Pet Of The Month – March

7 March 2016

Barley is a 9 year old Golden Retriever who was recently diagnosed with Diabetes Mellitus.

In November Barley’s owners noticed that he was drinking and urinating more than usual, and he was having a few “accidents” in the house.  His urine contained large amounts of glucose, which is abnormal – usually glucose would be retained by the body to be used for energy. A fasting blood test also showed an abnormally high level of glucose in Barley’s blood, which confirmed our suspicion that he had diabetes mellitus.

Diabetes is relatively common in middle aged and older dogs and cats.  It occurs when the pancreas doesn’t produce enough insulin, or when the body’s insulin receptors become less sensitive. Insulin is the hormone responsible for moving glucose from the bloodstream (where it passes after being digested) into the body’s cells, where it can be used for energy.  A lack of available glucose causes the body to break down fat instead, and the by-products of this fat breakdown can cause a very serious condition called diabetic ketoacidosis, which can be fatal.

Unlike people with Type 2 diabetes, we cannot control dog and cat diabetics with diet alone -they require twice daily insulin injections to regulate their blood glucose levels.  We have to start treatment with a relative low dose and monitor the animal’s response carefully, because an excessive amount of insulin will cause blood glucose levels to drop too low, which can lead to seizures and even death.

Barley’s owners were keen to do everything they could for him, so we taught them how to give the injections and he started his lifelong insulin therapy.  A few weeks later he came back to Cogges for a glucose curve, which is a day of regular blood glucose monitoring. In a healthy, non-diabetic animal, or a diabetic who is well controlled with insulin, the curve will start high as glucose enters the bloodstream after breakfast.  Over the course of the day, the glucose level drops as insulin transports glucose into the body’s cells.  Later in the afternoon the liver releases some of its glucose stores to keep a constant level, and the curve rises again.

A normal glucose curve In Barley’s case, the blood glucose level stayed abnormally high all day, indicating that his current dose of insulin was insufficient.

Barley's glucose curve

This was confirmed by his owners’ report that he was still drinking and urinating frequently.  We increased his dose slightly, his owners continued the injections at home, and we saw him back in another fortnight for a further glucose curve.  Because Barley is a friendly dog and doesn’t need a fluid line or sedation while he is staying with us, he spends his glucose curve days upstairs in the office and sitting room with the staff dogs, instead of downstairs in a kennel.

This process of gradual increases in dose and regular monitoring, continued until the end of January, when Barley finally had a normal glucose curve.  This means that for the time being, we have found a dose of insulin that keeps his blood glucose levels within safe limits.  He will still need to be carefully monitored by us, and his owners know they need to be very observant of any changes to his appetite, or other signs of illness as these are likely to affect his glucose levels.  He will need treatment and monitoring for the rest of his life.