Equine Alimentary Diseases Flashcards
what is colic?
abdominal pain in the horse - a sign not a diagnosis
what are the clinical signs of colic?
rolling pawing flank watching lip curling rolling and throwing themselves around if severe
when may a horse show signs of colic that are not related to abdominal issues?
if there is pain elsewhere in the body
what do the signs of colic depend on?
severity of case
what is the key question that must be answered when examining colic cases?
will this horse require emergency surgery now or not?
how should all colic cases be treated until proven otherwise?
that they are surgical unless absolutely certain they are not
what is the most important body system to examine when checking a colic case?
cardiovascular system
what parameters (including blood tests) are used to assess cardiovascular function in colic patients?
HR and rhythm RR temp PCV TP lactate
why must cardiovascular status be carefully monitored in colic patients?
very important
will have huge influence on decision making
acute conditions of the GI tract can lead to endotoxaemia, dehydration, shock and coagulation disorders - all detected through CVS parameters
what can acute conditions of the GI tract lead to?
endotoxaemia, dehydration, shock and coagulation disorders
what should be done before administering any analgesia or sedation to a patient?
attempt to get HR reading
following cardiovascular exam what is the next area that should be assessed in colic patients?
abdomen
is auscultation of the gut useful in colic cases?
variable - hugely increased sounds or silence may indicate issue but otherwise not very useful and definitely not in isolation.
what would increased gut sounds in colic patient potentially indicate?
spasmodic colic
what would decreased gut sounds in colic patient potentially indicate?
stasis
strangulation
how should the abdomen be auscultated?
in 4 quadrants (upper and lower on left and right)
what should you look for when examining the abdomen?
distention
what does obvious abdominal distention indicate?
emergency in horses
what pathology does obvious abdominal distention in horses indicate?
large colon torsion
what is the most useful part of an initial exam when diagnosing colic?
rectal exam
what can be felt during a rectal exam?
only part of the abdomen
can detect displacement, impaction and distension of LI
some SI distension
what is the main risk associated with rectal exam?
risk of tear
what equipment is needed for a rectal exam?
rectal sleeve lube sedation LA buscopan
what is buscopan used for?
stops contraction of gut temporarily
what is stomach tubing used for?
administration of fluid
medication
relief of gastric overfilling
what is the role of stomach tubing in emergency?
empty the stomach to prevent rupture
how may gastric overfilling occur?
stomach continually secretes fluid
if there is a blockage in the GI tract this fluid will back up into the stomach and fill it
if pressure is not relieved the stomach will rupture as horses cannot vomit
what can be avoided by placing a stomach tube in a horse with gastric overfilling?
death and rupture of stomach
what is the main risk associated with stomach tubing?
epistaxis - very common
what equipment is needed for stomach tubing?
stomach tube 2 buckets (1 with water) funnel jug twitch sedation lube
what are the methods of ultrasound that may be used to diagnose colic?
rectal transabdominal (more common)
what equipment is needed for ultrasound?
machine
clippers
spirit
gel
what is abdominoparacentesis?
belly tap
what can be shown by abdominoparacentesis?
intestinal damage haemoperitoneum rupture of stomach (food content) inflammation neoplastic cells
what is the risk associated with abdominoparacentesis?
low risk
care with diagnosis of gastric rupture (and then euthanasia) due to food matter in sample as this may be due to needle passing into gut
what signs would you expect to see with gastric rupture?
tachycardia
groaning
sweating profusely
what are the 2 techniques that can be used for abdominoparacentesis?
using 23G 2 inch needle or teat cannula and 15 blade
is abdominoparacentesis useful for every case?
no
how can abdominoparacentesis show intestinal damage?
blood
WBC
protein
when may abdominoparacentesis be useful?
can show presence of obstruction before stomach fills and evidence is seen on stomach tubing
what equipment is needed fro abdominoparacentesis?
clippers scrub sterile gloves plain tube EDTA tube either: 23G 2 inch needle or teat cannula, 15 blade and 2ml of LA
is an oral exam required for colic patients?
no
what equipment is needed for oral exams?
sedation gag torch head stand flush mouth
what can gastroscopy be used for?
diagnosis of ulceration, outflow obstruction and impaction
assessment of choke before and after treatment
biopsy
how long should patients be starved before planned gastroscopy?
at least 12 hours
what equipment is needed for gastroscopy?
sedation gag / short stomach tube gastroscope (long endoscope) air water
when is radiography useful in abdominal assessment of horses?
foals
adults to see if there is sand build up
why can sand cause GI issues?
taken in if grazing on sandy soil or having hay in arena turnout. Irritates LI wall
what tests can be performed on blood samples to diagnose GI issues?
