Cats and Dogs differ in the way bone cancer
matures and how treatment should be administered. Because of the rapid
nature of osteosarcoma, treatment should be sought as soon as possible.
The only trouble is that the most common sign, lameness and pain usually
happens when it is already taken firm hold. It is also mistaken by
owners at first as arthritis, stiffness or pulled muscle in which
veterinarian care is usually not immediately sought.
Osteosarcoma is the most common long bone tumor in dogs and cats. This
is a very aggressive tumor causing lysis (disintegration of bone) or
bone production or both. There is some degree of soft tissue involvement
and metastasis (transfer of the disease to another part of the body) is
common in the early part of the disease.
Canine Osteosarcoma Treatment
There are several available options for the treatment of osteosarcoma.
Chemotherapy in combination with surgery are considered to be the
primary therapy in dogs without any detectable metastasis. Amputation or
limb sparing will resolve the primary tumor and resolve the pain and
lameness associated with osteosarcoma. However, on cases where surgery
alone is performed, 90% of affected dogs will die of metastasis within
one year.
The goal of surgery is to remove the tumor along with a clean healthy
cell margin. This is usually accomplished by amputation. Limb sparing
could also be done with insertion of an allograft after removal of the
affected segment of bone. An allograft is a graft of tissue taken from a
donor of the same species sufficiently unlike genetically to interact
antigenically.
Also, chemotherapy significantly prolongs the survival of dogs with
osteosarcoma when used in conjunction with surgery. Medicinally,
Cisplatin alone or in combination with doxorubicin markedly improves
survival time to a median of 8-10 months with the percentage of dogs
alive after 11 months at 50%. Carboplatin another drug with less renal
toxicity has the same survival time as Cisplatin.
Furthermore, radiation therapy is also used in the treatment of
osteosarcoma. This is very important for limb saving procedures, since
it aids in local control after marginal resection (removal). It usually
provides pain relief after the 3rd or 4th session. This option is
attractive for those who do not want to pursue amputation procedures.
Most animals adapt mentally well to amputation. Probably because
survival is a basic instinct and they do not have any social pressures
associated with it. Physically, animals that are young and not
overweight adjust the best. As a veterinarian, I find that the immediate
key to a successful amputation is the aftercare and the ability to keep
the pet from licking or biting at the wound. Animals that are not
compulsive in this manner require less care and heal more quickly with
less chance of additional infection.
Feline Osteosarcoma
Unlike its canine counterpart it has a much lower rate of metastasis and
longer term survival can be expected with complete excision. Median
survival for cats with osteosarcoma is approximately 2 years with many
cats outreaching that. Due to the slow metastatic rate, radiation
therapy can play an important role in osteosarcoma that cannot be
totally excised. Though, chemotherapy is not routinely warranted due to
the slow metastatic nature of feline osteosarcoma, it should be
considered in a case to case basis.
Conclusion:
This actual pet owner's testimonial says it all:
"In July of last year, (2001) our 8 year
old dog was diagnosed with a fast growing type of bone Cancer. Since
there was nothing that our vet could do for him, and we were told that
his bones would eventually become so brittle that they could break with
him just going up and down the stairs of our home, it was decided that
we would have to have him put to sleep.
My husband and I did not want to face his death
so soon so decided to wait and see how things went. Over the next few
weeks he almost gave up eating altogether and had lost about 20 lbs. He
felt bad for him because his ribs were sticking out and so we scheduled
to have him put to sleep later that same week.
I received a call a few days later from a friend
that told me about Transfer Factor,
and so we decided to give it a try what did we have to lose. We began
giving him 2 capsules a day for about 2 months. He seemed to be
improving so we stopped giving it to him. After a few weeks he stopped
eating again and he was dragging his front leg again. We thought that we
were beginning to lose his battle with Cancer.
We did not realize that with someone as sick as
our dog was, their immune system is weak and they need the constant help
of Transfer Factor to stimulate
the immune system to continue working. So once again after a follow up
call from my friend, in December, we decided to start him back on 2 Transfer
Factors in the morning, and 2 in the evening.
It has been 7 months now since we first got the
bad news, and much to our vets amazement, our dog is continuing to
improve. We will have another x-ray in a few months to see how the bone
is healing, but the swelling has totally subsided, and he is once again
running and playing with his friends again. The neighbors really feel as
though this is truly a miracle, and I tell them no, it is what our
bodies are designed to do when our immune systems are strong. Gismo our
Dog is continuing to improve, and we still give him 2-4 Transfer
Factors a day. I will be anxious to see what his x-rays show in
a few more months."
LM / Washington State