A Veterinary Journal by Claire Poole
March
Chapter 3 - Page 3
Chapter 1
Chapter 2
Chapter 3
Tuesday 10th March
Tuesday 10th March
One of life’s strange coincidences again this month: Diabetes mellitus is not a particularly common condition - in a small practice like this, we might see two or three cases per year; but, guess what? ... two came in last week. Excess drinking and urinating are cardinal signs of the disease, and these 2 patients presented with exactly those symptoms. Finn, a 14-year-old cat, had been drinking increasing quantities of water and had taken to wetting in the dog’s bed. The drinking had largely escaped his owner’s notice, but constantly changing the dog’s bed was beginning to irritate her. My request for a urine sample was easily granted, and a blood sample confirmed the diagnosis. Diabetes mellitus is caused by a shortage of a substance known as insulin. When food is digested, the glucose produced is taken in the blood stream to provide fuel for every cell in the body. Insulin is required to allow the glucose to pass from the blood into the cells – if it is not present, blood glucose levels remain high, triggering the kidneys to pass out the excess. This increased urination in turn causes excess thirst. As the glucose is unavailable for fuel, body fat is broken down in an attempt to provide the energy that the body needs. The animal loses weight and feels unwell as a result of the toxic by-products of fat breakdown. The main treatment for diabetes in animals is to provide the missing insulin in the form of regular injections, usually once or twice a day. It is important to get the dose of insulin correct - too little and the damage to body organs continues; too much and the blood glucose levels drop so low that there is insufficient to power the brain - a condition known as hypoglycaemia. Hypoglycaemia initially causes confusion and dopiness, progressing eventually to fits, loss of consciousness and death.
Both Finn and the other patient, Guinevere, also a cat, have been started on daily insulin injections – first administered by me, and then by their owners as they have become confident with the procedure. Owners are initially terrified of having to give injections, but after being introduced gradually to the daily routine, most manage very well. The patients are fed and injected at the same time each day. Improvement in symptoms indicates that treatment is having the desired effect, and urine test strips checked at home help to monitor the effects of treatment, but serial blood samples taken every couple of hours throughout the day give a more complete picture of how controlled the disease is. This is why both cats are in today. The plan is to feed and inject as normal, and take blood every 2 hours to determine the blood glucose levels over the day. Ideally, the sampling period should extend over a full 24 hours, but practically, both vet and patient are flagging before then - we routinely manage 14 hours, but will continue overnight if the results after this time are not easily interpreted. So ... at 8 a.m. this morning, we had an influx of diabetic cats, complete with everything necessary to see them through the day – bowls, food, vials of insulin, toys and favourite blankets.
After an initial flurry of activity settling both patients in, we take our first samples. Both cats are then fed and injected with insulin. We carry on with the other operations of the day, falling into the familiar routine every 2 hours - Guinivere out first then Finn. We have a small piece of equipment known as a glucometer which makes today’s procedure possible. Used by human diabetics, this instrument is designed to measure blood glucose from a mere spot of blood. Humans prick their finger to collect this; we use a small hypodermic needle to quickly nick a small blood vessel in the ear flap. This yields enough blood for the test and the usually the patients don’t object. Unfortunately, Finn has sensitive ears, well frayed at the edges as a result of many cat fights - and he gets harder to handle each time. We start to dread the clock creeping round to the end of another 2 hours. Guinevere was a terror in her youth, but has fortunately mellowed with age and seems almost to be enjoying the day. She is usually alone while her owners are at work so perhaps today’s company is a novelty. Julie and I have added extra interest by each backing a cat. Julie bets that Finn’s glucose levels will drop lower than Guinevere’s. I am backing Guinevere. In between blood samples, we spay 2 bitches, castrate 2 cats and clean a terrier’s teeth, so the day passes quickly. Guinevere and I win the bet so Julie will buy the doughnuts next operating day. Jay helps me with the evening samples until the cats are picked up after 10 p.m. We now have a graph of how each cat’s blood glucose levels vary over the day which I have used to decide what changes must be made to the daily regime. It has been a long day, and we all have some battle scars from when Finn decided that blood letting should be for everyone, but it has also been satisfying to be able to fine tune the treatment to best effect.
Copyright Claire Poole 2005
