Colic in Horses Flashcards
1
Q
5 basic types of lesions that occur in Colic
A
A. Spasmodic/flatulent colic - perfectly fine, but just a bit of stomach pain (90% of the time) - need 1 dose of analgesics usually
B. Simple Non-Strangulating Obstruction - infection or slight displacement/obstructions
C. Strangulating Obstruction -always need surgery
D. Inflammatory Colic - ex: acute colitis
E. Non-GIT colic - ex: horse with liver disease but is showing colic, not related to the GIT, biliary stone or kidney stone for example
2
Q
Pain in Colic
A
- Pain is a very important indicator of need for surgical intervention
- helps us tell how sick the horse is: medical or surgical?
- how quickly does it respond to the analgesics given?
3
Q
Sedatives in Colic
A
- Need to decide if you want to give analgesics or sedation to be examine them properly
- slowed down motility of the gut shouldnt be an issue: need to examine properly!
- start with rather low dose and then work up if needed in order to to examine
- Don’t want to give sedatives if unecessary bc it will affect mucus membrane interpretation and CVS readings
4
Q
Important Questions to Ask When Doing History
A
- SHED-C
- certain age groups of horses develop different types of colics: younger may get worms and strangulation may be more common in older horses
- If there was strangulation: you would see more signs of pain or how long it has been going on and in what severity
- Owners may give them satchets of Bute and other things (very common in the states to give the horses Flunixin before vet arrives, hides the true degree of pain!)
- Ask when did the horse pass feces?? - should be up to 8 or 10 times a day in a normal environment
- Has it been dewormed and when? - worms can be a common cause of colic
5
Q
Example of Complete History
(SHED-C)
A
- risk factors in change of environment for colic
- these are all different risk factors for developing colic
- has not passed feces for a while
- acute colic
6
Q
Focuses for Physical Exam
A
- Most horses with “simple” colic will not appear depressed
- Abrasions around head suggest recumbency, rolling
- Abrasions indicate that the horse may have had a severe bout of colic… may not present at exam but if there are abrasions/depression, may have had a bout of colic in the night (could even have been colicing for about 12 hours)
7
Q
TPR for colic horse
A
- Increased respiratory rate may be from stress or it could be from abdominal distension
8
Q
Other things to check for examining
A
- can use digital pulses or the facial artery for pulse (quality)
- check how quick jugular fills –> slow (may be dehydration/shock?)
- if tent is there–> dehydration
- If any of these things are present –> may be more severe colic
- other than slightly elevated HR in mild colic
9
Q
Intestinal Motility and “PING”
A
- signs equate to how many gut sounds there are
- ping indicates gas build up and distension
10
Q
Abdominal Distention in Colic
A
11
Q
Aims for Rectal Exam
A
- CARE: Restraint, Sedation, Spasmolytic (BUSCOPAN!), Lubrication
- abnormal structures could be an abcess
- If you don’t feel something, doesnt mean it isnt there!
12
Q
Normal Structures on Rectal Exam
A
- refer to the glass horse CD for anatomy!
- how displacements and entrapments in the gut occur
13
Q
Nasogastric Tubes in Colic
A
- Need to relieve gastric distention!
- Non-negotiable part of it –> have to be able to pass a tube as a vet!
- Horses cannot vomit, if there is an obstruction they cannot rid of the accumulating fluid
- stomach will distend and distend, the stomach will rupture and there is nothing you can do to save them
- must pass a nasogastric tube!
- Measure tube, generally about 2m –> pass it down into stomach
14
Q
How much fluid via NGT is too much reflux?
A
- use syringe to get negative pressure and use a siphoning technique
- Inicates there is a large intestinal problema and not a large intestinal problem
15
Q
Abdominal Ultrasound in Colic Horse
A
- could work up if you don’t have one, but it is very useful to have in the clinic!
