Radiographs will typically show if the cancer has metastasized to the lungs. If it has, amputation is discouraged due to the poor prognosis of this condition.

While x-rays are standard protocol, they are imperfect. As Dr. Hady says in this Tripawds blog post, radiographs can only pick up lesions larger than 3 mm.

Another problem with radiographs is that it may be hard to distinguish between a lung met and an alveoil. With X-rays, a tumor can only be seen from a few angles. If possible, always choose a vet who uses digital x-rays over film, which will show more detail.

Vets tell us that even if lung metastasis isn’t seen on x-rays, it’s there, but in microscopic size (known as micrometastasis). Still, if mets are invisible on x-rays, amputation and chemotherapy is usually encouraged because it’s assumed that even with micrometastasis, our dogs have a fighting chance at beating the odds.

What if CT Scans are an Option?

If you want a more accurate picture of what’s happening in your dog’s lungs, you may want to consider a CT scan before amputation. CT scans are more expensive than radiographs, but they’re best at detecting small abnormalities, such as metastatic cancer in the lungs. CT scans require general anesthesia and sometimes contrasting agents must be injected into the body to enhance the images.

We bring this to your attention because recently, Tripawds member Zeus posted in his blog about what happened when his pawrents opted for a CT scan instead of radiographs.

If you are in the early stages of diagnosing bone cancer and considering amputation for your dog, we advise you to read Zeus’ post about what happened when the CT scan results came back, and his pawrents had to decide whether or not to proceed with treatment anyways.

Here’s an excerpt from his blog post,  “Zeuspod: The Story Begins”

” . . . A few days later the vet called with the devastating news that the radiologist reported a lesion on a lung and a lesion on the liver.  Without further biopsies, the lesions could not be confirmed as cancer, but it is likely cancer.  Obviously, this led us down the road of thinking “the mets are visible so chemo will likely not help.”

We thought we were part of the unlucky bunch that would only have, according to the statistics, three or four months (or less) with our baby.  Additionally, we couldn’t leave the leg on due to the immense pain and the risk of it breaking just during walking and causing even more excruciating pain.

Was it fair to Zeus to remove the leg and go through the pain and recovery when he would only just recover before succumbing to the cancer?  I will admit that euthanasia was on our minds. Then something occurred to us. . . “

continue reading Zeus’ story here

We hope this will help you as you decide the best option option for your pup and your pack. Always keep in mind that there are no “right” decisions, just the one that works best for all of you. And whether or not you choose to amputate, we are here to help any way we can. Since we’re not vets, if there is any information here that you want to add to or clarify, please don’t hesitate to do so in the comments below. Thanks!

Recommended Reading:

ZeusPod: the Story Begins
Tripawds News Blog: Dr. Hady Demystifies MRIs and CT Scans
Dr. Dressler’s Dog Cancer Blog: Can a Dog Cancer Diagnosis Be Wrong?
Dr. Dressler’s Revised Dog Cancer Guide

The most common advice given by veterinary professionals would be to explore pain management options, such as Fentanyl combined with a non-steroidal such as Deramaxx. The downside is these types of drugs can leave dogs in a fog, and rarely do they provide permanent pain relief from bone cancer. Plus, the side effects of long-term heavy use, such as gastrointestinal damage, may reduce quality of life.

Another option for some is radiation therapy, a pain management technique that aims intense beams of radiation at tumors to help shrink them and reduce pain. Unfortunately, this is only available in a few select clinics.

More recently, there is a promising new option for non-amputation candidates: bisphosphonates. You’ve probably heard of them: Fosamax and Boniva are two. This class of drugs is used in human patients with osteoperosis, or those with prostate or breast cancer that has metastasized to bone.

Now, many veterinary oncologists are using bisphosphonates for canine patients, to build and stabilize bone, and effectively manage pain. In some cases, bisphosphonates can also be used for dogs with osteosarcoma metastasis to bony areas such as the spine or skull.

Typically, non-amputee dogs being treated for osteosarcoma are given the bisphosphonate drug Pamidronate. This drug is given as a two hour IV injection every four weeks. Pamidronate may also be given in conjunction with radiation therapy for pain control.

At the Veterinary Cancer Center (VCC), dogs have the most powerful bisphosphonate available; Zoleddronate. For the last year, the VCC team has conducted a Zoledronate clinical trial on dogs with bone cancer, and so far, the results are promising.

