View Full Version : High Phosphorus levels

6th January 2011, 03:47 PM
Our vet wanted to see Spangle this morning when I asked for a further supply of her meds. When we got there he asked if he could take some blood tests to check her kidney function and her thyroid (he commented that her coat was coarse ).

He phoned me about an hour ago to tell me that Spangle`s phosphorus levels in her bloodstream were quite high and he wanted to put her on a binding agent to mix with her food. The rest of her results will be back next week.

What I wondered was if anyone has gone through this and can give me any advice please?
I am assuming that the meds she is one are causing problems with her kidneys?

6th January 2011, 05:04 PM
What medication is she on?

6th January 2011, 05:41 PM
It was increased to :100mg gabapentin 4 x day
30mg codeine 4 x day
5mg prednislone every other day
last October.

6th January 2011, 06:20 PM
High phosphorus is usually indicative of kidney issues and the high level makes things worse :(

So sorry to hear this news :(

I'm hoping Pat might know more about this?

Kate H
6th January 2011, 07:37 PM
My understanding is that it's the diuretics which SM dogs are on that cause possible kidney problems. Diuretics not only reduce the cerebral-spinal fluid in the brain but also all the fluids in the body. The kidneys need to be flushed through regularly and if not, things like phosphorous can accumulate (hence the need for dialysis for people with kidney failure). That's why Cavaliers on frusemide or similar need to have blood checks regularly. Sorry that the phosphorous level is worrying, but good that your vet picked it up and can do something about it.

:hug: and :xfngr:

Kate, Oliver and Aled

6th January 2011, 11:41 PM
What are you feeding her?

7th January 2011, 12:49 AM
Yes, actually I am one of the moderators in a yahoo canine kidney failure group......

Can you get a copy of her blood chemistry report and urinalysis and post all of her values? With kidney failure, you will see an increase in BUN (blood urea nitrogen), increase in creatinine and increase in phosphorus. You will also see a lowered urine specific gravity (indicates inability to concentrate urine) and a lowered hematocrit (also called packed cell volume) as kidney failure causes anemia. Depending on what these numbers are, kidney failure is staged according to the severity. Kidney failure can be chronic or acute. Acute failure can be caused by infection, a kidney injury (such as ingesting a toxin or a drug reaction or leptospirosis or a tick borne disease), etc. Acute failure can be reversed in about half of the cases, but about one-fourth (if I correctly remember the stats I learned at AVMA convention) of acute will lead to chronic failure. Chronic failure is related more to aging or a result of poor perfusion from heart failure or similar.

Increased BUN reflects dehydration, and an increase can be caused by many things. Long term diuretic therapy almost always causes BUN to rise above normal values. I've seen this in my own dogs on heart meds. I personally would be very reluctant to use furosemide (US spelling) on a long term basis for SM, but then again I've not had a dog with SM and I have had dogs with kidney failure. And I know what long term furosemide use does to kidneys. Pred can be hard on kidneys also I think (I'll have to check Plumbs when I get home.)

Creatinine is a much more accurate indicator of true kidney functioning. Urine specific gravity is a measurement that tells you how well the dog is concentrating urine. A low USG is the first sign of kidney problems, and it shows up long before blood chemistry values are abnormal. (This is why I always run urinalysis when I run blood chemistry, and you need a first morning urine sample to accurately measure USG.) When BUN, creatinine and phosphorus are above normal, generally one only has about 25-30% kidney function remaining. But dogs with chronic kidney failure can be maintained for a long time with a reasonably good quality of life with good treatment and a little luck.

It would be odd to have elevated phosphorus from kidney failure without having elevated BUN and creatinine. Elevated phosphorus happens when a dog's kidneys aren't working well enough to clear the waste/toxins from the blood. Elevated phosphorus causes a dog to feel nauseous and unwell and not have an appetite. Foods that are high in protein are also high in phosphorus, but the newer thinking is not to feed low protein foods per se but rather to try to feed a diet that is higher in good quality protein (such as egg whites) but lower in phosphorus. (Also commercial kidney food is very high in fat which can often trigger pancreatitis, which is why I prefer a home cooked diet for dogs in kidney failure.)

There are several ways to treat kidney failure - low phosphorus diet, some meds that help the symptoms, giving IV fluids at the vet's and/or subq fluids at home (done commonly in the US but for some reason UK vets often resist letting their clients give subq fluids at home) and using a phosphorus binder.

I believe the most effective phosphorus binder is aluminum hydroxide. It must be given with food or immediately after the dog eats in order to work. The liquid (Alternagel) tastes bad. I have always used alum hydroxide powder in capsules and coated the capsules with raw honey. (Don't use cheese or deli meat, etc. - very high in phosphorus.) The binder takes phosphorus out through the gut so the kidneys don't have to work as hard. I always gave it immediately after my dog ate rather than mixing it in food (tastes bad) thus risking rejection of the meal. Other products that are supposed to bind phosphorus are things like Epakitan, Azodyl, etc. but they are not as effective (in the experience of many members of my kidney group).

I have had several Cavaliers with kidney failure, so I've been down that road. My beloved boy (Capers) had end stage heart failure and concurrent kidney failure, but with a wonderful cardiologist and good treatment, his symptoms were well under control and he ended up being PTS at 16 1/2 for other reasons.

Does she have any symptoms now? How is her appetite? If you can post her exact numbers, that will tell me more, although I have a hard time with UK lab values while US lab value meanings are pretty well burned into my brain as far as staging of disease. I do have some expert sources that I can consult. There are some great websites - Mary Strauss' Dogaware site and Tanya's UK feline kidney failure site are both excellent.

Sorry this is so long - it's a big topic. Probably way more than you wanted to read, but this subject is one to which I've devoted years of study.


7th January 2011, 09:50 AM
Many thanks for all your replies, especially Pat. I`ve printed what you have said and will take it to my vet this morning to try to find out more.

The thing that stood out for me and rang some very loud bells was your comment Pat about giving capsules in cheese or deli meat. I`m now very worried because that is exactly what I use to get her to take all her meds. I had such a problem at first, she was never a good eater as a youngster and getting tablets down her was a nightmare until I used very thin cooked ham or chicken from a packet!

I will stop that from now and try her with honey.

Back to this phospherous problem, she has no symptoms at all, she is food mad and loves to eat anything. She does not seem unwell at all to me (obviously except for some SM symptoms sometimes).

Off to the vets now, I will post later with any more details and thanks again for helping me to understand so much more.

7th January 2011, 12:44 PM
It's very good that she has no symptoms so maybe this is some strange fluke or I wonder even about a lab error? A normal sign of kidney failure and high phosphorus is that dogs stop eating or become very picky eaters. A week is a long time to wait for lab reports - maybe vet can phone the lab and ask for expedited service. My vet sends blood and urine out to a local lab (Antech) but we get results back late the same day or the next day at the latest.

Lots of people (including me) use cheese or deli meat to give pills and usually it is not a problem. But if a dog is truly in kidney failure, you want to closely watch the amount of phosphorus in the diet. There are good web sites (like nutritiondata.com) where you can look at different foods and get info such as amount of protein, phosphorus and other minerals, fat, etc.

I'm now hopeful that this isn't true kidney failure.