Urine specific gravity and disease process
Question: Dear Dr. Mike:
Thanks again for another prompt response. Kori's urinalysis results came back
normal except for the Sp. Gr. was 1.015. With this result, the facial
paralysis, excessive drinking of water, and slight balance issues, does
any other
possible cause come to mind? I am taking her back tomorrow for a follow up
appointment. Thanks again for your suggestions and
information.
Lori
Answer: Lori-
There are several recognized ranges of urine specific gravity that can be helpful in determining if a disease is present and what the disease might be.
Urine in the range from 1.008 to 1.012 is considered to be isothenuric, or approximately the same specific gravity as the serum that filters through the kidney (the glomerular filtrate). This means that the kidneys are not concentrating the urine, nor are they diluting it. Since the only way to be sure that the kidneys are able to perform these functions is to have urine samples outside the isothenuric range, it is important to get serial urine samples to see if this happening when a urine sample falls in the isothenuric range. Consistently isothenuric urine may indicate that kidney failure is present and can be seen with hormonal disorders in some cases.
Urine in the range below 1.008 in specific gravity indicates that the kidneys are diluting the urine. This happens with disorders like diabetes insipidus. It is an indication that the kidneys can function, since they are actually making the urine dilute, though.
In dogs, urine specific gravity above 1.030 indicates that the kidneys are able to adequately concentrate urine and values above this level are reassuring, due to this. Specific gravity ranges between 1.012 and 1.030 are indicative of some kidney function but are not high enough to say that the kidneys are functioning fully.
There is a broad range of urine specific gravity that can be found in any
individual urine sample. It is not at all uncommon for the specific gravity to
be low when a dog is drinking normally and the sample is taken during
the day. Dogs
tend to be urinating more frequently during the daytime and there isn't much
need for the body to concentrate urine. If the first
urination of the morning, which should be more concentrated, falls into
the lower
ranges of specific gravity there is more reason to be suspicious of a problem.
So at this point I think you have to look at this sample as being unhelpful in ruling in or out any of the possible disorders that affect urine. However, it is a good indication of the need to continue to monitor urine specific gravity until it can be determined that samples are going to stay in this range or until a sample is concentrated enough to indicate you can stop worrying or dilute enough to make it necessary to look for problems that cause urine dilution.
Balance problems in conjunction with facial paralysis are a stronger indication of a problem affecting the inner ear than facial paralysis alone.
Mike Richards, DVM
10/29/2001
Calcium oxalate stones
Question: Dear Doctor,
I have a female Japanese Chin, eight years old, 15 pounds (large for the breed but not overweight). She has a collapsing trachea, a heart murmur, and her heart is enlarged. Of most immediate concern, though, she has calcium oxalate bladder stones. We discovered the stones because one has almost totally blocked her urethra so she had a great deal of difficulty urinating.
She had unsuccessful surgery on June 29; some stones were removed but some remain, and her urethra is still partially blocked. I understand that the stones cannot be dissolved by diet or medication. She is not a candidate for urohydropropulsion, and I don't care to subject her to more surgery since it would probably be no more successful than the first.
We have changed her diet, and plan to start her on calcium citrate, to prevent more stones forming, or existing stones enlarging. However, my main concern at the moment is the one stone that is partially blocking her urethra. If that stone shifts even slightly her bladder will be totally blocked and we will have an emergency.
I understand that sonic shock wave treatment can disintegrate existing stones, but I haven't been able yet to locate a treatment source within reasonable driving distance of my home (central Alabama), nor do I know any details.
Please tell me if you would recommend the shock wave treatment, and any details you may have. I am especially interested in the success rate because I don't care to put the dog through an extremely painful (and undoubtedly expensive) treatment with little chance of success.
I would also appreciate any other comments and suggestions you may have.
Thanks in advance, Wayne
Answer: Wayne-
You are correct that calcium oxalate stones are not easily dissolved through dietary means, as struvite stones sometimes are. So usually it is necessary to remove these stones. It is supposed to be possible to remove many stones through voiding urohydropropulsion but surgical removal is probably still the most common method of removing these stones.
