Cassie’s CLL

A routine blood test for a senior dog—where would it lead?

Cassie, my 8-year-old springer spaniel, seemed very healthy and energetic, so I thought nothing of getting a routine blood test, which my vet had recommended for a senior dog. But there’s where the trouble began—elevated white cell (lymphocytes) counts. A year earlier, Cassie had the same trouble with a blood test prior to surgery to remove a few bumps. A re-test a few weeks later resulted in normal cell counts, probably a minor infection, the vet had said.

This time a re-check showed Cassie’s white cell counts had climbed by a few hundred to 8,500 per µL. No symptoms, only the blood test.


“I’m afraid Cassie has leukemia,” the vet told me over the phone. “The good news is that of the various types of leukemia, chronic lymphocyte leukemia or CLL is the best one to have. Its progression is very slow and we can use drugs to keep her white cell counts in check. We should re-test Cassie’s blood levels every other month to monitor her cell counts. When her white cells get above 50,000 per µL then we need to start treatment with chemotherapy drugs.”

So began our steady trips to the vet, as Cassie’s counts steadily rose to 15,000, 25,000, 40,000 and more. After six months her counts exceeded 50,000. Normal levels for dogs are below 5,000.

Springer spaniel by Christmas tree
Cassie during her last Christmas.

Leukemia is cancer. It took a long time to sink in. Cassie seemed so healthy.

My husband and I discussed our options:

  • Do nothing since she was asymptomatic – but the vet assured me that at some point her platelet count could become too low due to an over abundant amount of white cells. Then her blood would not clot and even a minor bruise could cause her to bleed to death.
  • Use chemotherapy drugs to control her white cell count. Leukeran (Chlorambucil) at 2 mg every other day was the standard recommendation. The steroid Prednisone increased the effectiveness of Leukeran. The vet also prescribed Famotidine for stomach upset. Many possible side effects could occur from this cocktail of drugs from vomiting and diarrhea to possible seizures, with additional long-term problems, especially from the Prednisone.

I felt I didn’t have many options other than trying the chemotherapy drugs. With concerns about initial side effects, we postponed giving Cassie the drugs until we had returned from a two-week trip to Germany. Fortunately, Cassie did not show any initial side effects.


Routine blood tests continued every other month as the vet adjusted Cassie’s prednisone levels to the lowest amount needed to control her white cell counts within the normal level.

Although Cassie continued to walk a total of 6 miles a day with me back and forth to work and seemed to have unlimited energy, the drugs started to show their side effects.

  • The first was leakage of urine while she slept. I’d find little pools of urine on the floor and damp spots on her fur. Since Cassie worked with me, I couldn’t let her stain the office carpeting, so I used diapers. I learned to stock up on low-cost washable diapers and to bring several with me each day in case she made a mess. I also used sanitary pads and not the diaper liners to keep the costs down. Over the 2 ½ year period that she wore diapers, I ended up buying about 8 diapers and used about 3 – 4 sanitary pads a day.
  • Cassie’s fur thinned and grew dull. Since I shaved her fur over the summer, this wasn’t noticeable until late fall, when her fur took a long time to grow back. The fur on her tail fell out and didn’t grow back, especially on the tip. Her tail resembled a rat’s tail.
    • Cassie had a compromised immune system from the chemotherapy drugs, so the vet told me not to take her to groomers, dog parks, or stores, where there were many dogs. So I shaved Cassie myself, sometimes with bad-hair-day results.
  • Increased hunger. Cassie always acted as if she was starving, so I had to watch her weight.
  • Delayed healing of skin wounds and surgeries. My vet would only do surgery if absolutely necessary due to her slow healing.
  • Eventually, Cassie’s skin started to break down and a wound on her back refused to heal after months.

Although Cassie’s white cell counts remained in the normal range, she started developing nervous issues after she had the disease for about three years. The vet thought Cassie’s frequent tripping was due to arthritis in opposite legs. I had tried laser therapy on one of her legs but did not see any response. The vet also recommended walking Cassie over a ladder placed on the ground encourage her to pick her paws up higher. This actually worked very well. Cassie was a former agility dog and liked to do tricks like this. Her tripping decreased substantially for several months.

But by the middle of April, Cassie lost her balance twenty or more times each day. Often she caught herself, but sometimes she bashed her chin on a step or fell to the ground. My vet mentioned trying the laser treatment on her other arthritic leg, but unfortunately, it did not help.

Cassie was diagnosed with a brain tumor, possibly a secondary cancer formed from her leukemia. My husband wanted a second opinion – always good to do with a serious illness. The veterinary neurologist told us the same prognosis as my vet. They suggested doubling Cassie’s Prednisone dosage, which might slow the growth of the tumor, giving her a few more months. Since Cassie had been taking Prednisone for about 3 1/2 years by then, the higher dose had no effect.

Cassie degenerated rapidly, within a few days she could no longer walk, even with the assistance of a sling and harness for support. Her body curved into a C and she could not straighten. Although she still enjoyed eating, when she could no longer relax her body enough to eliminate, we knew it was time to euthanize her, at the age of 11 ½.

Lessons learned

  • Shop around for the cost of drugs. Prednisone and Famotidine are very low cost, but the price of Leukeran doubled overnight after the first of the year. Leukeran was very expensive. When Cassie first started taking it, the cost was $70 for 15 pills, which was a month’s supply. Then in January 2014, the price doubled. For the first month, I found one pharmacy that had not increased their price, but they did the following month. We researched drugs from Canada, which had much lower prices. My vet was skeptical, but after she did some research, she recommended a few companies. Since Leukeran needed refrigeration and shipping took about a week, I would buy quantities of 100 pills so I could have them shipped during the cooler months. Purchasing Leukeran from Canada saved us a ton of money, a six-month supply cost us the same as a two-month supply from the local pharmacy.
  • Realize that CLL is a long-term disease, so veterinary costs do add up. But I do recommend getting blood tests done frequently, so your vet can tweak the Prednisone dose as needed.
  • If needed, purchase washable diapers and use sanitary pads.
  • Purchase doggie wipes to dry wash messes on their fur and prevent them from smelling of urine.

My only regret is that since Cassie had seemed so healthy, I hadn’t anticipated that her leukemia could spread to other organs. My vet had said that Cassie could live a full life, so I was shocked when she developed a brain tumor.

Please feel free to comment, email me a story about one of your pets, or read my page on Leukemia to find out more.

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