Michelle Gerhard Jasny, V.M.D. has been practicing veterinary medicine on the Vineyard since 1982 and writing the Visiting Vet column for more than 25 years. She lives and works in West Tisbury. She can be reached at drjasny@comcast.net.
At 11 years old, Nana, the beagle, has been through a lot in her life. A skin condition from demodectic mange mites. A difficult pregnancy with only two of six puppies surviving. A mammary gland infection called mastitis while nursing. A painful infection behind her eye called a retrobulbar abscess. Tick-borne disease. But Nana is a survivor, taking each challenge in stride, still cheerful, still wagging her tail. Then a few years back she developed a lump on her hip.
“It doesn’t feel like a lipoma,” I said, referring to a type of benign fatty growth frequently seen in older dogs. Her owners consented to a “fine needle aspirate,” a quick diagnostic procedure done in the exam room without anesthesia. Although rarely sufficient for definitive diagnosis, a pathologist can often give a general idea of what we are dealing with from an aspirate like this — in Nana’s case, possibly a malignant tumor.
“The pathologist says it’s probably a kind that doesn’t tend to metastasize,” I reported. Cancers with high metastatic potential often spread from their original location to distant sites in the body, such as lungs, lymph nodes, or bones. Those with low metastatic rates tend to stay in one place but can be locally invasive and aggressive, causing serious damage. I still advised X-rays prior to surgery, just to be sure there was no evidence the cancer had spread. Her films looked fine so we proceeded to surgery.
Removing the growth, it was hard to tell where tumor ended and normal tissue began. Some masses are well-encapsulated, shelling out easily, but not this one. We cut as wide as possible, and sent it for biopsy. The final diagnosis was nerve sheath tumor, a low-grade malignancy with minimal risk of spread but significant chance of eventual recurrence.
“They can’t say for sure that we got it all,” I explained. “It may never come back, or it may regrow.” I offered options. More surgery. Referral to an oncologist. Radiation therapy.
“Let’s wait and see if it comes back,” Nana’s owners decided.
Time passed. Nana ate rat poison and was treated on emergency. She was okay. Nana binged on a stash of snack food, eating them bags and all — Fritos, Cheetos, Smartfood popcorn. Everything eventually passed. She was okay. Two years after her surgery, Nana started having a series of minor complaints. A swollen eye. Dental tartar. A fatty lump on her chest. A small lump reappearing on her hip. A cough. Addressing one concern after another, we eventually got to the cough. Her heart sounded fine, so not cardiac disease. Her lungs were clear, her temperature normal, so pneumonia was unlikely. Perhaps she had caught an upper respiratory infection, like kennel cough. We prescribed antibiotics, advising a recheck if the cough didn’t improve.
A few weeks later, the cough was better but not gone. A chest X-ray looked normal, and we made a presumptive diagnosis of allergic bronchitis, a common problem in older dogs.
“It’s worse in the mornings,” her mom shared. “Maybe the wood stove is bothering her.”
A logical theory, I agreed. We tried cough suppressants. We tried corticosteroids. The lump on her hip was growing slowly. We wanted to pursue a second surgery, but preferred to wait until the cough resolved.
“I think she’ll improve once spring comes, and we stop using the wood stove,” her mom said. Months passed. April arrived. Nana’s cough did seem better, though not 100 percent.
“It may never clear up entirely,” I sighed, suggesting we start preparing for surgery with preoperative blood tests. We offer two “levels” of screening. Her mom opted for the more comprehensive one. Good call. Everything came back completely normal, except one test. Nana’s calcium levels were elevated.
“It’s called hypercalcemia,” I explained, “but very often it is a spurious finding caused by lab error.” We repeated the test, this time fasting Nana overnight before the blood draw, and sending it to the big reference lab instead of running it here on our little machine. But the retest came back with the same results, confirming the hypercalcemia was real.
“Hypercalcemia of malignancy” is a condition in which a cancer produces a substance similar to the hormone normally responsible for regulating calcium levels. The body gets fooled, thinking it’s supposed to release calcium from the bones into the blood, thus causing the hypercalcemia. Lymphosarcoma and anal gland carcinomas are the most common tumors associated with this problem, not nerve sheath tumors. I checked Nana again. Her anal glands were fine. Maybe we were missing something? Although we had taken X-rays five months previously, we decided to snap more before proceeding with surgery.
There it was. A mass in her chest, just above and in front of her heart in an area called the cranial mediastinum. It was a really large mass, the size of a hefty avocado, compressing her wind pipe and bronchi. Without a biopsy, we couldn’t determine exactly what kind of cancer, but the radiologist doubted it was related to the nerve sheath tumor on her hip. Most likely it was a heart base tumor arising from the aorta or pulmonary artery, hemangiosarcoma, lymphosarcoma, or even a thyroid tumor. The radiologist was frank. “Masses in this location are often quite vascular making successful sampling both difficult and risky. CT or MRI . . . would be very informative but would require anesthesia and is more expensive.”
Definitive treatment requires definitive diagnosis, but was putting Nana through risky and painful procedures in her best interests when the long-term prognosis is very guarded? We had followed a long trail, through the many maladies of her youth to a tumor on her hip, from a cough to hypercalcemia to a second, far more serious tumor. For now, Nana is still wagging that tail. We are trying various medications in hopes of controlling her cough and keeping her comfortable. Her owners have some difficult decisions to make. Choosing to do “nothing” can be tough, but sometimes it may be the right thing to do.
