Lecture 10 2/7/25 Flashcards
What are the extra-GI differentials for acute large bowel diarrhea?
-acute pancreatitis
-acute kidney injury
-acute liver disease
-hypoadrenocorticism
What are the primary GI differentials for acute large bowel diarrhea?
-dietary indiscretion
-stress
-endoparasites; esp. whipworm, poss. giardia
-bacterial enteropathogens
What are the risk factors for Clostridium difficile infection?
-pet therapy dogs
-recent antibiotic administration
-hospitalization
-immunosuppressant drugs
What are the diagnostics for acute large bowel diarrhea?
-fecal float +/- direct smear
-giardia ELISA
-CBC/chem if patient presents with fever, abdominal pain, and/or severe hematochezia
What are the four “Fs” of acute large bowel diarrhea management?
-food change
-fiber
-fenbendazole/deworming
-fortiflora/probiotic use
What are the characteristics of food change as a treatment for acute large bowel diarrhea?
-want a highly digestible, low residue diet +/- fiber enrichment
-want to feed in small, frequent amounts
-novel protein diets are NOT indicated when diarrhea is acute
What are the characteristics of soluble fiber?
-fermented into short chain fatty acids by colonic bacteria
-absorb water
-provide energy source for colonocytes
-butyrate has anti-inflammatory properties
-can cause gas/bloating if added to diet too quickly
-example is psyllium husk/metamucil
What are the characteristics of insoluble fiber?
-less fermentable
-fecal bulking properties
-examples are pumpkin and fiber one cereals
How does soluble fiber impact the GI tract?
-slows down GI transit
-absorbs water
-firms and bulks stool
-provides food for microbes
-can cause diarrhea, flatulence, bloating, and discomfort
How does insoluble fiber impact the GI tract?
-speeds up GI transit
-draws water into lumen
-softens and bulks stool
-can cause constipation and decrease nutrient digestibility
How is fiber typically used in patients?
a blend of soluble and insoluble
What is the benefit of using probiotics in acute large bowel diarrhea cases?
it decreases the duration of acute diarrhea
What are common differentials for chronic large bowel diarrhea?
-stress colitis
-occult parasites
-Tritrichomonas blagburni
-inflammatory enteropathy
-colonic polyps
-neoplasia
-infection
-histiocytic ulcerative colitis
What are the characteristics of Tritrichomonas blagburni/
-single-celled protozoan
-most common in cats younger than 2 years old
-adult cats can outgrow clinical signs and serve as carriers
-diagnosed via saline prep or PCR
-treated with ronidazole
Why is ronidazole treatment reserved for cats that are symptomatic for Tritrichomonas infection?
the drug has a narrow therapeutic range with dose-dependent neurologic signs
What are the characteristics of histoplasmosis?
-can affect small and/or large bowel
causes severe intestinal thickening and colonic granulomas
-targets liver, lung, bone/bone marrow, skin, eyes, and/or CNS
-presents with severe GI signs and multi-systemic involvement
How is histoplasmosis diagnosed?
-abdominal ultrasound
-rectal scraping
-lymph node aspiration
-colonic biopsy
-histoplasma urine antigen test
What are the characteristics of histoplasmosis treatment and prognosis?
-treated with long course of antifungals
-difficult to clear even with antifungal treatment
-guarded prognosis, especially if systemic
What is the signalment for histiocytic ulcerative colitis?
-young
-boxers
-french bulldogs
-english bulldogs
What are the clinical signs of histiocytic ulcerative colitis?
-severe large bowel diarrhea
-hematochezia
-weight loss
What causes histiocytic ulcerative colitis?
invasive E. coli that are not cleared after breaking through mucosal barrier
How is histiocytic ulcerative colitis diagnosed?
colonic biopsy:
-presence of neutrophils and macrophages
-macrophage infiltration/PAS positive staining
-fluorescence in situ hybridization
-culture
What are the characteristics of histiocytic ulcerative colitis treatment and prognosis?