The University of Tennessee has a lithotripter that they use on dogs and they
are reporting good success with this procedure. Purdue University is the only
other place that I know of that is doing this procedure, but
there may be
others, as this sort of thing changes frequently. In addition, there are some
people around the country who are experimenting with laser
fragmentation of bladder stones but I don't know where they are, as
this was just
mentioned as a possibility in a seminar we attended on lower urinary tract
disease this spring. I know that the Virginia-Maryland
Regional
College of Veterinary Medicine (Blacksburg, VA) has done the laser procedure on
horses but I haven't seen anything about small animals
that I can remember.
At the seminar we attended, Dr. Osborne from the University of Minnesota showed
some pretty amazing slides of stones they had managed to retrieve through
voiding
urohydropropulsion,
but if this has been tried by someone who is good at it and it didn't work, then
this may not be an option. Also,
in some cases it is just obvious that a particular stone is too large
to be removed
in this manner, so if that is the case then it isn't an option, either. There is
an article in the September 1, 1993 issue of the AVMA
Journal with good diagrams of this procedure and I think it is covered
in one of the
Clinics of North America issues, too.
Your vet should be able to arrange a referral to the University of Tennessee if that isn't too far to go.
Mike Richards, DVM
8/23/2001
Copy from www.vetinfo.com/dogurinary.html - dated 7 Sept 2004 by Fion
FYI
Vaccination Protocol Changing
Subscriber Question: Have been receiving info from different sources that the veterinarian schools are in the process of changing the protocol for vaccinating. All the information I've received states that vaccinations should be less frequent but they don't all give the same agenda.
What is the proper protocol? I'm under the impression that
adult dogs do not need yearly vaccinations and that rabies vaccines need be
given only every three years. Also that in most cases Lepto and corona vaccines
are not necessary. I must admit that I have not been giving either of these
vaccines to my dogs for several years due to bad reactions in the past.
Thank you, Jan
Answer:
Jan-
At the present time there is no universally accepted vaccination protocol for
dogs or cats. Veterinarians are really divided over the best way to vaccinate.
These are the main camps:
1) Vets who think that vaccinations should be given every year. Their logic:
a) The labels say to do that and following label directions lessens liability.
b) There isn't much published information in refereed (scientifically reviewed)
journals that refutes the once yearly vaccination schedule.
c) It is the way things have always been done and there is an obvious decrease
in distemper, parvovirus, etc, so why stop something that is working?
d) Bacterial vaccines (leptospirosis, Bordetellosis, possibly Lyme disease) are
not noted for long term protection -- they may not even provide a year's
protection --- so these vaccines may be necessary yearly or more often if they
are necessary in a particular area.
2) Vets who think that vaccines should be extended to every three years. Their
logic:
a) It is obvious that some dogs react badly to vaccinations, either at the time
they are given or several weeks later by experiencing immune mediated hemolytic
anemia (IMHA). There is a documented rise in the cases of IMHA for the month
following vaccination in dogs but it is a slight rise -- just barely enough to
be statistically significant. Therefore, it seems important to give vaccinations
only as often as is necessary.
b) There isn't enough information to tell how long vaccines really last (see b
above) BUT it seems pretty obvious they last longer than one year -- so every
three years seems like a reasonable bet. It is likely the vaccines last that
long just based on clinical experience alone and it cuts down some on the
reactions to extend the interval to every three years.
c) The veterinary schools and organizations have settled on every three years as
a good compromise between what is known and not known, for the most part, so
there is support for this approach in the literature, making it fairly safe from
a liability standpoint.
d) The duration of immunity provided by vaccinations probably varies from one
vaccine to the next, depending on the strain of virus/bacteria used, the
adjuvents used in the vaccine and the production methods -- therefore, until
each vaccine is tested for duration of action, it will be hard to make blanket
judgments about how long vaccine intervals should be.
