Logical Approach to Weight Loss Flashcards
What is the first step in approaching a weight loss problem?
DEFINE the problem - is it actually weight loss due to a pathology?
> Caloric intake correct? [for life stage and exercise]
> Palatability? [ food change? fake dog food?]
> Muscle atrophy rather than fat weight loss? eg. temporal myositis
What is the second diagnositc step?
REFINE the problem - Weight loss due to inappetance
OR
Weight loss despite a normal or increased appetite
If decreased appetite is noted, how may the problem be refined further?
CANT eat or WONT eat? - Cant eat: Prehension difficulties eg. temporal myositis Painful mouth eg. dental disease Dysphagia eg. melanomas - Wont eat: Loss of smell? Esp cats. Eg respiratory disease True anorexia - no apetite
What may cause true anorexia?
Direct CNS pathology
Feeding satiety centres in hypothalamus affected by
- blood glucose
temperature
metabolic products (eg.renal/hepatic disease)
neural GIT input (inflammation/distenion)
substances released by neoplasia
psychic factors (stress, separation enxiety etc.)
What is the next stage after the problem has been defined and refined as True Anorexia?
- Define the system: CNS
- Then.. Primary v secondary CNS problem?
Secondary most common BUT anorexia with lethargy may be only early manifestation of CNS disease
What are potential secondary CNS disease causes of anorexia?
- Endogenous toxins
- Exogenous toxins
- Pyrexia
- Electrolyte disturbance
- Hepatic disease
- Neoplasia
- Pyschic factors
If no decreased appetite is noted, what are the potential causes of weight loss?
Maldigestion (normal digestion impaired)
Malabsorption (digested normally but not absorbed)
(sometimes termed malassimilation together)
Malutilisation (utilised abnormally by the body OR lost)
What are the potential causes of maldigestion? Which is most common?
EPI in dogs, most common
2ndry enzyme deficiency (luminal conditions not optimal for enzyme function.)
Bile acid deficiency
Loss of brush border enzymes
What are the potential causes of malabsorption?
Structural disease of SI (1ry GI disease)*
Metabolic disease making absorption more difficult (2ndry GI disease)*
Give 5 examples of primary GI disease causing malabsorption
Infiltrative diseases of the gut - IBD - Lymphangiectasia - GI lymphoma - severe SI bacterial overgrowth - dry FIP \+ fungal infection is abroad (US, Asia etc.)
What are the clinical signs associated with malabsorption?
- Often despite normal/increased appetite BUT may have decreased/capricious appetite due to inflame etc.
- Diarrhoea from slight to severe
- Sometimes coprophagia
Give 3 examples of secondary GI disease causing malabsorption
- Hepatic disease (bile acids important for digestion and absorption of fats esp.)
- Right sided cardiac disease (->portal hypertension and pericardial effusion)
- Hyperthyroidism -benign but functional tumour (Gut transit time decreased, poor absorption. Weight loss also due to ^metabolic rate)
What two ways may malutilisation occour?
Failure to utilise nutrients OR loss of nutrients after absortion
How may malutilisation be identified?
Usually diarrhoea not present
- except hyperthyroidism
What are the potential causes of malutilisation if normal or slightly increased appetite is present?
Diabetes mellitus CHF Dirofilariasis (Not UK) Neoplasia Hyperthyroidism Liver disease? Usually inappetant Renal disease - protein losing nephropathy - tubular disease with only slight decrease in appetite
