But it wasn't the Burgman College year 12 student who's health was in danger it was her champion horse's, Wallaroo Tallow.

''It's actually really lucky that he's still alive,'' Gruen said.

''Its quite an incredible journey that we've been on with him.''

Eighteen months ago Tallow was diagnosed with diabetes an uncommon ailment among horses.

Gruen said her family was unsure initially about what was going on with his health.

''About a year and a half ago, he was really really sick and no-one knew what was wrong with him,'' she said.

''He had really bad founder, which is where their feet get really sore and they can't walk properly. And we had lots of blood tests done.''

The blood tests showed that Tallow had diabetes.

''He has to have a very strict diet,'' Gruen said.

''He's not allowed to eat grass, and he has to have soaked Lucerne hay three times a day ... he basically can't eat sugar.

''He seems to be quite happy, and as long as he's happy then we'll just keep him going,''

And he is back, healthy, and winning again.

Gruen and Tallow are doing so well that they are taking on unfamiliar events such as dressage.

For more, pick up a copy of today's Canberra Times