By Dr Larry van Niekerk
Q We adopted Taffy, a YorkshireTerrier x Schnauzer, at seven weeks of age from Kitty and Puppy Haven. From the time we got him he was plagued by what was then diagnosed as continuous bladder infections. Only when we had him neutered at seven months did alarm bells go off with me. His recovery rate was slow and he took at least four days to get back on his feet. I went from pillar to post trying to get veterinarians to get to the bottom of what was ailing my Taffy.
The breakthrough came on 26 May 2012 when once again my dog was unresponsive, running a high fever and we were doing the midnight run to the vet. Coincidently, the vet on duty administered valium, putting Taffy at death’s door. The following day I set off for a good 40-minute drive at break-neck speed to a vet and friend I trusted. After performing a sonar scan and running a few tests, they understood what was wrong. Within three days he was home, but with an impending operation on his bladder as he had stones (he had stopped urinating on his own) – at this stage we didn’t know what kind they were and how serious his condition was. He recovered well after the bladder operation but had a small setback in October last year when he passed a stone. In May this year he developed a bladder infection and was put on Lactulose permanently as well as a course of Flagyl.
Although Taffy has been diagnosed with an Extra-Hepatic Portosystemic Shunt, we have had no side effects such as the circling, head banging or staring into corners. He did suffer from wakefulness, although this seemed to almost disappear after his operation and he was put on Flagyl and Lactulose. I feel that the Flagyl should be permanent treatment – which it was when in Johannesburg. Since moving to Cape Town, however, our new vet is hesitant to prescribe it. I know there are side effects, but in my opinion the side effects of his condition are far worse without the Flagyl. I do feel that different dogs may react differently to the treatment. How do I get my vet to understand that I feel the medication works for my dog? Or is my dog responding to the Flagyl all in my mind?
Taffy is a good-natured and otherwise healthy dog with a zest for life. I really don’t want his candle to be snuffed out too early, yet I still want to do the best for him. My only wish is that I can help him as much as humanly possible to live a pain-free and happy life.
Francee Mateus – Bloubergstrand, Cape Town
A Taffy certainly fits the breed profile (being a Yorkshire Terrier) for extrahepatic liver shunts in dogs. It also occurs in Miniature Schnauzers, Poodles, Lhasa Apsos and Pekingese. Some cases are presented with urinary problems such as blood in the urine and struggling to urinate due to specific crystals that form in the urine, called urate crystals. Portosystemic liver shunts should always be suspected in any young animal with a prolonged response to anaesthetics or tranquillisers that need to be broken down by the liver, such as phenothiazine tranquillisers and diazepam (Valium). Because the liver is smaller and not filtering toxins or drugs, the effects of any drug is exacerbated. The bladder operation, or cystotomy, would be to remove the urate crystals but would not prevent them from reforming as the primary problem is the portosystemic liver shunt. Conservative or medical management is aimed at decreasing the amount of toxins absorbed from the intestine, using antibiotics that decrease the bacteria that produce ammonia, and with changes to his diet. Understand that this conservative management will be lifelong, unless something surgical is done about closing the shunt.
Q How many bladder operations can he have before one needs to draw theline and weigh up other options?
A The urate crystals will still reform after surgery to remove them, although there are specific veterinary diets to help prevent the crystals from forming.
Q When would we need to consider closing the shunt and what are his chances of surviving it?
A The life expectancy of animals that are managed medically is reported to be between two months to two years. However, the older the dog is when it’s presented, the better it responds to medical management. Restoring the correct blood flow from the intestines through the liver, although not without risk, is the best solution. In this case, provided the shunt is extrahepatic and can be well identified, an ameroid ring applied surgically by a specialist surgeon will slowly close the shunt and allow the liver to regenerate, recover, and direct the blood from the intestine through the liver before being released into the general bloodstream.
What is a Portosystemic Shunt?
