Page 741 - Clinical Small Animal Internal Medicine

65 Cirrhosis and its Consequences 709

the presence and severity of cirrhosis, but it is crucial or idiopathic disease, specific treatment may not be
VetBooks.ir to attempt to identify the underlying disease that has possible. In all cases of cirrhosis, treatment must also
include management of any important complications of
resulted in the development of fibrosis/cirrhosis. This
will allow for specific treatment to be directed at the
Colchicine (0.03 mg/kg/day) is the only specific drug in
underlying cause. cirrhosis.
Due to the risk of coagulopathy in dogs with hepatic veterinary medicine currently used to stop the formation
disease, coagulation testing including PT, PTT, platelet of fibrosis. It is thought to stimulate collagenase activity,
count, and possibly buccal mucosal bleeding time (BMBT) increasing the breakdown and decreasing the formation
should always be performed prior to liver biopsy. of collagen. Colchicine is reported to have important and
Interestingly, results of these parameters do not consist­ common side‐effects, including vomiting, diarrhea, and
ently predict risk of bleeding after liver biopsy in human neurologic signs. Additionally, there are no large studies
patients with chronic liver disease. Fibrinogen concentra­ that have shown positive benefit from this medication, it
tion should also be evaluated if possible, as it may be has not been evaluated in cats, and it is currently cost‐
decreased in cirrhosis. In humans, thromboelastography prohibitive for many pet owners. As a result of these
(TEG) analysis can predict bleeding tendencies in cir­ problems, most clinicians do not currently recommend
rhotic patients, but the value of TEG in predicting bleed­ its use, even in documented cases of hepatic cirrhosis.
ing in our canine and feline patients with liver disease is Glucocorticoids may be beneficial in some cases of
unknown. In cases of hypofibrinogenemia or other coagu­ cirrhosis. Steroids interact with TGF‐beta signaling
lopathy, transfusion with cryoprecipitate or fresh frozen pathways and may reduce fibrotic progression, although
plasma should be performed prior to biopsy. Vitamin K1 this effect may be relatively weak. More importantly,
therapy (1–1.5 mg/kg q12–24h for three doses) prior to prednisone/prednisolone (1 mg/kg/day) may be useful
biopsy may also be necessary, especially in cats.Assessment in inhibiting hepatic inflammation, if present. This
of coagulation status should, however, not be a substitute decrease in inflammation will result in decreased activ­
for proper technique and adequate post­operative care. ity of hepatic stellate cells, responsible for formation of
Biopsy may be obtained through ultrasound‐guided further fibrosis. Glucocorticoids may be most benefi­
“Tru‐Cut” needles, laparoscopically, or via exploratory cial for treatment of dogs and cats with active hepatic
laparotomy. Each method has practical advantages and inflammation that have not yet developed fibrosis/cir­
disadvantages when it comes to cost, time involved, rhosis. Evidence supporting use of glucocorticoids in
invasiveness, and availability. But collection of a wedge the absence of hepatic inflammation is lacking, so their
biopsy via laparoscopy or exploratory laparotomy is use may or may not provide additional benefit in treat­
generally considered to be a superior method of sample ment of cirrhosis alone. Moreover, the adverse effects
collection. It has been shown that morphologic diagnosis of steroids in animals with advanced fibrosis can be
of needle biopsy specimens and wedge biopsies (consid­ very significant. Due to their ability to cause gastric
ered the gold standard) only agreed in 40% of animals ulceration, they should be used with extreme caution in
with liver disease. If the “Tru‐Cut” biopsy method is animals with , as these animals already have a compro­
utilized, two or more samples should be collected to mised GI tract blood flow. Steroids cause muscle break­
minimize sampling error. Further details on the methods down so may also potentiate HE.Further details on the
to collect liver tissue can be found in Chapter 60. use of corticosteroids in dogs with chronic liver disease
can be found in Chapter 62.
Losartan is another medication that shows promise for
Treatment fibrosis/cirrhosis but has not yet been evaluated for this
purpose in small animals. Losartan is an angiotensin II
Cirrhosis is considered irreversible. Therefore, the receptor antagonist that has been shown in rodent mod­
most important aspect of treatment is addressing the els to inhibit hepatic stellate cell activation and attenuate
underlying cause of liver disease as early as possible to hepatic fibrosis. It is currently utilized in veterinary
prevent further development of fibrosis/cirrhosis, and medicine for its effects on proteinuria. No studies have
to minimize the risk of cirrhosis‐associated complica­ shown if losartan may be an effective therapy in prevent­
tions. Corticosteroids have been shown to have positive ing fibrosis development in dogs or cats.
long‐term effects in the treatment of idiopathic chronic
hepatitis, and may have minor antifibrotic properties Ascites
(see Chapter 62). Copper‐chelating medications such
as D‐penicillamine or trientine should be utilized in Ascites may spontaneously improve with specific
cases where primary copper‐associated chronic hepati­ treatment of the underlying liver disease. Reducing
tis is diagnosed. In cases of previous toxic hepatopathy hepatic inflammation, when present, may decrease PH