Lymphangiectasia

Signalment

• Breed predisposition:
  • Yorkshire Terrier
  • Lundehund
  • Rottweiler
  • Soft Coated Wheaten Terriers

Description

Lymphangiectasia is characterised by dilation and dysfunction of the lymphatic vessels of the intestines. Consequently, protein rich lymph leaks into the intestinal lumen, causing a protein-losing enteropathy and severe lipid malabsorption. It is relatively common in dogs but rare in cats.

Lymphangiectasia can be classified as primary or secondary. Primary lymphangiectasia may form part of of a localised or a more widespread lymphatic abnormality. Secondary lymphangiectasia is the result of lymphatic obstruction. The obstruction may be caused by:

• inflammation, neoplastic infiltration o fibrosis
• thoracic duct obstruction
• right sided cardiac failure
• caval obstruction
• hepatic disease

Lymphagiectasia often accompanies a lipogranulomatous inflammation, but it is not clear which is the primary event. Lymphangitis can cause lymphatic obstruction but the leakage of lymph can cause a granuloma to form.

Diagnosis

Clinical Signs

• Weight loss
• Chronic diarrhoea, steatorrhoea
• Ascites, oedema or chylothorax may result if there is severe hypoproteinaemia or lymphatic obstruction
• Increased appetite
• Vomiting, lethargy and anorexia (less common)

Laboratory Tests

Haematology

• Panhypoproteinaemia
• Lymphopaenia

Biochemistry

• Hypocholesterolaemia
• Hypocalcaemia due to hypoproteinaemia, vitamin D and calcium malabsorption
• Hypomagnesaemia

Other Tests

• Faeacal α1-proteinase inhibitor concentrations or chromium 51-labelled albumin may be used to confirm protein-losing enteropathy.

Diagnostic Imaging

Ultrasound

Abdominal ultrasonography may reveal pleural fluid or ascites as well as help to narrow down other differential diagnoses. Mucosa of intestinal loops may appear thickened due to oedema.

Endoscopy

Tips of the villi may be distended with chyle, which appear like the presence of white lipid droplets with prominent mucosal blebs.

References

• Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company.
• Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition) BSAVA
• Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.