Olfaction evaluation in dogs with sudden acquired retinal degeneration syndrome

Research output: Contribution to journalResearch articleContributedpeer-review


  • Kenneth L. Abrams - , Veterinary Ophthalmology Services (Author)
  • Daniel A. Ward - , University of Tennessee System (Author)
  • Agnieszka Sabiniewicz - , TUD Dresden University of Technology, University of Wrocław (Author)
  • Thomas Hummel - , Department of Otorhinolaryngology, Head and Neck Surgery (Author)


Purpose: To evaluate olfaction in dogs with sudden acquired retinal degeneration syndrome (SARDS) compared with sighted dogs and blind dogs without SARDS as control groups. Animals Studied: Forty client-owned dogs. Procedure: Olfactory threshold testing was performed on three groups: SARDS, sighted, and blind/non-SARDS using eugenol as the test odorant. The olfactory threshold was determined when subjects indicated the detection of a specific eugenol concentration with behavioral responses. Olfactory threshold, age, body weight, and environmental room factors were evaluated. Results: Sixteen dogs with SARDS, 12 sighted dogs, and 12 blind/non-SARDS dogs demonstrated mean olfactory threshold pen numbers of 2.8 (SD = 1.4), 13.8 (SD = 1.4), and 13.4 (SD = 1.1), respectively, which correspond to actual mean concentrations of 0.017 g/mL, 1.7 × 10−13 g/mL and 4.26 × 10−13 g/mL, respectively. Dogs with SARDS had significantly poorer olfactory threshold scores compared with the two control groups (p <.001), with no difference between the control groups (p =.5). Age, weight, and room environment did not differ between the three groups. Conclusions: Dogs with SARDS have severely decreased olfaction capabilities compared with sighted dogs and blind/non-SARDS dogs. This finding supports the suspicion that SARDS is a systemic disease causing blindness, endocrinopathy, and hyposmia. Since the molecular pathways are similar in photoreceptors, olfactory receptors, and steroidogenesis with all using G-protein coupled receptors in the cell membrane, the cause of SARDS may exist at the G-protein associated interactions with intracellular cyclic nucleotides. Further investigations into G-protein coupled receptors pathway and canine olfactory receptor genes in SARDS patients may be valuable in revealing the cause of SARDS.


Original languageEnglish
JournalVeterinary ophthalmology
Publication statusPublished - 2023

External IDs

PubMed 37399129
Mendeley 1e7f2922-1eb6-3fd2-b790-55404b3e724d
ORCID /0000-0001-9713-0183/work/150330700


ASJC Scopus subject areas


  • dysosmia, electroretinogram, endocrinopathy, hyposmia, olfactory threshold, retinal degeneration