New Hyperthyroid & likely Kidney Disease diags. :-( How to convert Phosphorous mg to Tanya's CRF chart?

[comp625]

Hello,

Leia is a 5.5 year old asthmatic cat (on Flovent 110mcg 2x/day) who was brought in for 4-day constipation and 2 vomits (across those 4 days, both non-bloody). We left the Vet with a Hyperthyroidism diagnosis and a likely Kidney Disease diagnosis. Sheesh. Her test results are at the bottom (although she did throw up 3 hours before the test which may skew the result?).

I've been doing a lot of research (especially referencing Tanya's Comprehensive Guide to Feline Chronic Kidney Disease). Question: We currently give Leia the Chewy-brand "American Journey" food. According to Chewy, it has approximately 300-450mg Phosphorous/100kcal (see their comment here). How do I convert this so that I can compare this food against the foods in Tanya's US Canned Wet Food chart?

Test: Leia's Result (Normal Range)
RBC: 9.88 (7.12-11.46 M/uL)
Hematocrit: 46.9 (28.2-52.7%)
Hemoglobin: 16.4 (10.3-16.2 g/dL)
MCV: 47 (39-56 fL)
MCH: 16.6 (12.6-16.5 pg)
MCHC: 35.0 (28.5-37.8 g/dL)
% Reticulocyte: 0.5 (n/a)
Reticulocytes: 49 (3-50 K/uL)
Reticulocyte Hemoglobin: 17.8 (13.2-20.8 pg)
WBC: 8.6 (3.9-19.0 K/uL)
% Neutrophils: 70.7 (n/a)
% Lymphocyte: 23.9 (n/a)
% Monocytes: 1.1 (n/a)
% Eosinophils: 4.3 (n/a)
% Basophils: 0.0 (n/a)
Neutrophils: 6.08 (2.62-15.17 K/uL)
Lymphocytes: 2.055 (0.85-5.85 K/uL)
Monocytes: 0.095 (0.04-0.53 K/uL)
Eosinophils: 0.37 (0.09-2.18 K/uL)
Basophils: 0 (0-0.1 K/uL)
Platelets: 577 (155-641 K/uL)
Glucose: 151 (72-175 mg/dL)
IDEXX SDMA: 14 (0-14 ug/dL)
Creatinine: 2.4 (0.9-2.3 mg/dL)
BUN: 24 (16-37 mg/dL)
Phosphorus: 4.5 (2.9-6.3 mg/dL)
Calcium: 10.2 (8.2-11.2 mg/dL)
Sodium: 152 (147-157 mmol/L)
Potassium: 4.5 (3.7-5.2 mmol/L)
Chloride: 111 (114-126 mmol/L)
Total Protein: 8.2 (6.3-8.8 g/dL)
Albumin: 4.2 (2.6-3.9 g/dL)
Globulin: 4.0 (3.0-5.9 g/dL)
Albumin:Globulin Ratio: 1.1 (0.5-1.2)
ALT: 41 (27-158 U/L)
ALP: 15 (12-59 U/L)
GGT: <1 (0-6 U/L)
Bilirubin - Total: 0.1 (0.0-0.3 mg/dL)
Cholesterol: 145 (91-305 mg/dL)
Amylase: 1,724 (623-2,239 U/L)
Total T4: 4.6 (0.8-4.7 ug/dL)
Free T4 (ng/dL): 3.0 (0.7-2.6 ng/dL)
Free T4 (pmol/L): 38.6 (9.0-33.5 pmol/L)

Thank you,
James & Leia

 

[WMM201]

Hi James,

You might want to try using this tool: Pet Food Calculator: Comparing nutrient levels between two pet foods . This asks for the "as fed" basis for amount of nutrient (phosphorus in this case), so you might want to ask Chewy if that number of 300-450mg per 100kcal is the guaranteed analysis (which is a minimum, not the exact amount), or the as fed or "typical analysis" amount for that food. There is another thread about phosphorus as fed that has some information, too: Phosphorus As Fed

Leia's test results look a lot like my cat Mumu's, and she recently got a hyperthyroid diagnosis with a Total T4 of 5.5. Leia's numbers don't look that far out of the normal ranges. I wonder if doing another blood test when she has stopped throwing up might be a good idea, before starting a treatment plan? Has Leia had other symptoms specific to hyperthyroidism like weight loss and increased appetite? That's what got my cat the hyperthyroid diagnosis. Constipation can happen for kidney disease kitties, and I give Mumu some miralax daily and make sure she gets lots of water.

 

[comp625]

Has Leia had other symptoms specific to hyperthyroidism like weight loss and increased appetite? That's what got my cat the hyperthyroid diagnosis. Constipation can happen for kidney disease kitties, and I give Mumu some miralax daily and make sure she gets lots of water.

