Last week’s webinar led by Professor Mike Willard made it abundantly clear that cats and dogs with biliary tract abnormalities will not be handing their diagnosis to the often frustrated vet on a plate. Instead, they like to make it as challenging as possible often presenting with vague clinical signs whilst delivering several red herrings along the way which could easily lead most vets up the proverbial garden path. Professor Willard not only offered these warnings in last week’s webinar, he also advised on how to spot the pitfalls which could so easily send vets in the wrong direction and how to get back on the right track to a correct diagnosis.

Professor Willard delivered this advice by calling on his own experience and citing a number of cases he had encountered over the years. The first of these cases was a seven-year-old MN boxer which presented with episodic anorexia and vomiting over the past 12 months. Bloods revealed only a stress leucogram with marked liver enzyme elevations. The ultrasound of the liver was unremarkable and the gall bladder was distended with sludge. Professor Willard’s first point was to ensure when working up these cases, that we should always consider performing a cholecystocentesis so bile can be cultured and cytologically evaluated. This is particularly important if any distension of the bile duct is noted as this could indicate an inflammatory process within the gall bladder. Infectious cholecystitis could be a potential reason for this inflammation and Professor Willard considers this to be a condition which is more common than we actually realise. Often patients with infectious cholecystitis will present with vague clinical signs and show no evidence of infection in their blood work and so a diagnosis can be easily missed if their bile is not evaluated.  Professor Willard explained it is normal to see a small number of bacteria within the bile but if large numbers are evident, this provides enough evidence to aggressively treat these cases with six weeks of antibiotics. If this treatment does not resolve the problem then a cholecystectomy needs to be performed.

Professor Willard also warned us of the often fatal necrotising cholecystitis which can develop as a result of an untreated bacterial infection (infectious cholecystitis) or a mucocele. Patients with necrotising cholecysitis can present completely collapsed or can show very little in the way of clinical signs. Even grossly the gall bladder can look normal despite being significantly diseased and this is why Mike advises NEVER biopsying a gall bladder no matter how healthy it looks as this may well lead to a disastrous outcome. A cholecystectomy should always be performed if the gall bladder is considered to be the underlying problem.

Extra hepatic biliary obstruction was another condition discussed by Professor Willard which usually causes gross enlargement of the gall bladder and bile duct within 24 hours. By far the most common cause of extra hepatic biliary obstruction is pancreatitis so much so that Professor Willard advises always assuming this is the underlying problem until proven otherwise. A mucocele is the next most common cause followed by the rarer tumours and gallstones. Diagnosing pancreatitis was discussed further within the webinar with Mike pointing out that although canine specific pancreatic lipase (cPli) is a very sensitive test for pancreatitis it will still miss around one in ten cases. On the other hand if the cPli is positive, it is always important to ask the question whether this animal does indeed have clinically important pancreatitis. Mike also wanted to stress that a pancreas can change dramatically on ultrasound over a short period of time and even if it looks normal at one point in time, it is always worth performing a repeat ultrasound 12-24 hours later.

A mucocoele is the second most common underlying cause for an extra hepatic biliary obstruction and given the risk of gall bladder rupture leading to the often fatal bile peritonitis, any gall bladder which has the classic ‘kiwi fruit’ appearance on ultrasound of a mucocele should be removed as soon as possible. However, beware of this advice for those gall bladders which have a more ‘honeycomb’ appearance in contrast to the ‘kiwifruit’. Mike advises these are often not at the point of rupture and represent ‘non gravity dependant sludge’ which often responds very well to medical management only.

Professor Willard ended this webinar by showing us some dramatic pictures of gallstones in both cats and dogs and in the case of an elderly dog which had elevated alkaline phosphatase and abdominal pain, Professor Willard explained he felt confident that the radiographic presence of a large number of gall stones must surely be the reason for this dog’s problems. This, unfortunately turned out not to be the case and demonstrates how easily the presence of gallstones can fool the best of us. This dog actually had an osteosarcoma on a rib which had been missed on the original x-ray explaining why it had the perceived abdominal pain and an elevated liver enzyme.  Professor Willard advised through the hard lessons learnt through this case, it’s imperative not to automatically assume the presence of gall stones is relevant or irrelevant to a patient’s problems and to always continue to look for other potential causes.

Professor Willard used his extensive experience of biliary tract disease in cats and dogs to deliver some cautionary tales offering some invaluable lessons. Think of this webinar as the ‘Aesop’s Fables’ of the veterinary world alongside some really useful and practical advice and you’ll understand why small animal vets should be taking full advantage of this engaging and excellent webinar.