Final: Intestinal diseases Flashcards
Which of the small instestinal diseases have a history of recurrent episodes of colic? (sort as strangulating and non-strangulating)
Strangulating:
Strangulating lipoma
Diaphragmatic hernia
Non-Strangulating:
Muscular hypertrophy of the SI
Adhesions in the SI (peritonitis)
How does a horse get Potomac Horse Fever? What disease is it mostly indistinguishable from?
Accendental infestion of trematode infected w/Neoricketsia risticii or of second intermediate host (aquatic insect)
Looks like salmonella
In addition to finding erosions in the GIT (including the mouth, and especially the colon) where can you find lesions due to Blister Beetle/Cantharidin toxicity?
Urinary tract
What are your 3 main differentials when you feel fewer than expected bowel loops on rectal palpation?
Diaphragmatic hernia
Epiploic foramen entrapment
Gastrosplenic entrapment
What are the 2 main risk factors for strangulating lipomas?
Older horses
Overweight horses (also if history of overconditioning since lipoma may have formed before the weight was lost)
What presentation of salmonellosis is classic in outbreaks in referral settings?
a. Fever with leukopenia
b. Colic with diarrhea
c. Colic without diarrhea
d. DPJ
e. Septicemia
a. Fever with leukopenia (due to neutropenia)
How is the treatment plan for a cecal impaction different from a LC impaction?
Administer cathartic: DSS or magnesium sulphate instead of mineral oil (which does nothing)
Also most likely surgical
An 11 year old Paint mare presents for severe colic with severe CV compromise.
NG intubation= 2L reflux, pH 6.8
Significant external abdominal distension.
Rectal: Large tihgtly distended, balloon-like structures with multiple bands, filling palpation field.
Abdominocentesis: Serosanguinous TP= 3.6 g/dl, WBC= 24,000.
Classify the colic.
Strangulating large colon disease
For points clicker question
What are the risk factors for a primary LC impaction?
Dental abnormalities (chewing improperly) *always look at the teeth*
Seasonality: Winter (when weather shifts to cold)
Inactivity (esp in horses that are usually active)
Water restriction (actual water and water in feed (e.g. old hay)
Horses prefer cold water, but drink less of it- always bring them lukewarm water or prevent water source from freezing. Can also salt their feed.
What are the 4 main types of non-strangulating displacement of the LC?
- Left Dorsal (Nephrospenic/Retrospenic ligament entrapment)
- Right Dorsal
- Retroflexion of pelvic flexure
- Non-strangulatng volvulus (<270deg) of LC
What acid-base abnormality do you expect with a LC volvulus? What treatment is COUNTER-indicated?
Profound acidosis: Metabolic and Respiratory
- MA- shock, endotoxemia, GIT compromise*
- RA- hypoventilation (extreme colonic distension)*
Do not treat with bicarb - because it will worsen the respiratory acidosis (more CO2 production)
What is the most common bacterial cause of anterior enteritits/ DPJ? What are some other causes?
Clostridium difficile
Others: C. perfringens, Salmonella, Pancreatitis
Which of the following is a feature of enteroliths that is not a feature of an impaction?
Pain
Inappetence
Recurrence
Palpable obstruction
Recurrence
What are the 3 pathophysiologic categories that you would include as differentials for a colic that looks like strangulating small intestinal disease?
True strangulating obstruction
Inflammatory
Thromboembolic
What is the best way to diagnose PHF?
PCR of feces or whole blood (looking for N. risticii DNA)
Are recurrent episodes of colic typical for a horse with LDD?
Yes
What do you administer for a sand impaction? Should it be given preventatively?
Psyllium (Metamucil)
Binds sand to help removal
No benefit to giving preventativly
Which of these exam findings is more consistent with a non-strangulating than a strangulating SI disease?
Severe CV compromise
Mild CV comromise
Variable reflux
Severely distended loops
Less tightly distended loops
Mild CV comromise
Variable reflux
Less tightly distended loops
What type of hay is a risk factor for enterolith formation? Which breed is predisposed? Living or having lived in what region is also a risk factor?
Alfalfa
Arabians
California
What are the infectious causes of colitis?
Salmonellosis
Potomac Horse Fever
Clostridial (enterocolitis)
Cyathostomaiasis
What are the most important factors predicting illness with Salmonella exposure?
Infective dose of bacteria
Inherent virulence of the bacteria
Inherent susceptibility of the host
Which 2-3 strangulating SI diseases do not cause serosanguinous abdominal effusion?
Epiploic foramen entrapment (dead gut ‘hiding’ in omental space)
Intussisception (dead gut ‘hiding’ inside live gut)
Diaphragmatic hernia (dead gut ‘hiding’ in thorax)
What are the options to diagnose salmonellosis in a horse? If it is diagnosed, what test do you run to find out whether the horse can be reintroduced to general population?
