|
|
|
|
Glomerular Disease Glomerulonephritis is a problem related to the immune system. When antibodies react to foreign material in the body they do so by binding to the unusual proteins (antigens) forming a large complex of antibodies and antigens. These become trapped in the small capillary blood vessels in the glomerular basement membrane and compromise its ability to filter blood. Numerous infectious diseases can stimulate this response, as can some tumours and certain types of inflammatory disease. The result is the basement membrane becomes too permeable and blood proteins leak through into the kidney tubules. There is also a reduction in the ability to reabsorb water, causing excessive urine production. The first sign of the kidney failure is usually excessive urine production (polyuria), matched by increased thirst (polydipsia), an increased level of urinary protein (proteinuria), and a degree of weight loss. As the kidney fails to filter urea its blood levels start to rise, causing a clinical state known as uraemia. In the dog it is responsible for vomiting, diarrhoea, anaemia, and sometimes oral ulceration. Excessive protein loss through the kidney leads to a depletion of blood proteins which causes oedema of the limbs and fluid build up in the abdomen or thorax. Oedema of the intestine can result in diarrhoea. Dogs in end stage renal failure will become significantly dehydrated. Diagnosis of renal failure is often made on the basis of the clinical signs, the measurement of urine protein, and the measurement of blood urea, creatinine and inorganic phosphate levels. The specific diagnosis can only be made by renal biopsy. If the animal is oedematous then diuretics should be used to reduce and control the fluid build up, frusemide is probably best for this purpose, it can be stopped once the fluid build up has disappeared. If uraemia is part of the problem then it is essential to reduce dietary protein intake (urea is a metabolite of protein). If vomiting is excessive then intravenous fluids should be given to correct dehydration and electrolyte deficiencies, antiemetic drugs such as metoclopramide can be given to help control vomiting. Most cases are well advanced by the time clinical signs appear and it is not possible to achieve a cure. The condition will progress and the long term prognosis is poor. Non-uraemic nephropathies can survive several months, occasionally over one year. |
|