Health Problems 843-615-0117
What is RD
Although renal dysphasia is clearly inherited, the genetic nature of this disease does not follow a classical Mendelian pattern. It is not sex-linked. Rob Loechel, who has been studying the disease at the University of Michigan and VetGen, believes that the disease is probably caused by two defective genes, both of which must be present to have an affected animal. This finding explains many of the mysteries of RD. Imagine that RD is a door with two locks, the regular door lock and a dead-bolt lock. In order to open the door you will need two keys. But you need the right two keys. Two door keys or two dead-bolt keys will not do. If you mate a dog with RD1 to a bitch with RD1, the puppies will have normal kidneys. If your dogs are highly lime bred, and therefore highly homozygous for RD1, you will not have a problem until you out-cross to a line which carries RD2. This would explain how a breeder can go along with healthy dogs for many years and suddenly have a whole litter with renal dysphasia. It would also explain the rare case in which two dogs that were biopsied clear have produced affected puppies. Eliminating only one of these defective genes through genetic testing could eliminate the disease, which is why your support of the research project discussed later in this flier is so important.
Testing
There are several traditional tests for kidney function, although only one of them will specifically determine whether abnormal kidney function is due to renal dysphasia.
BUN and Creatinine are two common blood tests of renal function. They are not elevated until 70-75% of the kidney is nonfunctioning and are therefore of little use in identifying mildly or moderately affected dogs. The BUN measures the blood-urea-nitrogen in the blood. When the kidney is not doing its job of removing these waste products from the blood they begin to build up in the bloodstream. The BUN test will then show an elevation of these waste products. The BUN can be elevated for other reasons which your veterinarian can explain. The creatinine test is a somewhat more accurate measure of renal function. This is because creatinine is not used by the body and all of it is excreted in the urine. By measuring the amount left in the blood, the filtration rate of the kidneys can be judged. The BUN and creatinine tests can be done from the same blood sample. Having a BUN and creatinine in the normal range means that the dog has at least 30% kidney function. It does not mean that the dog is free of renal dysphasia. Nor does an elevated BUN and creatinine mean that the dog necessarily has renal dysphasia, as such readings can be caused by other renal problems. Nevertheless, these tests can be of some use in identifying severely affected dogs, particularly puppies already drinking and urinating excessively.
Urine Specific Gravity can be measured by your veterinarian with an instrument called a refractometer. Only a couple of drops of urine are needed. Urine can be picked up from newspapers or floor with a syringe. Water has a specific gravity or weight of 1.000; normal dog urine has a specific gravity from 1.018 to 1.060. When a dog’s kidneys are failing they usually produce a very dilute urine with a specific gravity of 1.010 to 1.020. (Note that these numbers will differ in countries where tests are based on the metric system. Ask your veterinarian to provide normal ranges.) Most veterinarians will tell you that all readings of urine specific gravity ranging from 1.018 to 1.060 are absolutely normal. The ASTC Renal Dysphasia Committee has found that most adult Shih Tzu with normal kidneys usually have a specific gravity above 1.045. Again, the specific gravity of urine tells you about kidney function. It does not tell you that your dog is free of renal dysphasia
Examination of the kidney again will not tell you whether or not your dog has renal dysphasia, but it will help to identify many moderately affected dogs with normal BUN, creatinine, and urine specific gravity readings and no clinical signs of the disease. In severely and some moderately affected dogs, an
ultrasound may show scarring, smaller than normal kidneys that may be irregular in shape, and defects in the collecting ducts in the renal pelvis. An ultrasound-guided biopsy, which will help to ensure that the tissue is extracted from the most severely affected part of the kidney, is suggested if the ultrasound examination indicates that the kidneys are abnormal in ways associated with renal dysphasia. The ultrasound examination itself will not show the fetal glomeruli that provide definitive proof of renal dysphasia. Slightly affected dogs are likely to appear normal upon ultrasound examination.
