Affiliation:
1. Veterinary Ophthalmology Services North Kingstown Rhode Island USA
2. Department of Small Animal Clinical Sciences, College of Veterinary Medicine University of Tennessee Knoxville Tennessee USA
3. Department of Otorhinolaryngology, Smell and Taste Clinic Technische Universität Dresden Dresden Germany
4. Institute of Psychology University of Wrocław Wrocław Poland
Abstract
AbstractPurposeTo evaluate olfaction in dogs with sudden acquired retinal degeneration syndrome (SARDS) compared with sighted dogs and blind dogs without SARDS as control groups.Animals StudiedForty client‐owned dogs.ProcedureOlfactory 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.ResultsSixteen 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.ConclusionsDogs 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.
Reference94 articles.
1. Sudden acquired retinal degeneration in the dog: clinical and laboratory findings in 36 cases;Van der Woerdt A;Prog Vet Comp Ophthalmol,1991
2. VainisiSJ SchmidtGM WestCS et al.Metabolic toxic retinopathy‐preliminary report (abstract). 14th Annual Meeting of the American College of Veterinary Ophthalmologists. 1983;14:76‐81.
3. AclandGM IrbyNL AguirreGD GrossSL NitroySF NotarfrancescoKL.Sudden acquired retinal degeneration in the dog: clinical and morphologic characterization of the “silent retina” syndrome (abstract). 15th Annual Meeting of the American College of Veterinary Ophthalmologists. 1984;15:86‐104.
4. AclandGM AguirreGD.Sudden acquired retinal degeneration: clinical signs and diagnosis (abstract). 17th Annual Meeting of the American College of Veterinary Ophthalmologists. 1986;17:58‐63.
5. RiisRC.EM observations of a SARD case (abstract). 21st Annual Meeting of the American College of Veterinary Ophthalmologists. 1990;(21):112‐113.