Weight Loss - Logical Diagnostic Approach

Question 1

Remind yourself - What are the 4 “Define” steps in logical problem solving?

Answer 1

Define the problem
Define the system (how may it be involved)
Define the location (within the system)
Define the lesion

Question 2

What do you need to consider when you are refining the problem in weight loss?

Answer 2

Refine the problem:
- Weight loss associated with decreased appetite
- Weight loss associated with normal or increased appetite

Question 3

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?

Answer 3

Can’t eat or Wont’ eat?

Question 4

What are the top issues associated with “can’t eat”? What is the proper term for it?

Answer 4

Can’t eat = dysphagia
Defined as difficulties in prehension, mastication and/or swallowing

Question 5

Prehension and mastication difficulties are most often associated with disorders of what structures?

Answer 5

Mouth and pharynx

Question 6

What is happening in this photo? What must be examined with every single physical exam?

Answer 6

Question 7

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?

Answer 7

Loss of smell? Just picky?
Another animal getting the food?
True anorexia (actually not eating)?

Question 8

What is the difference between anorexia and hyporexia?

Answer 8

Anorexia is defined as a lack of appetite for food. Hyporexia means a reduction in appetite.

Question 9

What is pseudo-anorexia?

Answer 9

Animal who truly wants to eat, but cannot eat due to issues with mastication, prehension, etc.

Question 10

Where in the brain are feeding-satiety centers located?

Answer 10

Hypothalamus

Question 11

What is the control of appetite (feeding-satiety center) influenced by?

Answer 11

Blood glucose levels
Body temperature
Metabolic products
Neural input from GI tract
Substances released by neoplasia
Psychic factors

Question 12

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?

Answer 12

Can be only (early) manifestation of CNS disease
Need to differentiate between primary and secondary CNS causes of anorexia

Question 13

Are primary or secondary CNS causes of anorexia more common?

Answer 13

Secondary

Question 14

What is a main cause of anorexia in horses? What about this disease can mask significant weight loss?

Answer 14

PPID - pituitary pars intermedia dysfunction
Hypertrichosis (excessive hair growth) can mask significant weight loss

Question 15

What kinds of stressors can lead to weight loss in veterinary patients?

Answer 15

Separation anxiety
New baby/pet
Change in environment or routine
Loss of an owner or companion

Question 16

List some causes of anorexia

Answer 16

Endogenous toxins, Exogenous toxins
Pyrexia
Electrolyte disturbance
Hepatic disease
Neoplasia
Psychic factors
Primary CNS disease

Question 17

What are the 4 steps of food processing?

Answer 17

Ingestion
Digestion
Absorption
Utilization

Question 18

What is maldigestion of nutrients?

Answer 18

Normal digestion is impaired

Question 19

What is malabsorption?

Answer 19

Nutrients are digested normally but cannot be absorbed appropriately

Question 20

What is malutilization?

Answer 20

Nutrients are digested and absorbed normally, but are utilized abnormally by the body or lost

Question 21

What are the top reasons (in terms of food processing) for weight loss with a normal or increased appetite?

Answer 21

Malassimilation
- Maldigestion/Malabsorption
Malutilization

Question 22

List the reasons for maldigestion. Which animal is this usually most common in?

Answer 22

Exocrine pancreatic insufficiency
Secondary enzyme deficiency
Deficiency of bile acid
Loss of brush border enzymes

Question 23

Why is maldigestion less important in the horse?

Answer 23

Herbivorous diet (low fat) - bile acid abnormality not a huge deal
Pancreatic dysfunction extremely rare

Question 24

What pathogen causes brush border enzyme insufficiency in foals?

Answer 24

Rotavirus

Question 25

Where in the intestines is malabsorption (not) occurring?

Answer 25

Small intestinal absorption of nutrients impaired

Question 26

What are the 2 options for defining the system regarding malabsorption?

Answer 26

Primary GI (structural) vs. Secondary GI (metabolic) disease

Question 27

Why is malabsorption so important in the horse?

Answer 27

Can be due to structural disease of both large and small intestine Can be due to intestinal dysmotility

Question 28

T/F - Secondary GI disease causing malabsorption is very common in the horse

Answer 28

False - Secondary GI disease rare

Question 29

What are primary GI infiltrative diseases of the small intestine wall in the dog/cat?

Answer 29

Question 30

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?

Answer 30

Question 31

What is "malassimilation"?

Answer 31

Maldigestion/Malabsorption - paired together as they often present together

Question 32

What are the clinical signs of malabsorption in dogs and cats?

Answer 32

Weight loss Diarrhea +/- Coprophagia

Question 33

What type of diarrhea is associated with malabsorption in dogs and cats? (where in the bowel)

Answer 33

small bowel diarrhea

Question 34

What are the clinical signs of malabsorption in the horse?

Answer 34

Weight loss Diarrhea +/- Dependent edema due to PLE Recurrent colic

Question 35

List some secondary GI causes of malabsorption?

Answer 35

Hepatic disease Right sided cardiac disease Hyperthyroidism

Question 36

How does hepatic disease cause malabsorption?

Answer 36

Affects the production of bile acids, which are important for assisting in digestion and absorption of fats

Question 37

How does RCHF cause malabsorption?

Answer 37

Increase in edema in SI (ascites) which leads to a decrease in absorptive capability

Question 38

How does hyperthyroidism cause malabsorption?

Answer 38

Speed of transit of food through gut increased - less time for absorption Weight loss also due to increase in metabolic rate

Question 39

What is malutilization?

Answer 39

Failure to utilize nutrients appropriately that have been digested and absorbed normally OR Loss of nutrients after absorption

Question 40

T/F - Diarrhea is usually NOT a significant feature of malutilization in dogs and cats?

Answer 40

True! Except sometimes in hyperthyroidism and hepatic disease (metabolic issues)

Question 41

What is the most common cause of malutilization in the horse?

Answer 41

Loss of nutrients most common - PLE (protein losing enteropathy)

Question 42

In the horse, what part of the intestine is usually diseased, which causes a loss of nutrients?

Answer 42

More commonly associated with large intestinal disease due to larger surface area of equine large intestine

Question 43

T/F - chronic diarrhea is NOT usually a significant feature of malutilization in the horse?

Answer 43

False! Chronic diarrhea goes hand in hand with chronic weight loss in the horse due to large surface area of LI

Question 44

What are the underlying causes of malutilization of nutrients with either a normal or increased appetite in dogs and cats?

Answer 44

Dieabetes mellitus CHF Dirofilariasis Neoplasia Hyperthyroidism Liver disease (sometimes) Renal disease (protein losing nephropathies - damaged glomerulus)

Question 45

What are the underlying causes of malutilization of nutrients with either a normal or increased appetite in the horse?

Answer 45

PLE PPID Liver disease Chronic asthma Neoplasia Protein losing nephropathies

Question 46

What are the conditions that cause malutilization that are ALWAYS associated with increased appetite?

Answer 46

Diabetes mellitus Hyperthyroidism Occasionally: Neoplasia Liver disease