3) Vets who think that it is OK to go to much longer vaccination intervals based
on the available information which is primarily derived from unpublished studies
that have been widely publicized at meetings and other information sources, but
who believe strongly in the value of vaccination. Their logic:
a) This information can be found despite its non-published status. The
researchers are respectable within the profession.
b) It is highly likely that parvovirus vaccine provides lifelong immunity and
that distemper vaccine provides protection for more 5 to 7 years. It is
reasonable to assume that other vaccinations for viral illnesses work as well.
c) Vaccines can cause harm. Therefore, the individual risk to a particular
illness AND of the vaccine should be compared for each individual patient and a
vaccine schedule designed to fit the patient's needs. By doing this, the
veterinarian is serving the best interest of the patient. With this in mind --
there will always be room for controversy about vaccine intervals if the logic
of this argument is persuasive -- but it still could work out to be the best
approach for most patients.
d) Liability arguments don't seem to have much effect on this group of vets but
that might change if pets are accorded a status somewhere between property and
humans and things like "pain and suffering" are allowed in law suits concerning
pets. Currently, this isn't the case in most states but is being considered in
several localities.
4) Vets who think that all vaccines are bad. I have to admit that I can't come
up with any good logical reasons for vets to think this way, so it is hard for
me to provide the logic that these vets use, unless it is simply that they have
experienced some bad reactions and haven't been through a parvovirus, distemper,
leptospirosis, etc. epidemic in their practice area.
With all this in mind, this is what I do for my canine patients:
I stick to a mostly every three year vaccination schedule for the rabies (after
the initial one year vaccine) and DA2PP (distemper, parvovirus, adenovirus and
parainfluenza) vaccine. I don't use coronavirus vaccine, leptospirosis (but I
would as soon as I see enough cases to convince me it was a problem in my area),
Lyme disease vaccine (probably would use this if I saw lots of cases but I'm not
sure -- fortunately, I haven't had to make this decision) or giardia vaccine. I
advise using Bordetella (kennel cough) vaccine on an "as needed basis",
basically prior to boarding or for dogs that go to lots of shows or other events
where there are other dogs.
When a dog reacts badly to the DA2PP combination vaccine and they have had at
least the puppy series and one booster, I just don't give it again. I figure the
risk to that individual from the vaccine probably exceeds the risk of the
diseases during their lifetime (at least where I practice). If there are
reactions to the rabies vaccine we pre-treat with antihistamines or
corticosteroids and just give the vaccine, because it is required by law and
because the risk to the dog of not being vaccinated is high --- not only from
rabies but from the public health laws if it bites someone and isn't properly
vaccinated. In Virginia, fortunately, 3 year duration vaccines are accepted for
rabies protection. As long as the vaccine is being boostered instead of being
given for the first time, corticosteroids do not cause significant interference
with the production of an immune response to the vaccine.
You didn't really ask about cats, but this is how we handle cat vaccinations:
We give the kitten series for RCP (rhinotracheitis ( or feline herpes) ,
calcivirus and panleukopenia (feline distemper)) and rabies at >12 weeks of age.
We vaccinate for feline leukemia in kittens, unless the owner is certain that
the kitten will be an indoor only cat and there is little chance for contact
with other cats who might carry the disease. We don't use any other vaccines at
the present time.
We booster the vaccinations that seemed necessary at one year of age.
At this point we go to an every three year schedule for RCP and rabies but we
don't give feline leukemia vaccination to cats again. Our logic is that most
studies show that cats have a strong natural resistance to feline leukemia after
they are about 18 months old, so vaccination doesn't seem warranted given the
risk of vaccine associated sarcoma (cancer) in cats and the low risk of
acquiring the infection as an adult. This is probably the most controversial
decision we make about vaccinations (stopping the FeLV vaccine). We use the
every three year rabies vaccines but it is possible to make a very good case for
using PureVax (tm, Merial) rabies vaccine, which is thought to be less likely to
cause cancer at vaccine sites. PureVax has to be given yearly as it is only
approved for one year use.
