Ruminants Flashcards
What are the predisposing factors to displacement of the abomasum?
Hypocalcaemia Genetic predisposition Strenuous activity Abomasal atony Increased gas production (e.g. grain rich feed) Concurrent diseases e.g. metritis
What is the general underlying cause of erosive and ulcerative gastritis in cattle?
What are some examples of causes?
Increased contact time between epithelium and abomasal acid.
e.g. Dietary change, acidosis, BVD, impact, displacement, long periods with empty abomasum
What are the consequences of parasitic gastritis in cattle, such as that caused by ostertagiosis?
Ill-thrift Oedema Diarrhoea Protein loss Impaired acid secretion and elevation of gastric pH Epithelial necrosis Secondary bacterial infection
What does conservative treatment of a left displaced abomasum typically entail?
Casting and rolling (right lat. to dorsal, pause, to left lat.)
NSAIDs +/- Buscopan
Oral fluid therapy
Treatment and correction of metabolic imbalances
What are the surgical approaches to correcting a left displaced abomasum?
Right paralumbar with pyloro/omento-pexy
Bilateral paralumbar with pyloro/omento-pexy
Left paralumbar fossa with abomaso/omento-pexy
Right paramedian with abomasopexy
Toggle pin suture with or without laparoscopic correction
What are the complications associated with abomasal surgery?
Abomasitis +/- ulceration Hypomotility / atony Peritonitis Wound infections Pexy failure +/- redisplacement Adhesions Intestinal incarceration
What are the signs of potential endotoxic shock in cattle?
HR 100BPM+ Congested mucous membranes CRT >3secs Weak peripheral pulses Cold extremities
What would be the indications for surgical treatment of hardware disease?
Signs of acute cranial abdominal pain (elbow abduction, fast and shallow respiration, arched back)
Pyrexia
Grunting associated with reticular contraction
No response to conservative management within 24hrs
What medication is recommended in the conservative management of traumatic reticulopericarditis?
Broad spectrum systemic antibiotics
NSAIDs
Oral fluid therapy
How does primary “frothy” bloat develop?
Change to fermentable diet that lowers the rumen pH (e.g. high concentrates, lush grass, legumes)
Gas bubbles and RR contents form a stable foam
This blocks the cardia so eructation cannot occur
Rumen distends as nowhere for gas to go
What are possible causes of secondary bloat?
Oesophageal/cardial obstruction
Innervation disorders
Failure of oesophageal groove closure
What is the difference between primary and secondary bloat?
Primary: dietary change leads to gas build up, which causes the obstruction
Secondary: obstruction occurs first, which then causes build up
What is a ‘bloat line’ on post mortem?
Demarcation of congested proximal oesophagus (sign of potential bloat)
How does ruminal acidosis develop and lead to death?
High carb diet causes increase in lactic acid production due to microbiota changes
This reduces the pH of the RR
The osmotic pressure in the RR increases, drawing water from circulation
This leads to dehydration, circulatory collapse, rumen atony and death
How can ruminal acidosis progress into ruminitis?
Excess acid can damage squamous epithelia
Lesions can allow secondary bacterial infection to develop
Or opportunistic fungi to penetrate wall
What are the effects of bacterial ruminitis as an infection secondary to ruminal acidosis?
Necrosis of rumen with ulcers and scars
Embolism to liver leading to abscesses
Development of necrotising hepatitis
What are potential consequences of mycotic rumenitis?
Peritonitis
Vasculitis leading to thrombosis and infarction of ruminal mucosa
Abortion through spread to placenta
What are the four types of Vagal indigestion?
I: Damage to vagus nerve leading to eructation failure and bloat
II: Damage leading to a failure of omasal emptying into abomasum
III: Damage leading to abomasal impaction or displacement
IV: Compression of nerve due to pregnancy-related abomasal shifting
What are the main causes of calf diarrhoea?
Rotavirus
Coronavirus
Cryptosporidia
Enterotoxigenic E. coli
Nutritional diarrhoea in calves is due to poor clotting of casein. What can cause this?
Failure of sufficient acid and enzyme secretion Poor quality milk product Incorrect concentration of milk powder Feeding milk at incorrect temperature Irregular feeding times Abomasal infection Overfeeding
Calf diphtheria is caused by…
Fusobacterium necrophorum
Treatment for Calf Diphtheria
Penicillin, Improved hygiene, avoid coarse food
Clinical signs of immature rumen syndrome
Pot-belled appearance, thin pasty faeces, hungry calf (vocalisation)
Cause of immature rumen syndrome
Often if weaned too early
Calves eat large volumes of fibre which immature rumen cannot fully digest
Rumen becomes dilated and calf is still hungry
Treatment for immature rumen syndrome
Drastic reduction in roughage
Swap straw bedding for shavings
Feed palatable concentrates
Inoculate rumen with adult ruminal fluid
Advantages of right paralumbar laparotomy for LDA
Good visualisation of right abdomen
Low recurrence risk
Animal can stay standing
Assistant not required
Advantages of left paralumbar approach to LDA
Good visual of abomasum Can break down adhesions Low recurrence Animal can stay standing Useful in cows in late gestation
