Tumors and Cancers in Cats


When is cancer NOT malignant

Question: I would like to bring to your attention a statement at the following page: http://www.vetinfo.com/cencyclopedia/cehyperthy.html "A small percentage of the cancers are malignant." Cancer IS MALIGNANT. As opposed to tumors in general, which may be EITHER bening OR malignant, such that if they are MALIGNANT, they ARE "cancers". Could you please rewrite this description at your page so that readers can understand what you are actually trying to say. Answer: Kathleen- Not to be too flip, but the answer to your question: when is cancer NOT malignant is ---> when it is a neoplasia in a veterinary patient that is benign in nature. I think that you are probably correct that the term cancer, when used in human medicine, generally refers to malignant tumors --- although I can find some exceptions in the general use in human medicine, as well. In veterinary medicine, as taught at the veterinary schools I am aware of, cancer is used to describe neoplasia and then it is modified by the use of benign or malignant. An example of this use, from Colorado State University's cancer web side, can be found at "http://mail.justice.com/jump/http://www.csucancercure.com/faq.cfm">http://www.csucancercure.com/faq.cfm If you trust me to quote them accurately, the following is their definition, which is consistent with what my wife and I learned about cancer at Iowa State University and the Virginia-Maryland Regional College of Veterinary Medicine, respectively: "Throughout this web site, the words TUMOR and CANCER are used interchangeably. Technically, a tumor is just a swelling which may or may not be a cancer. Cancer is a disease of uncontrolled cell growth which can be benign (not invasive and does not spread) or malignant (usually invasive into surrounding tissue and capable of spreading to other areas of the body). " (from the CSU site) The difference in the way that medical terms is used is sometimes confusing between veterinary medicine and human medicine and oncology is one of the areas in which there are significant differences. It is really important to have a veterinary pathologist, or at least a pathologist familiar with the use of pathology terms as veterinarians view them, perform the evaluations of veterinary tissue samples when cancer is suspected, because of these differences. I am glad you wrote to us, as it probably is best if we put the definition used above on our cancer pages, as well, since it does appear to differ from the way the term is generally used in human medicine. Mike Richards, DVM 12/7/2002

Pancreatic Adenocarcinoma - Bailey is doing fine

Dr. Mike, Last fall I asked if you knew anything about feline pancreatic adenocarcinoma as my 13 year old dsh Bailey had just been diagnosed. Realizing you get tons of email, but thought you'd enjoy some good news...on July 15, Bailey went to the vet and had a thorough teeth cleaning and was given a clean bill of health! The vet ran pre-dental blood work and it came back great, her weight is up 1# since her Oct. tumor removal (to 12.5 #) and he noted no tumors or growths when palpating her abdomen while under for tooth cleaning. He did note some internal firmness, which he attributes to scar tissue (she's had 4 major abdominal surgeries in her lifetime) ...and while he did remind me that this type of cancer is extremely aggressive and has a high return rate...he admitted his own surprise at her incredible good health! [:)] He said he didn't expect her to survive past last Christmas. I reminded him that there wasn't a lot of information of feline ad.carcinoma and just perhaps, Bailey was outside the bell curve....(I think he humored me a bit!) So please share this with your readers...that the will to live, great vet care and a lot of TLC can bring about some special miracles. FYI...Bails is on Fancy 2X a day, plus 1/2 c. Purina Senior crunchy cat food plus all the meat treats she wants...chicken, beef, tuna....higher protein and lower carb....seems to be the ticket for nutritional support. Her coat is thick and glossy...and she is as nosy, busy and feisty as ever. Thanks! Kathy

Answer: Kathleen- I am glad to hear that Bailey is doing well. I am sure that your vet feels like I do about this sort of situation. We have to be realistic with people about the general odds for any disorder -- but we always hope that we're dealing with an exception. There are times when being wrong is a real joy and one of those times is when a pet has a serious problem but goes on to beat the odds. Thanks for letting me know that Bailey is doing that! Mike Richards, DVM 8/5/2002


Question: I wondered if you would be willing to take a telephone call, or someone from your staff that would help my veternarian who is trying desperately to find more definitive information on Subcutaneous Hemangiosarcoma in a cat. (The tumor was removed from the top of her paw. We have reached out to the Boston area oncologist and NO ONE so far has ever handled a case in a cat. He is trying to find information so that he can help my cat in the best manner possible but there is 'little' information on felines. AND he is trying to find out, as I am if treatment would help to irradicate this, or if that is not possible. PLEASE, please,....time is of the essence....if you can't help at least please let me know one way or the other, or refer us to some place that could....no help locally because of it's rarity!!! Jane Marie

Answer: Jane-

I have not personally dealt with a case of subcutaneous hemangiosarcoma in a cat. So I have no experience to offer in this case.

There is a fair amount of information on hemangiosarcomas in cats in the most recent edition (3rd) of "Small Animal Clinical Oncology" by Withrow and MacEwen.

A summary of this information is:

1) hemangiosarcoma is much less common in cats than in dogs 2) hemangiosarcoma in cats arise about 50% of the time in the abdominal organs and about 50% of the time in subcutaneous tissues. 3) Where possible surgical removal is the best option. It isn't stated clearly in the book but I believe that amputation would probably be the only way to ensure that adequate tissue margins were achieved in a tumor occurring on the foot 4) chemotherapy in cats is usually done with doxorubicin alone or doxorubicin in combination with cyclophosphamide 5) radiation therapy doesn't seem to be proven to be effective in reducing survival time, even when the tumor is on an extremity. I am not sure that I would totally rule out its use, though. It just seems like there isn't much data if I am interpreting the situation correctly. 6) The mean survival time for cats with subcutaneous hemangiosarcoma, even after surgical removal, was reported to be 44 weeks in the only study quoted, by Scavelli T, et al, Journal of the American Veterinary Medical Association, 1995.