Many things happen at birth. One of them is the sudden independence from the mother and the edirection of blood flow in the liver. In the uterus, the mother filters the baby’s blood via the placenta to protect it from toxins. Since nutrition is not passing through the puppy’s intestines in the uterus, there is no need for the blood to be diverted from the intestines through the liver and it is sent straight to the heart. After birth the large blood vessel diverting blood around the liver quickly shuts down, forcing the blood supply back
through the liver. In some animals, however, the vessels do not close and blood continues to bypass the liver. This is known as a congenital portosystemic shunt. These diversions can occur outside the liver (extrahepatic) or inside the liver (intrahepatic). About 60% are single vessels outside the liver and can be surgically corrected if identifiable.
What signs will my dog show if it has a shunt?
Signs can show from a few weeks of age, as the animal starts to eat solid foods. Patients are usually the runts of the litter. Breeds having extrahepatic shunts are small Terriers, particularly Yorkshire Terriers. Other breeds affected are Poodles, Lhasa Apsos and Pekingese. Intrahepatic shunts are more common in larger breeds such as German Shepherds, Golden Retrievers, Doberman Pinschers, Labrador Retrievers, Samoyeds and Irish Wolf Hounds. The patient now no longer has the liver filtering toxins from the intestine and signs start to show as gastrointestinal, urinary tract infections and crystal formation, to nervous signs. Gastrointestinal (stomach and intestinal) symptoms may include:
• Lack of appetite (inappetence; anorexia)
• Excessive appetite (excessive ingestion of food; polyphagia)
• Pica (craving for unnatural materials or articles of food; often involves ingestion of faeces) In the urinary tract, signs may include:
• Blood in the urine (haematuria)
• Difficulty urinating (dysuria)
• Abnormally frequent urination (pollakiuria)
• Abnormally large volume of urine (polyuria)
• Abnormally large intake of water (polydipsia)
• Enlarged kidneys (bilaterally)
• Kidney and/or bladder crystals or stones (ammonium urate or biurate uroliths)
Other assorted signs of a shunt may include:
• Stunted growth (common)
• Itchy skin (pruritus, often intense)
• Slow recovery from anaesthesia or tranquillisers
• Poor/unkempt hair coat
The signs are very varied and may be extremely difficult to recognise in some animals. Since the signs are so different, it is often hard to put them all together and identify them as a single illness. Most animals visit the vet many times before the pieces of the puzzle are put together. Tell-tale signs to watch out for include –
• Repeated bacterial infections at a young age, especially urinary tract infections
• Excessive drinking and urination
• Taking several days to recover after the first anaesthetic administered for neutering
What tests might my vet do?
Once a shunt is suspected, your vet will test the liver’s function by taking a before- and after-meal blood sample. Your vet might also conduct contrast studies. Diagnosing a shunt with ultrasound needs an experienced ultrasonographer.
What treatments are there and are they successful?
Logically, the best treatment would be to close off the diversion of blood so that it filters via the liver. An ameroid ring, which closes over time, gives the liver a chance to readjust to the blood flow. But making the diagnosis and surgically identifying the vessel, presuming it is outside the liver, is not always so easy. Patients are often stunted and weakened and the liver might be small and unable to handle a sudden
diversion through it. Complications around the time of surgery are common and these cases are best handled at specialist referral centres with diagnostic ability, surgical expertise and good patient aftercare to ensure survival. Most surgical cases where the shunt can be partially or fully closed improve well, with the liver even regenerating and the animal leading a longer and healthier life. Medical management is used to stabilise patients before surgery and manage those that are not suitable surgical candidates. This is aimed at feeding low protein (but high quality) diets to minimise the production of toxins in the gut before they reach the bloodstream. Antibiotics and lactulose are administered to decrease the number of bacteria in the intestine that produce toxins. In summary, some animals – just like humans – are born with congenital conditions, which, just like us, can with veterinary care be given the chance of a full and healthy life. Consult your veterinarian and assist by providing a detailed history, in the understanding that not all diagnoses are simple.