Chiari-like Malformation and Syringomyelia

CM stands for Chiari-like malformation, which is characterised by a defect in the development of the skull causing the hind-part of the brain to herniate or protrude from the opening at the rear of the skull.

This can place pressure on the spinal cord and alter the flow of cerebrospinal fluid (CSF) along the small space in the centre of the spinal cord, which is called the central canal. As a result, a fluid-filled cavity may develop within the spinal cord,called a syrinx. The presence of one or more syrinxes in the spinal cord is the condition termed syringomyelia (SM).

Each dog gets a CM grade of 0, 1 or 2 with grade 0 showing no evidence of CM.

Each dog is also graded for SM.

• Grade 0 - normal
• Grade 1 - (CCD) central canal dilation which has a central diameter of less than 2mm
• Grade 2 - (SM) central canal dilation which has a central diameter of 2mm or more, separate syrinx, or pre-syrinx with/without central canal dilation

The grade is followed by an "a, b or c" to determine age of the dog.

• a - over 5 years old
• b - 3 to 5 years old
• c - 1 to 3 years old

Possible Test Results :

• CM0 SM0 a
• CM0 SM0 b
• CM0 SM0 c
• CM0 SM1 a
• CM0 SM1 b
• CM0 SM1 c
• CM0 SM2 a
• CM0 SM2 b
• CM0 SM2 c
• CM1 SM0 a
• CM1 SM0 b
• CM1 SM0 c
• CM1 SM1 a
• CM1 SM1 b
• CM1 SM1 c
• CM1 SM2 a
• CM1 SM2 b
• CM1 SM2 c
• CM2 SM0 a
• CM2 SM0 b
• CM2 SM0 c
• CM2 SM1 a
• CM2 SM1 b
• CM2 SM1 c
• CM2 SM2 a
• CM2 SM2 b
• CM2 SM2 c

Chiari-like Malformation and Syringomyelia is a recommended test for the following breeds :

• Cavalier King Charles Spaniel
• Griffon Bruxellois