Approach to weight loss

Question 1

What are the mechanisms of weight loss?

Answer 1

• reduced intake
  ◦ inappropriate feeding, unable to obtain feed, competition for feed, dental disorders, dysphagia, pain (gastric disease)
• reduced digestion, absorption or assimilation of nutrients
  ◦ dental disorders, malabsorption syndromes
  ◦ liver disease
• Increased losses
  ◦ protein losing enteropathy (or nephropathy)
  ◦ sequestration to body cavity (peritonitis or pleuritis)
• Increased requirements
  ◦ pregnancy, lactate, sepsis, neoplasia, other systemic disease

Question 2

How do you approach a weight loss case?

Answer 2

Question 3

What lab tests can you undertake on a weight loss case?

Answer 3

◦ CBC
‣ increased WBC, neutrophilia
‣ eosinophilia seen in parasite infestation or generalised inflammation
‣ anaemia
◦ Biochemical profile
‣ Urea/Creatinine (SDMA?)
‣ Hepatic (AST, GGT, GLDH, bile ac., urea, bilirubins, TP)
‣ Systemic inflammation (Fib, SAA, Fe++ others)
◦ liver, renal, inflammation (acute phase proteins)
* if the first set of bloods don’t give you a diagnosis, repeating the same tests more than once more rarely will
◦ reference ranges are calculated to include 95% of the normal population - any given horse, 1 in 20 results will be abnormal
* abdominocentesis
* faecal worm egg count - tapeworm

Serum proteins - interpretation
* total protein
◦ decreases may be masked by concurrent hypocolaemia
◦ hyperproteinaemia usually due to hyperglobinaemia
* hypoalbuminaemia
◦ GI loss far more common than renal
◦ effusions - peritonieal/pleural
◦ liver disease - rarely a cause
* hypoglobulinaemia
◦ GI loss
* hyperglobulinaemia
◦ chronic inflammatory disease
◦ neoplasia

Question 4

What further diagnostic tests can you undertake in weight loss?

Answer 4

• oral glucose absorption test
• GI biopsy
• abdominal ultrasound