If your dog is exhibiting signs that may indicate Cushing’s disease, contact your veterinarian. A comprehensive physical exam will need to be done, along with various tests and obtaining the history of your pet. In some cases, an abdominal ultrasound or MRI may be needed. Diagnosing Cushing’s disease can take time, and the results of these tests may still be inconclusive.
About 85% of dogs diagnosed with Cushing’s disease have a benign tumor on the pituitary gland, and 15% have adrenal gland tumors. The overuse of steroids causes some cases of Cushing’s. Female dogs are more prone to adrenal tumors than male dogs, and poodles, dachshunds, and Boston terriers are diagnosed with Cushing’s more than other dog breeds.
Cushing’s disease, or hyperadrenocorticism (HAC), is an endocrine disorder that causes excessive production of the hormone cortisol, which is produced when the pituitary gland in the brain sends information to the adrenal glands in the abdomen. HAC can affect humans and cats, but it is most common in dogs. Here are four facts dog owners should know about Cushing’s disease.
When Cushing’s disease develops because of the overuse of steroids, your dog will need to be weaned off the steroid medication gradually. When the condition is pituitary- or adrenal-dependent, medical or surgical intervention will be necessary. We may recommend a daily oral medication to help decrease the amount of cortisol the body is producing. These medications, along with routine monitoring, can often control the disease for dogs with a small, benign pituitary tumor. Dogs with benign adrenal tumors can often be cured with surgery. Malignant tumors, however, carry a poor prognosis.
Age data were available for only 91 of 104 dogs with HC. Mean (± SD) age for dogs with HC was 9.8 (± 2.5) yr, and only 5 of 91 dogs (5.5%) were ≤ 5 yr old. Gender data ( ) were available for all 104 dogs with HC and only for 19,059 of 21,177 dogs in the control group. Of 104 dogs with HC, 19.2% were intact females, 43.3% were neutered females, 29.8% were intact males, and 7.7% were neutered males. In the control group, 10,015 were male (52.5%) and 9,044 were females (47.5%). More specifically, 8,663 were intact males (45.4%), while 4,857 were intact females (25.5%), 4,187 were neutered females (22%), and 1,352 were neutered males (7.1%). Overall, considering sex regardless of neutered status, 62.5% were females and 37.5% were males. Females had higher risk for HC compared to males (OR 1.84; 95% CI, 1.24–2.75); neutered dogs had higher risk than intact dogs (OR 2.54; 95% CI, 1.72–3.73); and neutered females had a higher risk compared to intact females (OR 2.61; 95% CI, 1.54–4.42) ( ). No difference was noted between neutered and intact males.
To be enrolled in the study, a dog had to present with clinical signs compatible with HC (e.g., polyuria, polydipsia, polyphagia, enlarged abdomen, and symmetrical alopecia), laboratory findings consistent with HC (increased serum alanine aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase, hypertriglyceridemia, hypercholesterolemia, hyperphosphatemia, thrombocytosis, lymphopenia, diluted urine, and proteinuria), and a positive result to at least one endocrine test between ACTH stimulation test (cortisol concentration 1 h after administration of 5 μg/kg of tetracosactide acetate IV >22 μg/dl was considered positive), low-dose dexamethasone suppression test (LDDST) or high-dose dexamethasone suppression test (HDDST). In some patients, these tests were combined with urine cortisol-to-creatinine ratio or with endogenous ACTH concentration. The medical records of the different clinics had been re-evaluated by a board-certified internist (F.F.) in order to confirm the conformance with inclusion criteria. The dogs were divided according to the list of dog breeds approved by the Italian Kennel Club (ENCI).
Both pre-existing cases (diagnosed with HC before data collection began) and incident cases (newly diagnosed with HC during the data collection period) were included in the prevalence estimate. This was calculated by dividing the number of HC cases by the total number of dogs attending participating clinics during the study period. The prevalence in the reference center was calculated separately. Standard methods were used to calculate the 95% confidence intervals (CIs) to indicate the precision of the estimate. To investigate the presence of a breed predisposition for HC, the prevalence was evaluated and compared with the control group only for those breeds that had at last two individuals with HC. The reported age was the one reported at the time of HC diagnosis. Similarly, to assess the gender predisposition, both dog populations (HC and control) have been divided according to their gender, with subgroups of neutered and intact.