-treated with fluoroquinolone for at least 8 weeks
-great prognosis as long as no previous antibiotics were given and full 8 week course is given
What are the steps to a chronic large bowel diarrhea diagnostic approach?
-careful history and physical exam
-rectal exam
-minimum database; CBC/chem/UA
-fecal float and giardia SNAP
-cytology
-abdominal radiographs and ultrasound
-colonoscopy
What are the management steps for chronic large bowel diarrhea?
-start with food changes, fiber, deworming, and probiotics
-move to a hypoallergenic diet if no response to first tier
What are the indications for colonoscopy?
-chronic large intestinal diarrhea
-normal bloodwork and imaging
-no response to prior treatment attempts
-uncontrollable hematochezia
-suspicion of colonic mass
Which sections of the GI tract are biopsied during a colonoscopy?
-colon
-cecum
-ileum
What should always be done for a colonoscopy?
-36 hour clean out
-take biopsies even when tissue is grossly normal
What are the treatment steps for colonic IBD?
-hypoallergenic diet
-corticosteroids
-secondary immunosuppressive agent as needed
What is constipation?
infrequent, difficult, painful evacuation of feces
What is obstipation?
-severe, intractable constipation refractory to cure or control
What is megacolon?
-irreversible dilation of colon not caused by mechanical obstruction
-secondary to chronic constipation/fecal retention
-may be due to congenital dysfunction
What is the signalment for constipation?
-any breed and age
-common in older cats, especially with CKD
-can be seen in intact male dogs with prostatomegaly
-increased incidence in breeds with high risk of spinal cord malformation
What are the clinical signs of constipation?
-infrequent, rock-hard stools
-dyschezia/vocalizing during defecation
-tenesmus
-vomiting following defecation
What are the differential categories for constipation?
-inflammation
-neuromuscular
-mechanical obstruction
-metabolic and endocrine
-pharmacologic
-environmental and behavioral
Which inflammatory conditions can cause constipation?
-chronic colitis
-perianal inflammation
-anal sac abscess
Which neuromuscular conditions can cause constipation?
-spinal cord dz
-hypogastric or pelvic nerve disorder
-submucosal or myenteric plexus neuropathy
-idiopathic megacolon
Where can a mechanical obstruction that causes constipation be located?
-intraluminal
-intramural
-extraluminal
Which metabolic/endocrine conditions can cause constipation?
-dehydration
-hypokalemia
-hypercalcemia
-hypothyroidism
-obesity
What are the management steps for mild constipation cases?
-hydration; SQ fluids
-fiber-enriched diet
-possible addition of more fiber into diet
What are the management steps for moderate constipation cases?
-hydration; SQ or IV fluids
-fiber-enriched diet +/- addition of fiber
-enemas
-stool softeners
-probiotics
What are the management steps for severe constipation cases?
-similar medical management as moderate cases
-de-obstipation
-colonic prokinetics
What is the last resort treatment option for constipation?
subtotal colectomy in cases of idiopathic megacolon in which there is recurrent obstipation despite medical management
What are the clinical signs of anorectal dz?
-dyschezia
-hematochezia
-fecal retention/constipation
-scooting
-flattened stool
Which diseases affect the anorectal region?
-anal sac abscess
-rectal/perianal tumor
-perineal hernia
-perianal fistula
-prostatomegaly
-pelvic fracture
-pelvic lymphadenopathy
-rectal polyp
What is a perianal fistula?
ulcerative tract(s) in the perianal region
What are the clinical signs of perianal fistulas?
-dyschezia
-hematochezia
-scooting
-licking anal area
-looking at tail
-fecal retention
-concurrent diarrhea
How are perianal fistulas diagnosed?
-sedated/anesthetized rectal exam
-exclusion of other differentials, including anal sac impaction/infection, perianal tumors, and bite wounds
How are perianal fistulas treated?
modified cyclosporine
