How to Treat Portosystemic Shunts in Yorkshire Terriers
If you've noticed symptoms of portosystemic shunts in your Yorkshire terrier, like excessive drooling and thirst, loss of vision, seizures, vomiting, and diarrhea, take it to your vet for a diagnosis, since portosystemic shunts don't go away on their own and need treatment. Allow your vet to assess your dog's symptoms and take a blood test, which will be sent off to a specialist. They will also prescribe medication to reduce your dog's symptoms. Once you've got your dog's results back, discuss treatment options with your vet, which may include surgery and further medication.
Keep an eye out for the neurological symptoms of PSS. Signs of a PSS take two forms in puppies: neurological signs as a result of toxins acting on the brain and physical symptoms caused by the toxins. Neurological problems cause a variety of issues. The dog may show signs such as drooling or hypersalivation, excessive thirst, seeming disoriented or confused, unsteadiness on the feet (as if drunk), loss of vision, head pressing, seizures, and coma. Typically most dogs show neurological symptoms within 1 - 3 hours of eating, as the levels of toxins peak in the blood at this point. Look for the physical signs of PSS. These usually include stunted growth and poor coat condition. Many dogs also have a poor appetite and are prone to regular episodes of vomiting or diarrhea. The physical symptoms of PSS are similar to the symptoms of a variety of other health problems. However, whatever the cause, if you notice these symptoms in your dog, you should get it checked out by a veterinarian. Some dogs struggle along with waxing and waning symptoms, and the problem becomes gradually worse as the months pass. Pay attention to a slow recovery from anesthetic. Typically, many dogs with PSS are diagnosed after their desexing surgery. This is because they take an abnormally long time to recover from the anesthetic. In fact, they may be unusually sluggish for days afterwards. This is because the liver has not broken down the anesthetic agents as it would in a healthy dog. Understand the disease. PSS begins with a developing fetus in the womb. The fetus is supplied with "clean" blood, via the placenta, that meets all the puppy's needs. The fetus has no need to "detox" placental blood, and so their circulatory system has a specific blood vessel, or shunt, that bypasses the detox center of their liver. All canine fetuses have this shunting blood vessel, but it normally closes within a few days of birth in healthy puppies. However, if the shunt fails to close down after birth, and persists in its activity of bypassing the liver, this can lead to health problems. This is because the process of digestion and the workings of the body produce natural toxins that are potentially poisonous to the dog and affect the brain. This is where the liver comes in, as one of its function is to be major waste-recycling center that deactivates those toxins into something that is safe in the circulation. When a shunt persists, this toxic blood bypasses the liver and remains in circulation, causing the symptoms associated with a PSS. Take your dog to a veterinarian. Although you may not be certain that your Yorkie puppy has PSS, the symptoms you are witnessing should be enough to get the dog looked at. Any dog that is having severe digestive and mental problems, such as those connected to PSS, should get a thorough check by a vet. Keep track of the puppy's symptoms so that you can tell the vet what is going on. Be sure to document when and how often each occurs. Talk to the vet about what type of screening is necessary. Your vet may have a suspicion based on the pattern and timing of the dog's symptoms. However, the diagnostic path is a long one that starts with blood screening. This helps eliminate other causes of illness. A specific blood test looking at liver function is run, which is not specific to PSS but can confirm that there is an issue with the liver so the diagnosis should be pursued. Another test that can point towards a PSS is a raised level of ammonia in the blood stream. This is the main toxin resulting from digestion that causes neurological symptoms. However, a raised blood ammonia amplifies the suspicion of a PSS but is not sufficient evidence to reach a conclusive diagnosis. Discuss the need for specialist expertise. A definitive diagnosis is made by visualizing the shunt itself. This can be done by a skilled ultrasonographer ,who can identify the extra blood vessel and the blood flowing through it. Referral to a specialist center may be necessary to access this level of expertise. Other imaging options include a CT-scan, after an intravenous contrast agent is given, or nuclear scintigraphy. Both of these methods produce a physical picture of the blood circulation to the liver and the bypassing blood vessel. Get the dog stabilized. For most cases, surgically closing the PSS is the ideal solution. However, the patient must first be stabilized in order to reduce the anesthetic risk. This is done using a combination of feeding a high-quality protein, but in reduced quantities, along with dosing with lactulose and an antibiotic called metronidazole. Stabilizing the dog is also appropriate if surgery is not possible for any reason. Discuss treatment options with your veterinarian. Once PSS has been diagnosed, you will have some decisions to make about how you would like to proceed with treatment. This decision is usually based on a combination of what is best for the dog's condition, what treatments the dog can physically take, and what your financial situation is. Consider medical management instead of surgery. This includes using the drugs used for stabilization, lactulose and metronidazole. Treatment is continued permanently, or until surgical correction is undertaken. Dogs that are managed medically for the duration of their life, can go on to lead normal lives, but may not live as long as unaffected animals. The rationale behind this therapy is that it is the products of protein breakdown that produce the most toxins. Therefore, feeding the minimum requirement reduces the loading on the system. Likewise, a toxic metabolite, called ammonia, is produced by the action of bacteria in the bowel. Metronidazole reduces this population of bacteria, leading to less ammonia production, while lactulose encourages food to pass through the bowel so that less ammonia is absorbed. Decide whether to go forward with surgery. Surgical correction of the shunt is preferred, as it is a more permanent solution. However, this is a technically demanding procedure, usually undertaken by a specialist. It involves a general anesthetic and a laparotomy (surgically entering the abdomen) to identify the PSS itself. The shunt is then closed down. The chosen technique for closing the shunt is largely a matter of personal preference by the surgeon. Options include using suture material to tie off the vessel, instilling a special 'glue' that swells to block the shunt, instilling a coil that has a similar effect, or placing a cellophane band around the blood vessel which gradually swells and slowly occludes the shunt. Continue to monitor your dog's condition. Not all surgeries are 100% successful and sometimes repeat surgery is necessary. Also, the vet may wish to monitor the patient's progress by repeating the liver function tests to check that the body is responding appropriately. This testing helps guide the clinician when it comes to deciding if the dog can transition into a normal adult maintenance food or if it needs to remain on a low protein diet. 
Keep an eye out for the neurological symptoms of PSS. Look for the physical signs of PSS. Pay attention to a slow recovery from anesthetic. Understand the disease. Take your dog to a veterinarian. Talk to the vet about what type of screening is necessary. Discuss the need for specialist expertise. Get the dog stabilized. Discuss treatment options with your veterinarian. Consider medical management instead of surgery. Decide whether to go forward with surgery. Continue to monitor your dog's condition. 