I wish that I could help you more.

Mike Richards, DVM 1/26/2002

Tracheal tumor with secondary infection, Filaroides osleri other possibility

Question: Our 17 year old tabby has just been diagnosed with a malignant tumor in her trachea. She has had asthma for several years also. Additionally, she has a secondary infection. the tumor is restricting about 50% of her air passage.

She is in good health otherwise. She has been give prednisone on various regimens (same dose, but differing intervals) over the past several years to control the asthma. When it became worse her breathing became labored and she would cough excessively.

Monday Morning she was experiencing great difficulty breathing. We took her to the doctor and a growth was discovered by touch and confirmed by xray. A wash was done, tests requested and we found this evening that she has a malignant tumor (type not known) with a secondary inflammatory infection.

What are our options with upside and downside. We are not second guessing our Dr., but just trying to gather as much information as possible. The tumor is INSIDE the trachea.

Thanks. Your quick response will be greatly appreciated.


Answer: Don-

Tracheal tumors are very unusual in dogs and cats. However, they do occur in rare instances and I am sorry to hear that your cat have been unlucky enough to have this problem.

It would be very helpful to know what type of tumor was present. Lymphomas can occur i the trachea and may be as responsive to chemotherapy there as in other places. So chemotherapy would be a reasonable option in that case. Other tumors may respond to radiation therapy, although I believe that this may only be possible for tracheal tumors that occur in the section of the trachea that is in the neck, not the portion in the chest.

Surgical removal of tracheal tumors is possible in many cases. It is possible to remove a fairly large portion of the trachea and still be able to suture the two ends back together. We have dealt with trauma cases in which at least a fourth of the trachea was missing and have been able to put the remaining sections back together successfully in our practice. Unless the tumor is very large, or located adjacent to the larynx or the point in the chest where the trachea divides into the large bronchi, it should be possible to remove the entire section of trachea in which a tumor is located and then suture the two sections of trachea that remain back together. Your veterinarian may not be willing to do this surgery, especially if the portion of the trachea affected is inside the chest cavity. However, it should be possible to refer your cat to a surgical specialist for an evaluation of whether surgery is an option. I am not sure how much the asthma would impact on the decision making for surgery.

If a biopsy has not confirmed cancer (washes can be misleading, although in some cases they do produce pretty definitive results and this may be one of those cases), there is probably a small chance that that this is an infection or possibly even a parasite infestation. Filaroides osleri is supposed to be able to cause granuloma formation in the trachea which would resemble a tumor, although not usually as large as what you describe. Capillaria aerophila can also live in cat tracheas but I am not sure whether it can cause lump formation like Filaroides osleri can. An local infection might also be possible. Your vet has probably considered these options and ruled them out, but it seemed best to mention them.

You may want to ask your vet about referral to a veterinary surgical specialist for an evaluation of the potential benefits of surgery. It is supposed to produce the best chance for a good long term outcome for tracheal tumors. Depending on where the tumor is located, a temporary tracheostomy may be possible, to allow her to breathe easier until is possible to make a more definitive decision about what to do.

Mike Richards, DMV 9/21/2001


Question: Bear, my cat is 13 years old and has been in excellent health except for his hips. In early July he had FHO surgery where an orthopaedic surgeon removed the ball and took a sample of a "suspicious area" in the cup of his hip. The orthopaedic surgeon thought it was nothing but to our surprise it was osteosarcoma. He said this was extremely rare and that there was nothing that could be done. Surgery would probably be too traumatic and that in the end - no matter what I did - the cancer would win. I understand this but the cancer has not spread to Bear's lungs. I am told it is very aggressive cancer and Bear would probably only live 2 months if I don't do anything - which seems to be the way the orthopaedic vet was leaning. Although Bear continues to recover from the surgery and not "act sick", I want to do anything I can now. I asked orthopaedic vet to consult an oncologist but it has been a week and he is now out if the office for two weeks. I am continuing to pursue the oncologist and hope to hear from him tomorrow. I thought that cats tolerate radiation and chemo relatively well. My original vet had given all three of my cats their rabies shots between the shoulder blades. This was probably two or three years ago. They all developed lumps immediately and she said to ignore them. Could Bear's sarcoma be a result of the vaccine? They all still have the lumps - should I have biopsies done on the other two cats? (feline vaccine-associated soft tissue sarcoma) One of the cats is Emily - who is Bear's sister. Is it silly to suggest bone marrow transplants? Is it done? in a teaching facility? I live in Fort Lauderdale, Florida. Is there a teaching facility near (or far)?

Is there anything that I can do that the vet has not suggested? I have modified his diet to include the things that you suggested in another letter for a cat with cancer which included adding omega fatty acids more protein, fat and less carbs. (just for curiosity - although cats need more fat in their diet than humans - why do you give more fats to cats with cancer and less fats to humans with cancer?) There does not seem to be much information on osteosarcoma that I can find on this subject except for dogs (which is also very limited). Do you know of any web sites or books that I can read? I have only found a clinical discussion on vaccine associated sarcomas by Leslie Fox DVM, MS, Dip ACVIM from University of Florida. Her discussion suggests that the most I can hope for is survival of less than two years if treatment is remotely successful.

So I guess you will need the full 72 hours to answer this one huh? sorry for the length :-)

Truly - any comments you have will be greatly appreciated. Thank you. Liz

Answer: Liz-

There are several questions in your letter, so if I miss one of them, just write again.

