ileum, caecum and colon.
- Can look like LDA -> prognostic factors the same
Dilation, volvulus and torsion of the caecum signs, treatment and prognosis
- Signs
○ anorexia and abdominal pain.
○ right flank becomes distended - USUALLY DISTEND ON THE LEFT (rumen)
○ very scanty faeces. auscultation percussion right abdomen ‐ a high pitched resonant “ping” high in the right paralumbar fossa.
○ rectal ‐ dilated apex of the caecum detected in pelvic cavity. - treatment
○ Right paralumbar fossa laparotomy exteriorise apex of caecum, drain (small incision), then exteriorise until get to the twist
§ May need to get whole caecum out to get to base where twist is but easier if deflated at this point
○ correct torsion or volvulus - Prognosis
○ If twist easily then generally do well otherwise risk of secondary complications
Definition of abdominal distension, bloat and drench
- “Abdominal distension”
○ The term usually reversed for abdominal enlargement due to causes other than simple obesity - “Bloat”
○ What farmers call abdominal distension, but also the name of a specific condition - “Drench”
○ give something orally
○ give an anthelmintic by any means
Principles in diagnosing abdominal distention
- What is distended
a. left, right or both sides?
b. Is it acute or chronic
c. Is it air or fluid ?
d. Infectious, traumatic or metabolic ? - Air or fluid ?
- a “ping” means trapped air
Left abdominal distention how common, what is most likely cause and the 3 main mechanisms
- Most common
- Likely the rumen (possibly a displaced abomasum)
- Mechanisms:
a. Cannot belch gas
§ Free Gas Bloat
§ Obstruction of oesophagus -> if any fluid over cardia it WILL NOT OPEN -> will die of bloat before it opens
§ Recumbency -> lateral recumbency is an emergency -> the cardia is in liquid at this point
b. Rumen not contracting
§ Actinobacillosis of rumen/reticulum
§ Simple Indigestion
§ (Acidosis)
c. Reduced outflow from rumen
§ Vagus indigestion
§ (Dietary Abomasal Impaction -already covered)
§ (Intestinal Phytobezoars-already covered
Left abdominal distention what causes bilateral and trilateral and does LDA cause
Bilateral
- Bilateral abdominal distension is generally just a progression from left sided distension
Trilateral
- Left, right and cranial
- Problem is that once the rumen can go no further laterally -> It expands cranially and squashes the lungs -> death
LDA -> DOES NOT CAUSE BLOAT
- Cranial so behind ribs and therefore do need distend, increase pressure result in bing
What are the 3 main diseases that cause abdominal distention and causes within
- Primary (Frothy) Bloat
- Secondary (Free Gas) Bloat
○ Acute
§ Recumbency
§ (Hypocalcaemia)
§ Oesophagealobstruction
○ Chronic
§ Simple Indigestion
§ Vagus Indigestion - Right sided distension (fluid)
○ Ascites
Bloat what type of problem, 3 main types and causes within
- Is a ‘herd problem’, if one cow has it, others are at risk
1) Primary Rumen Tympany
○ “Frothy Bloat”, “Pasture Bloat”
○ Foam covers cardia so gas cannot escape
2) Secondary Rumen Tympany
○ “gaseous bloat”
○ Acute
§ Recumbency
§ (Hypocalcaemia)
§ Oesophagealobstruction
○ Chronic
§ Simple Indigestion
§ Vagus Indigestion
3) Post Mortem Tympany
○ Cows stop eructating at death!
Frothy bloat/pasture bloat which side distention and pathophysiology and things can do
○ Starts on the left side but eventually extends to the right side ○ Pathophysiology § Cow eats a large amount of Grass § Reaction in the rumen causes foam production § Foam blocks entrance of oesophagus to rumen - prevention § Cow can’t Belch § Gas keeps being produced § Cow Bloats - Bloat oil, stomach tube § Rumen squashes lungs Cow dies of respiratory failure - Emergency - STAB
Frothy bloat/pasture bloat treatment 3 main types and when does bloat generally occur
1) drenching cows with bloat
2) tubing cows with bloat - stomach tube - can also treat for obstruction
3) stabbing cows with bloat (rumenotomy)
○ When does bloat occur
§ “ruins a nice day”
§ Within 20 mins of access to bloaty pasture
§ Especially if they haven’t been fed for a while (ie after milking)
§ High moisture content, high clover content pasture
Drenching cows with bloat what use, how much give and when see relief
□ “oil calms water” and disperses the bubbles.
□ Any (mineral) oil (paraffin oil), and most detergents. (Registered products preferably!)
□ Give about 100 - 200mls oil.