Fecal culutre
Rectal biopsy culture
PCR of feces (same test as for biosecurity) - caution w/false positives
Ready for GP: 3-5 negative cultures in a row
What conditions are secondary large colon impactions associated with?
Sand enteropathy
Enterolithiasis
Colonic displacements
What is an important risk factor for a large colon torsion?
Pregnancy- broodmare 1 month pre to 1 month post-partum
Which type of colitis is stress-induced?
Salmonellosis
Often nosocomial because asymptomatic carriers shed the organism when stressed
Which of these is consistent with a type 1 cecal impaction and NOT cecal dysfunction (type 2)?
Distended cecum
Firm dry content
Fluid filled content
Empty ventral colon
Firm dry content
What is the specific treatment for blister beetle toxicity?
There is none
What liver enzyme can be elevated with a right dorsal displacement of the LC?
GGT
Due to bile duct obstruction
Which of these findings makes a diagnosis of DPJ more likely than a true strangulating obstruction?
Fever (101.5-102.5F)
Pain
Acute onset
Pain relief after reflux
Peritoneal fluid high protein but lower than expected WBCs
Fever (101.5-102.5F)
Pain relief after reflux
Peritoneal fluid high protein but lower than expected WBCs
- Another sign is thickened intetestinal walls on US*
- Both are painful and acute onset*
- True strangulating also significantly distended bowel loops*
Is strangulating disease more common in the small or large intestines?
Small intestines
What are the 2 most important components your intitial treatment of a case of DPJ?
Fluid therapy
Gastric decompression (NG intubation)
Treatment for endotoxemia (antimicrobials etc.) also important but without the fluids and reflux the horse could die suddenly
How do you differentiate a cecal impaction from a LDD?
Cecal impaction will be on the RIGHT side of the abdomen and palpable in the right dorsal quadrant
What will be abnormal on trasnrectal palpation in a horse with LCC? What can you see on ultrasound?
Spleen pulled ventrally and medially (away from body wall)
Bands of colon oriented vertically (in left quadrant)
If you can reach, can feel colon in space on ligament
US: Cannot visualize left kidney
How is PHF treated?
Tetracycline
+ supportive therapy (fluids, anti-endotoxemia, anti-inflammatories…)
Alternative= Doxy but ORAL ONLY!
What presentation of salmonellosis is typical when foals and neonates are affected?
a. Fever with leukopenia
b. Colic with diarrhea
c. Colic without diarrhea
d. DPJ
e. Septicemia
e. Septicemia
When palpating a horse with a LC impaction, where do you expect the colon to be displaced to? What else may you feel?
Caudally and toward the right
Contents is depressible
What part of the GIT must be involved if a horse has diarrhea?
Large colon
You are presented with a weanling that has a true strangulating obstruction of the SI (15L of reflux, multiple sausage-like tight bands on rectal, abdominocentesis serosanguinous TP 3.2 g/dL 20k WBCs, silent abdomen, congested MMs and 3.5s CRT).
What are your disease differentials?
Volvulus (should always be a ddx, any age or signalment)
Small intestine to Small intestine intussisception
Mesenteric rent (can occur after intestinal surgery esp in young horses)
What should you give a horse prior to surgery for a large colon torsion?
Anti-endotoxemia therapy: Polymixin B, endoserum
Inflammatory disease (mucosa through serosa) of the proximal SI manifests by ______ and _____.
Extensive reflux
Ileus
Which of the following is not a true strangulating obstruction?
Strangulating lipoma
Volvulus
Duodenitis proximal jejunitis
Intussusception
Epiploic foramen entrapment
Duodenitis proximal jejunitis
Inflammatory
Which of the following is most compatible with small colon distension on transrectal palpation?
a. Large balloon-like structure with a band
b. Multiple bandless tubular structures
c. Large baloon-like structures
d. Multiple tubular structures with a band
d. Multiple tubular structures with a band
* For points clicker question*
What are the nutritional/toxin and drug related causes of colitis?
Antibiotics
Phenylbutazone
Grain overload
Sand enteropathy
Alfalfa hay (Blister beetle tox- Cantharidin)
Why can a strangulating lipoma not (usually) cause obstruction in the large intestines?
Mesentery prevents stalk from wrapping around the loops
If you suspect sand in the GIT and the horse is not actively colicing, where and when would you auscult to hear changes?
Ventral midline of abdomen
After a ‘wave’ of contraction
(sounds like rubbing palms together gently)
What are some important risk factor for ilial impactions?
