Chronic GI Diseases

What is a chronic enteropathy?

>3-4 weeks of GI signs and non-GI disease has been excluded

What are common chronic causes of GI disease?

Neoplasia, infectious dz, idiopathic chronic inflammatory enteropathies

What tools do you have to use out systemic disease?

Baseline blood work

Urinalysis

Baseline cortisol

T4

specPL

Bile acids

What can abdominal ultrasound tell you?

Intestinal wall changes like thickness, decreased layering, mucosal hyperechogenicity

How are most chronic enteropathies definitively diagnosed?

Histopathology

What are some types of idiopathic chronic inflammatory enteropathies (CIE)?

Food or nutrient responsive enteropathy

Microbiome responsive disease

Immunosuppressive response enteropathy (IBD)

What are causes of idiopathic inflammatory enteropathies?

Multifactorial factors of dietary antigens, enteric bacteria, and mucosal immune response

What is a good broad spectrum empirical dewormer for chronic GI?

Fenbendazole

What is your approach to empirical treatment?

1. Deworm

2. Diet/nutrient-response trial

3. Steroids/immunosuppression

What are the different diets for chronic GI trails?

Easily digestible carbohydrate sources

Limited/novel ingredients like duck/pea, venison/potato

Hydrolyzed diets

How do GI diets work?

They have a simple ingredient list to have less antigen presentation to GI lymphoid cells

When do GI diets fail to work?

Dogs without FRE (food or nutrient responsive enteropathy)

What is the theory behind using a limited/novel ingredient diet?

Present antigens to GI lymphoid cells that are not primed for reaction

Do limited/novel ingredient diets work?

Sometimes as finding a novel diet can be very difficult

What is the theory of hydrolyzed diets?

Avoid GI hypersensitivity by breaking down protein so much the immune system does not recognize it

Do hydrolyzed diets work?

They are lower fat and highly digestible but components might not be small enough depending on the dog

What are some tips for diet trial success?

Keep out all other protein/carbohydrate sources including topical HW or flea preventative, dose it at beginning of trial, stopping toothpaste, e-tube if you really need to

How long does a diet trial work?

Improvement in 2 weeks and remission in 6 weeks

What is the signalment of dogs of respond to diet trials?

Younger, LI, or mixed bowl diarrhea or vomiting without diarrhea

What is the diet trial success rate in dogs with only SI diarrhea?

5% response rate

What is the signalment of a successful diet trail in cats?

<5 years old but only a 30% success rate with current data yet

When can you reintroduce other food after a diet trial?

75% can after 12 weeks of the diet trial but few owners want to as they are now healthy

When would you do an immunosuppressive responsive test?

GI signs >3-4 weeks with exclusion of other causes with a failed diet trial and a positive response to immunomodulation

What is the ideal way to verify immunosuppression is necessary?

Document inflammation on GI biopsies

What are your choices for immunosuppression?

Prednisone in dogs, prednisolone in cats

Budesonide

What immunosuppressive other than steroids work in cats?

Chlorambucil

What immunosuppressive other than steroids are available in dogs?

Cyclosporine

Mycophenolate

Chlorambucil

How do you treat colonic CIE (chronic inflammatory enteropathy)?

1. Novel protein diet

2. Fiber trial

3. Microbiome-targeted therapy

4. Immunosuppression

What is the prognosis of canine CIE (non-FRE)?

70-80% response rate with immunosuppression (30% complete remission)

30% euthanasia due to IBD

What is a good combination therapy for large bowel diarrhea in dogs?

Both a high fiber diet and a probiotic

What are negative prognostic indicators of canine CIE (non-fre)?

High clinical score, low albumin, hypocabalaminemia, high endoscopic score, low Vit D levels

What are the theoretical pathogenesis that would indicate an antibiotic trael?

Increased total number of bacteria

Dysbiosis

Mucosal barrier defects

Contact with pathogenic bacteria increased

What is the efficacy of antibiotic trails?

No controlled studies with dogs with CE and metronidazole treatment

Tylosin caused recurrence

Fecal microbiome alterations remain with clinical improvement

What is the recommendation when antibiotic trials should be done?

