CANINE CUSHINGS SYNDROME
‘Hyperadrenocorticism’

by Marian Godwin Clifford

What is Cushings Syndrome? Cushings Syndrome or hyperadrenocorticism is a common clinical syndrome in dogs, especially in older dogs. It occurs when the hormone Cortisol is produced to excess.
This is usually caused by an ACTH (adreno-corticotrophic hormone) secreting pituitary tumour (85% cases ), which then over stimulates the adrenal gland which produces too much cortisol. The pituitary gland is a mass of specialised cells at the base of the brain. The adrenal glands are small pockets of specialised cells sitting behind each kidney.
Sometimes, however, Cushings is caused by an adrenal gland tumour, which starts to produce cortisol independently of the pituitary gland.
The third cause of Cushings is over-prescribed medications, specifically those corticosteroids to treat itching skin. This third cause is reversible by slowly withdrawing the steroid medication which will allow the adrenal glands to resume functioning.
It is not yet known whether Cushings in Scottish Terriers is an inherited predisposition.

What are the Symptoms? It is important for the Scottie owner to be familiar with the symptoms, as they are sometimes mistaken for the aging process. No dog will present with all of the symptoms, and some symptoms are more common than others. Symptoms also depend on the duration of the disease.

  - Increased thirst (polydipsia) with associated increased urination (polyuria) Most common symptom, may be viewed by the owner as incontinence or a behavioural issue. Some owners wrongly believe that the problem will be resolved by withholding water. Never withhold water from a dog that is drinking excessively until your dog has been examined by a veterinary surgeon. In Cushings, the increase in thirst is directly related to the increase in urine production. When water is withheld, the same volume or urine is produced and dehydration and kidney failure can result;
  - Increased hunger (polyphagia) Common symptom, occurs in most dogs. Not a normal hearty appetite, but a voracious appetite which can lead to bad behaviour such as food stealing, raiding bins;
  -

Pot belly Common symptom, due to enlarged liver, distribution of fat, muscle atrophy in the abdominal wall;

  - Muscle atrophy Or wasting which can also affect the limbs and the head, resulting in a thin-legged dog with a bony, skull-like appearance of the head;
  - Panting;
  - Coat changes (dry, thin, brittle coat or baldness) Begins with symmetrical hair loss on the flanks (alopecia);
  - Weakness Could be due to muscle weakness. Dog less willing to exercise, tires easily;
  - Skin changes There are a number of these and any or none can be present at any one time: Thinning, loss of elasticity, slow wound healing, bruising, hair loss, lacklustre coat, dandruff, comedones (blackheads), calcinosis cutis (calcium deposits in the skin);
  - Reproductive problems (unaltered dogs) Where, in bitches, they stop cycling and in dogs, they may undergo a reduction on the size and firmness of the testicles;
  - Myotonia Rigidity of the muscles (rare);
  - Neurological Problems Affects the nervous system due to the presence of a mass pressing on the brain in the case of a pituitary gland tumour. Symptoms include: Dullness, depression, head pressing, walking in circles, ataxia, behavioural changes, loss of appetite, blindness, seizures (epilepsy), and unequal pupils. (Rare);
  - Diabetes Mellitus Occurs in about 10% of affected dogs.

How is Cushings Diagnosed? On the basis of the history, diagnosis is made by examining the clinical symptoms and confirmed with selective blood and urine tests. There is no single test to diagnose Cushings, and this syndrome is often difficult to diagnose .

How is Cushings Treated? Considering that most Cushingoid dogs are elderly, they could have concurrent health problems making treatment difficult. Surgery is rarely recommended and most dogs are medically managed.
Until recently, there were no licensed medicines available in the UK and special importation licences had to be obtained for drugs with potentially harmful side effects. A new product, ‘Vetoryl' (Trilostane) developed in the UK, is now available. Medication is easy by administering an oral capsule, which is then given daily for life.
According to the literature , the early results are extremely promising in controlling what has been, until now, a difficult disease to treat.
Monitoring and Checkups Cushingoid dogs should be regularly monitored. My vet suggests a check-up every 4 months to evaluate the progress of the therapy.