On the lumps between the shoulder blades -- yes, these should be biopsied if they are still present. It is better to biopsy the lumps rather than trying to remove them, so that a well planned total removal of the tumor can be done, if that turns out to be necessary. The last two lumps we have biopsied that we thought might be vaccine associated sarcomas were not tumors, so there is a chance for a good biopsy result.

If an oncologically trained surgeon does the first surgery to remove a vaccine associated sarcoma the long term success rate (no return of tumor) is about 50%. It is important to get this surgery done correctly the first time.

An osteosarcoma is not the type of tumor that occurs as the result of a vaccine reaction and the location is not suggestive of this problem, either. So I think that Bear's problem is not the result of a vaccine reaction.

Osteosarcomas behave differently in cats than they do in dogs. The advise you got from the orthopedic surgeon would be true for a dog but may not be for a cat. You have made the correct choice in consulting with the oncologist. I think you may find that the prognosis is better for a cat, since the tumors do not metastasize as readily in cats as they do in dogs. If amputation is possible cats are reported to have a median survival time of 24 months, according to information in the "Textbook of Veterinary Internal Medicine, 5th edition" by Ettinger and Feldman. This is much longer than dog owners can expect. I can not find enough information to pass on an opinion about the effectiveness of radiation therapy but it can help with pain relief in dogs, even though it doesn't have much effect on spread of the tumor or survival time.

Good luck with this. I hope that the oncologist's experiences don't differ from those reported in Ettinger and Feldman's book.

Mike Richards, DVM 7/27/2000

Melanoma in cat with renal problems

Question: I wanted some advice about my 16 year old cat, Max. We live in the UK. She was diagnosed with renal failure about 10 months ago and has since repsonded well to a KD diet. Her bloods were last done done in January and urea had gone down to 17.06 and creatine down to 360. I am told that these two are at the lower end of the high level. The other bloods are apparently fine.

The vet found a melanoma on her neck, just under her chin. It is operable but the vet said that the renal problems will not allow this. She is not proposng any other treatment.

What options are there other than do nothing. Is the risk really too great to operate. I also wondered about other treatments including laser.

Any suggestions

thanks, John

Answer: John-

I would probably be willing to operate on a cat with a melanoma and the lab work that you have forwarded, if that is the only problem.

We have pretty good success using a sedative/pain relief combination and local anesthetic for small surgeries. This would alleviate a lot of worry about general anesthesia, if Max is cooperative enough to allow this. A melanoma would normally be within the size of tumors that are we very comfortable removing in this manner. The location may be a little tricky, in this case, though. You'd have to think about how Max would react to surgery in an area that would require being held in an odd position.

We also do a lot of our surgeries using isoflurane gas. The gas does not seem to cause kidney problems, in our experience, and so we are willing to anesthetize pets even when we know that kidney problems exist. Administering fluids intravenously during surgery can help to minimize the risk of kidney complications even further.

If your vet has not tried surgery using local anesthetics she may be a little reluctant to do this. I didn't think it would work as well as it does when I first started doing it. I worried about pets struggling during surgery, what would happen when the local wasn't quite sufficient and whether I would be forced into using general anesthesia, at times, to resolve problems like that. Our experience has been that if we use a good combination of sedation and pain relief (there are several that work well), the reactions to local pain are minimal, but recognizable. This makes me feel that we are not hurting our patients unintentionally and that we are getting good pain relief. We have had a few dogs and cats who decided mid-surgery that they were tired of lying in one position or of being held on the table. This has not caused major problems but it can be difficult for a few minutes. We have given up on a few patients and gone ahead with gas anesthetic induction. If isoflurane or sevoflurane gas are not available options, this might be more difficult. Other gases take longer to induce a patient and are therefore more difficult to use as a back-up.

It is always hard to balance one need against another in a patient with multiple problems. I would tend to lean towards removing a melanoma or at least getting a biopsy of a suspicious tumor, in this circumstance. However, I do understand the reluctance to do anything that could make the overall situation worse. If it is possible to minimize this worry by using local anesthesia or by using gas anesthetic alone, then I would be comfortable doing surgery as long as there wasn't something else about a physical examination or in the lab work that also worried me.

Ask your vet about the feasibility of a local anesthetic for this, unless you already know that Max isn't likely to tolerate it well.

Mike Richards, DVM 7/26/2000

Nasal lymphomas in FIV pos cat

Question: Dr. Mike,

Max is a 10-11 year old male tabby, FIV+ and recently diagnosed with nasal lymphoma.

He was diagnosed with FIV over 5 years ago and up until the past 5 months never had the slightest bit of complications from the FIV - in fact I had him re-tested for FIV when they took blood prior to anesthesia recently(for x-rays of his head) thinking that he may have been mis-diagnosed before.

His recent symptoms started with a clear discharge from his right eye and nose, progressing to a green discharge (from his nose) for which he was prescribed Baytril. Unfortunately, I didn't take it seriously enough when they suggested endoscopy, especially when another vet from the same clinic said that FIV cat's can take a long time to fight off bugs (I went along with her idea that it was an infection)...so three months worth of antibiotics later and progressively worse symptoms (sneezing, blood from nose, blood in vomit and slightly blood-tinged eye discharge,and horrible congestion) I finally took him in for testing for a definitive diagnosis.

They took x-rays to check for bad teeth or a possible tumor and found a darkened mass which they aspirated (from the roof of his mouth) for samples. They also collected samples from a nasal flush (no blade of grass as I'd hoped). It all boiled down to nasal lymphoma.