X-rays to determine the size of the kidneys may be helpful. If both kidneys are markedly reduced in size, a presumptive diagnosis of dysphasia can be made. The size of affected kidneys will range from a reduction of 20% of normal to tiny, shrunken kidneys. Again, this is not a definitive diagnosis, particularly in older dogs that may have old-age kidney problems.
Biopsy of the kidney involves the surgical removal of a wedge-shaped section of kidney. A needle (trucut) biopsy does not supply enough tissue for diagnosis of renal dysphasia and therefore is of no value. There have been no known complications for the dog due to the wedge biopsy procedure, although there is a risk as there is with any surgery and anesthesia. Anesthetic should not be given to a dog with an elevated BUN, as such a dog is a surgical risk. The kidney biopsy is the most accurate method to date of determining if a dog has or does not have renal dysphasia. In a few cases a Shih Tzu will be so mildly affected that even a kidney biopsy will show no signs of the disease. The collection of the specimen of kidney tissue for microscopic examination can be performed by an experienced pathologist familiar with this disease.
It is recommended that the tissue be sent for examination to Dr. Michael Goldschmidt, University of Pennsylvania School of Veterinary Medicine, Department of Pathology, 3800 Spruce St., Philadelphia, PA 19104 (Phone 215-898-8857), preferably with a pedigree to aid in research on the mode of inheritance of this disease. Your local veterinarian should call to discuss methods of collection and preservation of kidney specimens. Breeders can also submit kidneys from puppies that die mysteriously at a young age, but DO NOT send kidneys of puppies less than eight weeks old because their kidneys are not sufficiently developed to identify the disease.
The kidneys must be collected from the animal immediately after death and placed in 10% formalin solution; freezing destroys the tissue and precludes a diagnosis. We also recommend that the kidneys of adult Shih Tzu that die for any reason be sent to Dr. Goldschmidt, even though the presence of other forms of kidney disease in older animals may at times preclude a definitive diagnosis. To aid in current research to locate a genetic marker for the disease, individuals willing to provide DNA samples from young dogs diagnosed as having renal dysphasia, or dogs over the age of 13 with normal urine specific gravity readings, should contact JoAnn Gustafson of the ASTC Gene-Mapping Committee at 7265 F & S Grade Rd., Sedro Wooley, WA 98284-9664 (e-mail ningsia@ncia.com) for cheek swabs (you can take the samples yourself) and instructions for sending the samples to VetGen. The identities of the
dogs will remain strictly confidential.
New Linked Marker Genetic Test for Renal Dysphasia in Shih Tzu, Lhasa
Apsos, and Soft Coated Wheaten Terriers
VetGen announced in February 1999 that it had just developed a linked marker DNA test for one of the defective genes believed to be involved in renal dysphasia in three breeds in which the disease is believed to be genetically identical. This test is noninvasive and the sample does not have to be collected by your veterinarian. By using this test and breeding dogs that only test clear of this marker, you can reduce the likelihood of producing Shih Tzu with renal dysphasia by about 80%. It is strongly recommended that all breeding stock be tested using this new test. It detects carriers as well as affected dogs and can be used on young dogs before they begin their show careers or are included in your breeding program, which makes it much better than anything we have had up to this time.
We now have a second test used to find markers time will tell how well it does.
Meanwhile, research continues to identify the defective gene itself (which would make the test 100% accurate), to determine whether this gene is dominant or recessive, and to find whether or not a second defective gene is involved in this disease.
Conclusions
Every dog used for breeding should be tested for urine specific gravity and urine concentration. If specific gravity is above 1.045 (or the metric equivalent) you can skip the other tests and go right to the biopsy. If specific gravity is low then do BUN and creatinine tests. If these are elevated you may not want to risk anesthetic and the biopsy. Do as your vet advises. If urine and blood tests are normal and you are unwilling to do a biopsy, you may be able to detect the presence of the disease with ultrasound, although a normal ultrasound will not prove that your dog does not have renal dysphasia. While a biopsy may occasionally indicate that a slightly affected dog is normal or fail to pick up a normal carrier, there are no false positives. If a wide wedge biopsy indicates that the dog is affected, it is likely to pass the disease along to some or all of its offspring in varying degrees and should not be bred.
