Primary liver tumors in dogs

Surprisingly, hepatocellular carcinoma can carry a favorable prognosis, despite the sometimes huge size of some of these tumors. In dogs, malignant liver tumors outnumber benign tumors in which hepatocellular and biliary carcinomas are the most common primary liver tumors. They tend to occur in older animals (10-11 years old) and males are more commonly affected than females. The cause of liver tumors is unknown in dogs: the liver functions to detoxify mutagenic (potentially cancer causing) compounds and this may render the hepatobiliary system more susceptible to their effects. Liver tumors present in three different forms: solitary (massive), nodular and diffuse. Hepatocellular carcinomas most commonly present in the solitary (massive) form.

The treatment of choice for solitary masses is surgery. Seventy-five percent of the liver can be surgically removed and the liver will regenerate to complete functional levels in 6-8 weeks. Chemotherapy is reserved for high grade solitary tumors or the diffuse/nodular forms, but is often not effective. For dogs with massive (solitary) hepatocellular carcinomas metastatsis is less common and tumor regrowth is slow. One recent study of 48 cases of hepatocellular carcinomas reported a metastatic rate of only 4.8%. Reported survival times for massive hepatocellular carcinomas are > 1,460 days in which the ability to perform surgery was the main prognostic factor. In this study, no further treatment beyond surgery was pursued or recommended. JAVMA Liptak et al. Oct. 15, 2004.

Dr. Walshaw has removed quite a few extremely large liver tumors at our practice with excellent outcomes for the patients! If you do an ultrasound and find a massive tumor, it doesn't mean we can't help that patient!

Vaccine Associated Sarcomas

Hello everyone! Finally back from 2 quick vacations spread over the past several weeks!



I have been speaking to veterinary groups for the last 2 years on the topic of vaccine associated sarcomas in cats, and have 4 lectures planned for this month alone. It always amazes me that so many veterinarians do not believe that this disease exists anymore. Sadly, I can assure you it does. Just today, we saw a 3 year old patient that was diagnosed with a vaccine associated sarcoma in the hip area. This patient has already undergone surgery at her referring veterinarian's hospital and will now undergo radiation therapy.



This disease is preventable. As veterinarians, we need to inform our clients of the risks of vaccination and offer vaccines known to reduce or eliminate the risk of future tumor formation. ALWAYS INFORM!!!



As pet owners, we need to be aware and informed of the care our pets receive. Just as you would for your children, ask as many questions as possible before vaccinating your cats. BE INFORMED!!!!



For more detailed information, go to our website http://www.veterinarycancer.com/ and click on "cancer types" and go to vaccine associated sarcomas. It contains a PDF file of an article Dr. Walshaw and I wrote regarding VAS in cats.