Hormone Disorders in dogs

May 24th, 2008

Sue Moses takes a look at the most common hormone disorders in dogs  and finds out how they can be treated.

Any suggestion of a hormone disorder is enough to send most dog owners into a panic. But on average, of the 1000 sick dogs that are treated at clinics, less than 10 of these will be diagnosed with a hormone disorder, according to Victorian veterinarian Dr Glen Hastie. And even better news is that a hormone disorder is something a dog will usually live with, rather than die from as long as proper care and medication is provided.

What are hormones?

Put simply, hormones are chemical messengers that affect the activity of cells and tissues throughout the body. Hormone disorders can affect any breed and although they are uncommon, the four most widespread are diabetes, Cushings disease, Addisons disease or hypothyroidism.

None of these are necessarily a death sentence, Hastie says. The medical management of these disorders has been fine-tuned over the years, allowing us to give these animals a relatively normal life. The treatment for all of them is forever, as there is no magical cure.

But Hastie is quick to point out that owners of dogs with these disorders will become very familiar with visiting their local hospital as treatment requires ongoing monitoring, medication and dedication.


Most people will be familiar with diabetes, as it is an increasing problem in people, although diabetes in dogs is quite different to diabetes in humans. Nearly all dogs with diabetes are insulin-dependent for the rest of their life, unlike the more common type-2 diabetes in humans that is related to diet, obesity and genetics.

Hastie points out that dogs diagnosed with diabetes are usually in their middle to older years. Early signs can include drinking more, urinating more frequently, increased appetite and ironically weight loss, he says.

One patient I recall, a Labrador that had been quite obese, went from 51 to 26kg in a very short time. The cause is a failure of the insulin-producing cells in the pancreas to produce that hormone, and its thought to be associated with the dogs immune system destroying these cells. As the cells are lost, there is less insulin and glucose builds up in the blood stream. It is then not available as energy for the dog.

So, insulin must instead be administered. This is usually done by way of injections twice daily.

Hastie says this is a fact that alarms most dog owners. All of a sudden they are faced with having to give injections and they are worried about causing pain to their pet. And while this is a shock on its own, there is also the necessity for the injections to be given strictly 12 hours apart even 15 minutes either side can create difficulties. A special diet is also required, and exercise must be regulated and kept to a daily routine to maintain glucose levels.

Hastie says that while medication can be costly, depending on the size of the dog, it is the regimented routine that presents the most problems for owners. Some people just don’t have a lifestyle that is flexible enough, and any change to routine, like holidays, requires careful planning.

However, most clients do adapt and choose to go ahead with treatment. They quickly become used to giving the injections and after a while think nothing of it even a grandmother in her 80s got the hang of this for the sake of her dog, Hastie says. The injections are simple, and most people give them while the dog is eating its meal and doesn’t even notice.

Dogs that become diabetic can die within weeks if not treated. Once they are stabilised, the biggest danger is weakness, collapse or seizures if glucose levels fall too low. It can be an emergency situation, Hastie warns.

When a dog is first diagnosed, it will require weekly visits to the vet until insulin and glucose levels are balanced. Testing (which cannot be done at home) will then become less frequent.

Dogs normally live a fairly uneventful life with their diabetes, thanks to the commitment and love from their owners, but one serious consequence is cataracts in the lenses of the eyes. This condition will eventually deplete up to 90 per cent of the dogs sight, but can be corrected with surgery.

Cushing’s disease

This is a condition that occurs when there is an excess of the hormone cortisol. This is the bodys own form of cortisone and is essential for a variety of body functions, including fat production and the response to inflammation.

There are two forms of Cushing’s disease. The most common is when a growth occurs on the pituitary gland, causing an overproduction of a hormone that stimulates the adrenal glands to produce cortisol. Smaller breeds of dogs are most likely to be affected with this form of the disease.

The second form is nastier and occurs when an often malignant tumour appears on one of the adrenal glands. These tumours cause the cells to produce excessive amounts of cortisol.

Adrenal gland tumours can sometimes be surgically removed, but if the tumour returns, the condition is likely to shorten the dogs life. This form usually affects larger breeds.

The more common form can be managed with medication quite well, and as most dogs diagnosed with Cushings disease are well into middle age, it is often some other condition that ends the dogs life.

Hastie says initial symptoms of Cushing’s disease include drinking, eating and urinating more, and panting. A dog with Cushing’s can also have fairly dramatic changes in appearance, including a pot belly and hair loss, and may be prone to skin infections.

Dogs with Cushing’s disease will need regular checks that include blood tests and high blood pressure tests to monitor the condition so that the correct doses of medication can be given.

Addison’s disease

This condition is the opposite of Cushing’s disease. It occurs when the adrenal gland is underactive, and it can affect young to middle-aged dogs.

Cortisol is among the hormones which stimulate the fight-or-flight response, and therefore a lack of it results in a dog that is lethargic and even depressed. Other signs can be a decreased appetite and vomiting. It can actually look just like gastro, so is often difficult to diagnose.

Blood tests will confirm if the symptoms are caused by Addisons. The treatment is ongoing tablets, and regular blood tests are required to monitor cortisone and electrolyte levels.

Stress such as kennelling usually requires the dog to have higher doses of medication, Hastie says. Owners of dogs with Addisons disease need to anticipate and recognise stressful situations.


This condition is the result of low thyroid hormone production by the thyroid glands in the neck. It is a less dangerous condition than the three listed above, but will still require lifelong medication.

Signs of this condition are subtler and may include skin and coat changes, some with hair loss and skin infections. More obvious symptoms can be nerve changes that can affect the nerves in various parts of the body, including the face, reproductive problems and sometimes lethargy and weight gain.

However, Hastie says most dogs respond extremely well to treatment, the medication is not overly expensive, and there are rarely any long-term complications of this disorder and its management.


Much-loved 11-year-old Pomeranian, Tamurah, had lost a bit of weight over a few weeks, but not enough to cause alarm. But on the day that Rhiannon, Michael and Joanne Jenkins had a holiday planned, the little dog fell critically ill.

Tamurah consumed about one and a half litres of water in an hour and was vomiting constantly. By this time her weight had dropped from 11 to 6.5kg. A rushed trip to veterinarian Dr Glen Hastie saw little Tamurah diagnosed with diabetes.

Joanne Jenkins tells Dogs Life that the greatest shock was nearly losing the precious family member. The diagnosis of diabetes a treatable condition was a huge relief. We were devastated at nearly losing her, so we didnt baulk at the treatment that would keep her alive, Jenkins says.

We really had no problem giving the [twice-daily insulin] injections, though it took some adjusting to put a schedule in place. But we took the view that this was what we needed to do to keep her well and happy. Now we couldnt be happier she is again a happy and energetic little dog.

A $60 vial of insulin lasts about 35 days. Luckily, she is a little dog or the cost would be much greater, Jenkins says.

Tamurah did develop cataracts a complication of diabetes that were rectified by an operation costing about $4000. She also has a coat condition called Alopecia X, so we clip her because her coat doesn’t grow properly. She looks a bit strange but we love her! Jenkins says.

Every couple of months we take her to Dr Hastie, who takes a series of blood glucose tests to see how Tam’s sugar levels are. Sometimes we feel a little bad having to give her needles all the time, but we know it is for her health. She doesn’t mind either, because she knows that as soon as she’s had her insulin, she gets food. Some people think that we are restricted by Tamurah’s condition, but she is part of our family and looking after her is part of that.

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