Effect of brachycephalic, mesaticephalic, and dolichocephalic head conformations on olfactory bulb angle and orientation in dogs as determined by use of in vivo magnetic resonance imaging

Aseel K. Hussein School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G61 1QH, Scotland.

Search for other papers by Aseel K. Hussein in
Current site
Google Scholar
PubMed Close
 BVMS, MSc
,
Martin Sullivan School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G61 1QH, Scotland.

Search for other papers by Martin Sullivan in
Current site
Google Scholar
PubMed Close
 BVMS, PhD
, and
Jacques Penderis School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G61 1QH, Scotland.

Search for other papers by Jacques Penderis in
Current site
Google Scholar
PubMed Close
 BVSc, PhD
DOI:
https://doi.org/10.2460/ajvr.73.7.946
Volume/Issue:
Volume 73: Issue 7
Online Publication Date:
01 Jul 2012
Restricted access
Sign In Reprints and Permissions Purchase Article

Abstract

Objective—To determine the effect of head conformation (brachycephalic, mesaticephalic, and dolichocephalic) on olfactory bulb angle and orientation in dogs by use of in vivo MRI.

Animals—40 client-owned dogs undergoing MRI for diagnosis of conditions that did not affect skull conformation or olfactory bulb anatomy.

Procedures—For each dog, 2 head conformation indices were calculated. Olfactory bulb angle and an index of olfactory bulb orientation relative to the rest of the CNS were determined by use of measurements obtained from sagittal T2-weighted MRI images.

Results—A significant negative correlation was found between olfactory bulb angle and values of both head conformation indices. Ventral orientation of olfactory bulbs was significantly correlated with high head conformation index values (ie, brachycephalic head conformation).

Conclusions and Clinical Relevance—Low olfactory bulb angles and ventral olfactory bulb orientations were associated with brachycephalia. Positioning of the olfactory bulbs, cribriform plate, and ethmoid turbinates was related. Indices of olfactory bulb angle and orientation may be useful for identification of dogs with extremely brachycephalic head conformations. Such information may be used by breeders to reduce the incidence or severity of brachycephalic-associated diseases.

Abstract

Objective—To determine the effect of head conformation (brachycephalic, mesaticephalic, and dolichocephalic) on olfactory bulb angle and orientation in dogs by use of in vivo MRI.

Animals—40 client-owned dogs undergoing MRI for diagnosis of conditions that did not affect skull conformation or olfactory bulb anatomy.

Procedures—For each dog, 2 head conformation indices were calculated. Olfactory bulb angle and an index of olfactory bulb orientation relative to the rest of the CNS were determined by use of measurements obtained from sagittal T2-weighted MRI images.

Results—A significant negative correlation was found between olfactory bulb angle and values of both head conformation indices. Ventral orientation of olfactory bulbs was significantly correlated with high head conformation index values (ie, brachycephalic head conformation).

Conclusions and Clinical Relevance—Low olfactory bulb angles and ventral olfactory bulb orientations were associated with brachycephalia. Positioning of the olfactory bulbs, cribriform plate, and ethmoid turbinates was related. Indices of olfactory bulb angle and orientation may be useful for identification of dogs with extremely brachycephalic head conformations. Such information may be used by breeders to reduce the incidence or severity of brachycephalic-associated diseases.

Contributor Notes

The study and Dr. Hussein were supported by the Iraqi Ministry of Higher Education and Scientific Research.

Address correspondence to Dr. Penderis (Jacques.Penderis@glasgow.ac.uk).
Cover American Journal of Veterinary Research
American Journal of Veterinary Research
Publication Date:
01 Jul 2012

  • 1. Miller ME, Christensen GC, Evans HE. Anatomy of the dog. Philadelphia: WB Saunders, 1964.

  • 2. Stockard CR. The genetic and endocrine basis for differences in form and behavior. New York: The Wistar Institute of Anatomy and Biology, 1941.

    • Search Google Scholar
    • Export Citation

  • 3. Evans HE. The skeleton. In: Miller ME, ed. Miller's anatomy of the dog. Philadelphia: WB Saunders Co, 1993;122–218.

  • 4. Smith BJ. The brain and associated structures. Philadelphia: Nieginski and Nieginski, 1999.

  • 5. Hennet PR, Harvey CE. Craniofacial development and growth in the dog. J Vet Dent 1992; 9:11–18.

  • 6. Regodón S, Vivo JM, Franco A, et al. Craniofacial angle in dolicho-, meso- and brachycephalic dogs: radiological determination and application. Ann Anat 1993; 175:361–363.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 7. Bannasch D, Young A, Myers J. Localization of canine brachycephaly using an across breed mapping approach. PLoS One 2010; 5:e9632.

  • 8. Hunemeier T, Salzano FM, Bortolini MC. TCOF1 T/Ser variant and brachycephaly in dogs. Anim Genet 2009; 40:357–358.

  • 9. Nöller C, Hueber J, Aupperle H, et al. New aspects of brachycephalia in dogs & cats basics: insights into embryology, anatomy & pathophysiology. Proceedings of the ACVIM Forum, San Antonio, Texas, USA, 2008;713–715.

    • Search Google Scholar
    • Export Citation

  • 10. Smith FO. Challenges in small animal parturition—timing elective and emergency cesarian sections. Theriogenology 2007; 68:348–353.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 11. Tseng ZJ, Wang X. Cranial functional morphology of fossil dogs and adaptation for durophagy in Borophagus and Epicyon (Carnivora, Mammalia). J Morphol 2010; 271:1386–1398.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 12. Ellis JL, Thomason J, Kebreab E, et al. Cranial dimensions and forces of biting in the domestic dog. J Anat 2009; 214:362–373.

  • 13. Foley CW, Lasley JF, Osweiler GD. Digestive system: abnormalities of companion animals: analysis of heritability. Ames, Iowa: Iowa State University Press, 1979;119–120.

    • Search Google Scholar
    • Export Citation

  • 14. Hendricks JC. Brachycephalic airway syndrome. Vet Clin North Am Small Anim Pract 1992; 22:1145–1153.

  • 15. Hedlund C. Brachycephalic syndrome. In: Bojrab MJ, ed. Current techniques in small animal surgery. 4th ed. Baltimore: The Williams & Wilkins Co, 1998;358–362.

    • Search Google Scholar
    • Export Citation

  • 16. Beitz AJ, Fletcher TF. The brain. In: Miller ME, ed. Miller's anatomy of the dog. Philadelphia: WB Saunders, 1993;894–952.

  • 17. Williams P, Warwick L. Gray's anatomy of the human body. Philadelphia: Lea and Febiger, 1973.

  • 18. Schwarz T, Sullivan M, Hartung K. Radiographic anatomy of the cribriform plate (lamina cribosa). Vet Radiol Ultrasound 2000; 41:220–225.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 19. Hayes HM, Priester WA, Pendergrass TW. Occurrence of nervous tissue tumors in cattle, horses, cats and dogs. Int J Cancer 1975; 15:39–47.

  • 20. Lyras GA. The evolution of the brain in canidae (Mammalia: Carnivora). Scripta Geologica 2009; 193:1–93.

  • 21. Weidenreich F. The brain and its role in the phylogenetic transformation of the human skull. Trans Am Philos Soc 1940; 31:320–442.

    • Search Google Scholar
    • Export Citation

Advertisement