Is it safe to perform radiation/chemo on an FIV cat? I know very little about this type of cancer. Apparently it's rare but is successfully treated with radiation therapy (according to info I found at www.vetradtherapy.com) with survival time of appproximately 2 years.

Can you please tell me about radiation therapy. Is it as bad as chemo? What are the affects on the animal? How would I know if Max is a good candidate for this? How would I know not to try and pursue it? As much as I want to do whatever I can to help him, I don't want him to suffer needlessly. I'd like the remainder of his life to be as compfortable and happy as possible.

Max has always been such a tough little guy. It breaks my heart to see him this way. He's still eating, still purring, still wants to look out the windows but since I took him in for testing he's just been kind of lying around more than usual, lost a bit of his spunk and he's congested enough that his breathing is restricted (in right nostril). Would the aspiration have made the cancer spread more rapidly?

I really appreciate any insights you may be able to give me with all this while I try to decide what route is in Max's best interest at this point.

Thanks for your help - Becky

Answer: Becky-

Nasal lymphomas in cats do respond very well to radiation therapy, with many cats treated living more than two years post treatment. I found a couple of retrospective studies on nasal lymphomas and around 80% of cats responded well to radiation therapy out of about 50 total reported cases.

There are some reported complications, such as cataracts (since the eyes are in the radiation field) and fistulas (openings) developing between the oral cavity and nasal cavity post treatment. The patients in our practice who have had radiation therapy for oral or nasal tumors have not been too bothered by the radiation therapy. I do not see these patients until they are home from the oncology center so there may be some acute effects I don't see, but within a few days, when we see them, our patients are doing well.

I can not think of any reason why an FIV positive cat shouldn't be treated with radiation but this would be a good question to ask the oncologist too, obviously.

There doesn't seem to be any advantage to doing both radiation therapy and chemotherapy, unless there is reason to suspect that the lymphoma has spread to other organs. I think that you would have to carefully consider what to do, given Max's overall condition, if there is evidence that there is spread of the cancer. If enlarged lymph nodes are present or tumors are visible on chest X-rays, the prognosis is worse and the treatment more difficult. This is where the advice of an experienced oncologist would be even more valuable.

There is some evidence that nasal lymphomas respond better to radiation if they are large, so having waited a while to get to a definite diagnosis may not impact the outcome much at all.

I really think that with the track record of response to radiation and the way Max has handled the FIV infection so far, that radiation therapy is definitely worth considering.

Good luck with this.

Mike Richards, DVM 7/24/2000

Nasal sarcoma treatment problems - is it the anesthesia (Isoflurane)

Question: Our 6-yr old Maine Coon has been undergoing treatment for a nasal sarcoma (I wrote you about this before). His most recent chemo was Taxol and we are hopeful.

He undergoes frequent anaesthesia (Isoflurane) and then the vet flushes his nasal cavity with saline and removes bits of dead tumor.

Twice, he has come out of the anaesthesia crying loudly, staring, and with his front legs very stiff and straight. The first time was about 2-3 months ago. It took about half an hour before his paws bent again. There were no apparent lasting effects.

Our vet was very surprised and worried as this had not happened to her before. She was much relieved (as I was) when the "seizure"(?) stopped. She feared a stroke or that the tumor had made a hole through the bottom of the skull. (A subsequent MRI a week later indicated the tumor had not crossed into his brain. We've been on chemotherapy ever since and seem to be making progress).

The second episode was this past Monday. He seemed to "come out of it" faster, but on Wednesday morning I noticed that his left legs did not seem to be quite "normal". Both are slightly stiff and remain so today (Thursday).

He is walking but holds his legs in a "stiff" position and when I hold him or touch his foot he holds it stiffly. If I lift his front end a few inches off the ground the right paw goes to my arm; the left sticks straight down toward the ground. He can flex his toes.

Your answer in http://www.vetinfo.com/canesthesia.html indicates that perhaps he was somewhat oxygen deprived during the anaesthesia. He was "out" for a fairly long time and he may have been under more deeply than usual as there was quite a bit of activity in his mouth.

I thought I'd run this past you to see if it sounds (like Vicky in Spain from your Web pages) like oxygen deprivation.

Fluids are easy (we give subcu) as is feeding (we're hand-feeding). There has been no indication of further seizures after the first yowling and staring (if indeed this was a seizure; that's how I would describe it).

I'm a bit concerned about the stiff paws although in the grander scheme of things I think the priority is to reduce the tumor. His eyesight seems to be normal as near as I can tell, as is his hearing.

He's on 3x daily doses of .1 ml torbugesic, antibiotics, and once-a-month fibronil (FrontLine (TM)) tick-preventative, along with the Taxol and the weekly isoflurane.

I'm a bit nervous about the next anaesthesia... also worried about whether the tumor has crossed the skull (but with the chemo and this being a second episode I'm hoping that the explanation is less sinister than that). Obviously, only another MORI (with a really nasty IV anaesthetic) can prove what's is happening in his head.

Just wondering about your thoughts on the subject.

Sorry for rambling - Vicki

Answer: Vicki-

When there is a period during anesthesia when the patient doesn't receive adequate oxygen, there is usually blindness as a clinical sign. It is often temporary but it occurs easily and is one way of helping to differentiate between seizure-like activity occurring for other reasons and seizure-like activity occurring when the brain has been deprived of oxygen. This can also happen when blood flow is compromised, which may occur with manipulations of the head and neck (for the same reason --- the lack of blood flow leads to low oxygen levels in the brain tissue). As you seem to be aware, in this instance there is also a pretty good chance that the tumor, or swelling or vasoactive compounds from the tumor or tissue damaged by it, may also induce these problems. Since there is no evidence of blindness it seems more likely to me that there is another cause other than anesthesia but I do not know how to be certain of this.