- can see if there is extra peritoneal fluid
- assess distension
- liver, kidney, spleen
- possible distention of SI
- and injury or damage to wall of intestine (thickening)
- nephrosplenic entrapment: would not be able to see kidney on US
16
Q
Analysis of Peritoneal Fluid in Colic Horse
A
- Method: Teat cannula (need to make incision) vs. Needle (more common in UK)
- tells us whether there is devitalised gut in the abdomen or not
- might be uneccessary in mild cases
- may help when you suspect strangulation of the gut
- strangulation: will see reddish color (serosangiousnous) , part of the intestine is damaged, leaking protein/cells into abdominal cavity
- Make sure to be sterile! - needle goes into most ventral part of abdomen
- may even see food material in there if there has been rupture of the stomach
- if the horse is fine and you pulled out green/brown–> you may have accidentally pulled from intestine
- Also: Lactate is an indication of anaerobic metabolism –> will indicate strangulation
17
Q
Summary of Diagnostic Approach to Colic
A
- when colic is surgical, you need to know quickly or they may die! –>would need to refer to surgery
- Know this approach and system for clinicals
18
Q
Decision Making (Table) Colic
A
- Colic is a bit different to other diagnoses: about management decisions more than making a clincal finding and THEN treating specifically
- Colic generally falls into 3 categories
- simple colics: looking happy, normal - can treat in the field
- if you arrive, horse is beaten up from throwing itself, high HR, profrusely sweating –> need to get it quickly to hospital or euthanase
- What worries us are the cases in the middle of these extremes! (not simple, but not severe)- a lot of times you really won’t know as the equine abdomen is so large
- need to decide to defer or not
19
Q
Colic and Abdominal Pain
A
- In horses when we say colic we are usually implying it is a GI incident in an otherwise previously normal horse (assume it has been healthy until now, but in reality may have had other issues before GI problem) - assuming it hasn’t had concurrent diseases, but hard to know!
- distension of intestine, peritonitis can be very painful as well
- ischaemia is very painful
20
Q
Distension
(Gas, Fluid, Ingesta)
A
- what is accumulating? Usually one of these three options
- why are they accumulating? there is an obstruction and they arent moving through as they should
- can be mechanical (physical obstacle, in front, twisted) if so strangulating or non-strangulating? (is blood supply compromised?)
- if compromised- then that region of the intestine it supplies will start to die
- Non-strangulating gives you a bit more time to work with
- or it can be functional obstruction (motility issue)
- strangulating lesions are generally related to twisting and torsion, or incarceration
- Non-strangulating: impaction - ingesta buildup or displacement - the colon is not well fixed in place so there is a lot of space for colon to go to
- volvulus - around short axis
- torsion - around long axis
- ileus : a non-moving intestine
- enteritis- inflammation of SI
- post surgery- the gut can fail to start moving again
- grass sickness- autonomous NS of the horse dies off
21
Q
Inflammation vs. Ischaemia
A
- colitis or typhlitis - obisously colon, but can be used loosly as inflammation of all large intestine
- enteritis: Inflammation of the SI
- peritonitis- inflammation/infection of peritoneal cavity
- main ischemia one: S. vulgaris migrates through the large vessels and by doing that they sometimes damage the vessel and cause thrombus formation that cuts off the blood supply
22
Q
Non-Strangulating Lesions
(Spasmodic Colon, Impaction, Displacement)
A
- Spasmodic: they have pain, it goes away and you never really know the cause (catch all term)
- Impaction always refers to large intestine and specifically the colon
- food material gets accumulated in colon, gets so firm and dry in the colon, that it alters the motility
- need fluids to soften the ingestion to get the impaction to move
- The impactions are much larger than you think! (often a small sized child in crouched position)
- Displacement also always is usually LI, colon poorly fixed in space and moves a lot - can resolve spontaneously but can get quite stuck and need surgery to get them back into correct position
23
Q
Non-Strangulating Lesions
(Enteritis/Ileus, Typhlocolitis, Peritonitis)
A
- non strangulating by definition but still may need quite a bit of intensive treatment
- enteritis means that the SI doesnt transport the fluid back to the LI as it should, but it builds up in the stomach –> need to pass a NG tube for the horse to evacuate stomach
- may see large volumes coming out of NG tube (6 or 7L every 2 hours –> 100L a day!!)