Yup, she's lost 0.25lb and does seem to have an increased appetite compared. Also, we just started on Miralax for her (1/2 teaspoon scattered throughout her meals). I've begun switching her over to foods with more water (where water or broth are listed higher in the ingredients list).

I also saw Tanya's CRF food site. It seems most foods contain high amounts of Phosphorous, which is bad for kitties with Kidney issues. Sigh.

 

[comp625]

Hi James,

You might want to try using this tool: Pet Food Calculator: Comparing nutrient levels between two pet foods . This asks for the "as fed" basis for amount of nutrient (phosphorus in this case), so you might want to ask Chewy if that number of 300-450mg per 100kcal is the guaranteed analysis (which is a minimum, not the exact amount), or the as fed or "typical analysis" amount for that food. There is another thread about phosphorus as fed that has some information, too: Phosphorus As Fed

Leia's test results look a lot like my cat Mumu's, and she recently got a hyperthyroid diagnosis with a Total T4 of 5.5. Leia's numbers don't look that far out of the normal ranges. I wonder if doing another blood test when she has stopped throwing up might be a good idea, before starting a treatment plan? Has Leia had other symptoms specific to hyperthyroidism like weight loss and increased appetite? That's what got my cat the hyperthyroid diagnosis. Constipation can happen for kidney disease kitties, and I give Mumu some miralax daily and make sure she gets lots of water.

Also, I saw yours and Mumu's posts on the Hyperthyroid Groups.io page. Glad to see a fellow member as our kitties both share this new scary journey.

 

[FeebysOwner]

Hi. I was just typing a message to you regarding the hyperthyroidism forum - but, I see you've already found it! They helped me to start getting a better a grip on Feeby (16+ yo) who was diagnosed last October. There are many members on this site who have joined that group over the years!

 

[WMM201]

Yup, she's lost 0.25lb and does seem to have an increased appetite compared. Also, we just started on Miralax for her (1/2 teaspoon scattered throughout her meals). I've begun switching her over to foods with more water (where water or broth are listed higher in the ingredients list).

I also saw Tanya's CRF food site. It seems most foods contain high amounts of Phosphorous, which is bad for kitties with Kidney issues. Sigh.

Miralax has worked well for my cat. She gets 1/8 tsp mixed with her food once a day. I saw on the food chart that Fancy Feast reformulated their pate food and now it has more phosphorus, which is really unfortunate because my cat loves Fancy Feast pate and it's high protein, very low carb. She ate the turkey American Journey pate for a while, but decided she didn't like it anymore. She isn't anywhere near the point of having to do prescription diets, so we'll just keep giving her lots of water. She really likes her fountain, in case Leia doesn't have one yet?

 

[comp625]

Update: Vet is putting Leia on 5mg of Methimazole per day (2.5mg at breakfast, 2.5mg at dinner). I should also mention the Vet's confidence in Hyperthyroidism is because she lost 0.25lb (she went from 8.25 to 8lb) despite increasing her food over the past month. He also wants to see how the Creatinine kidney levels react with a lowered Thyroid level (to help determine if I-131 is a viable option for her).

Multiple members from both the Feline Chronic Kidney and Feline Hyperthyroid Groups.io communities said 5mg of Methimazole is really high. What do you all think?

 

[neely]

Vet is putting Leia on 5mg of Methimazole per day (2.5mg at breakfast, 2.5mg at dinner). Multiple members from both the Feline Chronic Kidney and Feline Hyperthyroid Groups.io communities said 5mg of Methimazole is really high. What do you all think?

Hi there, our cat was recently diagnosed with Hyperthyroidism and I've been posting in both threads by FeebysOwner and W WMM201 . Antonio65 had a cat with H-T too and has been very helpful.

IMHO, yes, 5.0 mg of Methimazole is high especially to start out with. Our guy is on 1.25 mg twice a day. Maybe I missed it but did your vet do a T-4 test for Leia? Is she on the pill form of Methimazole or transdermal gel?

 

[FeebysOwner]

Vet is putting Leia on 5mg of Methimazole per day (2.5mg at breakfast, 2.5mg at dinner)...Multiple members from both the Feline Chronic Kidney and Feline Hyperthyroid Groups.io communities said 5mg of Methimazole is really high. What do you all think?