ASTC Gene-Mapping Project
The ASTC is funding research into renal dysphasia that has already led to the first noninvasive test for a genetic marker strongly linked to the disease. This research is being done at the University of Michigan and VetGen. Donations to the ASTC Gene-Mapping Fund should be sent to ASTC Treasurer, 38506 Highway 58, Dexter, OR 97431. The Official Book of the Shih Tzu is a major source of funding for this research. Send orders ($35.95 each, checks payable to ASTC) to Janet Danner, 5104 Stratford Chase Dr., Virginia Beach, VA 23464-5518. Check our elsewhere on our website for other ways you can help with gene-mapping fundraising and to learn more about gene-mapping research.
Our thanks to Dr. Bovee, Rob Loechel, and the ASTC Renal Dysphasia Committee for providing information used to prepare this material. We hope that you will find it useful.
Portosystemic Vascular Anomalies
{ liver problems }
{ liver problems }
We will abbreviate this to PSVA. This is a developmental birth defect resulting in the diversion of blood that would normally circulate to the liver. What John Fondacaro, D.M.V., a researcher in PSVA states " A normal blood supply to the liver maintains body metabolism, synthesizes proteins and sugars, manufactures enzymes and removes blood-borne waste products and toxins from the system. When some of the blood supply is shunted away from the liver, the liver cannot function properly, resulting in an animal that may be stunted, thin depressed and especially after eating, exhibits bizarre behaviors, such as staring into space, standing in a corner, head pressing, pacing, staggering, blindness, deafness,, tremors or seizures." these clinical signs usually show up before 1 year of age, and as early as a few months of age.
PSVA has three variations:
Portal Systemic Shunt
{ PSS }
{ PSS }
This is an abnormally formed vessel or a condition in which the embryonic vessels feeding the liver fail to close at birth, so the blood shunts around the liver instead of to the liver. This type of Shunt according to Dr. Fondacaro impedes the liver's ability to detoxify waste products. The shunt can be found either inside the liver {intrahepatic} or outside the liver {extrahepatic}. The extrahepatic shunts are seen more in small dogs.
Micro-vascular Dysplasia
{MD}
{MD}
This is similar to a PSS, except instead of having a big, single abnormal vessel, hundreds to millions of abnormal microscopic shunting vessels exist.
Hepatic Arteriovenus Fistulas
{HAF}
{HAF}
This is also a birth defect in which an abnormal vessel link forms directly between an artery and a vein. You see capillaries exist between the artery and a vein, with HAF the blood flows directly out of the organ without performing its function. jacquelinebales@bellsouth.net
HAF and PSS may be partially or wholly surgically corrected by ligating or binging, the shunting vessel and forcing the blood into the liver.
MD has no surgical intervention.
What's to do?
The above Liver dysfunction's can only be diagnosed by a Veterinarian. This page is just for a small amount of information that you may fine helpful.
Although the Genetics of PSVA are unknown, Dr. Fondacaro notes that " because it is a congenital disease, it is a more likely that if it occurs in a family, it's likely to occur again if you breed the same pair ". He advises against breeding close relatives: the more inbreeding, the more the likelihood of passing birth defects
This is just an example of what good tests are
Test results on Tu Chu Jail House Rock
AKC Number TP13975302
DNA Number V222708
Micro Chip Avid-016-889-797
Blood/Laboratory Test Results
ALKP/Alkaline Phosphates.
This is an enzyme produced by the biliary tract {liver}. High levels indicate bone disease, liver or bile flow blockage.
Normal Range is 23-212 Elvis-27
BUN/Bloody Urea Nitrogen.
This is produced by the liver and excreted by the kidneys. Decreased levels are seen with low protein diets,
liver insufficiency and the use of anabolic steroid drug. Increased levels indicate any condition that reduces the kidneys ability to filter body fluids or interferes with protein breakdown.