PCV TP lactate haematology biochemistry fibrinogen serum amyloid A
what tests can be performed on peritoneal fluid samples to diagnose GI issues?
gross appearance
cytology
protein
what should peritoneal fluid look like?
yellow
straw coloured
clear
what tests can be performed on faecal samples to diagnose GI issues?
egg count
culture
why may a glucose absorption test be performed in horses?
suspected SI malabsorption
what techniques may be used for invasive investigations or biopsies?
laparoscopy
laparotomy
what dental diseases can horses suffer from?
eruption disorders dental decay periodontal disease fractured tooth diastema
what can be done with teeth that are causing issues?
filling
widening of diastema to prevent impaction of food
removal
what are the issues with the removal of horses teeth?
hypsodont - if removed the opposite one will have nothing to grind against and will overgrow
how often do horses teeth need to be rasped?
at least once a year
why do horses need to have regular teeth rasping?
teeth continuously erupt and if natural grinding on other teeth isn’t even hooks can develop at the front and back as well as sharp edges
what is the risk associated with not regularly rasping horses teeth?
dysphagia
impaction in LI from not chewing properl
describe how to examine a horses mouth for dental disease?
watch horse eat palpate mouth sedate and place mouth gag wash out mouth use torch and mirror to look at all surfaces of teeth
what is an emergency condition seen in the oesophagus?
oesophageal obstruction / choke
what are the usual primary causes of choke?
bad luck
eating too fast
dry concentrate
poor dentition
what are the more rare secondary causes of choke?
oesophageal damage (usually from previous choke) mass
what are the immediate clinical signs of choke?
neck extended
food/discharge from nose
cough
gagging
what are the signs of chronic choke?
dehydration
acid-base imbalance (due to saliva loss)
weightloss
what are the risks associated with choke?
aspiration pneumonia
rupture
stricture or diverticulum long term
how is choke diagnosed?
auscultation cardiovascular parameters gastroscopy stomach tube (bloods, ultrasound, plain and contrast radiography more rare)
what is the goal of choke treatment?
relieve obstruction without causing damage or aspiration
how can a stomach tube diagnose choke?
will stop at blockage before it enters stomach
how is choke treated?
sedate to lower head
place stomach tube and lavage obstruction through tube
tube is not used to push blockage
why is a lowered head during choke treatment desirable?
reduce aspiration risk
what can be done in desperation if choke won’t shift?
GA and use cuffed ET tube
what drugs may be given to hep with choke?
buscopan / oxytocin to relax smooth muscle
what can be done if horse is becoming fed up with tubing during treatment for choke?
leave sedated and muzzled on IVFT and try again in an hour
what should be done once choke is cleared?
use gastroscope to check definite clearance, mucosa isn’t damaged
check trachea with endoscope for aspiration (TW if choke has been ongoing)
check for underlying issues
rest from feeding
what drugs may be needed following choke?
antibiotics and antiinflammatories
what equipment is needed for treating choke?
endoscope / gastroscope sedation twitch stomach tube 2 buckets (1 with water) funnel and jug overalls
what are the 2 areas of the horses stomach?
glandular and non-glandular
where may stomach ulcers form?
in either glandular or non-glandular area
what can stomach ulcers cause?
inflammation
erosion
ulceration
perforation
how may ulcers be graded?
0 (none) to 4 (actively bleeding)
how prevalent are ulcers in horses?
10-100% depending on literature and whether grade I is considered relevant
in how many foals is gastroduodenal ulceration seen?
25-57%
what causes ulcers?
imbalance between inciting and protective factors
why may foals show higher prevalence of glandular ulcers?
reduced mucosal blood flow anyway
when sick this further reduces
NSAIDs will increase problem
what are the inciting factors of gastroduodenal ulcers?
HCl
bile acids
pepsin
what are the protective factors that will prevent gastroduodenal ulcers?
mucus bi-carbonate layer mucosal blood flow mucosal prostaglandin E epidermal growth factor production gastroduodenal motility
what are the risk factors for gastroduodenal ulcers?
empty stomach exercise diet (high concentrates) NSAIDs hospitalisation
what increases the risk of squamous ulcers?
exercise on an empty stomach
what increases the risk of glandular ulcers?
