Health Issues
Portosystemic Shunts
CEPS/Veterinary Extension
2938 Vet. Med. Basic Sciences Bldg.
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Joseph Hahn
Information Specialist
University of Illinois
College of Veterinary Medicine
In railroad tracks and electrical circuits, shunts are useful things, allowing train cars or the flow of current to be diverted from one pathway to another. But a portosystemic shunt, which allows blood to flow abnormally around instead of to the liver, is a serious health problem in pets. Both dogs and cats can have portosystemic shunts, although it is much more common in dogs.
Normally, the blood carries toxins and toxic by-products of metabolism from the stomach and intestines to the liver, where the toxins are removed. "In animals with portosystemic shunts, the blood bypasses the liver and is diverted to another blood vessel, allowing toxins to circulate through the body," says Dr. Jennifer Brinson, a veterinarian who specializes in internal medicine at the University of Illinois College of Veterinary Medicine Teaching Hospital in Urbana.
Shunts can be either congenital--a condition the animal was born with--or acquired--a condition that developed later in life. Congenital shunts are generally diagnosed in animals less than one year old. Acquired shunts can occur at any age and are often caused by liver disease. Shunts are also categorized as intrahepatic (within the liver) or extrahepatic (outside the liver).
"Congenital shunts are most commonly seen in small breed dogs, such as Yorkshire terriers or toy poodles. These dogs generally get single, extrahepatic shunts," says Dr. Brinson. "This disease can also affect large breed dogs. Unfortunately, larger dogs typically get intrahepatic shunts, which are much more difficult to treat."
Dogs with congenital shunts tend to be small for their age and breed. Other signs of shunts include excessive drinking, frequent urination, and a condition known as hepatic encephalopathy. This condition arises shortly after eating and may appear as depression, muscular incoordination, coma, and seizures--signs caused by ammonia (a by-product of protein digestion) reaching the brain instead of being cleared by the liver.
Diagnosis of a suspected portosystemic shunt is often done in three stages. The first stage is checking a blood and urine sample. If these samples are suggestive of a shunt, second stage tests, consisting of a pre- and post-bile acid test and an ammonia challenge test, are performed. These two tests help determine the functional capacity of the liver. Finally, an ultrasound or nuclear scan may be used to try to locate and determine the extent of the shunt.
Treatment and prognosis of shunts depend on their location and severity. "A congenital, single, extrahepatic shunt that is caught early is a good candidate for surgery," says Dr. Brinson. "Intrahepatic shunts commonly must be treated medically."
The medical treatment for portosystemic shunts is aimed at reducing the amount of ammonia circulating in the body and decreasing the symptoms. A low-protein diet and lactulose to reduce absorption of ammonia are prescribed. In emergency cases, enemas with water or lactulose are used to reduce ammonia absorption immediately. If portosystemic shunts go untreated, the symptoms will get progressively worse and eventually the pet may die.
If you would like further information, contact your local veterinarian.
Canine Hypothyroidism
CEPS/Veterinary Extension
2938 Vet. Med. Basic Sciences Bldg.
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Joseph Hahn
Information Specialist
University of Illinois
College of Veterinary Medicine
All mammals have a thyroid gland. It is located in the neck and constantly produces thyroid hormone which speeds up metabolism. Hypothyroidism occurs when the gland stops functioning and producing thyroid hormone. It is one of the most common hormonal diseases.
"Hypothyroidism usually happens for unknown reasons," says Dr. Leslie Henshaw, a dermatology resident and veterinarian at the University of Illinois College of Veterinary Medicine Teaching Hospital at Urbana. "Most of the other cases are caused by a destruction of the thyroid gland by the immune system."
This disease usually affects middle-aged dogs and while it is seen frequently in Golden Retrievers, Irish Setters, and Dobermans, it can manifest in any breed.
"The first symptom that is usually seen is hair loss," remarks Dr. Henshaw. "It is usually not associated with other skin problems." Other symptoms may include weight gain, muscle loss, lethargy, and a tendency to seek heat (especially in winter). Pet owners usually attribute many of these symptoms to the pet's aging process.
"This is not a life-threatening disease," says Dr. Henshaw. "If it is left untreated however, the lethargy will get worse, the dog may experience a mental dullness, and the heart rate can slow."
"The symptoms with hypothyroidism are usually subtle at first," she observes. "It is a gradual process which takes months to one year to develop."
Diagnosis of this disease is done by a series of blood tests. These tests are fairly common and can be conducted by your veterinarian.
While hypothyroidism is not a curable disease, notes Dr. Henshaw, it is very treatable. "The treatment consists of oral supplementation of the thyroid hormone on a daily basis. It is very safe, life-long, and relatively inexpensive. Treatment often rejuvenates a dog." Many dog owners are familiar with hypothyroidism because it is a disease which also occurs in people. Although there are many similarities, owners of hypothyroid dogs should follow the advice of their veterinarian, as the dosage of thyroid hormone supplementation is very different for dogs..