I agree it is too high to start with. The baseline dose seems to be to start at 1.25 mg twice a day, and then test 3-4 weeks after starting, then again in another month. Feeby, after I consulted with the H-T group, was started on 1.25mg twice a day, After 3 weeks, she dropped from a T4 of 4.5 to 2.6. After another month, she went to 2.9. We thought we might have found the right dose. But, after 5 months she increased from 2.9 to 3.8, so we upped her dose once a day to 1.875 mg, and kept the other dose at 1.25 mg. Will be taking her back for another check in the coming weeks. Start low and the adjust accordingly.

 

[John Perram]

Are you aware that hyperthyroid can be treated without using drugs?
Radioactive iodine therapy: radiation to treat abnormal thyroid tissue might be an option for you.

 

[WMM201]

My vet had started Mumu on 2.5 mg twice per day, same as you, C comp625 , but after two days and reading all the group messages from here and the other groups, I called my vet to ask for the 1.25 mg dosage. Since Mumu's T4 was 5.5, and normal range ends at 4.7, I did not want to be too aggressive, especially with her CKD. After 3.5 weeks, her T4 is already down to 2.9 and she didn't have side effects or discomfort from the lower dosage. I'd really suggest you tell your vet that you want to start at the 1.25 mg dose, since Leia is really still within the normal reference range for her T4. It's always better to add dosage if needed.

 

[comp625]

Hi there, our cat was recently diagnosed with Hyperthyroidism and I've been posting in both threads by FeebysOwner and W WMM201 . Antonio65 had a cat with H-T too and has been very helpful.

IMHO, yes, 5.0 mg of Methimazole is high especially to start out with. Our guy is on 1.25 mg twice a day. Maybe I missed it but did your vet do a T-4 test for Leia? Is she on the pill form of Methimazole or transdermal gel?

OP here. Her T4 tests are in my original post at the very bottom (in red).

Total T4: 4.6 (0.8-4.7 ug/dL)
Free T4 (ng/dL): 3.0 (0.7-2.6 ng/dL)
Free T4 (pmol/L): 38.6 (9.0-33.5 pmol/L)

When you say "1.25mg twice a day," do you mean 0.75mg at breakfast and 0.75mg at dinner? Or do you mean 1.25mg at breakfast and 1.25mg at dinner?

I agree it is too high to start with. The baseline dose seems to be to start at 1.25 mg twice a day, and then test 3-4 weeks after starting, then again in another month. Feeby, after I consulted with the H-T group, was started on 1.25mg twice a day, After 3 weeks, she dropped from a T4 of 4.5 to 2.6. After another month, she went to 2.9. We thought we might have found the right dose. But, after 5 months she increased from 2.9 to 3.8, so we upped her dose once a day to 1.875 mg, and kept the other dose at 1.25 mg. Will be taking her back for another check in the coming weeks. Start low and the adjust accordingly.

With Feeby's T4 test results, are you referring to Total T4 or Free T4?

Same question I posed to neely. When you say "1.25mg twice a day," do you mean 0.75mg at breakfast and 0.75mg at dinner? Or do you mean 1.25mg at breakfast and 1.25mg at dinner?

Are you aware that hyperthyroid can be treated without using drugs?
Radioactive iodine therapy: radiation to treat abnormal thyroid tissue might be an option for you.

Yes, we're hoping to do I-131 but the kidney levels in my original post are making the Vet hesitant with I-131. Also, some members in the Groups.io communities feel Leia's T4 levels are high, but not drastically so, where pursuing I-131 should be taken with caution.

 

[FeebysOwner]

With Feeby's T4 test results, are you referring to Total T4 or Free T4?
Same question I posed to neely. When you say "1.25mg twice a day," do you mean 0.75mg at breakfast and 0.75mg at dinner? Or do you mean 1.25mg at breakfast and 1.25mg at dinner?

Different labs have different ways of denoting the levels. Feeby's was done by Antech. Her T4 was 4.5 on a reference range of 0.8 - 4.0 ug/dL. Her free T4 was >100 with a range of 10-50 pmol/L, if that helps any. The >100 means it was not on a scale they could quantify.

The dosage initially was 1.25mg twice a day. So, 1.25mg at breakfast and then 1.25mg at dinner.

Have you also checked out this web site - Animal Endocrine Clinic | Where science and compassion cure?

 

[comp625]

Different labs have different ways of denoting the levels. Feeby's was done by Antech. Her T4 was 4.5 on a reference range of 0.8 - 4.0 ug/dL. Her free T4 was >100 with a range of 10-50 pmol/L, if that helps any. The >100 means it was not on a scale they could quantify.

The dosage initially was 1.25mg twice a day. So, 1.25mg at breakfast and then 1.25mg at dinner.

Have you also checked out this web site - Animal Endocrine Clinic | Where science and compassion cure?

