Page 39 - WSAVA2018
P. 39

copper. Combining all this information allows optimal treatment of the patient. It is not possible – and indeed is potentially dangerous – to give specific treatments
for CH (such as copper chelators and steroid or other immunosuppressive therapy) without biopsy confirmation of disease.
Treating the cause of the disease
If a significant amount of copper is found in the biopsy, in · proportion to the severity of the disease, copper storage disease should be strongly suspected and treated with chelation and dietary therapy. If copper storage disease
is ruled out, the type and distribution of inflammation present may suggest a cause for the disease. There are more details in the liver biopsy lecture tomorrow.
Steroids should never be used without a liver biopsy because they are not indicated in non-inflammatory fibrosis and cirrhosis: if used in these cases in the presence of portal hypertension they have no clear benefit and conversely they increase the risk of serious consequences including increased water retention and gastrointestinal ulceration. None-the-less, corticosteroid therapy should offer the best chance of survival in dogs with true autoimmune CH so should not be withheld if the clinician and pathologist believe on the basis of liver biopsies that this is the most likely cause of disease in
a particular dog. There are also some promising results from a study in the USA using cyclosporine for dogs with suspected immune-mediated chronic hepatitis.
TREATING CLINICAL SIGNS AND SUPPORTIVE THERAPY
Treating the clinical signs of disease non-specifically is
a very worthwhile aim in CH because it improves the quality of life of the patient. Ultimately, most dogs with CH die because the owners request euthanasia due to poor quality of life, so improving the quality of life should also improve life expectancy in these patients. The factors to consider and treat are:
· Ascites: if present, this should be treated with spi- ronolactone as the primary diuretic and addition of loop diuretics as necessary
· Vomiting, diarrhoea and evidence of GI ulceration: these are common in animals with portal hyperten- sion and should be treated predominantly by careful little and often feeding to provide nutrition for gut wall healing and avoidance of potentially ulcerogenic drugs such as steroids. H2 antagonists such as ranit- idine or proton pump inhibitors such as omeprazole could be used, together with sucralfate, although evidence for their efficacy in ulceration due to portal hypertension is lacking.
· Jaundice: when pre hepatic causes and post hepat- ic obstruction have been ruled out, this should be treated with ursodeoxycholic acid and anti-oxidants. Ursodeoxycholic acid has a large number of poten- tial benefits in animals with CH including choleresis, displacement of toxic bile acids and anti-oxidant properties. There are no contraindications to its
use but, like all other therapies in canine CH, the evidence for its efficacy is very sparse. However, it makes logical sense to use it. It also makes sense to use anti-oxidants in this circumstance since refluxed bile damages mitochrondrial membranes and is a strong oxidant toxin. A combination of S-adenosyl methionine, silybin and vitamin E is advised. The clini- cian should try to choose neutraceuticals with proven bioavailability in dogs.
Hepatic encephalopathy (HE): this is not as promi- nent or easily recognised in dogs with CH as it is in young dogs with congenital portosystemic shunt. None-the-less, it can be an important cause of confu- sion and unusual behaviour in these animals due to the development of acquired portosystemic shunts secondary to portal hypertension. It should be treat- ed carefully: marked protein restriction is not indicat- ed in these dogs, as they are likely to be suffering from protein-calorie malnutrition already. HE can be addressed by treating any underlying inflammatory trigger and also any precipitating gastrointestinal bleeding and giving a highly digestible, high quality diet little and often. Antibiotic and lactulose therapy may also be considered. Dietary protein restriction is very rarely necessary in these cases
Your Singapore, the Tropical Garden City
· Treatment of protein-calorie malnutrition: many dogs with CH present in negative nitrogen balance. They are often thin with partial anorexia and vomiting and diarrhoea which contribute to nutrient malabsorption. It is therefore very important to prioritise nutrition in the treatment of these patients. Ideally, they should be fed a highly digestible, high quality diet little and often and this diet should not be protein-restricted.
        37
            
















































































   37   38   39   40   41