Normal Range is 7-27 Elvis-13.6
Normal Range is 7-27 Elvis-13.6
CA/Calcium-
Blood calcium levels are influences by diet, hormone levels and blood protein levels. Decreased levels indicate acute damage to the pancreas or under active parathyroid. Muscle twitched may occur in decreased level. Increased levels can be an indicator of certain types of tumors, parathyroid kidney disease.
Normal Range is 9.5-12 Elvis-8.99
CREA/Crealine
This is a by-product of muscle metabolism and is excreted by the kidneys. Elevated levels can indicate kidney disease or urinary obstruction, muscle disease, arthritis, hyperthyroidism and diabetes. An increased BUN and a normal creatine suggest and early or mild problem, An increased creatine and increased BUN with elevated Phosphorus indicate a long standing kidney disease.
Normal Range is .50- 1.80 Elvis- .74 jacquelinebales@bellsouth.net
GLU/ Blood Glucose
This is in High Levels can help diagnose diabetes and can indicate stress, excess of the hormone progesterone, an overactive adrenal gland, Low levels can indicate liver disease, tumors or abnormal growth on the pancreas or under active adrenal gland.
Normal Range is 77-125 Elvis-120.7
T4/Thyroid
This is an Autoimmune test and low level thyroid function. They can have Hypo-decreased levels or Hyper increased levels. If and animal is out of normal range an extensive Thyroid study should be done.
Normal Range is <20 Elvis-7
T.P/ Total Protein
Increased indicate dehydration or blood cancer, bone marrow cancer, decreases indicate malnutrition, poor digestion, liver or kidney disease, bleeding or burns.
Normal Range is 5.2-7.2 Elvis-6.9
TBIL Total Billirubin
A component of bile, billirubin is secreted by the liver into the intestinal tract. High levels can lead to jaundice and indicate destruction in the liver and bile duct.
Normal Range is 0.00 to 0.95 Elvis-0.1
Von Willebrands Assey
This is a bleeding disorder problem.
Normal Range is 70-100% Elvis-94%
ALT/ Alanine Aminotransferase
This is an enzyme that becomes elevated with liver disease.
Normal Range 10-100 Elvis 94%
OFA/Orthopedic Foundation For Animals inc.
This is for Hip Dysphasia.
Results can be Severe, Moderate, Fair, Good and Excellent. This was done by Dr Sheri Newell
Results Elvis Good
ENDOCRINOLOGY.
This is a tool we use to measure Thyroid Disease: Elvis results
TT4: - 8 normal: 8-67
TT3 -0.6 normal:1.0-2.5
Free T4 by Dialysis -32 normal: 15-67
Free unbound T3 Ft3 -3.2 normal: 3.2-12.0
T4 autoantibody- 7 normal: <20
T3 autoantibody -0 normal: <10
Thyroid stimulating hormone -20 normal 0-37
Thyroglobulin Autoantibody -126 normal <200
This is a wonderful example of a dog that will not pass on genetic problems to
Puppies.