One thing you have to remember about our vaccine protocol is that we developed
it for our area. We live in a very rural community and we don't have dog parks
or limited areas that lots of dogs play in --- we have mostly stay at home dogs
who interact with a few dogs in their neighborhood. Our cat patients may also be
less likely to interact with lots of other cats compared to suburban or urban
cats, as well. So we made our vaccine protocol decisions with this situation in
mind. Other vets have to make their decisions based on different circumstances
that influence their decision making about the risks and benefits of specific
vaccines in their practice area.
I hope that this was helpful.
Mike Richards, DVM
8/7/2003
犬膀胱結石症
Cystolithiasis in a Dog
學生姓名：彭曉嫈 學號：48048034 報告日期：85.3.7.
病歷號碼：84-3667 掛號日期：84.12.14. 教師簽署：
【 摘 要 】
病犬因嚴重頻尿、血尿、食慾廢絕而於12月14日被帶來本教學醫院就診。經各項臨床檢查，診斷為膀胱結石症，於是施行膀胱切開術移除結石，
術後五天排尿即恢 復正常。而結石分析其成份為草酸鈣，建議主人採用Hill's處方食品s/d、u/d皆無法配合，仍採以往之餵飼方法，
判斷複發的可能性相當高。
一、病史：
病犬為5歲、體重50.7Kg之雄性西藏獒犬，於12月14日下午
至本教學醫院就診。據畜主描述其有嚴重頻尿、血尿情形已二到
三日且食慾廢絕，於地方動物醫院就醫，經建議而轉診至本院，
而其開始有血尿情形已達一年以上。飼養狀況為每日餵食二次；
早上吃乾飼料，晚上則為各種肉品。
二、臨床檢查：
1.身體檢查：
(1)心跳72次/分，呼吸60次/分。
(2)觸診：膀胱積尿脹大。
(3)導尿：導出尿液為暗紅色，量約500ml。
2.放射線學檢查（導尿之前）：
可見膀胱積尿脹大，並可見膀胱內有五顆高密度、低穿透
性之顆粒影像，其中一顆位於腸骨前緣，近尿道口處。
3.血液學檢查：參見附表一。
血小板減少，應為膀胱出血消耗所致。
嗜酸性球增多。
4.血清生化學檢查：參見附表二。
LDH、CK上升。
Total protein偏高。
Alb、A/G偏低。
5.尿液學檢查：參見附表三。
尿液試條結果顯示尿液偏鹼，有嚴重血尿、蛋白尿，且
對葡萄糖、酮體、膽紅素、尿膽素原、亞硝酸鹽皆有反應。
尿渣鏡檢可見紅血球、大量白血球、顆粒性圓柱、炎症性晶
體、精蟲、細菌。
6.尿液培養：
無培養到細菌。
7.結石細菌培養：
無培養到細菌。
8.結石分析：
（1）數量：5個。
（2）外觀：黃白顆粒，表面粗糙。
（3）成份：二分子水草酸鈣（calcium oxalate dihydrate）
（4）形狀大小重量分別為：
立方體 1.8cm×1.4cm×1.4cm 3.86g
三角錐體 1.5cm，1.5cm，1.4cm，1cm 1.13g
三角錐體 1.4cm，1.3cm，1.3cm，1.2cm 1.07g
四角錐體 1.2cm×1cm，0.7cm 0.85g
三角錐體 1cm，0.9cm，0.8cm，0.4cm 0.42g
註：錐體測量以一面以為底之各邊長，而最後一項為高。
三、診斷：
犬之膀胱草酸鈣結石症
四、治療：
醫師經臨床檢查及評估後，決定馬上施以膀胱切開術移除
結石，於就診當日（12/14）下午6點30分進行手術。
1.術前剃毛並給予：
Atropine(0.05mg/ml) 2ml S.C.
Citosol(25mg/ml) 30ml I.V.
