1) New chemotherapy agent available for cats with sarcomas! Ifosphamide is an alkylating agent tolerated by dogs with refractory lymphoma at relatively low doses. Cats, however, can tolerate almost 3 times the canine dose, and responses have been seen in non-resectable vaccinal sarcomas. This drug requires intensive diuresis and MESNA infusion to prevent nephrotoxicity and hemorrhagic cystitis, but is well tolerated clinically. If you have a patient who may benefit, please contact us for more details.

2) More evidence for the efficacy of vinblastine/prednisone chemotherapy for dogs with "high risk" mast cell tumors! Dogs with grade III mast cell tumors, or with grade II mast cell tumors with regional lymph node metastases treated with vinblastine/prednisone therapy had median disease free intervals in excess of 700 days. We've been offering this therapy to dogs with aggressive mast cell cancer at SouthPaws for 5 years and have been pleased with the results in many dogs. Vinblastine is a well-tolerated drug in dogs — while a vesicant, if given carefully, few dogs have any reactions.

3) Smaller margins for mast cell tumors? In a very well-designed clinical study at the Animal Medical Center, surgeons and pathologists carefully marked centimeter distances around mast cell tumors in dogs. Most of the tumors were grade II as is typical. All were resected with 3 cm margins based on current recommendations. 78% had complete resection documented histologically at 1cm, while all were clear at 2cm! Deep margins on the head and trunk were complete at one fascial plane, while deeper resection was recommended for the limbs.

4) New drug for lung tumors in dogs? Navelbine (Vinorelbine) is a relative of vincristine and has been used to shrink non-resectable pulmonary masses in dogs with little toxicity.

5) Cats, ovariohysterectomy and mammary cancer. We've always suspected that early OHE in cats was protective against mammary carcinomas (as has been proven in dogs), but no one had actually done a definitive study. Now, we have statistics to prove the value of early OHE. In cats spayed prior to 6 months of age, the risk of mammary carcinoma is reduced by 91%. Between 7-12 months, the risk is reduced by 86%. After 12 months of age, OHE has no protective effects against mammary carcinoma in cats.

6) Can MRI predict malignancy? In an intriguing pilot study, dogs with ultrasonographically-diagnosed hepatic or

Angiotensin-converting enzyme (ACE) inhibitors are used commonly in heart disease. These agents act by decreasing the production of angiotensin II. Decreased angiotensin II results in decreased afterload through arteriolar vasodilation and decreased preload by venodilation. One of the major adverse effects of ACE inhibitors is exacerbation of renal insufficiency. Benazapril is associated with fewer adverse effects on renal function than other ACE inhibitors. It is used commonly by cardiologists in patients with concurrent congestive heart disease and renal insufficiency.

I have switched to using benazapril exclusively in glomerulonephritis (GN) patients. In GN, ACE inhibitors not only decreased glomerular hypertension but also act by maintaining the negative charge on the glomerular capillary wall, decreasing the size of the capillary endothelial pores and improving lipoprotein metabolism and lipid deposition. These added effects all act to decrease proteinuria. Anecdotal reports have shown an improvement in azotemia induced by enalapril by switching to benazapril. (Other treatments for GN include omega-3 fatty acids, aspirin, and low-protein diets).

The March, 2001 American Journal of Veterinary Research has also reported that experimentally the use of benazapril has slowed the progression of renal insufficiency in cats. It was found to decrease glomerular hypertension while maintaining GFR. In my experience, benazapril is not effective in reducing renal-induced systemic hypertension in cats. The recommended dose of benazapril is 0.25 - 0.5 mg/kg SID.

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