Isoflurane is pretty safe and we have used it daily for several weeks in a couple of patients who needed burn treatment or wound treatment that was painful. However, like any anesthetic, it can cause problems in some instances and there is some chance of an anesthetic problem, such as a crimped endotracheal tube, drops in blood pressure, mechanical failure of the anesthetic machine, etc. Sometimes there seems to be leg pain, or even neurologic problems, from positioning during a surgical procedure. We see this most frequently in dogs with hip or elbow dysplasia but I don't see why it couldn't occur in a cat. We have also had two cases of spinal disc disease that appeared post-surgically, presumably because they were ready to cause problems and we moved the patient in such as way that pressure was induced in the spinal canal. There are a lot of possibilities. I tend to agree with your assessment that debulking the tumors is likely to be helpful and is probably necessary even at some risk. To the best of my knowledge there is no increased risk of problems on subsequent anesthetic procedures because there was a problem with a previous one, although logically it seems possible, since there may be an underlying physical problem leading to these episodes. I wish that I had a clear answer to your question, but I don't. I tend to lean away from anesthesia as a cause in this case since there isn't blindness but it has to be considered as a possibility. On the other hand, there are many possibilities and some of them seem like reasonable possibilities, as well. Especially when a nasal tumor is present.

Mike Richards, DVM 7/4/2000


Question: My cat Armand has been diagonosed with Mesothelioma (vet is 95% sure). How does a cat get this? All my research says Absestos is the cause in humans. Is this the same in cats. Is there absestos in my home and I am not aware of it. Is cat litter dust a cause?

For your readers, symptoms were loss of weight, about 3 lbs in a couple of months. I took Armand to the Vet, he took blood, white count was high. Xrays showed fluid in chest. Took to specialist who did ultrasound, took fluid out of chest and sent it for testing. He diagnosed 95% that it was mesothelioma, which is a form of lung cancer. This has happened very fast and I am faced with putting Armand down before the holidays. We have the option of biopsy to determine exactly what it is but the Vet is 95% sure its cancer and its not curable. Armand is 9 years old. Your comments will be appreciated. You have a great site and I have put a check in the mail. But we need a quick response to determine what to do for Armand. Thanks again for your help.

Thank you, M.O.

Answer: M.O-

Mesotheliomas are a very rare tumor in cats and fairly rare in dogs, as well. There are no reports that I could find that suggest an underlying cause in cats but there was a study done in dogs in which three of five dogs studied who had mesotheliomas also had evidence of asbestos. (Slatter, Textbook of Small Animal Surgery, Second Edition and Scherding, The Cat, Diseases and Clinical Management, Second Edition). In these references, the authors state that mesotheliomas can not be diagnosed with certainty without an open biopsy because it is hard to tell mesothelial cells that are reacting to disease from mesothelial cells that are cancerous if only fluid from the chest is examined. Since these are tumors of the lining of the lungs (the pleura) they tend to produce fluid that builds up between the lungs and the chest wall but there are other causes of this type of fluid build-up. Mesotheliomas do not respond well to therapy, so treatment is aimed at controlling the fluid build-up to allow the cat to be comfortable until the tumor gets severe. Slatter's book says that the time period for successful treatment in this manner, in dogs, is around eight months. I think that if you want to be certain that the problem is mesothelioma before considering euthanasia you may want to ask about the potential for doing a surgical biopsy. If Armand's condition is bad and your veterinarian does not think that there is a good prognosis even if the tumor is not a mesothelioma, it might be better not to put him through the surgery in the face of low odds that it would change the overall prognosis. Your vet can give you a realistic idea of the odds of success for biopsy surgery and give you a better idea of Armand's overall chances than I can. It can be a hard conversation to have, for both you and your vet, but this is a time to be certain you understand what is happening and to be certain that the direction taken is the one you want. If you are willing to go for broke on a 5% chance for success, that is your decision. If you know in your heart that Armand is too sick to go on, you should trust that feeling, too.

I wish I could give you a clear path to follow but you still have some decision making to do. I always lean towards doing the complete diagnostic workup in my own pets because I don't like wondering about the decision afterwards. Many of my clients are comfortable trusting their instincts. You know yourself and you know Armand so this is a reasonable choice if you won't keep on worrying later.

I wish I could help more.

Mike Richards, DVM 11/21/99 Nasal Lymphoma in cat

Question: My male 5 year old cat has been diagnosed with Lymphoma in his nasal cavity after surgery. I am trying to find out any information that I can on his condition. I do know that there was a small swelling in the area, and a hole in the bone. He was being treated for a nasal infection for several months (after X-Rays of his head and chest revealed nothing). Please tell me what you can as to the progress of the disease, and how long I can expect my Indy to live without pain. I need to be prepaired to help him when I have to. I thank you in advance for any information you can give me. I. M. R.

Answer: I.M.R.

At the present time, the best therapy for nasal lymphoma is considered to be a combination of radiation therapy and chemotherapy. Both of these treatments are pretty successful alone, if it is not possible to do both. Reported survival times for radiation therapy vary some from place to place but two years or more seems to be about the median with complete remission occurring in several cats. Chemotherapy is close to this but complete remission seems less likely with chemotherapy alone. The combination of the two does better than either one alone, at least according to anecdotal reports.

