Diarrhea/enteritis Flashcards
**altered secretion caused by diarrhea=
disrupted enterocyte tight junctions destroy ion gradients needed for absorption
What is the n flow from bloodstream to lumen??
Blood- enterocytes- lumen
** increased ____ secretion: Pivotal event governing electrolyte and water loss in ___ ____(a condition)
chloride; adult colitis
**abn fluid and ion transport by GI epithelial cells include what two issues bc one-way street is compromised??
Hypersecretion and malabsorption
Enterocyte secretion can be active or passive. T/F
Truee
**What is the overall net result of altered secretion from diarrhea/enteritis? What is the outcome?
Cl-, Na+, K+, HCO3- and water secretion into the enterocyte (from blood to cell) and out of enterocyte (from cell to GI lumen and interstitium) moving elytes and fluid into the lumen; the whole outcome is veryyyy watery and voluminous diarrhea/enteritis!!!!
what open chloride channels?
PKA activation (protein kinase A which is activated by cAMP and Ca+)
**Why is diarrhea so watery?
fluid moves into the lumen and decreased sodium and water uptake with chloride secretion!!!
Pathophysiology of altered secretion**
leakage via mediator injury to vasculature and interstitium
**clin path data with diarrhea:
hypovolemia, hypochloremia, hyponatremia, hypokalemia, metabolic acidosis
**Lab findings with diarrhea/enteritis:
Leukopenia to leukocytosis, neutropenia to neutrophilia, lymphopenia, left shift with toxic changes (IF DEGENERATIVE= BADDD SIGNNN!!!)!!
**Very low numbers of ____ correlate with greater disease severity
leukocytes
**What is the HALLMARK of impending colitis???
LEUKOPENIA.. because marginalization of WBC from endotoxins
*What is the pathophysiology of diarrhea in adults vs. horses less than one year old??
Adult parasites (**Cyanthostomes**), strongylus vulgaris, toxins young horses less than 2-3 years get parascis equi, rotavirus, coronavirus
what is the most common cause of acute or chronic diarrhea???
Cyanthostomes- most common cause of acute or chronic diarrhea
- Small strongyles that parasitize the colon
- Diagnose via historical lack of anthelmintics that kill the encysted forms, risk factors for high cyathostomes burdens
How can we diagnose Cyanthostomes
historical lack of anthelmintics that kill the encysted forms, risk factors for high cyathostomes burdens
adult horses can be inapparent carriers of what disease that can kill foals and kids!!
Salmonella
Salmonella is more common in the summer. It invades __ cells of the ____ and ___ and then goes to attack enterocytes
M cells; cecum and colon
Is it common for salmonella to spread and cause septicemia?? what about in foals??
Not common in adults, common in foals (will spread to mesenteric LN, spleen, blood IN FOALLSSS)
Potomac Horse Fever-
Not common in MS, horse ingests IH and Neorickettsia risticii is the bacterial pathogen
What are 3 ways in which a horse can become infected with Potomac horse fever??
ingestion of infected eggs from trematodes
Ingestion of aquatic insect parasitized by cercaria
Metocercaria (developmental stage of the cercaria from the snail), cercaria will not survive in stomach pH
Anorexia, fever, diarrhea, colic signs, laminitis= what disease
when is it most common?? What ages are at risk??
Potomac horse fever CS; common in summer and early fall; all ages affected (weaning, yearling, adult) BUT RARE INFOALSSSSS because they are nursing not eating potential parasites from the ground
Does the vaccine for Potomac horse fever guarantee prevention?
no, there are like 14 strains and it only covers 1 strain
**_______ and ________ are signs of impending diarrhea!!!!!!!.
Leukopenia and neutropenia
what is a clostridial disease mostly in foals that causes HEMORRHAGIC diarrhea
C. perfringes
**What are the abx route used to target C. diff?
abx associated with C. diff usually need to be oralllll because it goes directly into GI tract***
**What esp. causes C. diff????
Macrolides/ Fluoroquinolones/ Baytril
Necrotizing enteritis moreso in cecum/colon in adults and intestines in foals=
C. diff
Equine coronavirus is more common in foals or adults?
foals
what condition is usually in rescue horses with fecal to oral transmission, diarrhea spreads and dissimates and will have CS that manifest viral disease with vili intact
Equine coronavirus
Equine coronavirus is highly contagious but not detrimental, has 2-3 week quarantine with recovery back to n. T/F
True!!
abx associated diarrhea is usually within __ days of abx use
7 days
Right dorsal colitis- what is the most common area and how do we tx it?
right dorsal colon becomes displaced (usually); usually caused from NSAIDs, can occur anywhere in the colon; tx with discontinue NSAIDs, give prostaglandins (Misoprostol)…Can prophylactically use them on horse with long term NSAIDs (fracture repair) or in post op colic horses
Cantharidin toxicosis-
blister beetle, most common signs are colic and poilakuria, swarm in late summer and fall and are baled in alfalfa hay. AS few as 4 beetles are fatal
carbs (CHO) overload decreases intestinal pH and causes….
diarrhea, colitis, endotoxemia, acidosis, LAMINITIS
What virus is most common in the winter (but can be in the summer), and is fecal oral route with high morbidity and low mortality?
