Weight Loss - Logical Diagnostic Approach Flashcards
Remind yourself - What are the 4 “Define” steps in logical problem solving?
Define the problem
Define the system (how may it be involved)
Define the location (within the system)
Define the lesion
What do you need to consider when you are refining the problem in weight loss?
Refine the problem:
- Weight loss associated with decreased appetite
- Weight loss associated with normal or increased appetite
How do you refine the problem of weight loss due to decreased appetite? What do you need to distinguish about what is happening with the patient?
Can’t eat or Wont’ eat?
What are the top issues associated with “can’t eat”? What is the proper term for it?
Can’t eat = dysphagia
Defined as difficulties in prehension, mastication and/or swallowing
Prehension and mastication difficulties are most often associated with disorders of what structures?
Mouth and pharynx
What is happening in this photo? What must be examined with every single physical exam?
How do you define the problem further in terms of patients who “won’t eat”? What questions do you need to answer about the patient?
Loss of smell? Just picky?
Another animal getting the food?
True anorexia (actually not eating)?
What is the difference between anorexia and hyporexia?
Anorexia is defined as a lack of appetite for food. Hyporexia means a reduction in appetite.
What is pseudo-anorexia?
Animal who truly wants to eat, but cannot eat due to issues with mastication, prehension, etc.
Where in the brain are feeding-satiety centers located?
Hypothalamus
What is the control of appetite (feeding-satiety center) influenced by?
Blood glucose levels
Body temperature
Metabolic products
Neural input from GI tract
Substances released by neoplasia
Psychic factors
What body system can sometimes only manifest as anorexia +/- lethargy/depression in early stages of disease? What do you need to make sure you distinguish?
Can be only (early) manifestation of CNS disease
Need to differentiate between primary and secondary CNS causes of anorexia
Are primary or secondary CNS causes of anorexia more common?
Secondary
What is a main cause of anorexia in horses? What about this disease can mask significant weight loss?
PPID - pituitary pars intermedia dysfunction
Hypertrichosis (excessive hair growth) can mask significant weight loss
What kinds of stressors can lead to weight loss in veterinary patients?
Separation anxiety
New baby/pet
Change in environment or routine
Loss of an owner or companion
List some causes of anorexia
Endogenous toxins, Exogenous toxins
Pyrexia
Electrolyte disturbance
Hepatic disease
Neoplasia
Psychic factors
Primary CNS disease
What are the 4 steps of food processing?
Ingestion
Digestion
Absorption
Utilization
What is maldigestion of nutrients?
Normal digestion is impaired
What is malabsorption?
Nutrients are digested normally but cannot be absorbed appropriately
What is malutilization?
Nutrients are digested and absorbed normally, but are utilized abnormally by the body or lost
What are the top reasons (in terms of food processing) for weight loss with a normal or increased appetite?
Malassimilation
- Maldigestion/Malabsorption
Malutilization
List the reasons for maldigestion. Which animal is this usually most common in?
Exocrine pancreatic insufficiency
Secondary enzyme deficiency
Deficiency of bile acid
Loss of brush border enzymes
Why is maldigestion less important in the horse?
Herbivorous diet (low fat) - bile acid abnormality not a huge deal
Pancreatic dysfunction extremely rare
What pathogen causes brush border enzyme insufficiency in foals?
Rotavirus
Where in the intestines is malabsorption (not) occurring?
Small intestinal absorption of nutrients impaired
What are the 2 options for defining the system regarding malabsorption?
Primary GI (structural) vs. Secondary GI (metabolic) disease
Why is malabsorption so important in the horse?
Can be due to structural disease of both large and small intestine
Can be due to intestinal dysmotility
T/F - Secondary GI disease causing malabsorption is very common in the horse
False - Secondary GI disease rare
What are primary GI infiltrative diseases of the small intestine wall in the dog/cat?
What are the primary GI infiltrative diseases of the small and large intestine wall in the horse? What is a common cause of intestinal dysmotility?
What is “malassimilation”?
Maldigestion/Malabsorption - paired together as they often present together
What are the clinical signs of malabsorption in dogs and cats?
Weight loss
Diarrhea
+/- Coprophagia
What type of diarrhea is associated with malabsorption in dogs and cats? (where in the bowel)
small bowel diarrhea
What are the clinical signs of malabsorption in the horse?
Weight loss
Diarrhea
+/- Dependent edema due to PLE
Recurrent colic
List some secondary GI causes of malabsorption?
Hepatic disease
Right sided cardiac disease
Hyperthyroidism
How does hepatic disease cause malabsorption?
Affects the production of bile acids, which are important for assisting in digestion and absorption of fats
How does RCHF cause malabsorption?
Increase in edema in SI (ascites) which leads to a decrease in absorptive capability
How does hyperthyroidism cause malabsorption?
Speed of transit of food through gut increased - less time for absorption
Weight loss also due to increase in metabolic rate
What is malutilization?
Failure to utilize nutrients appropriately that have been digested and absorbed normally
OR
Loss of nutrients after absorption
T/F - Diarrhea is usually NOT a significant feature of malutilization in dogs and cats?
True! Except sometimes in hyperthyroidism and hepatic disease (metabolic issues)
What is the most common cause of malutilization in the horse?
Loss of nutrients most common - PLE (protein losing enteropathy)
In the horse, what part of the intestine is usually diseased, which causes a loss of nutrients?
More commonly associated with large intestinal disease due to larger surface area of equine large intestine
T/F - chronic diarrhea is NOT usually a significant feature of malutilization in the horse?
False! Chronic diarrhea goes hand in hand with chronic weight loss in the horse due to large surface area of LI
What are the underlying causes of malutilization of nutrients with either a normal or increased appetite in dogs and cats?
Dieabetes mellitus
CHF
Dirofilariasis
Neoplasia
Hyperthyroidism
Liver disease (sometimes)
Renal disease (protein losing nephropathies - damaged glomerulus)
What are the underlying causes of malutilization of nutrients with either a normal or increased appetite in the horse?
PLE
PPID
Liver disease
Chronic asthma
Neoplasia
Protein losing nephropathies
What are the conditions that cause malutilization that are ALWAYS associated with increased appetite?
Diabetes mellitus
Hyperthyroidism
Occasionally:
Neoplasia
Liver disease