NSAIDs
what are the clinical signs of gastroduodenal ulceration?
varies from nothing to poor appetite, recurrent colic, tooth grinding, dog sitting, diarrhoea, poor performance
what is the aim of dog sitting in gastroduodenal ulcer patients?
movement of acid away from sore, sensitive non glandular area
how is gastroduodenal ulceration diagnosed?
gastroscopy
assumption
is the presence of GD ulcers always significant?
no - they may be incidental and not the cause of presenting issue
what does treatment of GD ulcers depend on?
cause
age of horse (adult or foal)
how are adult horses treated for GD ulceration?
omeprazole
misoprostal - increases blood flow to gastric wall
what are the issues with misoprostal?
off licence
is abortive in humans
how are foals with GD ulcers treated?
sucralfate
why are foals not given any NSAIDs in hospital?
contraindicated due to reduction in blood flow to stomach already seen in foals
what are the risks of giving omeprazole (any drug that raises pH) to foals?
may make the sick which increases likelihood of GI ulcers
what are the main causes of gastric dilation and rupture?
primary
secondary
idopathic
what are the primary causes of gastric dilation and rupture?
gastric impaction
grain engorgement
other
what happens during gastric impaction?
stomach stops contracting and amptying
what are the signs of gastric impaction?
acute or chronic colic
what is the cause of gastric impaction?
unknown
when is gastric impaction often discovered?
PM
why does gastric dilation lead to rupture?
horses are unable to vomit
what are the secondary causes of gastric dilation and rupture?
small and large intestinal obstruction
ileus (secondary to EGS)
what is the most common cause of gastric dilation and rupture?
small or large intestinal obstruction
what are the signs of gastric dilation and rupture?
overfilling of stomach (loads of fluid when tube passed) acute colic tachycardia fluid from nose dehydration
why does gastric dilation and rupture lead to dehydration?
fluid produced in stomach is not being absorbed from LI
what is a sign that a horses stomach is about to rupture?
fluid from nose - pass stomach tube immediately!!
how is gastric dilation and rupture diagnosed?
clinical signs and history
reflux (lots of fluid in stomach tube)
colic work up
gastroscopy
how is gastric dilation and rupture treated?
stomach tube ASAP treat underlying cause IV fluids IV nutrition (if gut stasis - only short term) electrolytes NPO
when can gastric dilation and rupture patients be fed?
when stomach tube is not producing fluid
is anterior enteritis common in the UK?
no
what is anterior enteritis also known as?
duodenitits-proximal jejunitis
what is anterior enteritis?
inflammatory condition affecting proximal small intestine
what is the cause of anterior enteritis?
in most cases unknown
may be bacterial involvement in some (can be cultured from reflux)
what bacteria may be involved with anterior enteritis?
Salmonella
Clostridia
where can bacteria causing anterior enteritis be sampled from?
gastric reflux
what is a high risk factor for anterior enteritis?
recent diet change to high concentrate
what are the main clinical signs of anterior enteritis?
distended SI and stomach
signs relating to gastric dilation
pyrexia
why does anterior enteritis cause distention of the SI and stomach?
hypersecretion in the proximal SI and functional ileus due to inflammation leads to build up of fluid as it is no longer propelled into LI
how is anterior enteritis diagnosed?
may be suspected SI obstruction and only surgery will determine difference
colic investigation
reflux
what are the findings in peritoneal fluid of a patient with anterior enteritis?
raised protein but not serosanguinous
what will be performed on the reflux of a patient with suspected anterior enteritis?
culture
what is usually needed to diagnose anterior enteritis?
ex lap as is hard to differentiate from SI
how is anterior enteritis treated?
repeated gastric decompression (q2h) antibiotics IVFT electrolytes nutritional support NPO analgesia ex lap with decompression of SI
what antibiotics are often used for anterior enteritis?
penicillin
gentamicin
metronidazole
what is the prognosis of anterior enteritis?