Zoledronate Bisphosphonate Trial in New Mexico

Zoledronate is one of the most promising bisphosphonate drugs available in veterinary medicine. Zoledronate is administered as a quick 15 minute IV drip, and can provide long-lasting pain control within 24 hours of the injection. The effects can last up to one month, and can even increase bone production to help form new bone. Dogs can stay on this treatment indefinitely. Several studies indicate that Zoledronate can also kill cancer cells locally and possibly prevent metastasis to other areas.

At over $1,000 per dose, Zoledronate is also one of the most expensive bisphosphonates. Which is why Dr. Kelly is so excited that her clinic is able to provide this drug at no charge to qualified canine candidates. After a year of studying its effects on patients, she says that so far the results have been “beautiful”:

Click here to view the embedded video.

The Veterinary Cancer Care center looks forward to helping as many bone cancer dogs as they can while funds are available for this trial. If you know a dog with osteosarcoma who is not a candidate for amputation, be sure to contact the VCC and ask them about the Zoledronate trial.

For further reading, please see:

• Veterinary Practice News: How to Treat Osteosarcoma When Surgery is Refused
• Veterinary Practice News: Pain Control in Cancer Management

Many thanks to the good people at the Veterinary Cancer Care for sharing this information with us. Catch our other interviews with the VCC:

• VCC Interview Part 1: “Dr. Hady Demystifies MRIs and CT Scans”
• VCC Interview Part 2: “Tripawd Max Does Swimmingly Well, Even After Hip Replacements”
• VCC Interview Part 4: “How to Pick a Veterinarian for Amputation Surgery”
  

“Veterinary Cancer Care P.C. is committed to providing compassionate, high quality treatment to all pets with cancer. Using state of the art therapies, nutrition and kind care, we treat the whole patient, not just the cancer. To alleviate the hardships of cancer, our staff provides a positive family atmosphere, filled with love and hope. We hold a great respect for the human-animal bond, and will always honor your relationship with your pet above all.”

The member wondered if we do amputate, aren’t we still in a no-win situation?

At the time, Dr. Lucroy didn’t have the study on hand, so we followed up with him recently and here’s what he said:

“I think your member is thinking about a study done several years ago (Pirie-Shepherd SR, Coffman KT, Resnick D, et al. The role of angiostatin in the spontaneous bone and prostate cancers of pet dogs. Biochem Biophys Res Commun 2002 292(4):886-91.) as a collaboration between researchers in Boston and Purdue University.

The researchers were studying angiostatin, which is a potent inhibitor of angiogenesis (development of new blood vessels). Because cancer requires nutrition to grow, it must recruit the growth of new blood vessels in order to grow beyond a handful of cells. The researchers discovered that the urine of dogs with osteosarcoma contained angiostatin fragments. Once the primary tumor was completely removed (by amputation) the angiostatin fragments were no longer detectable.

The theory is the primary tumor keeps the metastases in check. Clinically, we observe that very few dogs have metastasis visible on chest x-rays at the time of diagnosis, but if we we examine lung tissue there are osteosarcoma cells detectable under the microscope. After amputation, if nothing else is done, these micrometastases start to develop quickly. The results of this study provide the biological mechanism to explain our clinical observations.

But it is important to note that although we cannot see them with chest x-rays, microscopically the metastatic event has already occurred. So removing the primary tumor does not cause the cancer to metastasize faster, but simply allows the metastatic sites already present to start to grow.

Occasionally we have dog owners who are aware of this research and suggest we simply leave the bone tumor in place. Ethically, however, we cannot do this if we want to relieve suffering. Bone cancer is very painful, and we cannot easily control chronic pain.Therefore we are obligated to either amputate the affected leg or treat the tumor with radiation therapy and pamidronate to relieve the pain.

We now know that by doing this, we are removing the source of angiostatin – which inhibit the growth of the micrometastases. So, enter chemotherapy to slow the growth of these metastatic sites.”

Many thanks to Dr. Lucroy for taking the time to answer this valid question.

Sarah was one of those pawrents. She and her 5 year old Portuguese water dog, Jake, recently came to us through Tazzie, a mutual friend in Canada. Sarah posted in the forums, looking for advice when Jake’s spinal bone cancer became dramatically worse.

