To treat or not to treat? Navigating the gray area of Cushing syndrome

Denis Aglichev / stock.adobe.com

Diagnosing Cushing syndrome can be frustrating. Speaking at the Fetch dvm360^® Conference in San Diego, California, Kelly Cairns, DVM, MS, DACVIM (SAIM), vice president of Medical Excellence and Education at Thrive Pet Healthcare, explained that clinicians rarely encounter a textbook case of Cushing syndrome. Rather, they are often stumped by what she terms “the elusive gray-zone dog,” which is difficult to diagnose and plan treatment for.

Veterinary professionals are well versed in how to approach a dog showcasising typical signs of Cushing syndrome, but many struggle to determine the best course of action when endocrine diagnostic screening tests come back inconclusive or confusing. Cairns, who is based in Naperville, Illinois, reviewed diagnostic and treatment options for the clinician, as well as potential complications and the client education aspect of the condition, during the session.

Cairns said success in handling “borderline” Cushing syndrome cases comes down to 4 key areas: learning how to use and interpret the available diagnostic tests accurately and efficiently, understanding the complications of Cushing syndrome, creating action plans based on predetermined criteria, and implementing a comprehensive client education communication strategy to meet expectations. By analyzing a case through the lens of these 4 principles, clinicians can better determine a course of action when dealing with atypical or “gray area” signs of Cushing syndrome.¹

The decision to treat or watch and wait

“It comes down to treat or not to treat,” said Cairns. “Once you think you have a dog with Cushing [syndrome], that is the question.”

Cairns recommended that when determining whether to begin treatment with traditional pharmacologic therapy with trilostane (Vetoryl; Dechra Veterinary Products) or mitotane (Lysodren; HRA Pharma Rare Diseases) for Cushing syndrome, clinicians should consider the following questions¹:

• Are there symptoms affecting the patient’s quality of life?
• Are there symptoms affecting the pet parent’s quality of life?
• Are there complications that are concerning to the clinician?
• Will treatment improve quality of life for the patient and/or pet parent?
• Will treatment decrease risk or severity of complications of the condition?

Cairns said that the decision to treat a patient with Cushing syndrome can vary on a case-by-case basis depending upon the above factors. She said that considering these factors are important in addition to diagnostics because often test results may only be clear cut for classic, textbook cases. With regard to reference ranges on diagnostics and the value of taking them in context with other information, Cairns said, “Those values were established 5000 years ago when we were only diagnosing dogs with Cushing [syndrome] that [look like the textbook presentation].”

Cairns spoke about what to do if a watch-and-wait approach is the best course of action for the patient. She advised, “At the very least, you want to address and treat any complications that currently exist, and you want to monitor for future complications that may arise.”

Cairns also said that alternate therapy may be an option for those veterinarians and pet parents who are so inclined. The most common options for these therapies include melatonin (3-6 mg orally every 12 hours), HMR lignans (10-40 mg orally every 24 hours) and/or SDG lignans (flaxseed hull, 1-2 mg/lb orally every 24 hours).²

She said that although there are many acceptable approaches, she prefers to monitor and recheck these patients frequently.

“I like to see these patients every 3 to 6 months…and I’m paying particular attention to these things on a physical exam: muscle mass, tone, orthoneuro, skin. And it’s my touch base with the client,” Cairns said.

Client communication and education

“More than almost any other disease, [client education about Cushing syndrome] is key,” Cairns said. “We’re not trying to give them a PhD in biochemistry, but they need to understand it so that they can understand the ‘why’ behind your asks of them.”

Client communication and education are crucial in achieving optimal outcomes for the patient while setting and meeting client expectations. This means starting with the basics and explaining what Cushing syndrome is, as well as teaching them the major effects of glucocorticoid hormones on the body. It also means making sure they’re aware of the differences between annoying symptoms and serious complications so that they know when to seek help.

For pituitary-dependent Cushing [syndrome], Cairns had a stark recommendation: “I always say to the client, ‘This means your dog has a brain tumor.’ They need to hear that.” This comment leads into a good news/bad news conversation with the patient.

“The good news is that most dogs don’t die of Cushing [syndrome], studies show.…The bad news is that this is going to progress,” Cairns said. “It’s not goodbye, but the treatment is forever.”

Cairns recommended considering handouts to support client education efforts. She also suggested have one or more technicians become the “Cushing Ambassador” for clients. These ambassadors can serve as the point person for conversations and client questions after the initial conversations with the veterinarian.

The key takeaway from Cairns’ talk: There is no one-size-fits-all solution to diagnosing and treating Cushing syndrome. Multiple factors go into ensuring the case is a success from the standpoint of the patient’s health as well as the client’s expectations. When clinical diagnostic information doesn’t provide a clear path forward, practitioners should be asking themselves these important questions to determine the best course of action for a particular case.

References

1. Cairns K. Is this Cushing’s and do I care? Presented at: Fetch dvm360® Conference; San Diego, California. December 2-5, 2021.
2. Cairns K. Treatment option considerations for hyperadrenocorticism in dogs. University of Tennessee College of Veterinary Medicine. Updated January 27, 2016. Accessed December 3, 2021. https://vetmedsp.tennessee.edu/vmc/dls/Endocrinology/Documents/Treatment%20Considerations.pdf