ACID BILE TEST:
Elevated postprandial bile acids are supportive of hepatobiliary disease. The
Majority of animals with congenital or acquired portosystemic shunting have
Markedly increased postprandial values of >100 umol/L
is 5.5 Normal is 5.0-25.0
Eye problems:
Ocular Disorders Proven Or Suspected To Be Hereditary In The Shih Tzu
By Denise M. Lindley, DVM
The Shih Tzu has several genetic eye diseases. One of the most important diseases in this breed is due to the brachiocephalic skull. Brachiocephalic dogs are those dogs that have shortened noses and very prominent eyes due to shallow orbits. The orbit is the bony socket that surrounds the eye. The shallow bony orbit in the short-nosed dog causes the eyeball itself to be in a more prominent position, giving the appearance of being larger than dogs of similar sizes with longer noses. Along with this skull conformation, there is the problem of lagophthalmos. Lagophthalmos is an inability to properly close the eyelid over the cornea. Lagophthalmic dogs are generally those dogs that have an enlarged palpebral fissure. The palpebral fissure is the space between the upper and lower eyelids. Brachiocephalic dogs classically have all their cornea exposed when the eyes are open and generally they have sclera (the white of the eyeball) exposed also. This conformation causes two clinically serious consequences to the Shih Tzu. The first is they are more prone to exposure keratitus. Keratitus is inflammation of the cornea. In its most severe form, it is ulcerative. A deep ulcer can cause the cornea to rupture. Chronic low grade exposure keratitus leads to central scarring of the cornea and pigmentary changes on the surface of the cornea which can decrease vision. The second big problem related to brachiocephalic skull conformation that the Shih Tzu has, is proptosis. The brachiocephalic breeds of dogs are more pre-disposed to traumatic proptosis of the globe than dogs that have longer noses. When a globe moves forward out of the orbit, as happens with proptosis, the eyelids clamp behind the eyeball itself and cause the venous blood from the eye not to be able to return. This causes a lack of oxygen to the retina and can lead to blindness within minutes. If a Shih Tzu has a proptosed globe it is an emergency! Veterinary care has to be sought immediately (within 20 minutes) in order to attempt to save vision and save the eye.
Other problems found in the Shih Tzu include eyelash disease, which consists basically of two conditions. The first condition is distichiases. These are the eyelashes abnormally located at the eyelid margin which may cause ocular irritation. Distichiasis may occur at any time in the dog's life. The hereditary basis of the condition is not established. Distichiasis can cause severe scarring of the cornea and/or ulcers that could lead to blindness. Second condition is ectopia cilia. Ectopic cilia is like distichiasis in the fact that ectopic cilia are eyelashes that instead of emerging from the eyelid margin, the hairs emerge through the eyelid conjunctiva. They most commonly occur in the upper central eyelid. These are found in younger dogs and can cause significant pain as exhibited by squinting and facial wetness. Like distichiasis, corneal ulcers can occur.
Two conditions that involve the inside of the eye in the Shih Tzu include hereditary cataracts or juvenile cataracts and progressive renal atrophy (PRA). The breeding recommendation for either one of these conditions is NO. This is unlike the breeding recommendation in the previous conditions that were described, where the breeding advice is breeder option. A cataract is a lens opacity which can affect one or both eyes and may involve the lens partially or completely. In cases where cataracts are complete and affect both eyes, blindness results. Progressive retinal atrophy is a degenerative disease of the retinal visual cells which progresses to blindness. Usually seen in the young adult anima, it starts out as night blindness, which progresses slowly to complete blindness. PRA is recessively inherited in most breeds.
Other problems that the Shih Tzu has include dry eye, which is technically called keratoconjunctivitis sicca. Dry eye is dryness of the cornea and the conjunctiva. It is an abnormality of the tear film that most commonly is a deficiency of the water part of the tear film. The mucous and fat layers of the tear film are also affected, but when the water layer is not present the mucous in the fat layer makes very hard, dry, ropy debris which is found on the eyelids. Dry eye leads to chronic corneal irritation and this leads to ulcers or scarring which can cause visual impairment. A less common defect found in the Shih Tzu is retinal detachment. This is due to a vitreoretinal dysplasia. The vitreous is the gel found in the back of the eye, and it is very closely adhered to the retinas. Dysplastic means that it has not developed normally which means that the abnormal interface between the vitreous and the retina can cause the retina to come loose. This causes blindness.
The Canine Eye Registration Foundation (CERF) is most helpful in gathering information about inherited eye disease in the Shih Tzu and other breeds. CERF and the ACVO recommend annual eye exams on all animals. There is no minimum age. So first eye exams can be done as early as five to six weeks of age as these dogs are large enough that the opthalmologist can perform a complete eye examination.
God Bless and have a Happy Puppy
Jacqueline Bales RCPT