- need to replace with IV fluids! - same amount of fluid loss as the D+ –> need to be aware
- can overall be quite intensive
24
Q
Time Frame: Strangulating Lesions
(6-8hrs)
A
- need to be concious that you need to make important decisions quickly
- Need to always just assume until proven otherwise that you are dealing with a strangulating lesion
- If you sit on a strangulating lesion too long, it may turn necrotic and will die off. Want to be speedy and make correct decisions!
- a colon torsion and subsequent necrosis is even worse - usually the end of the horse
- even something as simple as a lipoma can cause these strangulating lesions
- As time goes on, the blood supply is compromised and then ultimately oxygen
- end stages it completely dies
- don’t take as a hard 6 hours, but a rough indication. depends on how much of the blood supply is cut off and what type of lesion you are dealing with
25
Q
Strangulating Lesions:
Small Intestine vs. Large Intestine
A
- small intestine: will go where it finds space, very mobile
- SI volvulus: pretty bad, if it twists around that root, then you are cutting off a big supply, mesentery supplies a large portion of the gut
- strangulating lipoma can be common in older horses, ponies and arabians
- stallions: inguinal/scrotal hernia
- intussusceptions: telescoping, can be considered strangulating as well
- Diaphragmatic hernia: (rare) - slit in diaphragm, SI goes through it, gets incarcerated
- mesenteric rent: gets through slits of the mesentery and get stuck
- Large Intestine: quite rare, but nasty if they happen!
- colon can twist around, usually right at the junction of the caecum
- you can think of the caecum at this point as a big bag of bacteria and it is huge
- Large intestine is full of bacteria, can escape if there is damage or bacterial toxins, making the horse very sick and it is a VERY difficult thing to resect and put together
- intussusception is quite rare but not good for the horse
26
Q
Small Intestinal Lesion vs. Large Intestinal Lesion
A
- how do we know which we are dealing with?
- SI: fits everywhere in the space of the abdomen, if that gets stuck, fluid gets backed up in it, if the stomach becomes distended –> bicycle tires happen (distended SI) and you get reflux on the NGT from stomach or see on ultrasound
- LI: horse can look almost completely round from gas accumulating in the colon, may feel gas accumulation in colon on rectal, usually no reflux retrieved from NGT
27
Q
Treatment:
Small Intestine vs. Large Intestine
A
- need to differentiate between SI and LI because we need to start thinking of possible treatment options
- If you see distended SI, need to start thinking of ways to correct it right away
- small intestine often leads to SURGICAL corrections! -other than enteritis/ileus and grass sickness (grass sickness is usually the end of the horse, but still requires surgical biopsy to diagnose)
- SI obstruction–> think surgery
- LI: much more balanced on the treatments –> surgical types can be difficult to solve
- surgical: colon torsion or volvulus, non resolving
- much more balanced in terms of treatment for LI
- Left Dorsal Displacement: synonym for Nephrosplenic Entrapment
28
Q
Reasons for Referral of a Colic
A
- slightest thought it may be strangulating, you are working against time!! the quicker it gets to a referral to be operated on, the better
- if you have small intestine lesion : NGT reflux or can palpate bike tires (distended SI) - most treatments are surgical anyways
- even enteritis needs intensive medical treatment: likely stil better ot refer
- colitis: usually lots of diarrhea, need a lot of fluid therapy ( may better to refer)
- If you treat an impaction that doesnt resolve via fluids (2 or 3 days), you may want to refer for more fluid or surgery at referral
- If willing, just better to monitor horse at referral
- there are caveats you need to think about though! - FINANCES $$
29
Q
Before you refer a Colic
A
- think about age, $$$, value of horse, quality of life
- ex: 35 year old pony (they only live at a stretch to 36)
- out of hours is extremely expensive (even just for medical) - at least 1000 pounds (estimate 1-3k)
- colitis/enteritis: require tons of fluids, still significant costs! - Fluid therapy may need to be up to a 100L a day in some cases
- what kind of insurance do they have? - up to which value is it insured, most go up to 5000 gbp. most go over the insurance limit though so owner has to pay for extra $$
- also be aware of EXEMPTIONS (needs to cover GI diseases)
- sometimes they don’t want to put the horse through surgery and will want to put them to sleep on site
30
Q
The Facts about Colic
A
- Tend to split up colics into medical can treat in field) or surgical
- most of the time when you examine a colic horse in the field you will be able to treat them medically
- Need to know which require surgery and which don’t though!