Granulomatous colitis

What is histiocytic ulcerative colitis or boxer colitis?

Granulomatous colitis

What is the pathogenesis of granulomatous colitis?

Adherent-invasive E. coli (AIEC) is present and there is a genetic defect causing immune impairment and AIEC can invade mucosa leading to granulomatous inflammation

What is the signalment for granulomatous colitis?

Boxer and French bulldog (usually young)

How do you diagnose granulomatous colitis?

Neutrophilic granulomatous inflammation on histopathology

FISH test with intracellular gram-negative coccobacilli

Culture for AIEC

What are the C/S of granulomatous colitis?

Large bowel diarrhea: colonic ulceration, hematochezia, mucus, weight loss

How do you treat granulomatous colitis?

Enrofloxacin (improvement in 2 weeks) continue for 8 weeks

40% resistance unfortunately

Why should you also culture granulomatous colitis?

FQs are 40% resistant so you can have a backup if its resistant to FQs

What is different about cats?

They are true carnivores

Cats being true carnivores makes what different?

Dietary tolerances, altered metabolism, nutrient deficiencies

What are the most common causes of chronic GI dz in cats?

Idiopathic inflammatory enteropathies and small cell lymphoma

Smaller causes are enteric coronavirus, Tritrichomonas foetus

What happens to Cobalamin if cats have GI disease?

The half life is 5-7 days instead of 14 days. This leads to a functional deficiency within one month

Where in the GI tract is cobalamin absorbed?

Ileum

Where is cobalamin secreted?

Stomach

Why are cats more susceptible to cobalamin deficiency?

Intrinsic factor is only secreted by the pancreas and intrinsic factor binds to cobalamin in order to reabsorb cobalamin

What are the most common causes of chronic GI dz in cats?

Idiopathic inflammatory enteropathies

Small cell lymphoma

What are your role ofancillary diagnostics in cats with chronic GI dz in cats?

Baseline blood work: Rules out systemic dz

GI panel

Abdominal US

What benefit is a SI ultrasound in cats with chronic diseases?

It can maybe point you to lymphoma or IBD if thick, but every disease could be thick, normal, thick and layer loss

What is feline eosinophilic sclerosing fibroplasia?

Unique inflammatory enteropathy in cats that shows eosinophilic inflammation, reactive fibroblasts, and collagen on biopsies

What is the significance of feline eosinophilic sclerosing fibroplasia?

It looks very similar to neoplasia due to palpable abdominal mass, enlarged LN, cytology resembling neoplasia

Where are the GI predilection sites for feline eosinophilic sclerosing fibroplasia?

Pylorus and ileocaecocolic junction

How do you treat feline eosinophilic sclerosing fibroplasia?

Surgery if possible (location of mass is very hard to remove)

Immunosuppression

What is the prognosis of feline eosinophilic sclerosing fibroplasia?

Guarded but better if complete surgical resection is possible

What is the prognosis for feline CIE (chronic inflammatory enteropathy)?

Variable response with steroids and often MST in 2-3 years

Similar MST with small cell GI lymphoma

What are the classifications of rectoanal diseases?

Rectal disease

Anal sac disease

Perineal disease

Diseases of defecation or storage

What is proctitis?

Rectal mucosal inflammation

What are the etiologies of proctitis?

Colonic inflammation

Rectal prolapse

Foreign body

What are the C/S of proctitis?

Dyschezia, hematochezia, tenesmus

If diarrhea, the colonic involvement too

How do you diagnose proctitis?

Histopath showing lymphoplasmacytic inflammation most often

Can also show neutrophilic, eosinophilic, granulomatous inflmmation

How do you treat proctitis?

Same as idiopathic IBD/colitis (GI diets, fiber diets, hydrolyzed diets, probiotics)

What is rectal-anal stricture?

Narrowing of rectal or anal lumen

What are the etiologies of rectal-anal stricture?

Circumferential neoplasia, FB, severe colonic IBD or proctitis, perianal fistula, surgical complication

C/S of rectal-anal stricture?

