Exam 1 - Weight Loss Due To Malassimilation Flashcards
what are the 3 main causes of weight loss in small animals?
decreased caloric intake
malassimilation
hypermetabolic state
how can you differentiate protein losing enteropathy from other causes of severe hypoalbuminemia?
start with cbc/chemistry, fecal, urinalysis, gi panel, & baseline cortisol
must rule out other diseases that cause hypoalbuminemia
what is malassimilation?
decreased ability of the gi tract to incorporate nutrients into the body
what 2 components make up malassimilation?
maldigestion & malabsorption
what is maldigestion? what is a common example of this?
failure of adequate degradation of dietary constituents within the gi tract
EPI
what is malabsorption?
failure of passage of nutrients from the intestinal lumen into the bloodstream
what is protein losing enteropathy?
loss of protein from the intestines due to intestinal disease - strictly any disease causing intestinal protein loss is a PLE
T/F: in order to cause protein loss, there has to be a mucosal injury or lymphatic obstruction in the intestines
true
what is the most common cause of PLE in dogs?
intestinal lymphangiectasia
followed by inflammatory bowel disease
how is intestinal lymphangiectasia characterized?
dilation of the intestinal lymph vessels resulting in the leakage of protein rich fluids into the intestines
what dog breeds are predisposed to primary intestinal lymphangiectasia?
yorkies, maltese, rottweilers, & norwegian lundehunds
can lead to secondary inflammation
what causes secondary intestinal lymphangiectasia?
obstruction of the lymphatic vessels from either inflammation or increased venous pressure
T/F: in practice, it is often impossible to differentiate between primary & secondary intestinal lymphangiectasia
true
what are the most common causes of PLE in dogs?
intestinal lymphangiectasia
IBD
others: neoplasia (lymphoma), fungal, intussusception, & gi parasites
when trying to diagnose inflammatory bowel disease, what other causes of inflammation should you rule out first?
food responsive enteropathy
antibiotic responsive enteropathy
parasites
inflammatory bowel disease is characterized by ______ _________ ___ _____ ______ ____
chronic inflammation of the gi tract from things such as dietary antigens, their intestinal microbiome, & host-immune response
what are the most common inflammatory cell types seen in IBD dogs?
lymphocytes & plasma cells
how is IBD classified?
according to the predominant cell type
T/F: in order to cause protein loss, the IBD must be severe
true
what are the major consequences of PLE?
decreased oncotic pressure - leading to edema, ascites, & loss of fluid from the dog’s circulation
malnutrition
increased risk of thromboembolism
hypomagnesemia/hypocalcemia
what dog breeds are at risk for developing IBD?
yorkies, soft-coated wheaten terrier, norwegian lundehund, basenji, & rotties
T/F: some dogs with IBD have no clinical signs
true
what clinical signs are commonly seen in dogs with IBD?
usually small bowel diarrhea, vomiting, weight loss, abdominal distension due to ascites, limb & ventral swelling due to edema, & respiratory distress due to thromboembolism
T/F: PLE is a syndrome & NOT a disease
true - once the dog is diagnosed with PLE, important to try and identify the underlying cause usually by collecting intestinal biopsies
if you suspect PLN in a dog that presents with a serum albumin <2.0 g/dL, what diagnostic test should be done next to investigate? what do you expect the the serum globulin concentration to look like?
urine protein to urine creatinine ratio - suspicious if > 2.0
normal to high
if you suspect hepatic insufficiency in a dog that presents with a serum albumin <2.0 g/dL, what diagnostic test should be done next to investigate? what do you expect the the serum globulin concentration to look like?
serum bile acids - would expect to be very elevated
normal to high
if you suspect PLE in a dog that presents with a serum albumin <2.0 g/dL, what diagnostic test should be done next to investigate? what do you expect the the serum globulin concentration to look like?
rule out other causes/fecal alpha 1 proteinase inhibitor
can be decreased, normal, or high
T/F: hypoadrenocorticism is an important differential diagnosis for a dog that presents with serum albumin levels < 2.0 g/dL
true
if you have a dog with IBD, and you do an ultrasound to investigate further and see this upon imaging, what do you suspect? why?
lymphangiectasia
hyperechoic mucosal striations are present which is characteristic of lacteal dilation in dogs
healthy dogs can have them after a fatty meal
why do an intestinal biopsy for dogs with IBD? what criteria is used to evaluate the specimens?
