Canine Ovarian Cancer Chemotherapy Side Effects

by Mihoko Hosokawa
(Tokyo, Japan)

Hello.

I have questions about avoiding the side effects of chemo drugs.

My dog is shiba inu(a kind of Japanese dog), 11 years old, and female. She was diagnosed with granulosa cell tumors after she had the surgery February 15, 2010. The surgery was to remove completely the female reproductive organs and one lymph node near the intestines.

After that, she had chemotherapy(Doxorubicin 7.8mg, her weight was 7.6kg) on 27th in February. She had CT on 15th in March. The comparison with her previous pictures(10th in February and 15th in March) showed one unchanged lymph of her chest, two unchanged lymph of her abdomen and two swollen pelvis lymph.

As My vet and I, however, did not have CT after the surgery, it was unclear whether Doxorubicin succeeded or not. The second chemo was Carboplatin(200mg/‡u This is Japanese scale, not 300mg/‡u of US) on 29th in March, and the result of CT on 15th in April was that two pelvis lymph was smaller and others did not change.

On 3rd in May, she had the third chemo(Doxorubicin 8.2mg because her weight was 8.2kg). CT is scheduled for 26th in May. Now, she is in a stable condition(she keeps the weight of 8.2kg, is playful and gets a healthy appetite.).

I want to try to use Carboplatin again for the next chemo. However, in Japan, there is not any information for Carboplatin. I really worry about side effects, especially bone marrow suppression against Carboplatin.

It is too long (7 to 21 days) to suffer. How many times do you check CBC after administration? Do you check CBC at 7 day intervals, 5 days or shorter? Could you please give me your advice?

Sincerely,

Mihoko Hosokawa

Vet Suggestion

Hi Mihodo,

I am sorry to hear about your dog’s fight with cancer, but it sounds like you are providing her with excellent care. I am not a veterinary oncologist, but did a little research into your questions about carboplatin and this is what I can tell you.

It is typical for a veterinary oncologist to recommend checking a dog’s blood counts on day 7, 14 and 21 after the treatment with carboplatin. The decision regarding when and if to use the drug again depends on how low the neutrophil and platelet counts go and how quickly they rebound. For example, one doctor waits to treat again with carboplatin until platelet counts rise over 100,000 to 125,000/ul and will switch drugs if the count ever drops below 50,000 platelet/ul.

I hope that helps.

Regards,

Jennifer Coates, DVM