31
Q
Mild Colic
A
- Recumbency: horse lying down a lot, may be a sign of mild colic
32
Q
Pawing
(pain)
A
- pawing and staring at ground in pain
- more than mild colic
33
Q
trying to go down or rolling
A
- moderate to severe colic
34
Q
Depression and Abrasions above zygomatic Arch
A
- likely had a bout of severe colic (overnight if they are standing still when you see them)
35
Q
Signs Indicating Need for Referral
A
- anytime you have some moderate to severe pain
- 80% of the time when they are persistently painful and oyu cant figure out why–> referral
- recurring colic–> referral considered
- any signs of HYPOVOLEMIA: idicates severe underlying reason
36
Q
Reasons for Surgery in Colics
A
- There is always an unknown area of the equine abdomen in hte middle - US shows only 30 cm in and your arm is only so long
- There is not one single finding or combination of findings that clearly distinguish medical and surgical colics
- Need to make a decision based on that individual horse and its owners
- Key thing: equine abdomen is like a big black box- can be really hard to tell everything from rectal and US. middle area that you won’t know
- If the horse is PERSISTENTLY painful, need to figure out why! - exploratory celiotomy may be appropriate
- non-resolving displacement –> nephrosplenic entrapment that doesn’t resolve itself
- impactions may not be resolved by fluid as they should be–> may need surgery
37
Q
common workups in Colic case
A
- US: can find SI distension - or by rectal
- changes in peritoneal fluid
- CVS compromise
- etc.
38
Q
Medical vs. Surgical
A
- in general more normal the horse is the more likely they dont need surgery
- sometimes you can make the deicision of the initial examination alone
- sometimes may need additional diagnostics
39
Q
Some additional Diagnostics
A
40
Q
whats worse? referring or not?
A
- underlying reason is that if you dont know what is going on in abdomen and there is constant pain –> want to refer to make sure the horse isnt in danger
- we don’t know what is in there, so best to find out and look surgically
41
Q
Complications after Colic Surgery
A
Short term (immedietaly after surgery)
- anaesthetic complications in horses are much higher than in SA/people –> 1 in 100 almost (1% have a fatal outcome)
- post-op colic can be common, usually treat as medical - usually don’t find out what it is commonly
- post-op ileus - gut not moving again like it should - can be serious if doesnt resolve in a couple days
- peritonitis: if there is an anastomses there and then there is a leakage of ingesta
- laminitis: pedal bone detaches from hoof capsule–> default response for very sick horses
Long Term (life after that time period)
- operations can cause adhesions: parts of gut stick together - happens to humans post op as well
- incisional infection can lead to being prone of hernia, muscle of body wall are not strong enough or don’t heal properly. result in these ventral pouches –> may need surgery again
42
Q
Prognosis
A
- anything you can treat medically generally has a good prognosis (80-90% rate)
- non-stragulating: usually good (70-90% survive)
- Strangulating: bit worse of a prognosis, with resection is worse
- long standing lesions (especially in colons) can be grave for horses in colic
- when the colon is too compromised, it is extremely difficult to get those horses back
43
Q
Signalment and History
A
44
Q
Physical Exam Findings
CVS status
A
45
Q
Physical Exam Findings-
Gastrointestinal System
A
46
Q
