1. 1. Brown, M.R., Thompson, C.A. and Mohamed, F.M. 2005. J. Vet. Diag. Invest. 17: 272-276.
2. 2. Clercx, C., McEntee, K., Snaps, F., Jacquinet, E. and Coignoul, F. 1996. J. Am. Anim. Hosp. Assoc. 32: 139-145.
3. 3. Jones, T.C., Hunt, R.D. and King, N.W. 1997. pp. 528-529. In: Veterinary Pathology, 6th ed. (Jone T.C., Hunt R.D., King N.W. eds.), Williams & Wilkins, Baltimore.
4. 4. Heseltine, J.C., Panciera, D.L. and Saunders, G.K. 2003. J. Anim. Vet. Med. Assoc. 223: 821-824.
5. 5. Holoymoen, J.I., Bjerkas, I., Olberg, I.H. and Mork, A.V. 1982. Nord. Vet. Med. 34: 362-367.