Portosystemic shunt is a canine disease. Our four-legged friends can inherit or contract this dangerous disease, which can still be cured if diagnosed in time.
Intra and extrahepatic portosystemic shunt is a serious congenital or acquired disease that affects both dogs and cats. In animals with portosystemic shunt, whose acronym is PSS, poor blood flow occurs in the liver. The blood should follow a path through the digestive tract to get to the liver through the portal vein, to then end its journey into the vena cava, the large blood vessel that carries blood back to the heart.
In a portosystemic shunt, the blood flow does not reach the liver, but goes directly to the venous circulation system, via the vena cava.
Failure to pass into the liver has serious consequences, as toxins are not eliminated from the blood, many of which are by-products of the proteins used for digestion. Failing this "cleansing" of the blood, these toxins circulate freely in the body, causing clinical symptoms, many of which are neurological.
The complex of neurological diseases and behavioral signs generated by this liver disease is called hepatic encephalopathy.
The portosystemic shunt can either be acquired due to the onset of a disease, or it can be congenital, meaning the animal was born with the shunt.
The congenital variant of this disease generally manifests as a single large abnormal vessel, which is a remnant of normal embryonic development. This type of shunt is defined as intra-hepatic or extra-hepatic dysfunction in relation to the position of the blood vessels relative to the liver. Most dogs with congenital portosystemic shunt show clinical signs as early as the first months of life. How portosystemic shunt is inherited is still the subject of study and analysis, so at the moment it is not known how it is transmitted from parents to children.
Many veterinarians agree that there are some breeds that are particularly at risk of portosystemic shunt: most of them are small breeds, especially the Yorkshire terrier, Miniature schnauzer, Cairn terriers and Maltese.
PSS Intra hepatic: large and giant breeds, especially the Irish wolfhound and, less frequently, the Australian cattle dogs, the Golden retrievers and the Labrador retrievers. However, there are some signals that can be interpreted by the owner: the symptoms are generally connected with the central nervous system, the gastrointestinal tract, or the urinary tract. These signs can be quite inaccurate and can involve loss of appetite, depression, lethargy, weakness, lack of balance, disorientation, blindness, fits, vomiting, diarrhea and coma. These symptoms can worsen, subside, or worsen over a short period of time. It should be emphasized that the failure of the liver to eliminate ammonia leads to increased urinary excretion with consequent injury to the kidney, bladder or urethral due to stones due to accumulation.
Generally the diagnosis of congenital PSS is based on history, clinical and laboratory symptoms. generally a dog with PSS is young, of a breed with a predisposition for this disease, with clinical signs and laboratory tests relating to hepatic dysfunction. The best way for a veterinarian to ascertain the presence of PSS is by contrast radiography. With congenital PSS, a large amount of the contrast fluid goes directly into the vena cava, the large vessel in the venous circulation that carries blood to the heart. Contrast radiography facilitates assessment of the success of correcting the shunt surgically. Contrast radiography also serves to identify whether the shunt is intra or extra-hepatic.
Surgical occlusion of the shunt can be either partial or complete. An intrahepatic shunt is usually technically more complex to correct than an extrahepatic one. Your veterinarian may recommend that your dog be taken to a specialist center, in order to guarantee him a better procedure carried out by an experienced surgeon and a close post-operative monitoring, with which it is verified that there are no symptoms of hypertension.
The latter can occur twenty-four hours after surgery, due to increased blood flow to the liver once blood is no longer forced through the shunt. With a single extra-hepatic shunt, there are comfortable chances of a very good prognosis for a normal life for the dog after surgery. Dogs that have presented an intra-hepatic shunt may still have some biochemical abnormalities even after surgery, but clinically they show many improvements.
Everyone agrees that individuals with PSS and their parents should not be used for breeding: if affected puppies were to be born, parent rearing should be stopped.
As with all diseases, both prevention and understanding the symptoms of the disease are important. There is no need to be alarmed if one day we see our dog a little down or with stomach problems, but observing him and asking your trusted veterinarian for advice is certainly the best attitude.