Anorexia and weight loss

• What is the definition of malnutrition?

  Insufficient calories ingested to maintain body condition.
• What is the definition of maldigestion/malabsorption?

  Sufficient calories ingested but not bing absorbed properly.
• What is the definition of malutilisation?

  Sufficient calories ingested and absorbed but not used in the right way.
• Malnutrition - diet

  Inappropriate - e.g.

  • Puppy vs adult diet
  • Normal vs prescription.
  • Neutered and weight loss diet - feeding a neutered diet to a non-neutered animal can cause weight loss, reproductive tract can take 10% of energy even if the animal is not pregnant.

  Not enough:

  • Consider size, age, activity levels etc.
  • Amount of feed varies between diets!
  • Don’t forget about changes such as pregnancy and lactation - need to alter the feed accordingly.
• Malnutrition - reasons for not wanting to eat

  Pain - when eating (dental pain is very common in dogs). Oral/pahrygeal/neuromuscular/ortho.

  Stress (common in cats)

  • Caused by visceral, vestibular and/or chemoreceptor trigger zone stimulus.
  • Many systemic diseases.

  Pyrexia

  • Many inflammatory/infectious conditions
  • Common cause of inappetance
• Malnutrition - physically can’t eat causes

  Dental disease

  Oral/pharyngeal/oesophageal masses.

  Mandibular/ maxillary abnormalities - e.g. craniomandibular oestopathy.

  Congenital abnormalities - e.g. cleft pallet, persistent right aortic arch.

  Neuromuscular disorders - generalised e.g. tetanus or botulism. Localised - masticatory muscle myositis, Cricopharyngeal ACh achalasia.
• Malnutrition - masticatory muscle myositis - overview and presentation

  Immune mediated inflammatory condition.

  Inciting cause unknown.

  Auto-antibodies against type 2 muscle fibres - found in the masticatory muscles.

  Presentation:

  • Acute phase (can be missed by owner).
  • Inflamed masticatory muscles.
  • Hard to open jaw as is painful- animals come in very sore, can feel the heat coming.
  • Chronic phase:
  • Fibrosis and atrophy - can not open mouth (differentiates from trigeminal neuritis).
  • No pain but anorexia and weight loss.
• Malnutrition - masticatory muscle myositis Diagnosis and treatment 


  Diagnosis:

  • Haemotology - eosinophilia
  • Biochemistry - increased globulin and creatinine kinase (particularly early on due to damage).
  • Electromyography (EMG) - spontaneous electrical activity.
  • Biopsy histology - lymphocytic-plasmacytic cellular infiltrates, muscle atrophy and fibrosis.

  Treatment:

  • Best chance of success in acute phase.
  • Immunosuppresive therapy (prednisolone 2mg/kg).
  • Dose gradually tapered over months.
  • Chronic - attempt to stretch jaw open under GA
  • Recurrence common.
• Malnutrition - Cricopharyngeal atelectasis overview

  Uncommon differential for dysphagia and regurgitation.

  Mostly springer/ cocker spaniels.

  Neuromuscular motility disorder causing incomplete/ asynchronous relaxation of the upper oesophageal sphincter.

  Usually congenital, rarely acquired. Can cause secondary aspiration pneumonia.
• Malnutrition - Cricopharyngeal atelectasis diagnosis and treatment

  Diagnosis - fluoroscopy

  • Cricopharyngeal muscle doesn’t relax.
  • Retention of barium in the caudal pharynx.

  Treatment - surgery

  • Cricopharyngeal myotomy or Cricopharyngeal and thyropharyngeal myectomy.
• Maldigestion/ malabsorption - history

  Any vomit/regurgitation/ diarrhoea/ change in faeces.

  Simultaneous changes (e.g. diet - include treats/supplements/ scavenging).

  Parasite control - what, when and how?

  Health of those in contacts/ family.

  Evidence of nausea - drooling and lip smacking.
• Maldigestion/ malabsorption - clinical exam

  Extra attention to abdominal palpation

  Pain (localise), thickened intestines, masses.

  Temperature - look at faeces on thermometer.

  Hydration
• Maldigestion/ malabsorption - diagnostic test

  Haemotology/ biochemsitry (including TLI, folate/B12).

  Specific tests for common systemic diseases causing GI signs (e.g. TT4, basal cortisol).

  Faecal exam (possibly culture, microscopy).

  Imaging (ultrasound, fluoroscopy, endoscopy)

  Diet trial

  Biopsy.
• Malutilisation - abnormal nutrient handling

  Protein losing nephropathies

  Diabetes Meletus

  Liver disease
• Malutilisation - increased demand for nutrients

  Neoplasia

  Hyperthyroidism

  Infection

  Cardiac cachexia

  Parasites.
• Malutilisation - full history

  Parasite control - when, what and how.

  Changes to drinking or urinating.

  Vomiting/ diarrhoea.

  Coughing/ sneezing/ respiratory effort.

  Changes to activity levels - decreased or increased.

  Behaviour changes.

  Appetite
• Malutilisation - clinical exam

  Thorough cardiac exam - HR, murmurs, dysrhythmias, pulses, CRT.