25-94% depending on the case
is malabsorption and maldigestion often seen in horses?
no - fairly rare
what happens during malabsorption and maldigestion?
animal is unable to absorb nutrients from food
what can cause malabsorption and maldigestion?
inflammatory type diseases
lymphosarcoma
what are the clinical signs of malabsorption and maldigestion?
weight loss
how is malabsorption and maldigestion diagnosed?
abdominoparacentesis
ultrasound
oral glucose tolerance test
laparoscopic / laparotomy biopsy
what can been seen on the ultrasound of a patient with malabsorption and maldigestion?
thickened SI wall
inflammation
what is the role of a glucose tolerance test in the diagnosis of malabsorption and maldigestion?
confirms lack of absorption
how is malabsorption and maldigestion treated?
method depends on diagnosis
resection
corticosteroids
no treatment
what is the prognosis of malabsorption and maldigestion?
depends on diagnosis and response to treatment
what are the main types of SI obstruction?
simple
strangulating
describe a simple SI obstruction
obstruction of the lumen without direct obstruction of vascular flow
what can simple SI obstruction be caused by?
course food material
ileal hypertrophy
ascarid impaction
adhesions
what is ileal hypertrophy?
thickening of the area between the ileum and the caecum leading to eventual blockage by food
what can ileal hypertrophy be caused by?
secondary to tapeworm and muscular hypertrophy associated with increased gut effort due to worms
why does ascarid impaction cause simple SI obstruction?
worms physically block lumen
describe a strangulating SI obstruction
simultaneous occlusion of intestinal lumen and its blood supply
what are the main causes of strangulating SI obstruction?
pedunculated lipoma epiploic foramen entrapment SI volvulus mesenteric rent inguinal or diaphragmatic hernia intussusception
what is a pedunculated lipoma?
benign fatty lump attached to the mysentery by a long stalk that can wrap around and strangulate SI
what does SI obstruction result in?
gastric overfilling as nothing can pass into LI through SI
deterioration of intestinal mucosa
intestine will die (increased length and severity with time)
sepsis
endotoxaemia
with what type of SI obstruction does deterioration of gastric mucosa happen faster?
strangulating lesion
what are the clinical signs of SI obstruction?
colic reflux tachycardia hypovolaemia distended SI on rectal exam serosanguinous peritoneal fluid with high protein and lactate
what will colic be like in a patient with an SI obstruction?
severe as the gut dies, will ease when the gut is dead
what can be detected by peritoneal fluid?
early strangulation
how is SI obstruction treated?
surgery
euthanasia
ileal impaction will very rarely clear alone (and this is by chance)
what is the prognosis for short term survival following SI obstruction surgery?
80%
what is the prognosis for long term survival following SI obstruction surgery?
60-70%
how much rest is needed following SI obstruction surgery?
3-4 months
what is involved in a simple cecal obstruction?
impaction, becomes blocked with food
what are the 2 main types of simple obstruction of the caecum?
primary
secodary
what is the reason for primary caecal impaction?
underlying motility disorder
what is the reason for secondary caecal impaction?
usually young horses following painful (e.g. orthopedic) procedures but not well understood
what are the clinical signs of caecal impaction?
colic (although not always) depressed not eating reduced faecal output may just rupture leading to severe shock and death
what must be monitored after any surgery to protect against caecal impaction?
faecal output
appetite
pain
what should be assumed if horse is inappetant, depressed and has low faecal output?
may be caecal impaction until proven otherwise
how is caecal impaction diagnosed?
clinical signs and history
rectal exam as can often palpate
abdominoparacentesis
how is caecal impaction treated preferably?
medically
when may surgical treatment of caecal impaction be needed?
if there is intestinal damage / endotoxaemia
what is involved in medial treatment of caecal impaction?
oral and IV fluids
what is involved in the surgical treatment of caecal impaction?
typhlotomy - open ceacum
caecal bypass if necessary
what is the prognosis of caecal impaction?
90% success due to close monitoring and prevalence in hospital
what are the 2 main types of caecal intussusception?
ileo-caecal
caeco-caecal
when is caecal intussusception often seen?
young horses
those with a high tapeworm burden
what are the clinical signs of caecal intussusception?
colic of varying severity
chronic colic if happening repeatedly and then correcting on it’s own
how is caecal intussusception diagnosed?
rectal
ultrasound
peritoneal fluid (although care as may suggest more extensive damage than is actually present)
how is caecal intussusception treated?
surgery
treatment for tapeworm
what is the prognosis for caecal intussusception?
as for colic surgery
what are the 2 main types of LI obstruction?
simple
strangulating
what is simple LI obstruction due to?