Dr. Henshaw remarked that hypothyroidism can complicate other skin diseases and, if left untreated, will affect the quality of life. Once diagnosed, there are virtually no side effects from the drug therapy and there is very little monitoring needed. Once the hypothyroidism is controlled with drug therapy, a dog will no longer be predisposed to other disease conditions. Dog owners are often pleasantly surprised that their "old dog" is acting "younger."
If you would like further information or would like to have your dog tested for hypothyroidism, contact your local veterinarian.
Renal Failure
Veterinary Extension
2938 Vet. Med. Basic Sciences Bldg.
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Joseph Hahn
Information Specialist
University of Illinois
College of Veterinary Medicine
What purpose do kidneys serve? Your pet's kidneys clear the blood of toxins and conserve water at times when an animal isn't drinking as much as it should. When the kidneys deteriorate (chronic renal failure), it can lead to serious health problems for your pet.
"Chronic renal failure is a slow deterioration of the kidneys resulting from a variety of inherited or acquired disorders," says Dr. Donald Krawiec, a veterinarian specializing in urology and chief of small animal medicine at the University of Illinois Veterinary Medicine Teaching Hospital at Urbana. "It occurs in middle-aged to older cats and dogs."
He explains that "the signs are so vague that they could mimic almost any other condition." These signs include excessive drinking or urination, weight loss, loss of appetite, vomiting, or general signs of not feeling well.
"There is still a lot we don't know about chronic renal failure," remarked Dr. Krawiec. "Most of the toxins that are cleared from the blood by the kidney tend to be products of protein metabolism. Therefore, we reduce the amount of protein in the diet to help alleviate this problem. We also know that animals in renal failure have a hard time regulating phosphorus and that plays a role in the progression of the disease. Finally, we know that in humans hypertension (high blood pressure) plays a role in the disease so in animals we tend to reduce salt in the diet as well."
The main treatment for renal failure is dietary. Protein, phosphorous and salt are reduced in the diet to help slow the progression of the disease. Your veterinarian can recommend an appropriate diet, most of which are commercially produced and readily available. The diet is also supplemented with water soluble vitamins. If necessary, the animal is treated for anemia if the condition is present.
Renal failure is usually first diagnosed with a blood test and urine sample and later with the help of radiography. Monitoring for mild renal failure is not rigorous. At first, animals will need to be seen monthly until the rate of the renal failure is determined. Once this is determined, most animals require only once- or twice-a-year visits.
"The progression of this disease is highly variable," explains Dr. Krawiec. "Renal failure will progress rapidly in some animals and slowly in others. Cats will tend to progress more slowly than dogs."
"As with people, the cause with chronic renal failure in dogs and cats is currently unknown," he says. "It is important to be observant with your dog and communicate any unusual changes or behaviors with your veterinarian. The changes may be subtle but it helps if it can be identified before the animal is overtly ill."
If you would like further information on chronic renal failure, contact your local veterinarian.
Genetics Of The Yorkshire Terrier
Blue Born & Red/Chocolate Born Puppies
The blue born puppies & red/chocolate born puppies are recessive colors being passed to the progeny. Puppies of these colors should not be sold as “rare colors”. Yes hopefully it is very rare to get them, Do not be misled by unscrupulous breeders about these dogs. The blue born puppies & red/chocolate born puppies should be spayed and neutered as soon as possible and should not be bred.
The Yorkshire Terrier is genetically a Black/Tan (B/T) dog that turns blue later in life. The blue color is created at another loci by the GG or Gg genes. Whenever you have a dog born one color that turns blue later in life, it is the GG or Gg genes that cause this to happen.
When a dog is born blue it is different genes that effects that then the GG genes. The dd gene is what causes this at birth and the Yorkshire Terrier should only be carrying the DD. A blue born puppy will also have self colored pigment, such as blue nose. The DD gene is what allows them to be born Black/Tan. The upper case always means dominant and the lower case always means recessive. This is obviously a deep buried recessive that the animals are carrying that they have passed onto the resulting puppies. The breeds that are born blue are born with the dd gene, but in Yorkshire Terriers this should not be the situation to cause the blue coloring.
Unfortunately with blue born puppies the situation is usually fatal. Very few live beyond the 1st few days. The ones that do survive almost always at the time they would normally break blue, lose all their blue body coat and get a very leathery skin that is like an elephant hide and causes the dog to be in extreme pain.
The red or chocolate born are affected by the bb genes. The red or chocolate born, referred to as liver in some breeds will also have self colored pigment, such as red, chocolate or liver nose. The Yorkshire Terrier should only be carrying the dominant BB genes. I have not heard of health problems with the red/chocolate born puppies. I have only heard about the health issues of the blue born puppies. Once again this is a recessive being passed on to the puppies from the parents.