Physical Exam Findings:
Other Organ Systems
A
47
Q
Nasogastric Intubation and Transrectal Palpation
A
48
Q
Response to Treatment
(medical vs. surgical lesion)
A
49
Q
Ligaments in the Stomach
(equine)
A
Ligaments of the Stomach:
- Gastrosplenic Ligament
- Gastrophrenic Ligament- postero-inferior surface of the stomach is covered by peritoneum, except over a small area close to the cardiac orifice; this area is limited by the lines of attachment of the gastrophrenic ligament
- Hepatogastric Ligament
50
Q
Omentum and the Epiploic Foramen
A
- Epiploic foramen (omental foramen) entrapment in the horse refers to the displacement of a segment of small intestine (as it is very mobile) through a small hole or foramen that separates the omental bursa (lesser sac) from the peritoneal cavity (Potential space between parietal peritoneum and visceral peritoneum)
*can find Epiploic Foramen by finding the caudal vena cava and tracing it up until it is crossed by the portal vein, beneath it should be a hole (epiploic foramen)
51
Q
US: Triad
A
52
Q
Duodenum in Horses
A
- Fisrt part of SI
- 1 meter in length
- suspended by dorsal body wall by a short mesentery: meso duodenum
- in healthy horse: duodenum cannot be palpated rectally as it is flaccid
- Second curve in duodenum: cranial flexure (encompasses pancreas)
- Descending duodenum passes dorso caudally and is attached to body wall by dorsomesentery
- At the caudal flexure, the duodenum passes around the base of the caecum and passes the midline caudal to the root of the mesentery
- ascending duodenum passes for short distance in cranio direction
- duodenocolic fold is used as a landmark in surgery for identifying the duodenum
53
Q
Jejunum
A
- The length of mesentery increases on the jejunum
- allowing loops of SI to become incarcerated through rents in mesentery
- epiploic foramen, inguinal canal, or twisted on root of mesentery
65
Q
Mild vs. Moderate vs. Severe Colic
A
- This table gives you a general idea of what signs a horse with mild vs moderate vs severe colic might have. Obviously a horse can have signs that fit with two, or sometimes all three categories, but the idea is to try to get an overview of how painful the horse is. If you just ask the owner whether the horse is painful or not, clearly they will say YES! so it is important to try to work out how painful based on the description of the signs they give. There are also differences in horses’ pain tolerance - some horses wont look that painful even with a severe lesion requiring surgery, whilst others will show very severe signs with a medical colic.
- The correct answer is: Sweating → Severe, Violent rolling → Severe, Occasional pawing → Mild, Intermittent recumbency → Mild, Restlessness → Moderate, Kicking at abdomen → Moderate
66
Q
Key Questions to Ask Owner about case
A
67
Q
Key things to look for in PE
A
69
Q
Gastroscopy
A
- A gastroscopy is a procedure where a thin, flexible tube called an endoscope is used to look inside the oesophagus (gullet), stomach and first part of the small intestine (duodenum).
- It’s also sometimes referred to as an upper gastrointestinal endoscopy.
71
Q
Sand Colic
A
- Sand colic is a relatively common occurrence for horses, resulting in around 5% of all colic cases.
- Sand colic occurs when your horse ingests sand when eating.
- Ingestion of sand can result in problems in his GI tract and abdomen
72
Q
Enteroliths
A
- Enteroliths are stone-like formations in the colon of the horse that can cause obstruction and colic.