Oh wow, sorry to hear about Feeby's super high Free T4. That puts Leia's 38.6 pmol/L well into perspective and now I understand why others have been using the term "gray zone" / borderline diagnosis.

Earlier, you mentioned Feeby's Total T4 dropping from 4.5 to 2.6 (and later increasing to 2.9 requiring medication dosage changes). How did Feeby's Free T4 change before and after the medication? Leia's Total T4 is similar at 4.6 -- we haven't started medication yet.

 

[neely]

When you say "1.25mg twice a day," do you mean 0.75mg at breakfast and 0.75mg at dinner? Or do you mean 1.25mg at breakfast and 1.25mg at dinner?

1.25 mg in the morning/breakfast and 1.25 mg in the evening/dinner. His Total T-4 was originally 4.3 and after one month on Methimazole in the transdermal gel form it dropped to 2.4. Based on his other lab results the vet said he would be a good candidate for I-131 treatment which we are taking into serious consideration.

 

[FeebysOwner]

Earlier, you mentioned Feeby's Total T4 dropping from 4.5 to 2.6 (and later increasing to 2.9 requiring medication dosage changes). How did Feeby's Free T4 change before and after the medication? Leia's Total T4 is similar at 4.6 -- we haven't started medication yet.

I don't know why another Free T4 hasn't been done on Feeby, but I will ensure it is part of her follow up testing.

 

[WMM201]

Chiming in, 1.25 mg in the am, and then 1.25 in the pm for Mumu also. In her next follow up blood work, we're doing a senior profile (including urinalysis) that will have even more kidney relevant numbers like potassium and phosphorus as well as the total T4. Since Leia is young, and her CKD seems very early, that kind of test is probably too much at this point. But if you want a good baseline set of numbers to have going forward for monitoring Leia's kidneys, you might ask your vet for something like that. Then you can figure out also whether you actually need to restrict her phosphorus in her food at this point in her diagnosis. It's a more expensive set of tests, though.

 

[comp625]

Chiming in, 1.25 mg in the am, and then 1.25 in the pm for Mumu also. In her next follow up blood work, we're doing a senior profile (including urinalysis) that will have even more kidney relevant numbers like potassium and phosphorus as well as the total T4. Since Leia is young, and her CKD seems very early, that kind of test is probably too much at this point. But if you want a good baseline set of numbers to have going forward for monitoring Leia's kidneys, you might ask your vet for something like that. Then you can figure out also whether you actually need to restrict her phosphorus in her food at this point in her diagnosis. It's a more expensive set of tests, though.

Thank you. Leia's bloodwork also contained Potassium and Phosphorous figures. Would these figures be any different in the blood vs. in the urine? From the original post above:

• Creatinine: 2.4 (0.9-2.3 mg/dL)
• BUN: 24 (16-37 mg/dL)
• Phosphorus: 4.5 (2.9-6.3 mg/dL)
• Calcium: 10.2 (8.2-11.2 mg/dL)
• Sodium: 152 (147-157 mmol/L)
• Potassium: 4.5 (3.7-5.2 mmol/L)

Since Leia is a gray borderline case, my wife and I are looking for an endocrinology specialist for further consultation. I know urinalysis checks for other things including a gravity test that helps identify kidney issues. Leia's issue though is determining whether the hyperthyroid is causing funky kidney activity, or if the hyperthyroid is masking a worse underlying kidney disease.

 

[FeebysOwner]

Thank you. Leia's bloodwork also contained Potassium and Phosphorous figures. Would these figures be any different in the blood vs. in the urine?

As far as I know potassium and phosphorus levels are not checked in urine - usually RBC, WBC, Protein, Glucose, Ketone, Bilirubin, Blood, Crystals, along with Specific Gravity & PH are the components looked at in urine.
Did you ask about Leia's Phosphorus level in the H-T forum? An older cat's phosphorus level, like Feeby's at 6.3 (range 2.4 - 8.2) is considered too high for her age. But, I don't think at your cat's age the level looks bad.

Leia's issue though is determining whether the hyperthyroid is causing funky kidney activity, or if the hyperthyroid is masking a worse underlying kidney disease.

I am by no means even remotely well-versed on H-T or kidney disease, but I am thinking you are on the right track to consulting with an endocrinologist. However, I am also wondering if you shouldn't be consulting with a urologist. I almost feel like Leia's issues are more closely tied to kidney disease than they are hyperthyroidism. Here is a link you might be interested in - American Society of Veterinary Nephrology and Urology (asvnu.org).

 

[WMM201]

Hi James, has Leia had another blood recheck for her kidney values? Sometimes not eating or not drinking could affect those numbers on a single given test. That certainly was the case for Mumu when she had several days of inappetence. Fingers crossed for her!