When your beloved animal companion is ready to transition, there are some things you may want to consider.
First, intuitively check in with your animal to find out if it is really time to help them with their crossing. If you are unable to do this, hire an animal communicator to assist you. I've worked with animals where it appears that they would want to cross, but they actually want to do a couple things or say a few things to you before they leave. Of course, sometimes, they are really ready. Remember that they are not afraid to die. They are actually more concerned about our well being at this time, than their crossing.
It is very important to give them permission, telling them it's okay, that you are sad and will miss them, but you'll be okay. Sometimes they wait until they actually hear their human tell them this.
Tell them how much you love them and appreciate all that they have done for you, and what you have learned from them.
You can also ask them to come back into your life in another body, if they want to. Tell them that if they decide to return, to make it really clear and obvious that it's them. :) They may decide to stay in spirit form, let them know that it's okay if they don't want to come back. They may feel that they can help you in higher levels, from the other side.
Really feel, sense and hear their essence, so when they 'visit' you when they are in spirit form, you'll know it's them. I've had clients tell me they swear they saw their pet out of the corner of their eye; or, they felt them brush against their legs. Some people will feel a heaviness on the bed, where the animal used to sleep. These are just a couple examples of how you'll know they are visiting. Remember that if you feel, see or sense them after they passed, BELIEVE it is them.
If your animal companion has a pack or some friends, that don't live in the house, you may want to invite them all over to have a visit before he/she crosses. Make it a celebration of their life (happy occasion).
We all know the sadness and grief that comes along with losing a pet in their physical form. Honor these feelings of grief. Know that they will ALWAYS be with you in some form and that they have unconditional love for you. I've never met an animal who is in spirit form that is 'mad' at you for whatever reason you may think they may be. They love you, always.