I didn't find statistics for this type of cancer when cats weren't treated at all but suspect it is similar to other forms of lymphoma, which is less than a year. Pain relief in cats can be a problem due to the limited number of analgesic (pain relieving) medications that can be used in cats. I'm sure the oncologist or your vet will work with you to find something that will help, when necessary, though.

It is important to figure out if the cancer has spread (staging the cancer) prior to deciding on treatment options. Checking regional lymph nodes, the chest and blood smears is necessary to rule out a spread of the cancer.

If you have additional questions as time goes on, please feel free to send them.

Mike Richards, DVM 11/3/99

Possible Cancer of the tongue in elderly cat

Q: Hi Dr. Mike, I need a very honest opinion on what to do about my favorite little calico, Mooshkie. She will hopefully turn 16 in August but, I was just told that she has a malignant tumor under the left side of her tongue. It was not noticed 4 weeks ago when i brought her in for a check up and when I brought her back to have (what I thought) one of her teeth pulled, our vet said that the drooling and licking and tongue hanging out the right side was from an inoperable tumor. She suggested to wait a few weeks then put her to sleep or to have a biopsy done and see about some kind of chemotherapy that cats supposedly respond well too. However, she didn't think I was going to extend her life that much and that the quality would be lessened.

I love my cat so much, and do not want to cause her pain, just to have her leave me anyway. I also don't want to lose a chance at a treatment if it could actually work. My vet said that this kind of "mouth cancer" was common in cats. Is this true? And is there any chance that they didn't notice the tumor 4 weeks ago and then did two weeks afterward because they may have used a "contaminated" needle during her check-up visit. By the way, they said that for a cat her age, her blood work looked good.

I'm just wondering if you had experience with his kind of cancer in cats, and any chemotherapy that worked well.

Thank you in advance for your honest opinion.

Peg S

A: Peg-

My honest opinion is that your vet can't tell if this is a tumor by appearance alone. That might sound weird but there are some disorders that look just like tumors that aren't. So I think a biopsy is a really good idea.

The most likely thing is that this is a squamous cell carcinoma. These can sometimes be reduced in size with radiation or surgery and radiation. Lately I have been reading about injecting these with carboplatin (a chemotherapeutic agent) but I don't know what the success rate is with this treatment. It may be worth a try since it isn't too invasive. The radiation is paliative, meaning that it won't cure the problem but may give her several months of additional good quality life. Sqaumous cell carcinomas are the most common tumor of the oral tissues in cats and they do occur with some frequency.

It would be hard for me to decide to do radiation therapy for this tumor on a cat of my own on the premise of an additional six or seven months of life because I don't view that as long enough to justify the expense and discomfort of radiation therapy -- but I have clients who have felt this was worthwhile and still thought so after doing it.

Eosinophilic granulomas can look exactly like some tumors in older cats, including oral squamous cell carcinomas. These are often responsive to therapy with corticosteroids or other immunosuppressive medications and would definitely be worth treating. I don't know what the odds are that this would be the problem but they are fairly low. However, an oncologist that I know to be straightforward posted a note on the Veterinary Information Network that stated that she has seen several of these that she mistook for cancer --- and that is her specialty!

Mast cell tumors can affect the oral tissues in older cats. These are more responsive to radiation than squamous cell carcinomas, I think. I don't know of an effective chemotherapy option for them but sometimes they respond at least somewhat to corticosteroids and cimetidine (Tagamet Rx).

Realistically, the odds are really high that this is a squamous cell carcinoma. But I'd still consider doing at least this much of a work up:

1) X-ray the chest to see if there is any evidence of spread of a tumor 2) Carefully check for enlargement of regional lymph nodes 3) Biopsy the lesion to be sure it isn't something other than a tumor --- and to know for sure which type of tumor it is.

At that point, you have enough information to make are a really rational decision about how hard to pursue this.

Your vet might be squeamish about biopsies of the tongue. They can bleed profusely. I can't remember a case in which we couldn't get the bleeding to stop but I do remember having to really work at it once or twice.

Good luck with this.

Mike Richards, DVM 6/28/99 Cancer -Leukemia or Lymphoma

Q: My cat has just been diagnosed with leukemia (blood cancer, not the virus). She is twelve years old and I was wondering what type of treatment there could be for her. My vet has recommended prednisone which she has been taking for a number of years for food type allergies.

Her symptoms have been vague. She has never been a very good eater only eating a 3 oz. can of IAMS a day. Sometimes not even all of this. Within the last month, she suddenly began to eat everything in site. She cried all the time to eat. As it was time for her shots, I took her to the Vet Monday and mentioned her appetite. He suspected thyroid and took blood for that ( I haven't heard back from that yet) and did a CBC. The CBC came back with a white count of 85,000. Another test was done the next day and sent to a pathologist where it came back at 120,000. More than the day before. She seems to feel fine and her eating is great.

What I would like to know, is what can I do to help to prolong her life. She's a very special kitty to all of us and I would like some advice as to what can be done.

A: D-

Probably the first thing to do in this situation is to confirm the presence of leukemia. Lymphoma is much more common than leukemia and can produce white blood cell counts in the range you are reporting. Lymphoma in cats is often intestinal and it is therefore hard to find, even with a very careful examination and radiographs (X-rays). Leukemia is definitely possible, it is just a lot less common.

The best ways to find lymphoma are probably ultrasonagraphy and endoscopic exam of the intestinal tract. Aspiration and evaluation of bone marrow by a pathologist is a good idea since it can help differentiate between leukemia and lymphoma and also give some insight into prognosis.