Bermuda grass hay (MOST COMMON CAUSE)
Fine fiber materials
Mesenteric vascular thrombotic disease
Geographic location: GA, FL, TX, LA
What are 2 things that intissusceptions are associated with?
Significant motility disturbances:
Changes in fecal consistency
Tapeworm infestation (often cecum involed)
Usually occurs in young horses
What type of colonic displacement can ultrasonographic evidence of colonic mesenteric vessels indicate?
RDD
Or 180deg volvulus
In a horse with a large colon colic, what usually occurs first pain or cardiovascular compromise?
Pain
A horse that ate shit on the ice last week has since had multiple recurrent episodes of colic.
When she presents to you, you have a difficult time passing an NG tube. The caudal abdomen feels ‘empty’ on transrectal palaption.
You do an abdominal tap and it is negative.
When you auscultate the abdomen it is silent but you can hear some borborygmi when you listen to the thorax. The horse is tachypnic but has no breathing difficulty.
What is your suspected diagnosis? What can you do to confirm this?
Diaphragmatic hernia
Ultrasound of thorax
Where are the pacemakers of the GIT? Why does a LC impaction cause concern for a disruption of motility?
Base of cecum
Pelvic flexure
Because pelvic flexure is most common place for LC impaction and the pressure/contents could compress/disrupt the nerve fibers leading to motility problems
What is the most painful colic?
Large colon volvulus
What are the classical clinical signs for a horse with Potomac Horse Fever?
Very high fever (>103.5F) before any diarrhea for 2-3 days
Laminitis (Severe and refractory to treatment; at onset of fever or onset of diarrhea)
+/ - Diarrhea
Which of these is common in old (>20y) and very old (>30y) horses?
Strangulating lipoma
Volvulus
Duodenitis proximal jejunitis
Intussusception
Epiploic foramen entrapment
Strangulating lipoma
How is clostridial colitis diagnosed? What is the treatment, in addition to supportive therapy?
ELISA for C. difficile toxins A and B
Mentronidazole (15mg/kg PO TID)
In addition to rectal examination and auscultation, how can you diagnose a sand impaction?
Sedimentation of feces (e.g. in glove)
Rads (to semi-quantify amount of sand)
What is a concern in a horse who had a chronic musculoskeltal problem and is producing less feces than expected post-op?
Type II Cecal Impaction/ Cecal Dysfunction
Which can lead to rupture of the cecum and death
How would you descibe diarrhea in a horse affected with salmonella?
Malodorous (characterstic odor)
Profuse
Watery
Which of the following features are most compatible with an epiploic foramen entrapment vs a strangulating/pedunculated lipoma?
a. Older horses
b. Presence of serosanguinous abdominocentesis
c. Reduced number of palpable loops of SI on rectal
d. Hx of cribbing in the affected horse
D. HX OF CRIBBING
- There is a consideration for older horses, but no data supporting*
- Lipoma= Serosanguinous abdominocentesis (requires compormised gut being contiguous w/peritoneum)*
When treating a LC impaction why do you expect things to get worse before they get better?
Humidifying content increases volume which increases distension which increases pain
More pain meds decreases motility (caution w/multiple doses of a-2 agonists, may want to upgrade to torb if you’re giving many repeated doses of xylazine)
What are the 5 things you do to treat a LC impaction?
- NPO except water
- Walking
- Pain control (a-2 agonists)
- Fluid per os (possible NG tube)
- Minteral oil (laxative that coats surface of fecal material) or DSS (Dioctyl sulfosuccinate; humidifies fecal content) or Magnesium sulphate/Epsom salts (not indicated if ulceration present)
How is salmonelosis treated? What if there is evidence of immune suppresion (leukopenia, neutropenia)?
Supportive therapy
Immune suppressed - Antibiotics
What is the typical signalment for a horse with LDD/nephrosplenic entrapment?
Large deep chested horses (Drafthorses, Warmbloods)
- They have a deep nephrosplenic space*
- Note: This is the most frequent LC displacement*
What type of stones are enteroliths? What does removing an enterolith that is not round or flattened on one or more sides indicate?
Struvite- magnesium ammonium phosphate
Indicates that there is more than one stone in there (stones should be round if single)
What is the medical treatment for LDD?
Phenylephrine (to contract the spleen- so check PCV to make sure this happened or you need to give more)
Rolling under anesthesia (don’t do if impaction is very tight)
What signs alert you that you have a Blister Beetle toxicity rather than a typical large colon volvulus?
Urinary signs: Dysuria, Pigmenturia, Polyuria, low USG, RBCs in blood
Significant hypocalcemia
Synchronous diaphragmatic flutter (SDF) (due to hypoK and hypoCa)
Metabolic alkalosis
