I laughed and answered: 'There are certainly situations that are hard. The fact is that no single veterinarian can possibly know all there is to know about everything to do with veterinary medicine, but for these situations we are well trained and we can usually find help or look things up. So I look on these occasions as more of an intellectual challenge than hard to handle. But there are situations that arise from time to time that can become, how would I say it, difficult.'

I went on to tell her a story, a prime example of how a difficult situation can develop. A couple of years ago I had a client come in with a golden retriever suffering from lethargy. His dog was usually hyperactive, but recently it would suffer bouts of lethargy that would take a few days to clear up. It sounded odd as there are not many problems that can cause such intermittent bouts of lethargy. Further questioning revealed that the dog was otherwise fine. It was eating, drinking and going to the toilet normally. There were simply no other symptoms. I examined the animal and found absolutely nothing wrong.

The owner lived nearby, so if there was an emergency he could rush the dog in at a moment's notice. I sent his dog home for observation and told the owner what symptoms to look out for. Sometimes symptoms may arise that will make diagnosis easier. After a couple of days the owner brought the dog back and said it was panting a little more than usual. Now we had a lead. A double check found the dog's heart and lungs sounded normal, but this time I noted by checking the colour of its gums that the dog was slightly pale. So I performed a blood test, which showed the dog was mildly anaemic - his level of red blood cells was low. I followed this test up with a blood smear, examining the actual red blood cells under a microscope.

The red blood cells were not their normal plump round shape but rather long and flattened. This was indicative of slowed blood flow through the spleen. The owner agreed to an ultrasound of the spleen and we found the problem. There was a very large lumpy growth that extended out of the normally smooth surface of the spleen. However, the ultrasound was unable to indicate what the lump was.

An option was to do a needle biopsy, which involves poking the spleen with a needle and excising a tiny sample to be sent to a lab for analysis. But with this procedure there is a big chance of getting a sample that is not representative of the disease, since the sample is so small. There is also a long turnaround time to get the specimen to a lab and have a pathologist have a look at. At worst, such a procedure could lead to a misdiagnosis or a delay in treatment of a possible tumour. The preferred way to deal with growths in the spleen is to open up the abdomen and examine it. The pros and cons of all options were outlined to the owner who, after weighing the options, decided on surgery.

The surgery went ahead and we ended up removing the spleen as the mass involved half of it. The dog's spleen can normally be removed with no ill effects. The dog went home a day later uneventfully. After a couple of weeks the result came back and it was good news. The lump turned out to be a benign tumour arising from the blood vessels of the spleen, very lucky for the dog as a malignant tumour would surely have meant death.

The treatment of this dog had been very logical and successful, but the owner was upset with the result. He argued that as it turned out the tumour was benign, we had not needed to do the surgery. I walked him through the decision process again. He finally saw that the decisions made were correct at the time they were made. What was confounding was that he was happy before the lab report because the dog had been cured of his lethargy and had returned to his normal active self. It just goes to show you can't please everyone and, even if all goes to plan, there are situations that are going to be difficult.