What a cutie! Thank you for taking in a neglected iguana. It makes us shelter operators jobs a little easier. One suggestion though, for Spike's continued good health:
Iguanas are obligate herbivores. They cannot process animal protein of any kind (insects, meat, dog or cat food, etc). Feeding bugs or other kinds of meat leads to kidney and liver failure at an early age.
With a completely vegetarian diet, igs can stay happy and healthy for 20 years or more, rather than the 6-10 years of those raised on animal protein.
IguanaDen has a ton of great info on iguana care and a great diet that we use both on healthy igs and rehabs alike.
Here's hoping Spike continues to have a long, healthy life with you