specific gravity

[codypup]

My puppy started wetting the bed and himself at night but never really woke up. I also noticed that he started drinking more and peeing more. I took a sample to the vet. They commented that his protien was slightly elevated and he had a low specific gravity. A blood panel showed no diabetes, the kidney and liver were fine also. We did antibiotics for two weeks and things cleared up. Five days after the antibiotics he leaked again so another sample went to the vet. A little bacteria showed up and again a low specific gravity. I asked the vet the importance of the low specific gravity but am not sure I still understand. What is wrong with dilute urine? I figure he must be drinking a lot for a 40 pound pup. For people I hear the lighter yellow the better. Any thoughts on the specific gravity thing?

[AK dog doc]

Urine specific gravity (USG) is an indicator of how well concentrated the urine is. Normal adult dogs have a USG of 1.020 or higher. Having a very dilute urine (ie, low USG) generally means that the kidneys are not concentrating the urine for one or more reasons, some of which are not a big deal. However, some of the reasons ARE a big deal, such as kidney failure and diabetes. (As a BTW, the elevated urine protein is common in bladder infections, but it can also be an indicator of more serious problems in the kidneys, such as infection or inflammation of the kidney and even kidney failure. In young pups the likely causes of kidney failure would be toxins or a congenital problem called polycystic kidney disease, but this is pretty unusual. The protein is *much* more likely to be related to infection.)

 

In general, puppies do NOT concentrate their urine as highly as adult dogs do. This is perfectly normal. Also, there is a tendency for any dog to form more dilute urine as a result of infections of the bladder or kidneys - this is generally temporary. Those two causes are to be expected in a pup who has had a UTI. However, it may be that there is another underlying cause to the dilute urine, and that could be more significant to the dog. So it may be that the low USG isn't a big deal, but it could be that it is.

 

If you want the mechanisms of urine dilution with some of these disease states - including infection, since that seems to be at least part of the issue here, and maybe all of it - let me know; I don't mind going over them, but I sometimes get WAY too technical and it may be TMI. And let me know if I didn't answer the question.

[codypup]

Thanks Doc. I think I understand a bit better. I'm going to assume that it may be from an infection since the blood work showed no diabetes and normal kidney function. Perhaps a second round of antibiotics are in order. And...I don't think I mentioned my pup's age. He's 11 months and will be a year on Valentine's Day.

[BigD]

Codypup-

 

I'm going through the SAME thing. But my pup is only 5.5 months. She's a she and has had 2 or 3 infections.

 

What is the specific gravity at? Marzipan at 8 weeks was at 1016 with an infection. She's been around 1018, then to 1024 (happy day!) then - boom - another infection and down to 1012 :confused: then we got her up to 1025. Her highest.

 

Our vet has been wonderful about this. He's concerned, but has done all the blood work, tests that he can do on this end. He is thinking she has a drinking problem and just likes to drink water. However, we don't know if the drinking causes the low specific gravity and then she gets the infection. (Bugs can live easier in dilute urine) Or if she is getting the infection and then drinking more, thus causing a low SG. ?????

 

He thinks it may be her age and that it's taking some time for her kidneys, etc to mature. She has been getting better.

 

My vet told me of a test that can be done to detemine what this could be. Basically (AK dog doc, help me with this) you monitor the dogs water and with hold water. They can not loose more than 5% or 10% of their body weight. So you have to weigh them daily and watch for dehydration. You do this for 2 or 3 days and then you give the water. You then measure the specific gravity. If it's high, then you are ok. If it's still low, there is a pill that they get which is treatment for a disease that I don't know the name of...I only know that it's a daily pill and it's expensive. Within a few hours, you measure again. If it's high, then the dog has that certain disease. If not...well...I think you are SOL at that point.

 

I've had 3 infections over 3 months with this pup. Things are improving....but your pup is older.

 

Let me know if you have any questions.

 

Denise

[codypup]

I have wondered about the amount of water intake. Cody, at 39 pounds, usually drinks two full bowls of water. The bowls are fairly big...7 inch diameter and 3 inches high. I've not filled them completely to see if that has made a difference. I'm not sure it has.

 

Really all of this started in late December. Seems he has a sensitive system over all because we have also delt many times with dirreah from food and coccidia.

 

I just hope my pup is alright...and yours.

[AK dog doc]

Hi Denise

Hmmm, not sure, but I believe you're referring to diabetes insipidus, which is the failure of the brain to make and release a hormone called antidiuretic hormone (ADH for short since all that it WAY too hard to say 10x fast). ADH tells the kidneys to concentrate the urine. If you supress ADH production (as in alcohol consumption) or block its ability to bind to the kidney cells (as in caffiene intake), the kidneys don't get the message to reabsorb most of the water going into the urine, so they let most of it out, and then the volume is large and the urine is dilute. The medication for this is desmopressin, which CAN be rather expensive, but we get it made up as eye drops for the dog.

