Angiotensin-converting enzyme (ACE) inhibitors may be beneficial in management of dogs and cats with chronic renal failure (CRF). Renal disease progresses to CRF as a consequence of functional adaptations of the remaining nephrons, including glomerular hyperperfusion and hypertension controlled by angiotensin II. These responses initially enhance nephron filtration capacity and compensate for the decrease of glomerular filtration rate but are detrimental in the longterm and cause further nephron loss. Administration of ACE inhibitors lowers glomerular pressure by decreasing systemic blood pressure and locally inhibiting angiotensin II. In animals with CRF, ACE inhibitors may decrease proteinuria caused by changes in glomerular membrane permeability and selectivity from mechanical injury induced by glomerular hypertension, potentially slowing disease progression. ACE inhibitors also tend to increase appetite and body weight in animals with renal failure. Enalapril is used in dogs at a dosage of 0.5 mg/kg, PO, once or twice daily; benazepril is used in cats at a dosage of 0.5–1 mg/kg/day, PO.
Dimethyl sulfoxide (DMSO) has been used in dogs with amyloidosis with variable results. It is given at a dosage of 80 mg/kg/day, divided tid, and given as a 10% solution either PO or SC. Thromboembolism and systemic hypertension are frequent complications of glomerular diseases in dogs, and to a lesser extent in cats, and should be managed as the need arises. Thromboembolism may be prevented by giving aspirin at 0.5–5 mg/kg bid, to high-risk animals such as those with serum albumin <2 g/dL, plasma fibrinogen >400 mg/dL, or plasma antithrombin III activity <70%.