Symptoms

The onset of the disease is noticed when the kitten is between 15 and 17 weeks old. It begins with weakness of the hind limbs and a slight, spreading tremor.

Kittens with the condition develop a strange, shaky way of walking with the hind legs and stand in the direction where the heels almost touch each other. They lose the powerful jumping ability by the time they are five months old and then walk with their abdomen in a wobbly way. Abnormal sensitivity to spinal contact, movement intolerance (poor condition), and heavy breathing are often noticed. After an initial period of rapid loss of function, the development of the condition is delayed or even stopped, with varying muscle atrophy, weakness, and mobility.

Life expectancy and quality of life in SMA are generally limited, but there are significant differences in severity and progression. Kittens with the condition are not in pain, they usually eat and play enthusiastically, are not incontinent and sometimes lead a comfortable life as a domestic cat for years. SMA cannot be cured. Any treatment is only aimed at relieving the symptoms.

In the meantime, a DNA test has been developed to show the presence of the defective gene. This means that with a responsible breeding program, SMA sufferers can be prevented.