Ribbon-like stool, dyschezia, secondary constipation or obstipation

How do you diagnose rectal-anal stricture?

Physical (Rectal) exam

Abdominal ultrasound

Proctoscopy/colonoscopy

How do you treat rectal-anal stricture?

Balloon dilation or bougienage

Or surgery

What are the indications for balloon dilation or bougienage?

Rectal-anal stricture that is non-infiltrative. Causes multiple repeat procedures with intralesional triamicnolone

What are the indications for surgery to fix a rectal-anal stricture?

Infiltrative disease

What are sx is don for rectal-anal stricture?

Rectal pull-through or resection anastomosis

What is post op treatment for a surgery to fix rectal-anal stricture?

Peri-procedural antibiotics

Easily digestible diet

Laxatives

What is a perianal fistula?

Perianal ulceration and formation of one or more perianal sinuses

What is the etiology of perianal fisulta?

Immune-mediated, dietary tolerance, bacterial or anatomic factures

What is the signalment for perianal fistula?

German shepherds, irish setters, labs that are middle aged and males

What are C/S of perianal fistula?

Severe perianal pain, dyschezia, foul-smelling mucopurulent discharge, self-mutilation, chronic diarrhea

How do you dx perianal fistula?

Physical exam (rectal)

Biopsy

How do you treat perianal fistula?

Immunosuppression (cyclosporine) can transmit to tacrolimus topical after some success

Daily cleaning

Pain management

Stool softener

Novel protein or hydrolyzed diet

What is the prognosis of a perianal fistula?

60-80% improvement in 4 weeks

70-90% resolve in 10-16 weeks

What are some complications of perianal fistulas?

Relapse is common

Fecal incontinence

Anal stricture

What are the diseases of defecation or storage?

Constipation, fecal incontinence, atresia ani

What is constipation?

Prolongation of GI transit, associated with hardened feces and difficult defecation

What are predisposing causes of constipation?

Iatrogenic, dehydration, electrolyte abnormalities, neurologic dz, ortho dz, endocrine/renal dz, lack of exercise, obesity

What electrolyte abnormalities can cause constipation?

Hypokalemia

Hypo or hypercalcemia

What endocrine diseases causes constipation?

Hypothyroidism

What breeds get neurologic disease resulting in constipation?

Max cats, English bulldogs, Boston terriers

What is a acquired neurologic disease that is a cause of constipation?

Dysautonomia

What orthopedic diseases can cause constipation?

Osteoarthritis, pelvic fractures, colonic masses, external mass compression, rectal strictures, prostatomegaly

What is an iatrogenic cause of constipation?

Drugs like opioids

Describe the role of impaired colonic smooth muscle function with feline idiopathic constipation?

It could be a cause or effect of the disease

Constipation leads to obstipation which leads to megacolon

What is the problem with megacolon?

Dilation and loss of function

Prolongation of GI transit and difficulty defecating

What is the signalment for feline idiopathic constipation?

Middle-aged male cats

What are the C/S of feline idiopathic constipation?

Days - months of duration with dry hard feces ± tenesmus, diarrhea, hematochezia

How do you diagnose feline idiopathic constipation?

Rule out local or systemic causes with abdominal radiographs to diagnose RADIOGRAPHIC obstipation

What is clinical vs radiographic obstipation?

Radiographic: colonic distention 1.5x length of L7

Clinical: loss of function

How do you treat feline idiopathic constipation?

Hydration, deobstipation, diet, drugs, probiotics, and surgery as a last resort

How can you increase water intake in cats?

Canned food or adding water to dry kibble

Water fountains

Flavoring to water (purina hydra care, low sodium chicken broth, water from canned tuna)

What diet can help with obstipation?

Depends on timeline of disease

Can use a high fiber or an easily digestible. Really depends on the case

What drugs can you give an obstipated cat?

Colonic promotility medications (Cisapride)

Laxatives

Probiotics can help maybe

What is the cisapride MOA?

Release of Ach to aid with motility