Foxton Raceway says it is unlikely it can rebuild facilities damaged in two fires this weekend.
The first on Friday night extensively damaged the member's grandstand. A stable building was destroyed in the second on Saturday night.
The Fire Service is treating the fires as suspicious.
Ponies trapped in the stable are understood to have been freed and were not injured.
Raceway president Jim Jaggard says the club is unlikely to be able to afford to rebuild.
About a quarter of the main stand was damaged in Friday night's fire and much of the remainder is smoke damaged.
The club committee will meet on Monday to decide if it can still host the Wellington showjumping championships this coming weekend.