Data were extracted from client-owned dogs selected from electronic databases of five veterinary clinics for cases matching the search terms “hyperadrenocorticism,” “Cushing’s syndrome,” “PDH/ADH,” or “HC” between September 2012 and September 2014. The teaching hospital of the Department of Veterinary Medical Science, University of Bologna is a reference center for HC, while the other four 24-h clinics, scattered throughout the Italian territory (four in northern Italy and one in southern Italy) in order to avoid regional and local effects, were selected for the presence of an adequate electronic patient records system. The veterinarians of the different centers participating in the study had to fill in a questionnaire with signalment (breed, age, sex, and neuter status), anamnesis, physical examination, clinicopathological data, diagnostic imaging, and specific endocrine evaluations of dogs at the time of the diagnosis of HC.
The overall dataset comprised of 21,281 dogs attending five clinics in Italy between September 2012 and September 2014. From the whole population, 104 dogs were identified with HC on the basis of history, clinical and laboratory findings, and positivity to at least one endocrine test. reports the partition of the dataset between the various clinics. The estimated prevalence for HC in the four private clinics was 0.20% (95% CI, 0.13–0.27) and was significantly different compared to the University reference center (1.46%; 95% CI, 1.12–1.80).
The cost of diagnosis can be inexpensive or not, depending on the degree to which the dogs symptoms confuse the clinician or on the number of affiliated problems a dog may be experiencing. $500 to $1,500 is considered typical for a complete diagnosis (though the low end of this estimate would not include an ultrasound).
Diagnosis is usually made based on screening tests that suggest the possibility of excess cortisol secretion. Confirmation is achieved through one or two challenge tests that measure the secretion of cortisol once injectable hormones are supplied. Measuring cortisol is not an effective enough approach given this hormones fluctuating presence in the bloodstream. Thats why the ACTH stimulation and low-dose Dexamethasone challenge tests are employed. These tests may also be used to discriminate between the two types of Cushings.
In the former case, the disease may go by the name of “pituitary gland adenoma,” a nod to the benign type of tumor most commonly responsible for Cushings or as adrenal gland hyperplasia by way of describing the brain tumors effect on the pituitary. In the latter case, Cushings can be referred to by the kind of tumor less commonly responsible for the disease: “adrenocortical tumor.”
A third type of Cushings disease exists and is known as “iatrogenic Cushings disease” or “iatrogenic hyperadrenocorticism.” This occurs when dogs or cats have been exposed to quantities of cortisol-like steroids over time, therefore eliciting the same symptoms as naturally occurring Cushings. This third form will not be treated in the discussion to follow.
Cushings Disease in Dogs: Natural Treatment
The epidemiological characteristics of spontaneous hypercortisolism (HC) were derived from 21,281 client-owned dogs selected from four private veterinary clinics and one university reference center for endocrinology. The odds ratio (OR) method was employed to investigate the risk of developing HC related to breed, gender, and sexual status. The estimated prevalence of HC in the four private clinics was 0.20% [95% confidence interval (CI), 0.13–0.27] and was significantly different compared to the university reference center (1.46%; 95% CI, 1.12–1.80). Sex, breed, and age resulted in risk factors for HC. Mean (± SD) age for dogs with HC was 9.8 (± 2.5) yr. Females had higher risk for HC compared to males (OR 1.85; 95% CI, 1.24–2.75); all neutered dogs (both males and females) had higher risk than intact dogs (OR 2.54; 95% CI, 1.72–3.73); and neutered females had higher risk compared to intact females (OR 2.61; 95% CI, 1.54–4.42). Using the mixed breed dogs as a control population (OR = 1), the risk of developing HC was significantly higher in the Standard Schnauzer (OR 58.1; p < 0.0001) and Fox Terrier (OR 20.33; p < 0.0001).
With regard to HC, this study identified an overall prevalence of 0.20%. The data support the existence of sex predisposition, with the highest risk for neutered females.
Data were extracted from client-owned dogs selected from electronic databases of five veterinary clinics for cases matching the search terms “hyperadrenocorticism,” “Cushing’s syndrome,” “PDH/ADH,” or “HC” between September 2012 and September 2014. The teaching hospital of the Department of Veterinary Medical Science, University of Bologna is a reference center for HC, while the other four 24-h clinics, scattered throughout the Italian territory (four in northern Italy and one in southern Italy) in order to avoid regional and local effects, were selected for the presence of an adequate electronic patient records system. The veterinarians of the different centers participating in the study had to fill in a questionnaire with signalment (breed, age, sex, and neuter status), anamnesis, physical examination, clinicopathological data, diagnostic imaging, and specific endocrine evaluations of dogs at the time of the diagnosis of HC.