If you want to work with animals many of the organisations listed on this site would be grateful for another pair of hands.
The Cinnamon Trust seeks volunteers to form a bond with an owner and pet, by giving a helping hand in the pet's care, whilst the animal remains with its owner at its own home.
Several larger charities such a the RSPCA have guidance on their site for both volunteers and those considering a career in animal care
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Smaller, local charities may need help fundraisng in additon to practical animal care.
International aid organisations like WSPA have several fundraisng schemes in operation which you can tap into. These may be a naming contest, raffle, or sponsored event. Check the site for details.
www.bluecross.org.uk has opportunities for volunteers to help their work
Links to all the organisations mentioned here can be found on Lost and Rehome pages.