it allows for a histomorphological diagnosis to be made - doesn’t always give the etiology
WSAVA criteria
what should be provided in a sample submission for pathology for an intestinal biopsy for a dog with IBD?
detailed but succinct history
signalment, history, lab test results, diagnostic imaging findings, & any questions that need to be answered
what is the mainstay of treatment for intestinal lymphangiectasia in dogs? why? what drug is used?
feed an ultra low diet that is easy to digest, palatable, has a high energy density, & low in fiber
the diets reduce the amount of fat that needs to be transported in the lacteals
immunomodulatory drugs - prednisone at 2mg/kg/day with cyclosporine as an alternative or add-on drug at 5mg/kg/day
why is a diet change sometimes not enough of a therapy for dogs with intestinal lymphangiectasia causing IBD?
the lymphangiectasia may be secondary to inflammation - even if it isn’t the case, the drugs may help prevent lipogranuloma formation
T/F: some dogs with intestinal lymphangiectasia may need a diet lower in fat that anything on the market indicating the need for a home cooked diet such as boiled fat free turkey, low fat cottage cheese, & egg whites
true - vitamins, minerals, & acids may need to be added in the longterm
T/F: some critically ill patients with intestinal lymphangiectasia may benefit initially being fed an elemental diet which is low in fat & easy for them to digest
true
why do a baseline cortisol in a patient you suspect PLE in?
rule out addison’s disease!!
what meds can you add on for a dog that has PLE & has a decreased appetite? what therapeutic procedure can you do?
maropitant & ondansetron
place a feeding tube
how is cobalamin supplemented for patients with serum cobalamin concentrations <400 ng/L?
cyanocobalamin given SQ weekly for 6 weeks & then once monthly
T/F: cyanocobalamin can be used as an appetite stimulant
true
what are some ways you can reduce the risk of thrombosis in PLE patients?
avoid placing unnecessary iv catheters
check catheter sites daily for inflammation
encourage patients to get up & move from time to time
prophylactic treatment with aspirin (0.5-2mg/kg every 24 hours) or clopidogrel (1-3mg/kg every 24 hours)
if you have a PLE dog that has low serum calcium levels on their biochemistry panel, what diagnostic test should you run?
ionized calcium - can see the correct calcium serum concentration
if you have a PLE patient that is severely hypocalcemic or symptomatic for hypocalcemia, what medications can you treat it with?
calcitriol (vitamin D - 30 to 60ng/kg/day) or tums dual action which is 320 mg calcium/65 mg magnesium (1/4 to 1 tablet every 12 hours)
you have a 1 year old female spayed border collie that presents with a history of chronic diarrhea that is voluminous, light tan in color, & no increase in frequency, weight loss (15% of body weight) over 2 months, & a good appetite - what diagnostics/treatment may you pursue?
fecal float
prescribe metronidazole, loperamide, fenbendazole, & switch diet to hill’s i/d
you have a 1 year old female spayed border collie that presents with a history of chronic diarrhea that is voluminous, light tan in color, & no increase in frequency, weight loss (15% of body weight) over 2 months, & a good appetite - her fecal float was negative, & you prescribe metronidazole, loperamide, fenbendazole, & a switch diet to hill’s i/d
she has a slight improvement to this, but as soon as the metronidazole is stopped, there is a complete recurrence of the diarrhea
what is your problem list/differentials?
small bowel diarrhea & severe weight loss despite a good appetite
ddx - EPI, antibiotic-responsive enteropathy, dietary intolerance/allergy, & IBD
you run a CBC/chem, urinalysis, fecal float & direct smear, giardia IFA, baseline cortisol, & gi panel on the 1 year old female spayed border collie with chronic small bowel diarrhea & severe weight loss despite a good appetite
abnormal values on CBC - mild leukopenia, mild thrombocytopenia, mild neutropenia, & mild monocytopenia
abnormal values on serum chemistry - mildly decreased lactate, moderate hypocholesteremia, & mildly elevated ALT
fecal float & direct smear & giardia IFA - negative
urinalysis - WNL
baseline cortisol - 3.3 ug/dL (reference range is 1-6)
cobalamin - decreased
folate - normal
cPLI - normal
cTLI - severely decreased
what is your diagnosis?
