Toby came in to the surgery the other day. He is a little Jack Russel Terrier, cute as pie to look at, but when he walks through the door, he turns into a whirling dervish. On the way to the surgery, he recognises that it is not the route to the riverbank. Whenever he’s been in the surgery, he has had injections and operations and although we have tried to bribe him with treats, he is having none of it. It’s fair to say that his adrenaline levels are already high by the time he arrives and when he barges into the consulting room, he’s out for blood and only a vet’s blood will satisfy him.
So, we’ve all heard of adrenaline and have experienced the effects it has on our bodies, but where does it come from and what else is there?
Adrenaline is produced by the adrenal glands which sit just in front of each kidney. They are quite small but pack a powerful punch. Inside the gland are two sections – the first releases adrenaline and the second controls salt levels within the body (mainly sodium levels) and the release of cortisol.
Adrenaline is also known as the fright, flight or fight hormone. If we experience a sudden shock, this hormone kicks in and prepares us for action – whether it’s to fight to the death or survive the Blackpool rollercoaster. Although too much adrenaline is harmful in the long term (perhaps exam stress), humans can become addicted to the excitement it adds to life. Just think of adrenaline junkies skydiving every weekend. Animals can enjoy it too. When my dog has a good old barking session at another dog passing the gate, she comes back tail up and smiling having seen off the enemy.
Cortisol is a hormone that allows the body to respond to stressful times by changing protein use, releasing stored sugars and by suppressing the immune response. The most common disease affecting this area of the gland is overproduction of cortisol hormone and is known as Cushings disease. This may be due to a problem within the adrenal gland itself, but it is more commonly caused by a problem of its regulation due to a disease within the brain. The symptoms caused by the high levels of steroids within the body include a raging thirst and hunger, weak muscles and changes to the skin resulting in baldness and blackheads. A series of blood and urine tests are needed to confirm diagnosis before treatment can be started.
I suppose the opposite of Cushings disease is Addisons disease and this is due to under-production of cortisol but there is usually disruption to the salt levels in the body due to a lack of the hormone aldosterone. This time, the symptoms are very vague and often it is down to recognising an “unwell” dog over a period of time. Again, a series of blood and urine tests are required to diagnose this condition and treatment relies on tablets and injections to replace the steroids and the aldosterone hormone.
The adrenals are small organs but they carry a lot of weight. Oh, and we all survived Toby’s visit, luckily without any blood loss.