  Respiratory assessment - MM colour, RR and effort, resp sounds, dullness.

  Abdominal palpation - pain, masses, thickened intestines, organomegaly.

  Palpate LNs and check goitre

  Check temperature.
• Malutilisation - diagnostic tests

  Haemotlogy - anaemia, evidence of inflammation/infection.

  Biochemistry - liver/kidney parameters, Ca2+.

  Urinalysis (dipstick and USG, UPCR)

  Specific tests (TT4, fructosamine)

  X-ray/ ultrasound/ echo.
• Definition of anorexia

  Not eating at all
• Definition of hyporexia

  Not eating enough for normal maintenance.
• Approach to anorexia/hyporexia - loss of appetite

  Signs of systemic disease on history or clinical exam.

  Particularly note drooling, pyrexia, pain.

  Consider Haemotology/ biochemistry/ urinalysis.

  Imaging is indicated.

  Common causes:

  • Renal/ hepatic differentials - toxin accumulation.
  • Any inflammatory/ infectious process causing pyrexia.
  • Neoplasia.
• Approach to anorexia/hyporexia - reluctance to eat

  Instigating factors - stress full event.

  Changes around feeding - location, bowl, other animals, diet.

  General changes at home - new pets, building work.

  Tempt to eat in other locations/ with other foods and monitor or improvement.

  Consider consulting behaviourists.

  Common causes:

  • Association of food with nausea/pain. stressful event.
  • Stressors e.g. other pets, building work.
  • Change to less palatable diet e.g. prescription renal diet.
• Approach to anorexia/hyporexia - mechanical inability to eat

  On exam able to open and close mouth normally. Tongue and oral soft tissue appear normal. Pain in neck, mouth or limbs.

  Better with wet vs dry food or eating at different heights.

  Any sign of dental/ oral/ pharyngeal pain - may need to sedate/ GA to fully assess.

  Often imaging is needed for investigations.

  Common causes:

  • Dental disease
  • Gingivostomatitis
• Approach to anorexia/hyporexia - treatment

  Treat the underlying condition.

  Tempt to eat (beware of causing food aversions).

  Appetite stimulants (e.g. mirtazapine)

  Anti-emetics if nausea (e.g. maropitant).

  Analgesia id painful conditions.

  Minimise stress.

  If anorexia or hyporexia is prolonged it can be associated with further health problems - GI disturbances (dysbiosis, intestinal hypomotility, reduced mucosal integrity), hepatic lipidosis, refeeding syndrome.
• Anorexia - hepatic lipidosis general and clinical signs

  Mostly cats if rapid weight loss due to absolute/ relative calories deficit. Increased risk if high BCS. Peripheral fat mobilisation exceeds livers capacity to redistribute or use it. Excess fat deposited in hepatocytes causing liver failure.

  Clinical signs:

  • Hepatomegaly
  • Jaundice
  • Lethargy, vomiting/ diarrhoea, Ileus, hypersalivation, pallor. neck ventrofelxion, coagulopathies.
• Anorexia - hepatic lipidosis diagnostic tests

  Biochemistry - increased ALT, ALP, AST.

  Heamatology - non-regenerative anaemia, poikilocytosis, increased Heinz bodies.

  Coagulopathy - possibly prolonged PT or APPT - low vitamin K.

  Ultrasound - hepatomegaly (homogenous hyperechoic parenchyma).

  Liver FNA - significant vacuolar distension of hepatocytes.
• Anorexia - hepatic lipidosis treatment

  IVFT - 0.9% NACL

  • NOT Hartmann’s as can not metabolise lactate).
  • Supplement K+, phosphate and B12 according to biochem results.
  • Start feeding slowly - high protein low carb diet (tube feeding).
  • Consider anti-emetics
• Anorexia - re-feeding syndrome general

  If patient fed to much/ to quickly after prolonged anorexia.

  Starvation causes electrolyte depletion (notably Mg2+ and K+)

  Insulin released by pancreas when re-feeding implemented.

  K+ and glucose co-transported into cells so serum K+ drops - hypokalaemia.

  Body response so sudden reintroduction of carbohydrates by making lots of ADP and ATP - sues lots of phosphorous - hypophosphataemia.
• Anorexia - re-feeding syndrome clinical signs

  Cervical ventroflexion.

  Severe muscle weakenss

  Acute red blood cell lysis.

  Respiratory failure.
• Anorexia - re-feeding syndrome treatment

  Immediately reduce feedino 50% and lower carb diet and increase slowly of 4-6 days.

  Check electrolyte levels and give potassium phosphate CRI as needed:

  • May need magnesium sulphate to or hypoK+ may be refractory.
  • Monitor electrolytes and glucose q4-6hrs and adjust accordingly.
  • Monitor PCV closely for hypophosphateamia induce haemolytic anaemia - transfusion if needed.
  • ECG - heart rate and rhythm.
• Anorexia - re-feeding syndrome prevention

  Reintroduce feeding slowly.

  • Max speed - 1/3rd RER on day one, 2/3rd day two, all day three.

  Monitor K+, Mg2+ and phosphorous at least daily and supplement as needed.