C-reactive protein (CRP) is a major acute phase protein and a marker of systemic inflammation in dogs. C-reactive protein, and indirectly the innate immune system, has not previously been evaluated in dogs with hypoadrenocorticism (HA). Accordingly, the aim of this study was to investigate if dogs with HA were able to mount an acute phase response assessed by an elevated CRP.

Medical records were reviewed for patients newly diagnosed with hypoadrenocorticism between May 2010 to March 2017. Dogs were considered having HA if both a pre- and post-ACTH stimulation cortisol were ≤55 nmol/L. Dogs were excluded if they were not newly diagnosed with HA, or had received treatment for either hypoadrenocorticism or hyperadrenocorticism, or if they did not have a CRP measured around the time of diagnosis.

Three hundred and twenty-two medical records from dogs with an ACTH stimulation performed were screened. Seventeen dogs with HA were identified. Of these, nine dogs with hypoadrenocorticism were included in this retrospective case series. The median age at time of presentation was 5.5 years and included three intact males, two neutered males, two intact females and two spayed females. The most prevalent clinical signs included vomiting (6/9), weight loss (6/9), and diarrhea (3/9), and all of the dogs had at least one of these clinical signs. Six of nine dogs had azotemia. The mean CRP was 62.2 mg/L, with an inter quartile range: 20.45–89.66 mg/L (reference 0–25 mg/L). Seven out of nine dogs had an elevated CRP. Interestingly, the two dogs with normal CRP were non-azotemic and clinically stable at the time of presentation.

In conclusion, dogs with hypoadrenocorticism are able to induce CRP production. This could indicate that at least part of the innate immune response is functional. Dogs with HA often have a normal neutrophil count, making neutrophils unreliable as marker of inflammation in HA. C-reactive protein could therefore be a useful biomarker for acute inflammation in patients with HA when other markers of inflammation are not reliable.

Disclosures

No disclosures to report.