2.採背臥位，氣管插管以isoflurane行氣體麻醉，術部清洗消毒。
3.於下腹中線開創，避開penis,將膀胱翻出。
4.於膀胱背側切開，取出結石五顆，可見膀胱壁明顯有增厚情形並有嚴重出血。
5.滴入抗生素,縫合膀胱、腹壁。
6.術後照顧：
（1）給予口服藥 Milisher(lysozyme chloride)、Cephalin (cephaloridine)、Excresin(furosemide)、Hope-B及20% glucose混合液，每日兩次。
（2）嘗試餵以處方食品 S/D，但患犬不願吃。
（3）患部每日噴優碘兩次。
五、結果：
1. 12/15：咬掉導尿管，排尿情形不明，無食慾。
2. 12/16：吃了一些乾狗糧與寶路罐頭，尿液呈咖啡色，末段尿為鮮紅色。
3. 12/17：恢復食慾，尿呈黃色，末段尿色較深。
4. 12/18：尿呈黃色，並排出一點點血塊，經評估准予出院。
5. 12/19：電話詢問排尿正常。
6. 預後：患犬不願吃處方食品，仍依照往日之餵飼法，推測其很有可能再復發結石。
六、討論：
1.結石形成（1）：
（1）首先形成一晶體病巢（crystal nidus），稱之為核形成（nucleation），有三種理論被提出：
Precipitation-Crystallization Theory：
尿中結石性晶體過飽和而沈澱，自發形成核。
Matrix-Nucleation Theory：
有機基質（matrix）形成核後，晶體沉澱上去漸而形成結石。
Crystallization-Inhibition Theory：
認為抑制結晶作用之因子減少或缺乏，為草酸鈣和磷酸鈣結石生成之首要條件。
（2）成長:晶體病巢形成後，可能被排出或停留泌尿道內繼而長成結石，推測其生長方式可能為：
Crystal growth：
晶體病巢形成後，於同種晶體過飽合情況下，繼續長成結石。
Epitaxial growth：
一種晶體在不同種類晶體之表面成長，可解釋結石通常為混合性成份之因。
Crystal aggregation：
因晶體聚集抑制因子缺損，晶體聚集而成結石。
2.草酸鈣結石病因：
（1）高鈣尿：
腸道對鈣之吸收增加（主要）、腎小管對鈣重吸收功能受損而致鈣排出增多、過度自骨中抽鈣（罕見）
（2）高草酸尿：
食物來源：
攝食高草酸含量之食物，如巧克力、小麥胚芽、菠菜、堅果、甜馬鈴薯等。
內源性：
維他命B 6缺乏時，草酸前驅物glyoxylate無法順利經轉氨基作用形成glycine，而形成草酸。
（3）低檸檬酸尿：
機制不明，但與酸鹼恆定有關；於酸中毒時尿中檸檬酸排出減少，鹼中毒時則增多。
（4）大分子晶體生長抑制因子缺損：
高分子量蛋白質，如 nephrocalcin，可增加草酸鈣的溶解度，而抑制其晶體形成。
3.草酸鈣結石之防治方法：
（1）無法以內科方法溶解草酸鈣結石，只能用物理方法移除：
膀胱切開術取出結石。
常形成細小結石，可輔以voiding urohydropropulsion或導尿管沖吸法使小結石排出。
（2）預防：
控制飲食：
勿吃高鈣食品，尤其乳製品，因乳糖會促進對鈣的吸收，另要限制草酸鹽、鈉鹽及動物性蛋白的攝取量。
若持續酸性尿可考慮投予尿鹼化劑，以增草酸鈣的溶解度，如檸檬酸鉀，其尚有與鈣形成可溶性鈣鹽之優點。
持續出現晶體尿可考慮投予維他命B 6，促進glyoxylate轉換成glycine，而減少草酸形成。
投予thiazide類利尿劑：
已證實草酸鈣結石症患犬投予hydrochlorothiazide兩週後，尿中鈣排出量減少。
4.大部分沒出現臨床症狀之結石症與尿路感染無關（部份草酸鈣結石症即無臨床症狀），但仍為誘發尿路感染之高危險因子，
因其會傷害膀胱黏膜，且造成不完全排尿，而致尿道沖刷力降低，故細菌易入侵滋生，並增加炎症性結石生成的機會。
在本病例中雖無分離到細菌，但尿渣中出現炎症性晶體，並見有細菌，且尿PH值高達8.5可能是細菌分解尿素所致，
故推測已有感染發生，而細菌已在先前之醫療行為時殺滅才沒培養到菌。
七、參考文獻：
1.李崇道。1992。獸醫病理學。國立編譯館。黎明文化事業公司。
台北。中華民國。pp.690-691。