There are chemotherapy protocols for both lymphoma and leukemia (either chronic or acute). They may help to provide a better quality of life and longer lifespan. If your vet doesn't want to provide chemotherapy you may wish to ask for referral to a veterinary oncologist or internal medicine specialist. Chemotherapeutic agents have to be handled carefully and practitioners who will not have the opportunity to use them frequently are often put off the by the handling requirements. We are fortunate in having a specialist nearby who will handle our chemotherapy cases and so we refer them.

I hope that this helps some.

Mike Richards, DVM


Q: Dear Dr. Mike,

Thank you for your quick response. I will try to give all the information that I have and hope that it helps.

Phinny - as we call him - is a 15 1/2 year old neutered male, whom we have had since he was 7 or 8 weeks old. We originally had him treated the beginning of this month (April 98) for an over active thyroid tumor. While he was at the vet office for that treatment, our vet found more tumors and we opted for exploratory surgery, just a little over a week ago. She found a tumor on his adrenal gland and liver. They took the left gland I think and I'm thinking quite a large portion of his liver. Unfortunately the tumor has moved to his lung or lungs. I have a copy of a biopsy test here with me, but I am not understanding fully the information it is giving me. I will type this word for word from this report.

Test Procedures Biopsy (2 tissue) Source/History Specimens from left adrenal gland and several liver nodules from cat presented with large cranial abdominal mass in which ultrasound examination showed liver involvement but liver biopsy indicated endocrine carcinoma. At surgery the liver had multiple metastatic foci and an enlarged left adrenal gland. Diagnosis 1. Left adrenal gland with mass: cortical compression and destruction by malignant pheochromocytoma. 2. Liver nodules: enfacement of hepatic parenchyma by multiple foci of malignant pheochromocytoma. Comments This large adrenal medullary tumor has nearly effeced the adrenal cortex and has apparently invaded veins transporting metastatic foci to the liver. Pheochromocytomas commonly metastasize to the liver and less frequently to regional lymph nodes and spleen.

The words that I am stumbling over are the endocrine carcinoma, hepatic parenchyma, foci of malignant pheochromocytoma, medullary tumor and a general idea of what they did. Plus just what I can expect the chemotherapy to do for him. Quality of life is important, not quantity. He is a real fighter, if we were going to lose him it would have been the end of January/begining of February. He reacted to Tapazole and his T4 was down to less then 0.4. He is doing well, eating everything in sight, he is on "val syrup" 1ml 2X daily (if I am reading the name on the hand written label right) by tummy tube; Rocatial 1 drop 2X daily; 125ml water (by tummy tube); Procrit 0.2 SQ every other day. The name of the chemo is Carbaplatin at 200 mg/m2, if I understand the Dr's note.

Phinny goes in for a blood test and stitches removal today. If the PCV is at 25 the therapy can begin. He has gained some weight. The tummy tube is going to be left in so I can feed him if he goes off his food. He is starting to show some signs of CRF. We also have his brother, a litter mate, who is showing stronger signs of CRF. We do have our hands full, and are looking for all the information we can to keep them healthy and happy into their old age.

I will be reviewing your old newsletter for more information about CRF and do appreciate another Doctors ideas and information on Phinny's cancer. This is all very new to me, but I'm not totally lost on some medical terms. Layman terms are just a whole lot more helpful. Thank you again for your time and help. Sorry this is so long, but I am his advocate and expect the same for him as I do for myself and my husband.

Sincerely, Lynne

A: Lynne-

Phenochromocytomsas are pretty rare in cats but have been reported. This is a tumor of a specific cell (chromaffin cell) that exists in the adrenal gland.

"endocrine carcinoma" means a cancer of a gland that produces hormones.These could be a description of a pancreatic tumor, a thyroid tumor, an adrenal gland tumor, etc. It is often hard to tell what tissue the tumor originated from when biopsying a place it has spread to (a metastatic site) so a non-specific term like this is used.

"hepatic parenchyma" means liver tissue, pretty much any part of the liver except the capsule around it and the bile ducts running through it.

"foci" = small areas, in this case small clumps of tumor cells that have spread from the adrenal gland where the pheochromocytoma originated, to the liver and lungs

"malignant" = a tumor (cancer) that has the ability to spread from the tissue it originated from to other areas of the body. Malignant tumors are therefore considered to be worse to have than benign tumors which may grow quite large but don't spread to other organs or other tissues

there are two distinct portions to the adrenal gland, the "cortex" or outer layers and the "medulla" or inner layers. These two portions produce totally different hormonal substances. The pathologist is just saying that this particular tumor started in the medullary portion of the adrenal gland.

Pheochromocytomas can cause very high blood pressure and it is usually necessary to use medications to control blood pressure when these tumors are present, in addition to whatever other treatment measures are taken. Dr. H did a good job in noticing the presence of these tumors and getting good samples for histopathology so that a chemotherapy plan can be worked out. I was not able to find much information on chemotherapy specifically for pheochromocytomas but carboplatin (Paraplatin Rx) is currently used frequently in cats for chemotherapy at the dosage you sent. Dr. H may be able to get some information from the oncologist about the prognosis. Monitoring of white blood cell counts is recommended prior to administering each dose of carboplatin in order to get a rough idea of toxicity as it will suppress neutrophils (a specific type of white blood cell) at toxic levels.

Phinny has been unlucky so far, so maybe it is time for him to get a break. I hope that the treatment will produce an improvement in the quality of his life along with some extension of his expected lifespan.