She and Jake had walked a long road up to the bone cancer diagnosis. His behaviors exhibited possible diagnoses ranging from a ruptured disc  to arthritis. When cancer was finally discovered, Jake wasn’t an amputation candidate because the cancer (later inconclusively diagnosed as chondrosarcoma) was in his spine.

Sarah found little information online about bone cancer in the spine, and unfortunately we too made the same discovery. Sadly, in just eight weeks, Jake’s health rapidly declined and the intense pain was too much to bear. After a bone biopsy was taken, he could hardly walk and suffered from bouts of intense pain. Sarah released him from his pain on December 12th, just two days later.

Afterward, Sarah told us that she was completely unprepared for the way in which bone cancer in the spine presents itself in dogs. It was distressing not to find even an ounce of hope or ways to cope.

But Jake’s death will not be in vain. Sarah wrote the following summary of her experience, to help anyone else who might find themselves with a dog suspected of having spinal bone cancer. We are grateful for the time she took to help others in this way.

Please read on to learn about the symptoms, behaviors and progression of this devastating presentation of bone cancer.

Swim on, Jake, you will never be forgotten . . .

Primary Chondrosarcoma of the spine – Jake’s Story

by Sarah Crook

Written in the hope that reading it you will be more prepared to cope with this awful disease than I was. The progress of the disease from no symptoms to death took 8 weeks. The cancer was located in the C7 vertebra (lower neck).

Early signs (first two weeks):

• A stiffness that developed after 15 to 20 minutes walking. Jake woke up in the morning seemingly fine – the stiffness was only obvious with exercise and occurred even with moderate exercise, like leash walking. Round the house Jake’s activity seemed normal and the stiffness was not apparent (this pattern seems unlike what I have read about arthritis where the dog wakes stiff, then it gradually wears off).
• A reluctance to go up/downhill that I noticed when walking Jake off-leash. Jake still followed but lagged behind.
• A cautious approach to going up/down stairs especially after a walk when he had stiffened up
• Cautious approach to getting in and out of car – fairly subtle. Just a hesitation before jumping and a preference to climb in rather than jump..
• A reluctance to stretch his head down to eat or drink. Backed off and barked at his food bowl until I raised it up.
• Very subtle – I only thought of this in retrospect – sometimes a slight unsteadiness when he cocked his leg for a pee.

Middle period (middle four weeks):

• After 2 weeks Jake was seen by a vet who physically examined him and found stiffness in his neck and a reaction (growl/snap) when upper back was pressed hard. Soft tissue injury was suspected and Jake put on Metacam and restricted exercise.
• On Metacam he seemed livelier around the house and more playful – but the stiffness and stiff-legged gait still continued when exercised and as things progressed, would start after only 5mins. A video clip taken at this time shows his normal walk when setting out, then the stiff-legged ‘walking on eggshells’ gait that he would suddenly adopt; and his cautious approach to going down a step.
• After 14 days of Metacam and no obvious improvement, Jake was put on Robaxin – a muscle relaxant. Robaxin made him much WORSE. He was clearly uncomfortable in the house – standing looking miserable, seemingly afraid of sitting or lying down (as if he thought it would hurt – which it probably did). His back legs became noticeably weak and he hard difficulty climbing upstairs (ataxia). I was especially aware of him being restless through the night (prior to this he slept well) – he would sleep for a few hours then wake apparently in discomfort and take 5 or 10 minutes to lever himself up and settle into a new position. Later, I found out from the oncologist that this was not unexpected – Jake’s muscles would have been protecting the painful part of his spine, and with the muscle relaxant they could no longer do this.
• After 5 days took him off Robaxin and the vet put him back on Metacam. Ataxia lessened, slept well again, things seemed to improve – but in retrospect he did not recover to pre-Robaxin level. Jake started doing ‘girlie’ pees and if he tried to cock his leg consistently lost his balance. I later learned the weakness in his back legs and the uncoordinated gait (‘ataxia’) that developed were the result of the tumour and/or associated inflamed tissue compressing the spinal cord.