impaction
displacement
what is strangulating LI obstruction due to?
torsion
where is impaction LI obstruction usually located?
pelvic flexure
why is impaction LI obstruction usually seen at the pelvic flexure?
narrows and there is a change in innervation
what can cause impaction LI obstruction?
food material poor teeth long fibre motility disorder so reduced movement recent box rest sand
what are the clinical signs of LI obstruction due to impaction?
mild colic (may be chronic) reduced faecal output or none
how is LI impaction diagnosed?
rectal exam (key) abdominoparacentesis
how is LI impaction treated?
oral fluids (repeated through stomach tube) cathartics analgesia (care with type) paraffin may help to move obstruction IVFT eventual surgery
what are cathartic drugs?
draw water into the gut
why should horses not be given pro-motility drugs?
can cause gastric / intestinal rupture
what is the prognosis for LI impaction?
excellent
fair if surgery required
what are the main types of LI displacement?
right dorsal
left dorsal
nephroplenic entrapment
what is nephrosplenic entrapment?
large intestine becomes trapped on the left side between the kidney and the spleen over the nephrosplenic ligament
what can happen with LI displacement?
may correct itself or with medical treatment
may remain displaced until gut becomes compromised and surgery is required
torsion - emergancy surgery
how is LI displacement diagnosed?
rectal exam
ultrasound
abdominoparacentesis to decide if surgical
what type of LI displacement is shown on ultrasound
nephrosplenic entrapment (NSE)
how is LI displacement treated if no evidence of gut damage and not too painful?
medically - fluids (oral and IV), analgesia
when will surgery be required to treat LI displacement?
if painful
evidence of gut damage
if persistant
how can NSE LI displacement be treated?
phenylepherine and lunging (shake it around!!)
what does Phenylepherine do?
shrinks spleen
when does LI torsion occur?
follows displacement
spontaneous
what is LI torsion?
strangulating lesion of LI
what are the clinical signs of LI torsion?
extreme, violent pain
distended abdomen
respiratory compromise
how is LI torsion diagnosed?
rectal exam - very difficult due to gas and LI
how is LI torsion treated?
immediate surgery with potential LI resection (although difficult)
what is the prognosis of LI torsion?
depends on damage to LI
risk of recurrance
what are the 4 types of diarrhoea?
acute
chronic
infectious
non-infectious
should diarrhoea cases be isolated?
if fever or until proven non-infectious
what are the 2 types of acute diarrhoea?
inflammatory
non-inflammatory
what are the causes of acute inflammatory diarrhoea?
Salmonellosis Clostridiosis Colitis (NSAIDs) Ehrlichia risticii parasites neoplasia
what are the causes of acute non-inflammatory diarrhoea?
excitement management change food hypersensitivity toxicity iatrogenic purges
what are the 2 types of chronic diarrhoea?
disruption of normal physiology
inflammatory / infiltrative disease
what causes chronic diarrhoea due to disruption of normal physiology?
dietary sensitivity
dental disease
antibiotic induced
what causes chronic diarrhoea due to inflammatory / infiltrative disease?
parasites
IBDs
neoplasia
how is diarrhoea assessed and cause diagnosed?
CVS parameters rectal exam ultrasound abdominoparacentesis rectal biopsy FEC faecal cultures
why are CVS parameters assessed in the diarrhoea patient?
assess how sick they are
what cardiovascular parameters will be assessed in the diarrhoea patient?
sepsis endotoxaemia dehydration WBC electrolytes
how is diarrhoea treated?
hydration electrolytes anti-endotoxic laminitis prevention (e.g. ice boots) treat underlying cause antibiotics plasma feeding through
what is the most crucial element of care for the diarrhoea patient?
nursing!
hand feed, clean and grooming
is small colon impaction common?
no
what is small colon impaction caused by?
foreign body (plastic bag) Salmonella
how is small colon impaction diagnosed?
difficult
guessed from history of intermittent diarrhoea and colic
how is small colon impaction treated?
medical treatment
many require surgery
what is peritonitis?
infection / inflammation of the peritoneum or peritoneal fluid
what is the difference between primary and secondary peritonitis?
primary is idiopathic
secondary follows surgery
what are the signs of peritonitis?
pyrexia
mild colic
how is peritonitis diagnosed?
abdominoparacentesis
how is peritonitis treated?
antibiotics
persistent or recurrent may need laparoscopy or laparotomy