Mike Richards, DVM


Q: Dear Dr. Mike, My 13 yr. old spayed calico cat recently had surgery to remove a growth just below her ribcage. Then end result was that my vet informed me she had "undiffertiated adenocarcinoma of the skin w/ lymphatic invasion and mastisis of the lymph node and connective tissue." What I heard was, she has a malignant cancer...what can I expect in the near future for her? She didn't and still doesn't appear to be in any discomfort, other than licking her stitches.. My vet suggested that I search the net for more info about this, but I came up empty. Any help would be appreciated. Sincerely, Jef

A: Jef- Adenocarcinomas are tumors of glandular tissue that are malignant (adenomas are tumors of glandular tissue that are benign). When the tumor cells are unrecognizable as a particular type of gland (sweat gland, ceruminous gland, etc) it is a bad sign. The fact that the pathologist thought this lump had already spread is also a bad sign. In general, chemotherapy is not too helpful in adenocarcinomas in cats. Radiation therapy can be palliative (meaning it can slow the spread of the condition and alleviate some of the discomfort that may be present) but it is not usually curative, unless there is newer research on this issue I am unaware of. Catching these tumors very early and doing a very wide surgical excision is the best course of action but that isn't possible at this point and may never have been possible. These tumors can be so malignant that they have spread when you find them, even if they are still very small.

I wish I had something good and useful to say but I don't. Sometimes malignant tumors don't appear to bother cats much even as they spread. This is probably the only small blessing associated with them in cats.

I hope you find information of more use somewhere on the net. Mike Richards, DVM Lymphosarcoma in liver

Q: My cat was diagnosed with lymphosarcoma in her liver, small intestine and lymphnodes. Before diagnosis, all she did vas vomit and her white blood cel count was a tad low. I have had her for six months. She was a stray and has been indoors for six months. The vet estimated her between six to eight years old. She had exploratory surgery and they said none of the cancer is removable but could be treated with chemotherapy. I was told 70% to 80% are treatable but usually the cancer is localized in one area. I'm having trouble deciding whether or not to put her through chemotherapy. Can you provide additional information on possible options? I know nothing is certain or guaranteed but I would be grateful of any additional information you can provide. I really want to do what's best for her and try to keep my personal wishes out of it. Thank you. J.

A: Of all the tumors, lymphosarcomas are supposed to be among the most responsive to chemotherapy, so that should be considered. On the other hand, this is a situation in which prolonging life is the goal, since curing the cancer usually isn't possible. Cats do not seem to be as bothered by chemotherapy as everyone thinks they might be but some definitely feel low during portions of the treatment. In retrospect most owners seem to think the quality of life was very acceptable, though.

It is a hard choice. If providing as much time, most of it of acceptable quality, is important to you, the chemo is probably the right thing to do. If you are more fatalistic and do not see the benefit in prolonging life for several months to possibly a year or so more than would otherwise be possible, chemo isn't the answer for you. The average life expectancy with chemotherapy is around 9 months but several cats have lived much longer. An oncologist can often give you a reasonably accurate estimation of the pluses and minuses for your particular cat responding to chemotherapy after an examination.

If you definitely are not going to do chemotherapy, prednisone often provides at least short term suppression of the lymphosarcoma signs and that can be worthwhile, too. It isn't a good idea to start out with prednisone until you are sure you won't do chemotherapy because it can make the chemotherapy less effective.

Hope this helps some. It may help to get an opinion from an oncologist, if that is easily done where you live.

Mike Richards, DVM

Abdominal mass with low platelet count

Q: Dear Dr. Mike, My 15 year old spayed cat has an abdominal mass and a disturbingly low platelet count. The ultrasound is scheduled but I have to wait a bit. (specialist is coming from another state) Should I prepare myself for the worst? Thank you.

A: An abdominal mass has to be taken seriously. Low platelets can occur with malignancies and the combination is frightening. You wouldn't be honest with yourself if you didn't consider the possibility that the ultrasound exam will reveal a problem that is likely to be fatal. Lots of times the worst doesn't happen, though. You can't help but worry some but try not to overdo it. Use the time to spoil your cat a little, instead. It is nice to be able to feed special treats and spend some extra time with your cat that you both can enjoy.

.Mike Richards, DVM

Fatty Cell Tumors (Lipomas)

Q: I enjoyed reading your questions and answers, now I have one. I live in Spain, but am American. My cat has developed a mound of fat under his ear, and it needs to be removed. It has grown over the past year since I had it checked, and she said it was fat and not to worry. Now I'm worried. Is it a difficult operation? I'm just kind of mad that it wasn't removed when I first discovered it. Is it normal procedure to wait? thanks The cat is a himalayan.

A: Fatty tumors (lipomas) are not as common in cats as they are in other species but they do occur. Usually it is possible to identify a lipoma quite easily by aspiration of the lump since only fat cells are recovered when this is done. They do have a very characteristic feel as well -- but I have been fooled a couple of times by lumps that felt just like a fatty cell tumor but were something else. These are very easy to remove in most cases and it is standard practice in veterinary medicine to leave them alone unless they begin to interfere with normal activity or function of some organ since they are almost always benign.

The only real problem with waiting would be a misidentification of the lump originally. Fortunately, most of the things that feel like lipomas are also benign, so the odds are very good that your cat will have a routine, uneventful surgery.

You should make arrangements in advance for any lump to be examined by a histopathologist unless it is obviously a lipoma, if you wish to know what the lump was. Your vet should have a pathology lab to refer specimens to. From a practical standpoint, knowing what the lump is is only important if you will consider follow-up treatment, such as more radical surgery or chemotherapy, if a malignancy is found. For many people, though, knowing what a tumor is helps by removing the uncertainty about prognosis and allowing better future planning for whatever course a tumor is likely to take.

Mike Richards, DVM

Last edited 03/16/07


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...