□ Detergent dose varies - start with 40mls
□ Relief in about 10 minutes
Stabbing cows with bloat (rumenotomy) when do, how perform and then what do
when in respiratory distress
□ Farmer advice
® A life saving measure - not a treatment
® Left side middle of the flank
◊ There are intestines on the right side
® Use trochar and canula (tube) if possible
◊ If need to stab with pocket knives -> stand to the side and don’t want the hole to be too large (hard to stitch up) -> stitch rumen to abdominal wall which will heal eventually and leave hole
◊ Likely to cause peritoneal infection -> DRAINAGE IS IMPORTANT
® Antibiotics
® Vet possibly (depending on hole size)
□ Remember
® The hole can block up but only need enough gas out so that the cow can breathe again
® Drench her with bloat oil then
Pasture bloat prevention what are the 4 ways
1) diet - restrict pasture intake, fill animals on hay before putting on high risk pasture
2) oils
3) detergents
4) monensin
Oils to prevent pasture bloat how long work for, how give and what do in outbreak situation
Work for 2- 4 hours □ Drench the cow □ Add to water □ Flank application (they lick it off) □ Spray on paddock - in outbreak situation ® Use 100mls Bloat oil per cow ® Use 1 part Bloat oil to 40 parts water ® Spray the paddock starting at one end ® Put the fence up when the tank runs dry □ Tympanyl (can be used) - mix practice
Detergents to prevent pasture bloat what use, how give and how long give protection
□ Teric -> not as common ® Drench ® Bail ® May provide up to 12 hours protection ® Used to be common, but not so much any more
Monensin to prevent pasture bloat what is it, what does it do and types
□ Ionophore antibiotic (no withholding periods but 7d ESI)
□ changes the ratio of volatile fatty acids produced in the rumen
□ main use is to improve feed efficiency (also prevention of coccidiosis)
□ it also decreases rumen methane gas production and reduces the amount of stable foam produced during fermentation
□ Types
® Powder -Mixed in with the feed
◊ Short lasting effect
® Bloat Capsules
◊ Last 100 days
◊ 80% effective
◊ Need to remove plastic cap otherwise won’t work
◊ Have a number on the capsule so you know if eructate then can know what number cow come from to replace
Monensin to prevent pasture bloat how used, what feed put in and do you use on horses
□ Often added to the grain ration fed to dairy cattle
® Increases propionic acid production
® Prevents coccidiosis in young stock
□ Typically occurs in feed at 11-18mg/kg (dairy) or 25-33mg/kg (beef)
□ Very Very toxic for horses
® Horses 20 times more sensitive than cattle (200x more than chooks!)
® Heart and skeletal muscle death from mitochondrial dysfunction
Secondary bloat what need to do first and causes of acute secondary bloat and how to stop from dying
○ Need to find primary cause AND TREAT THAT -> stop dying from ○ Acute § can be mild or severe § Causes □ ANY recumbency □ Oesophageal obstruction ® Turnips (when too small often swallow whole - obstruction, if large will chew) ® applies, gold balls, potatoes ® Often stuck near base of heart □ Hypocalcaemia Treatment § Treat underlying condition □ Buscopan - off label ® Hyoscine ◊ N-butyl bromide 4 mg/mL, dipyrone500 mg/mL ◊ Smooth muscle relaxant ◊ Use in cattle is off label
Chronic secondary bloat how severe and the 5 main mechanisms
§ generally not severe
1) Dysfunction of oesophageal groove and eructation
2) Compression of oesophagus
3) Simple indigestion
4) vagus indigestion
5) tetanus
Chronic secondary bloat resulting from simple indigestion clinical findings, diagnosis and treatment
® Clinical findings
◊ Off milk (chronic indicator), Off feed, Reduced rumination but cardinal signs normal
◊ Abdominal discomfort, Faecalchanges, mild bloat
® Diagnosis
◊ Based on history and clinical signs
◊ Differentiate from serious conditions
◊ History & Examination, Revisit if necessary
® Treatment
◊ Epsom salts (MgSO4) several times a day to encourage rumen emptying
◊ Alkalizing agents if excessive grain involved
◊ Vinegar if excess protein involved
◊ Cud transfer ?
◊ Palatable, quality feed
Chronic secondary bloat resulting from simple indigestion causes
® Causes ◊ Sudden change to diet ◊ Indigestible roughange; very wet grass; overheated, frosty or sour feeds ◊ Oral antibiotics ◊ Temporary disruption to fermentation ◊ Often self -limiting
Chronic secondary bloat resulting vagus indigestion what type of problem, distention of what structures, what occurs and causes
® An OUTFLOW problem
◊ At either end of the abomasum
® Progressive distension of Rumen/Reticulum
® Vagal nerve dysfunction - often secondary
◊ Runs along both sides of the oesophagus and terminates in branches that innervate the forestomach and abomasum -> many areas for disruption
◊ Causes
} Rumenitis and Peritonitis (impact vagal nerve)
} DECREASE OUTFLOW TO ABOMASUM
Secondary free gas bloat diagnosis/presentation
§ Gradual onset of disease
§ Abdominal distension, often with large rumen gas cap
§ Hypermotility of rumen (3-6 contractions per minute, but weak and ineffective) -> ONLY ONE IF BLOATY AS WELL
□ Often funny sounding -> ineffective contraction
□ DIFFERENTIATE FROM SIMPLE INDIGESTION
§ Ventral rumen sac enlarges –L shape, can feel per rectum
§ Sometimes, bradycardia (40bpm)
§ Small quantities of pasty or runny faeces -> simple indigestion -> normal faeces
Secondary free gas bloat treatment what are the 3 things needed and what do
1) Address Primary cause □ Peritonitis, obstruction, rumenitis □ Antibiotics / anti-inflammatories ® Antibiotics - oxytetracycline, TMS ® Anti-inflammatories ◊ Useful because they } Reduce inflammation (!) } Act as painkillers –which may increase appetite and exercise - short acting - flunixin, long acting - meloxicam ◊ NOT PHENYLBUTAZONE! - FORBIDDEN 2) Stimulate rumen contractions □ Feed, appetite stimulants, drugs - skyes drench 3) Rumenotomy □ Emptying and cud transfer
Sykes drench what does it do and the ingredients within
- appetite stimulant -> drink more -> pass more
- Magnesium sulphate
- Ammonium sulphate
- Calcium hydroxide
- Cobalt sulphate
