Well of course it is. The pack gives dose rates for each type of use, including for treating a strike. As with any med, exceeding the recommended dose rate can be dangerous. You have only to read the Operator Warnings for Crovect to realise that this is a very dangerous chemical.
The guidance says, when treating a strike, to use 2.5ml per 100-150cm2, which it says is approx. the size of a human hand, and that most strikes will need 5-10ml.
The maximum dose for any other use of Crovect is 30ml for a 40kg lamb. When treating a strike, 30ml would treat 1800cm2, or the area of 12 human hands.
If you've a lamb to 40kgs with more extensive strike than that, it'll be unlikely to survive anyway, and it'd probably be best to put it out of its misery.