Unexplained weight loss in senior cat

[Pawsings]

My friend has a 12 year old Maine Coon that has been experiencing weight loss for the last eight months. Twelve to nine pounds. This is the only symptom the cat has. Stools, urine, behavior, eating, sleeping are all the same. Superchem blood panel were all normal. Stool sample and UA were normal. Renal disease, hyperthyroidism and diabetes were ruled out.

The ultrasound of belly only showed "three mildly enlarged lymph nodes". There was no thickening of the intestinal walls and no peritoneal effusion. Liver, kidneys, spleen and pancreas appear normal. There was no diagnosis made. The differentials were cancer and allergies. Several weeks ago, the vet started the cat on Prednisolone and B12 injections, without any explanation as to why. The owner believes that the cat has gained a little weight since starting this treatment and does not want to have any biopsies done.

I realize that there are dozens of reasons that a senior cat could be losing weight. My friend is looking into hydrolyzed foods and novel proteins, but she isn't even sure that the food is the problem. I would appreciate your thoughts, suggestions or experiences about this perplexing problem. The vet hasn't discussed any diet changes, allergy testing or further diagnostics to determine the cause of the weight loss. Thank you for your help!

 

[Furballsmom]

The ultrasound of belly only showed "three mildly enlarged lymph nodes

Hi, the thyroid is a lymph node as well. Do you know if a free T4 thyroid test was done? It can detect hyperthyroid issues, when the regular thyroid test may read within the normal range.

 

[FeebysOwner]

Hi. I agree to start with more inclusive testing done for the thyroid. My cat's only 'symptom' was weight loss and yet she did prove to be hyperthyroidic. Hers, however, was, confirmed through the T-4. There are other levels of testing in addition to the free T-4, so ask about those as well so they can be done concurrently.

Beyond that, there is a less invasive way to at least check for cancer. It is called a fine needle aspiration (FNA) cytology, whereby tissue is aspirated with a needle from the enlarged lymph nodes during an ultrasound. It isn't a guarantee, but certainly not as invasive as a biopsy, nor is it painful. Of course, the FNA adds to the overall expense.

My cat, who has lymphoma, had two FNA's done, which were not definitive - BUT on the last FNA they also did a PARR Assay, which is a more in-depth tissue analysis than the FNA. It is done on tissue that is normally retained in a lab after an FNA, so it can be done 'after the fact' if the FNA produces inconclusive but suspicious cells. It was the PARR Assay that confirmed Feeby's lymphoma. And the PARR Assay is also an additional cost.

Either way, Prednisolone is usually often given with either IBD or lymphoma, as well as B-12 injections. Chemo is usually reserved for lymphoma but has also been given to cats who do not completely respond to the Prednisolone alone. The chemo being added after Pred is generally when additional testing is not done to try to confirm lymphoma, but better results are wanted beyond what the Prednisolone is providing.

And there is really no concern about the B-12 as whatever is not used by the body is excreted through the urine. So, no chance for 'overdose'. There is a test for checking low B-12 - cobalamin - levels but a lot of vets forgo that knowing that the B-12 won't pose a problem if not necessarily needed.

 

[Pawsings]

Hi. I agree to start with more inclusive testing done for the thyroid. My cat's only 'symptom' was weight loss and yet she did prove to be hyperthyroidic. Hers, however, was, confirmed through the T-4. There are other levels of testing in addition to the free T-4, so ask about those as well so they can be done concurrently.

Beyond that, there is a less invasive way to at least check for cancer. It is called a fine needle aspiration (FNA) cytology, whereby tissue is aspirated with a needle from the enlarged lymph nodes during an ultrasound. It isn't a guarantee, but certainly not as invasive as a biopsy, nor is it painful. Of course, the FNA adds to the overall expense.

My cat, who has lymphoma, had two FNA's done, which were not definitive - BUT on the last FNA they also did a PARR Assay, which is a more in-depth tissue analysis than the FNA. It is done on tissue that is normally retained in a lab after an FNA, so it can be done 'after the fact' if the FNA produces inconclusive but suspicious cells. It was the PARR Assay that confirmed Feeby's lymphoma. And the PARR Assay is also an additional cost.

Either way, Prednisolone is usually often given with either IBD or lymphoma, as well as B-12 injections. Chemo is usually reserved for lymphoma but has also been given to cats who do not completely respond to the Prednisolone alone. The chemo being added after Pred is generally when additional testing is not done to try to confirm lymphoma, but better results are wanted beyond what the Prednisolone is providing.

And there is really no concern about the B-12 as whatever is not used by the body is excreted through the urine. So, no chance for 'overdose'. There is a test for checking low B-12 - cobalamin - levels but a lot of vets forgo that knowing that the B-12 won't pose a problem if not necessarily needed.

My friend is going to talk to her vet about testing for free T-4. Any further diagnostics for cancer are not an option for her. Thank you for all that helpful information.

 

[Pawsings]

Hi, the thyroid is a lymph node as well. Do you know if a free T4 thyroid test was done? It can detect hyperthyroid issues, when the regular thyroid test may read within the normal range.

Only the standard T-4 test was done, not the free T-4. My friend will talk to her vet about testing for free T-4. The three enlarged lymph nodes, identified in the ultrasound, were only in the cat's intestines. Thank you for your helpful suggestion.

 

[FeebysOwner]

My friend is going to talk to her vet about testing for free T-4. Any further diagnostics for cancer are not an option for her. Thank you for all that helpful information.

Make sure your friend asks about the other thyroid tests beyond the free T-4. That might save on additional costs if the vet thinks they should be done after the fact because the free T-4 doesn't provide the resolution. This article will explain it better than I can.
Feline Thyroid Tests | Cornell University College of Veterinary Medicine