2.沈永紹。1991。獸醫實驗診斷學提要。第三版。華香園出版社。
台北。中華民國。
3.Lulich, J.P., C.A. Osborne, J.W. Bartges, and D.J. Polizin. 1995.Canine Lower Urinary Tract Disorders. In Textbook of
Veterinary Internal Medicine, 4th ed, S.J.Ettinger and
E.C.Faldman(eds), W.B. Saunders Co., USA, pp.1833-1844.
4.Lulich, J.P., C.A. Osborne, J.W. Bartges, and D.J. Polizin. 1995.Canine Lower Urinary Tract Disorders. In Textbook
of Veterinary Internal Medicine, 4th ed, S.J. Ettinger and E.C. Faldman(eds), W.B. Saunders Co., USA, pp.1848-1852.
5.Osborne, C.A., J.P. Lulich, J.W. Bartges, and L.J. Felice. 1990.Medical dissolution and prevention of canine and feline
uroliths:Diagnostic and therapeutic caveats. Veterinary Record.Vol 127:pp.369-373.
TABLE 1. Hematology
TEST\DATE 12/14 REFERENCE VALUES
RBC M/mm3 5.85 5.5-8.5
Hb gm/dl 12.9 12-18
PCV % 38.5 37-55
Thrombo. mg/dl 1.48×105 2-9105
Reticulo.% 1.2 0-1.5
MCV fl 65.8 60-77
MCHC g/dl 33.5 32-36
MCH pg 22.1 19.5-24.5
WBC /mm3 16100 6000-17000
Band % 0 0-3
Seg. % 58 60-77
Eosino. % 25 2-10
Baso. % 0 0-2
Lymph. % 13 12-30
Mono. % 4 3-10
Nucl.RBC /100WBC 0 0.75-2.4
*Direct blood film：microfilariae(-)
TABLE 2. Serum Chemistry
TEST/DATE 12/14 REFERENCE VALUES
AST U/L 25.8 0-40
ALT U/L 31.1 4-66
LDH U/L 234 <100
CK U/L 184 8-60
ALP U/L 45 0-85
Glucose mg/dl 93 71-115
BUN mg/dl 11.7 5-28
Ceatinine mg/dl 1.1 1-2
T.protein g/dl 9.1 5.3-7.8
Sodium mmol/L 142 141-155
Potassium mmol/L 4.6 3.6-5.6
A/G 0.15 0.6-1.1
Alb g/dl 1.2 2.3-3.9
TABLE 3. Urinalysis
TEST/DATE 12/14 REFERENCE VALUES
Sp.Gr. 1.015 1.015-1.025
PH 8.5 5-7
Protein >300 5-20
Glucose 0.25 －
Ketone ＋ －
Bilirubin ＋
Blood ＋＋＋ －
Urobilinogen 1 0.1
（Ehrlich unit/dl）
Nit ＋ －
W.B.C. ＋＋
Sediment.（HPF）
R.B.C. ＋ －
W.B.C. ＋＋＋＋
Cast. G＋
Cryst. ＋
Sperm. ＋
Bacteria ＋
Copy from http://www.vm.nchu.edu.tw/cc/vmcc/seminar/84-2/34a.htm