EPI with secondary hypocobalaminemia
for the 1 year old female spayed border collie you diagnosed with EPI with secondary hypocobalaminemia, what do you treat her with?
pancreatic enzyme powder - 2.5 teaspoons with each meal
tylosin - 400mg every 12 hours
cyanocobalamin - 800 ug SQ once weekly for 6 weeks & then once monthly
a 5 year old male neutered rottweiler presents with a 3 month history of chronic small bowel diarrhea & weight loss with a normal appetite - there has been no response to purina EN food or metronidazole
TPR is WNL, BCS is 3/9, patient is BAR
he has a fluid wave upon abdominal palpation & subcutaneous pitting edema of the distal hind limbs
what diagnostics should you run?
cbc/chemistry
urinalysis
fecal float & direct examination
gi panel
for the 5 year old male neutered rottweiler presenting with a 3 month history of chronic small bowel diarrhea & weight loss with a normal appetite - with no response to purina EN food or metronidazole
you ran a CBC/chem, urinalysis, fecal float and direct smear, & a gi panel with these results
CBC - total solids moderately decreased, mild neutrophilia, severe lymphopenia
chemistry - mild hypocholesteremia, decreased total protein, hypoalbuminemia
urinalysis - USG was 1.028 & UPC <0.4
fecal float & direct smear was negative
cobalamin - decreased
folate - decreased
cTLI - normal
cPLI - normal
what diagnostics should you do next?
ultrasound
this is seen upon abdominal imaging of the 5 year old male neutered rottweiler presenting with a 3 month history of chronic small bowel diarrhea & weight loss with a normal appetite - with no response to purina EN food or metronidazole
what is this?
intestinal thickening & peritoneal effusion
after seeing the intestinal thickening & peritoneal effusion on the 5 year old male neutered rottweiler presenting with a 3 month history of chronic small bowel diarrhea & weight loss with a normal appetite - with no response to purina EN food or metronidazole - you decide to do endoscopy to get biopsies of the stomach, duodenum, ileum, & colon
you receive this back - what do you see? what is this indicative of?
dilation of the central lacteals
suspected primary intestinal lymphangiectasia resulting in PLE
after seeing the intestinal thickening & peritoneal effusion on the 5 year old male neutered rottweiler presenting with a 3 month history of chronic small bowel diarrhea & weight loss with a normal appetite - with no response to purina EN food or metronidazole
what is your major problem & differentials for it?
PLE with secondary peritoneal effusion
ddx - lymphangiectasia, IBD, neoplasia, & histoplasmosis/another infectious disease
how do you treat the 5 year old male neutered rottweiler presenting with a 3 month history of chronic small bowel diarrhea you’ve diagnosed with primary intestinal lymphangiectasia?
cobalamin - 1,500 ug SQ once weekly for 6 weeks
ultra low fat highly digestible diet
tylosin - 800mg every 12 hours for 6 weeks
T/F: dogs with PLE may not have clinical signs consistent with gi disease
true
T/F: PLE is usually diagnosed by ruling out other causes of severe hypoalbuminemia
true
you see this on abdominal ultrasound of a patient with PLE - what are you suspicious of?
intestinal lymphangiectasia - hyperechoic mucosal striations are characteristic of lacteal dilation in dogs
what is the purpose of using a fecal alpha-1 proteinase inhibitor test for a dog with PLE?
increased fecal alpha(1)-PI concentration may signal the need to obtain gastrointestinal biopsies for a final diagnosis of PLE
fecal alpha(1)-PI concentration may be a useful test for early detection of protein-losing enteropathy before decreases in serum albumin concentration can be detected
what are 3 common causes of a dog having a serum albumin concentration <2.0?
PLN
hepatic insufficiency
PLE
use diagnostic tests!!!
for PLN - urinalysis & UPC ratio
for hepatic insufficiency - bile acids
for PLE - rule out other causes/fecal alpha-1 proteinase inhibitor test
why is the importance of fecal alpha-1proteinase inhibitor?
it is synthesized by the liver & it inhibits a variety of proteins - it is similar in size to albumin
so if gi disease is severe enough for albumin to be lost, fecal alpha-1 proteinase inhibitor will be lost as well, but unlike albumin, it IS NOT hydrolyzed by digestive & bacterial proteinases, so it can be used as an estimate of gi protein loss
what are the indications for running a fecal alpha-1 proteinase inhibitor test?
should be measured in dogs and cats with hypoalbuminemia that do not have clinical signs of gastrointestinal disease and where an extra-gastrointestinal source of protein loss cannot be identified
also dogs belonging to a breed that is associated with a high prevalence of protein-losing enteropathy (e.g., Norwegian Lundehund, Soft Coated Wheaten Terrier, Yorkshire Terrier) that don’t have any clinical signs of gastrointestinal disease, but are intended for breeding