- Usually made up of the minerals magnesium and phosphorous, they form around such strange materials as cloth, hair, gravel, metal, plastic and shavings
73
Q
Equine Gastric Ulcerations
A
- Gastric ulcers have been identified in the non-glandular stratified squamous mucosa, margo plicatus, glandular mucosa and pyloric regions of the equine stomach.
- Two age related clinical syndromes have been described, one in foals (< 9 months of age) and the other in yearlings and adult horses (> 9 months of age).
- Although ulcers are similar in foals and horses, the syndromes frequently have different inciting causes and may produce different clinical signs.
- A diagnosis of these clinical syndromes relies on recognition of clinical signs and endoscopic examination of the stomach.
- Can give omeprazole and sucralfate for 4 weeks as treatment in some cases
74
Q
Pottery Gait
A
- can help indicate extreme discomfort
- possible laminitis
- indicative of bilateral front limb lameness
76
Q
Equine Asthma
A
- Equine Asthma is a relatively new term for a well-known, age-old problem describing a spectrum of inflammatory respiratory disorders that you may know as Inflammatory Airway Disease (IAD) and COPD, RAO Broken wind or Heaves.
- Mild to moderate Equine Asthma was previously known as Inflammatory Airway Disease or IAD. Severe Equine Asthma describes what was previously known as Recurrent Airway Obstruction (RAO).
- Equine asthma is remarkably similar to human asthma.
83
Q
Lobes of the Liver
(Horse)
A
84
Q
Spleen of the Horse
A
- hilus is where splenic nerves and vessels are positioned
- gastropsplenic liganment: part of the omentum that connect spleen to other organs (possible entrapments for mobile small intestine)
- other ligaments: Renosplenic ligament, Phrenicosplenic Ligament
- Can locate the spleen on ultrasound by spotting the hypoechoic splenic vein
85
Q
Pancreas
A
- comprised of left lobe, body and right lobe
- portal vein passes obliquely through the pancreas to reach the liver
- sits on dorsal abdominal wall
102
Q
Clinical Signs of Colic
A
- pawing with front foot (one or the other)
- turning to look at flank
- stretching (plant head and lean backwards)
- Laying down (curl up after prancing around and flop onto belly)
- rolling (associated with severe disease)
103
Q
Gastric Impaction
(Obstruction)
A
- rare cause of colic
- therefore not recognized before surgery
- poorly masticated or dry feed stretches the wall of the stomach and may displace the spleen caudally
106
Q
Equine Gastric Ulcer Syndrome
A
- this syndrome occurs in 40%-90% of competitive and performance horses
- the most severe ulcers occurring in those animals that are worked the hardest
- More than 1/3 of horses used less strenuously develop mild ulcers
110
Q
Small Intestine Adhesions
(obstruction)
A
- adhesions involving the jeunum usually develop usually as a recent complication of small intestine surgery - such as an anastomoses
- If the intestine is minimally inflammed, a small amount of fibrous material may be deposited over the inflammed area
- The inflammation resolves following the first week of surgery - this fibronous tissue is removed by the fibrinolytic system in the abdomen
- As a result, the intestine heals normally allowing ingesta to move normally
- If the degree of inflammation at the time of surgery is more severe, additional fibrous material may be deposited on the surface of the affected intestine
- Consequently, fibrinous adhesions may develop between this affected area and an adjacent loop or mesentery - if the fibrinolytic mechanisms are impaired, the fibrinous adhesions will not be removed but will be replaced by firm fibrous adhesions
- SIze of the intestinal lumen may also be reduced by the formation of scar tissue
- Due to presence of scar tissue and firm fibrous adhesions, the bowel may become constricted and kinked –> impairing the normal flow of ingesta and gas
- This can lead to chronic obstruction with distention of the SI proximal to the adhesions
- In most cases, one or more loops of SI can be palpated during the rectal examination
113
Q
Signs Indicating Need for Referral for Colic
A
- painful and we cannot find out why
- recurrent colic
- high HR, low CRT –> inicating hyopvolemia or dehydration
