ECC Suggested Readings
April 2025
Christopher G. Byers, DVM, DACVECC, DACVIM (SAIM), CVJ
I'm a practicing criticalist/internist based in Omaha, Nebraska, USA who works full-time at VCA MidWest Veterinary Referral and Emergency Center and as locum teleconsultant for VET.CT. My clinical areas of interest are hematology/immunology, fluid therapy, sepsis, and endocrinology.
A paper that I recently liked…
Comparison between typical primary and eunatraemic, eukalaemic hypoadrenocorticism: 92 cases
Adrien Joaquim Da Silva, Eilidh Gunn, Pedro Jose Guzmán Ramos, Robert Edward Shiel, Laura Bree and Carmel Therese Mooney
Ir Vet J. 2024 Sep 28;77(1):18. doi: 10.1186/s13620-024-00280-1.
Paper Commentary
The study design
The study was a retrospective observational study of 92 dogs in Ireland with aims to describe any significant differences between primary typical and eunatremic/eukalemic hypoadrenocorticism (EEH) in a large cohort of patients and to determine the diagnostic utility of aldosterone concentrations in patients with EEH.
The study background
As one who loves endocrinology, hypoadrenocorticism has always been one of my favorite disease entities to treat. Patients with eunatremic/eukalemic disease (so called "atypical" Addison's) have always fascinated me given the fact electrolyte concentrations may remain within reference intervals despite aldosterone deficiency. Given the dearth of published data about this Addisonian manifestation, I was interested to explore more data that may be useful for making an efficient and accurate diagnosis of EEH.
Study considerations
Although this study was retrospective in nature, I do believe the data presented are a welcomed addition to the veterinary literature regarding EEH in canine patients. This study documented some similar findings to previously published data (e.g., EEH patients were older at time of diagnosis, similar incidence of occurrence). I found documentation of significant reticulocytosis in EEH patients to be very interesting; indeed, when combined with concurrent increased incidence of anemia and hypoalbuminemia documented in EEH patients, consideration of occult gastrointestinal bleeding seems very appropriate. I was also intrigued by the potential utility of measuring aldosterone to help confirm a diagnosis of hypoadrenocorticism, especially in patients with equivocal ACTH stimulation test results or those that had received prior corticosteroid therapy. All dogs with primary typical hypoadrenocorticism had undetectable basal and post-ACTH aldosterone concentrations, including a handful that had received dexamethasone within seven days of presentation. Basal aldosterone was undetectable for one third of EEH patients and remained undetectable in 60% of those patients post-ACTH stimulation.
Takeaways
Hypoadrenocorticism should be considered in any patient with gastrointestinal signs before proceeding with invasive diagnostics. Unexplained reticulocytosis should raise suspicion for hypoadrenocorticism and prompt screening. Basal undetectable aldosterone concentrations are a strong indicator of low post-ACTH aldosterone levels and can be used to confirm the diagnosis in patients with prior glucocorticoid administration or equivocal ACTH stimulation results. In EEH patients, normal electrolyte levels can be maintained if aldosterone concentrations are sufficient, but mineralocorticoid deficiency, evidenced by electrolyte abnormalities and/or aldosterone deficiency, may develop over time.
