Insulinoma in Ferrets

A Case Study by Richard Dobson

Compo My polecat hob Compo is a rescue ferret of about four years old. The first indication that he was unwell occurred when he was out playing while I cleaned out my ferret cubs. He is the noisiest of my ferrets and 'chuckles' almost continuously when he is in the exercise pen. I noticed that he was quiet and, as I watched him, he looked like he was falling asleep on his feet. His head started to slowly drop towards the ground and his sides twitched slightly as if he were sniffing something. He then started to fall to one side but before he fell over, he suddenly came around and started to walk about and chuckle. The whole episode took no longer than about 20-30 seconds. About 4-5 minutes later the same thing occurred again.

That same day I booked an appointment with the vet and took him along that afternoon. As is often the case, while at the vet's the symptoms did not recur. After a thorough physical examination (temperature, heart rate etc.) the vet told me that he could find nothing wrong, but that he would give him a dose of antibiotic in case it was an infection and that I should return with him after the weekend if he hadn't improved. A few days later there was no change so I took him back. Unfortunately it was a different vet, who repeated the examination and came to the same conclusion. However, he gave him a second dose of antibiotic along with a painkiller.

At this point I felt the need to talk to someone who was more familiar with ferret conditions than my vets appeared to be, so I phoned Dr June McNicholas who suggested that it sounded like insulinoma. She explained the illness to me and also gave me some ideas about possible medication and dietary changes.

Insulinoma is a condition caused by very small tumours forming on the pancreas which, although malignant tend not to spread throughout the rest of the body. This results in increased levels of insulin being released which suppresses the blood glucose level. The visible signs are a hypoglycaemic attack that gives the appearance of nodding off.

Fortunately my collection of ferret books contains some that deal with diseases and medicines etc so I looked up insulinoma and photocopied the relevant pages.

I decided to go back and see the first vet and I duly presented him with the photocopies and details of the books (just in case he wanted to buy them!). He said that although he had heard of insulinoma in ferrets he was more familiar with the disease in cats and dogs. He suggested a blood test so he kept Compo in for an hour or two.

Later that afternoon the vet called to confirm that Compo's blood sugar was low and that it did appear that he could have insulinoma. He had given him an injection of Prednisolone and said that he would investigate this condition in ferrets over the next few days. I was given a prescription of Prednisolone 1mg tablets and told to give Compo a quarter of a tablet twice daily. The following week on a follow-up visit the vet confirmed that Compo did have insulinoma and that he would need to be on the medication for the rest of his life. He also advised that an operation to remove the tumours from the pancreas and/or part of the pancreas was possible but life expectancy would only be about a year. However, it was not possible to predict his life expectancy without the surgery but the consensus of opinion was that it would probably be shorter than 12 months.

I've now changed the diet for all of my ferrets to increase the protein and fat content while minimising the carbohydrate content. Ferrets, being carnivores, require a diet high in protein and fat but low in carbohydrate. Carbohydrates are readily converted into glucose and too much glucose would raise the blood sugar level causing the pancreas to over-produce insulin.

At the time of writing, it has been less than a month since this first occurred but in that time Compo has improved, with his 'attacks' happening much less frequently and lasting only for about five seconds. However, when they do occur as an emergency measure I rub a very small amount of honey on to his gums to increase his blood sugar level to counter the effect of his high insulin level.

I've spoken to Dr June McNicholas on several occasions since my initial call and I've found her advice and experience of tremendous help and reassurance. If I hadn't made that call to her it is very likely that Compo's condition would have deteriorated very quickly and he could have gone into a coma and died. I can't thank June enough for that initial diagnosis and her ongoing advice.

The lessons for me from this experience areL

1. If you think that something is wrong with your ferret, it probably is.

2. Visit your vet and if he/she appears inexperienced in ferret health matters, or is dismissive, be persistent.

3. Talk to others who keep ferrets to see if they have ever experienced similar symptoms in their ferrets, and research the subject in the publications available.

4. Then re-visit your vet. My experience showed that he was only too happy to accept other sources of information.

5. This is important to help UK vets increase their knowledge base since currently most information on ferret illnesses is based on experiences in the USA and Australia.

(From Ferrets First Issue no. 20 October/November 2004)

Articles from Ferrets First