 

I think the test you're talking about is a water deprivation test, which is ideally done in a hospital setting with a metabolic cage (this is a cage that collects all urine and stool so you know exactly the input and output of the dog). The best way to determine if the dog is ABLE to concentrate its urine is to test serum osmolality, but this is something that is going to be done at universities and big referral centers mainly, and that may not be available to everyone. Normal dogs, if water deprived, will begin to concentrate their urine. This is a test which should be used with caution and close supervision, especially in puppies, because if they CAN'T concentrate their urine, and you allow them to dehydrate too much, you can cause significant problems.

 

I think I might've gone over the mechanisms of primary polydipsia (a dog that drinks a lot and hence has a dilute urine) vs. primary polyuria (where the urine is dilute so it forces the dog to drink a lot to keep up with losses) on another thread in this section. For a lot of people that's TMI anyway, but if you can't find it and want the info, let me know. I will say that diabetes insipidus is pretty unusual (I've had only 2 such patients in the last decade, one spontaneous, the other evidently as a consequence of the dog having been shot in the head). There are congenital kidney diseases they can be born with, but many of those are detectable with ultrasound. A few are real zebras - weird diseases that are almost never seen. In any case, it is much more likely that both pups have something more usual - I wonder if Marzipan might be a primary polydipsic, and in Cody I'm still thinking infection-related (although if he recurs again I'd suggest working up the urinary and reproductive organs for an underlying cause. Is he neutered, BTW?) Water requirements vary a lot based on activity, age, gender, reproductive status, weather and a variety of health parameters, but if you want to know exactly how much he takes in, you can fill his water dish as usual with a cup measure - as often as necessary - and at the end of 24 hours, measure whatever he's left behind and subtract from what you put in. (Bear in mind that diarrhea constitutes a fluid loss, so he may need to drink more if he has bouts of that, and ditto vomiting.)

 

CAVEAT: No matter what I suspect, I can't diagnose over the internet, so PLEASE be sure you pay more attention to your vet - who can see and touch your dog and has its enitre record in front of him/her - than to me. I think everyone here is pretty good about this, but I have to say it to ease my own mind.

 

Let me know if I didn't answer the question.

[BigD]

Yes - ADH, that's it! And yes, the water deprivation test. Our vet did mention the special cage thing and all that..but he said "we live on an island...so, you know how that goes. We will cross that bridge if we need to."

 

I'm hoping we won't have to cross it. Marzipan is getting better. It's been over a month since her last infection. And her water consumption is starting to be predictable. Lots of crazy play, drink, drink, drink...go pee...sleep. Wake up, pee, start cycle all over again. And we can leave her for 4 hours or 5 max and she is fine in her crate. Has to pee, but can hold it. And can make it over night from 10pm until 6am - 8 hours. And hold it.

 

I'm going to take another sample in a few weeks (when she goes to get spayed) and see if her specific gravity is up around 1030 - where the vet wants to see it. He says 1025 is good, better for sure than 1012, but he is shooting for 1030 and will be happy with that. Then we KNOW the kidney, brain and all are working and that there is no shunt or anything going on.

 

Good luck Codypup...it sure sucks when all this lingo gets thrown at you and you have to figure out what it all means and can mean.

 

And thanks AK Dog Doc! Hope you are keeping warm up there! Let's do a house swap some time (when it's warmer up on your end!!!). You can watch my guys and I will watch yours.

 

Denise

[KLR]

I cant offer you much advice but we too just went through all that with our 11 week old pup. He was urinating every 10 minutes plus he had some diarrhea and vomiting. We did the blood test which was inconclusive. There were some irregularities. We did another test where he was not allowed to have water for a certain time period. We then took a sample of his urine first thing in the morning. His levels were great then. He was automatically put on antibiotics when this all started. He is much better now and I dont know if we will ever find out what it was.

 

A couple of things I did which I have no idea if they actually helped or not. We tried keeping him a lot more busy so he wasnt drinking as much water out of boredom. We got the specific amount of water he should be drinking per day. I filled my juice container up with that amount so I could see if he was over drinking. Taking him for long walks is a must and since we started doing all this he maybe only has to go every 1 or 2 hours. We also have switched his dog food to Medi-Cal. He seems pretty much back to himself. He is very energetic and not lethargic anymore.

 

One last thing. Our pup was very dehydrated when he first got sick. He actually had to stay in the vets so they could get him rehydrated. I was told that dehydration can effect both liver and kidneys and that could be why some readings are off. You might want to look into that too.

 

Good luck