End Phase (last two weeks):

• Increasing unsteadiness of back legs so took Jake once more back to his vet. Same stiffness in neck and sore place on upper back. Blood samples were taken to rule out the slight chance of a tick born disease and vet referred Jake to a surgical specialist and a neurologist.
• Surgeon examined Jake and suspected ruptured disc – recommended MRI.
• Neurologist examined Jake and suspected lesion in lower neck and upper back (either two separate ones or one big one) Recommended CAT scan.
• Cat scan showed tumour in C7 vertebra about 2x2cm in size, and a biopsy was taken. I met with an oncologist and decided to have one radiation treatment to see if it would reduce the pain and inflammation. If not, I would have him put to sleep.

Last Two Days:

Jake came home on a Thursday afternoon after having the CAT scan and bone biopsy the previous night. He was on Perkocet but a couple of hours after getting home had a bout of severe pain – later I thought this episode must be similar to ‘breakthrough’ pain suffered by human cancer victims.

He had two more of these attacks on Friday night and then early Saturday morning, in spite of having started on stronger pain relief (morphine and Gabapentin – and more Metacam, although he deteriorated so fast I never got around to adding this to the cocktail) and they all followed the same pattern – 5 to 10 minutes of increasingly fast panting, signs of acute pain (groaning and struggling to his feet to stand hunched over, head hanging, tongue lolling) lasting 10 – 15 minutes; 20 – 40 minutes of gradually winding down (I could get him to sit on my lap and would rub him and try to calm him). On Saturday I decided enough was enough, it was too late to try radiation therapy, and I had him put to sleep that afternoon…

In retrospect

• I am not sure if I wish I had asked for an X-ray early on and found the tumor sooner. Early diagnosis would have meant when he could still run around I would not have been limiting his exercise and keeping him on-leash all the time… and there would have been time to plan treatment such as radiation therapy. However, the bone biopsy would also have been done sooner and maybe even early on the consequences (huge increase in pain and decrease in mobility) would have been the same as below – see next point.
• I would not have had the bone biopsy done without much more careful consideration – I blame this for the rapid deterioration in Jake’s condition at the end – hugely increasing the pain and causing increased inflammation that severely impacted his mobility and comfort level: he could hardly walk when he came home his back-end was so uncoordinated and weak.
• I would have asked the oncologist for pain meds. to deal with the ‘breakthrough’ pain (if indeed that was what it was). If there aren’t any effective drugs to deal with it, I would have at least discussed what I could/should do if these attacks happened.
• I would have had the consulting oncologist leave a prescription for stronger pain medication with an 24hr animal clinic in case Jake suddenly got worse in the night or at the weekend when she could not be contacted.
• I would have got the contact details of a call-out vet who could come and put Jake to sleep when Jake’s own vet clinic was closed….

Jake’s own vet and the specialists he referred me to were consistently caring and conscientious. Both contacted me this week after I wrote to them raising some of the issues I mention above. They spent nearly an hour going through things with me, so I think they deserve credit for this, especially my vet, as he must have known the length of time in getting to a diagnosis would be a tricky subject to discuss.

Not a happy end to a bright and loving creature. If you are facing the same I know reading the above will be distressing – but I hope it will help you make the right choices for your pet.

Best wishes, Sarah

Many thanks to Dr. Lucroy for providing some insightful answers and interesting ideas about the diagnosis and available treatments for canine cancer. Especially interesting to note was his discussion of NSAID use prior to amputation for cancer dogs…

‹oncovet› Starting on NSAIDs (Rimadyl, Deramaxx, Previcox, etc.) will make dogs with arthritis and early bone cancer more comfortable.  If bone cancer is there, using NSAIDs first simply delays diagnosis.

He also had some excellent advice for those dealing with possible spinal metastasis in their pups…

‹oncovet› Spinal metastasis do occur in osteosarcoma.  About 5% to 10% of dogs will have metastasis at diagnosis.  Almost all dogs develop them later.  The use of chemotherapy tends to increase the risk for bony metastasis.  In the spine, we generally have fewer surgical options, so we go for pain control.  That often means radiation therapy in combination with pamidronate or similar bisphosphonate drugs.

Other issues addressed included the use of Artemisinin and Metronomic therapy for fighting cancer and treatment options for subcutaneous metastasis, or subq mets. More information can be found in the transcript and Dr. Lucroy’s new book, The No Nonsense Guide to Cancer in Pets, or his veterinary oncology blog.

Stay tuned for the next live chat, or drop by to see if anyone is online now. You can usually find my pack hanging around the chat room most evenings but we can’t always be there, so schedule your own anytime!