Side Effects of Radiation and Chemotherapy

I had been told that dogs do not typically have the same, severe side effects from radiation and chemotherapy that humans do.  I was still surprised, however, that after the first couple of weeks of radiation and one dose of chemo, Strider seemed energetic and happy, with no visible effects from the treatments.  He had not been eating much while at Auburn, but we attributed that to the stress of being away from home, and on the weekends, he ate fairly normally.  At 105 pounds, he could certainly stand to lose a little weight, so we actually thought it was a good diet plan.  He did drop to 95 pounds over the first 3 weeks of treatment, but that is still large for a golden.  He is a big boned dog, and not obese at 95 pounds, but 90 would be better.

The first radiation treatment was given on November 29 and the first chemo was given on December 7.  One week after each chemo treatment, blood tests are performed to make sure his blood counts are staying high enough.  On December 14 or 15, I was told his test results were fine and he was feeling well.  He had started showing signs of irritation in his gums, but nothing major.

I picked him up at Auburn on December 17 to come home for the weekend, with only 3 more radiation treatments to go.  We got home about 2 pm and he was running around, playing with our other dog and chasing tennis balls.  I was quite smug about how well his treatment was going.

About 6 pm that night, he became very lethargic and refused food and water.  That continued through the night, and I took him to our local vet at 8am the next morning.  His temperature was 103.7, so Dr. R prescribed 2 antibiotics, metronidazole and amoxicillin, and an anti-inflammatory, previcoxx.  Dr. R believed he had an infection caused by his immune system being suppressed by the chemo.  It happened 10 days, instead of the expected 7 days, after the treatment was given.

We went home and I gave Strider the medication.  He immediately vomited it up.  I waited a little while, and gave it again with the same results.  I returned to the vet (luckily it's only a 5 minute drive from our house) and he gave him an injection of Cerenia for nausea.  I waited an hour, gave the medication again and he kept it down.  The Cerenia made him sleepy, so for the rest of the weekend Strider didn't do much but sleep.

We returned to Auburn on Monday and I explained what had happened over the weekend.  His temperature was normal at that point, so he was getting over the infection.  His gums were much more inflamed, even with the previcoxx, so there was some consideration given to waiting to give the next radiation, but ultimately, they decided to go ahead with the last 3 treatments.

I picked him up after his final treatment on December 22, very glad to get him home for Christmas.  The attending vet told me they had decided to delay his next chemo treatment, which was scheduled for December 27, by a week, to let his mouth heal a little from the radiation.  He was having trouble eating due to the irritation, and they wanted him strong for the next chemo.

We woke up on December 23 and Strider's nose looked really dry and scabby.  By the next day, Christmas Eve, it was much worse.  On Christmas morning, the scabs had come off and his nose looked completely bloody and he had lost most of the hair around his nose.  It looked terribly painful, but it didn't appear to bother him.

I need to back up and explain what else was going on from the time he came home on the 22nd.  He had started sneezing and snorting occasionally the prior weekend, and by the time he came home, it was constant.  During the night, he was keeping my son up almost all night with noise, since he sleeps in his room.  I tried to convince my son to kick him out, but he's too soft-hearted to do that.  Apparently, the sneezing and snorting is his trying to clear out the tissue, both cancerous and healthy,  in his mouth and nose that is dying from the radiation.  

I took him back for a follow-up with our local vet on December 27 and he said that in addition to the nose burn, there is a radiation burn on the roof of his mouth. 

As a result of the discomfort in his mouth and probably some loss of smell, Strider has been eating only soft food that he takes out of my hand.  He tries to eat it out of his bowl, but it seems to cause him discomfort to do so.  I am speculating that maybe the movement required of his tongue to pick up the food is hurting the roof of his mouth.  

I have attached some photos of him with the radiation burn on his nose.  It looks awful, but doesn't seem to bother him.  

The hardest part of the side effects so far is emotional, because before we started treatment, he was in no pain and was energetic and happy.  He just had a little lump in his mouth.  Seeing how sick we have made him, with more chemo to come, is difficult, but makes me feel better about the decision to not have surgery.

I discussed with the attending vet at Auburn that we would need to monitor the degree of side effects from future chemotherapy and weigh that against the uncertain benefit, and he agreed.  If Strider only has a short time left, I don't want him to spend most of it sick.  We have 4 months of chemo left, and that's a lot, relatively speaking, compared to his life expectancy.

So, we go back in 6 days for the next round of chemo.  It will be a different drug this time, so I don't know what to expect.  They are alternating carboplatin and doxorubicin, for 3 treatments of each.  For the chemo, I check him in early in the morning and pick him up late in the afternoon.  Hopefully, there will be some good movies playing to pass the time in Auburn.

As things change, I will update his progress.  As I posted earlier, I'm not sure that I can justify the $5-6 thousand that this will end up costing to prolong Strider's life by a year or so, especially given that the effectiveness of the treatment is totally uncertain, and the treatment itself may be more painful than the cancer. So I am hoping that the veterinarians at Auburn will learn something that will help other dogs in the future, and that maybe if anyone out there is looking for information, they will stumble upon this blog.   I have to almost view this process as a donation to veterinary science, and also hope that Strider's life in prolonged in a positive, healthy way.

I know he looks sad in the photos below, but that expression really means "I really want that piece of turkey in your hand, so please stop taking pictures and give it to me."

Normal nose on Ozzie
Radiation burn on Strider

Strider with radiation burn on his nose