What is the Long-term Prognosis for a Cushingoid dog? Although Cushings is incurable, frustrating to diagnose and expensive to treat, it is treatable. Fortunately, it is not painful and many dogs live for some years with excellent quality of life after having being diagnosed and receiving treatment. There is anecdotal evidence of dogs living many years after diagnosis, but it is practical to expect that the dog will live out its natural lifespan.
It can, however, lead to suffering in an untreated dog. It will progress and can leave the dog prone to various infections, as excess cortisol is immunosuppressive.
Ultimately, a dog with Cushings can have improved quality of life following diagnosis and treatment, and their lives may be extended. It is possible for this disease to be managed by the vigilant and committed owner for many years.

Personal Experience My 11-year old Scottish Terrier bitch, Ailish, was diagnosed with Cushings in June 2002, having 18 months previously been tested as borderline-Cushingoid. This is the basis for my interest and the reason for this article.

Ailish presented with the first six symptoms. The vet asked me to try and measure her intake of water, and it came to a combined intake of about three litres per day for two Scottish Terriers (one drinking normally). It was this that brought us to take her to the vet in the first place.
One of her most difficult symptoms to manage is the huge appetite and the lengths to which she will go to to steal food. A gift hamper was once left on the floor, and she gnawed through the corrugated cardboard in order to get to some biscuits inside. She has even stolen a box of tea from shopping bags, which had not yet been put away. We have to be patient and very aware of where we leave anything edible (or even inedible-but-smells-good i.e. sachet of Persil Aloe Vera inwash tabs).
She initially lost hair in the typical fashion i.e., two symmetrical patches on her flanks, but it has since grown back – but grey! In the manner of all elderly dogs, she is going grey, but in this case, from the bottom up! She had a bald patch at the base of her tail, which is also now growing back since diagnosis and medication.
The ‘dandruff’ has been controlled through a combination of the medication and medicated shampoo, Malaseb.

Ailish had several vet visits for blood and urine tests. She had to spend several hours at the vet on two separate occasions, and had to return once as the sample had degenerated by the time it got to the lab. And I am sure that the neighbours were very amused seeing me trying to catch a “morning sample” from my squatting Scottie. I found that fashioning a ladle or scoop from tinfoil, which I slid down under and behind her as she squatted, was the most effective way to get an ample amount for the urine test.

She was eventually prescribed one 60mg capsule of Vetoryl per day (£61.10 for 30 capsules). The most upsetting part about the medication, which I know is ultimately saving her life, is the fact that I have to handle the capsules with gloves (the precautions include not handling the capsules at all if pregnant or trying to become pregnant).
I am loathe to put these on my precious dog's tongue. So I coat them in peanut butter so that she doesn't have to have direct contact with them. Foolish, I know, but it helps us both as she is a difficult patient to administer capsules to.

The one thing that we struggle with constantly – even post-medication - is her “goopy eyes”. She needs her eyes cleaned daily and bathed several times a week in a mild saline solution. The vet says that there is no ulcer present, but it is simply conjunctivitis affecting an immuno-suppressed dog. We have decided against medicating, as this will only cause chemical conjunctivitis and perpetuate the cycle.

Although we have just recently made contact with a homeopathic vet, we are not yet under his care. In the mean time, I am supplementing her with a homeopathic canine geriatric supplement, colostrums, milk thistle and Echinacea.

It is now six months since her diagnosis and the start of her therapy and she has improved greatly. Her water intake has reduced considerably and I was heartened to see her start to hide food once again – under rugs, under her blanket, under cushions. This can only mean that her voracious appetite is abating.

I am hoping for her immune system to recover sufficiently for her eyes to return to normal. She has just turned 11 and I am hoping for at least another 12 – 18 months with her sweet presence.

Sources Consulted
Axiom Endocrine Fact Sheet No. 2.0
Axiom Endocrine Fact Sheet No. 2.1
clubs.akc.org/stca/geneticissues.htm#CS www.onlineveterinarypractice.com/ezines/ezine5.htm
www.supervet.co.uk/dog/cushings.html
www.kateconnick.com/library/cushingsdisease.html
www.arnolds.co.uk/newspage/articles/vetorylfaq.pdf


Thank you to my Vet, Ms Lucinda Khalil and to Ms Kate Connick of Courteous Cannines, llc for their perusal of this article and their comments. Please remember that I am not a professional and this is my personal experience. If you have any questions, please consult your vet in the first instance.

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