616 Journal of Small Animal Practice • Vol 52 • November 2011 • © 2011 British Small Animal Veterinary Association

LETTER

Dermoid sinus in Burmese cats

MADAM

In the June issue of the JSAP there was an excellent paper from colleagues in Finland concerning three dogs and a Burmese cat with dermoid sinus, spina bifida and neurological signs refer-able to a tethered spinal cord (Kiviranta and others 2011). The authors cite a paper concerning another Burmese cat from Australia with the same congenital anomaly ( Tong and Simpson 2009). We would like to briefly provide data on a third Burmese cat with a dermoid sinus and tethered spinal cord diagnosed at Sylvania Veterinary Hospital in Australia.

The cat was sold as a healthy kitten, but slowly developed signs of a hindlimb weakness and proprioceptive ataxia. A cervi-cal myelogram showed a dorsally tethered spinal cord, with con-trast medium tracking away from the subarachnoid space within the vertebral column, extending into a dermoid sinus in the cra-nial thoracic region (Fig 1). The cat was subsequently euthanased (Fig 2).

As Ian Fleming famously wrote (Fleming 1959), “Once is happenstance. Twice is coincidence. The third time it’s enemy action.” In this instance, it seems highly likely that the observed dermoid sinus represents an inherited neural tube defect in the Burmese breed, as it is in the Rhodesian ridgeback (and several other canine breeds). With the recent availability of the feline single nucleotide polymorphism microarray, it would be quite feasible to try to unravel the genetic basis of this problem at the molecular level, as has recently been done for Rhodesian Ridge-back dogs (Karlsson and Lindblad-Toh 2008). It might also be valuable to palpate young Burmese kittens at the final vaccina-tion examination for the presence of a dermoid sinus or a raised dermal papule between the scapular blades. Such a physical sign

might prompt further investigation of kittens prior to sale. There is a further report of a dermoid sinus in a Balinese cat from the United Kingdom (Henderson and others 1993).

We intend looking more carefully at Burmese cats in Australia for more widespread evidence of this defect. We would be very interested to hear from colleagues who have diagnosed similar cases in this or any other breed of cat.

David Simpson, Randolph Baral*, David Lee†, Michelle Sutherland† and Richard Malik‡

The Animal Referral Hospital, *Paddington Cat Hospital, †Sylvania Veterinary Hospital and ‡Centre for Veterinary Education, The University of Sydney, Sydney, New South

Wales, Australia

E-mail: richard.malik@sydney.edu.au

ReferencesKIVIRANTA, A.M., LAPPALAINEN, A. K., HUAGNER, K. & JOKINEN, T. (2011) Dermoid sinus

and spina bifida in three dogs and a cat. Journal of Small Animal Practice 52, 319-324

TONG, T. & SIMPSON, D. J. (2009) Spinal dermoid sinus in a Burmese cat with paraparesis. Australian Veterinary Journal 487, 450-454

FLEMING, I. (1959), Goldfinger. Jonathan Cape, LondonKARLSSON, E. K. & LINDBLAD-TOH, K. (2008) Leader of the pack: gene mapping in

dogs and other model organisms. Nature Reviews Genetics 9, 713-725HENDERSON, J. P., PEARSON, G. R., SMERDON, T. N. (1993) Dermoid cyst of the spinal

cord associated with ataxia in a cat. Journal of Small Animal Practice 34, 402-404

FIG 1. Cervical myelogram in a young Burmese cat with progressive hind limb ataxia and weakness. Note the widening of the ventral contrast column (*) caused by elevation of the thoracic spinal cord due to dorsal traction of the dermoid sinus (arrow), which extends to the skin surface. A microchip is situated cranial to the sinus. A synostosis malformation of the T4 and T5 vertebrae was also present

FIG 2. Necropsy photograph of the dermoid sinus extending down to the dura overlying the thoracic spinal cord

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