Equine coronavirus
____ ___is a parasite often seen in imported horses, usually resides in the jejunum and narrowing of the ileum in young animals (less than three years old).
Parascaris equorum aka horse roundworm.
____ occurs with foals on milk that can make them lactose intolerant, feal to oral route and supppperrr contagious
rotavirus
Vaccinate mares at 8,9 and 10 months of preg to help combat ___
rotavirus
Tx rotavirus with
lactose (can shed up to 10 days even without any CS, asymp. carriers can shed up to 8 months following infection but that is not common)
Lawsonia intracellularis-
Obligate intracellular bacteria, proliferative enteropathy of many species, fecal to oral route
2-3 week incubation
causes herd outbreaks in young horses, looks like they have parasites but they don’t– causes hypoproteinemia
Rhodococcus equi Tx
Macrolides or Rifampin
What virus causes increased WBC i foal with diarrhea and lungs being abnormal
Rhodococcus equi
what virus will result in “Penny in a well” water sounds of lungs, diarrhea, electrolyte imbalances, SI and colon inflammation
Rhodococcus equi
Diagnostic plan for weanling diarrhea:
fecal gram stain–> predominance of gram positive rods–> Clostridium
can also do a fecal culture
Differentials for diarrhea in nursing foals:
i. Foal heat (mom’s milk has different amounts of fat content and electrolytes), necrotizing enterocolitis (very sick foal with ischemia/sepsis!), C. perfringes, C. diff, Salmonella, Actinobacillosis, rotavirus cause lactase deficiency, crypto if housed near dairy calves, sand impaction
ii. Salmonella causes septicemia in FOALS but NOT ADULTS
iii. Actinobacillosis is a common cause of diarrhea and septicemia in foals with FPT
How to r/o all of the different diagnosis of foal with diarrhea?
**blood culture
Passive enteric secretion occurs:
- *leakage via mediator injury to vasculature & interstitium
- *Interstitial edema destroys barrier to fluids & macromolecules
SIRS clinically manifest as more than two of the following conditions:
- Abn TPR
- Abn leukogram
- tachycardia
- MM toxic line
Chem panel with diarrhea will show-
decreased sodium, K+, Cl-, Ca+
Acidosis (hypovolemia and sodium loss)
What type of clostridial condition is the primary pathogen in horses?
C. perfringens Type C
C. diff causes ____ and _____ of SI in foals but LI in adults
edema, hemorrhage
Cantharidin toxicosis (Blister beetle) causes what elyte abnormalities??
Hypocalcemia, hypomagnesium
Predominance of gram + rods=
clostridium
When do we use NaHCO3- in foals with diarrhea?
IF acidosis persists after rehydration (RARELYYYY needed)!!
N. risticii (Potomac Horse Fever pathogen) infects trematodes (Flukes), what are the DH for tremadtodes? what is the primary IH?
Bats, birds, and amphibians; primary IH is fresh water snail
How do we diagnose Potomac Horse Fever?
Fecal PCR
lights near water are a risk for ?
Potomac Horse Fever
Only test for ? in horses with CS
C. perfringens
Diagnosis of C. diff
Fecal PCR to find out if its A and B toxin– presence of either toxin is significant!!
how long do CS usually last with equine coronavirus?
1-4 days
What pathogen very rarely affects adults?
Lawsonia intracellularis
Can have ____ from right dorsal colitis
Hyporoteinemia (where the proteins leak into the lumen)
Usually use 5 consecutive fecal cultures for ____
Salmonella
What pathogen can be tested for using urine but requires liters of urine?
Cantharidin toxicity
____ is the most common cause of diarrhea in foals less than 6 months old
rotavirus
Name this disease
CS: subq/edema causing hypoproteinemia, depression and poor haircoat, progression may be death in days or chronic poor doer, crypt hyperplasia leads to ileal and jejunal thickening
Lawsonia intracellularis
Rhodococcus causes pneumonia but if foal has diarrhea, likely does not have pneumonia, but can T/F
True!!
correct dehydration with alkalizing crystalloids that address __ and ___ depletion plus supplementing what to elytes?
Na and Cl; Mg and Ca
tx potomac horse fever with ?
Oxytetracycline
Tx lawsonia with what drugs?
Erythromycin +/- rifampin (young horses)
Tetracycline and chloramphenicol with metro (in adults) and doxycycline
