What do you put in a 

First Aid Kit ?

Thermometer
Dedicated to dog use only! Learn what "normal" is for a dog

Peroxide
 
It can be used to clean any area of the body EXCEPT the eyes. You can clean the ears, wounds, abscess or scrapes without injury or added pain to your dog. It can also induce vomiting

Salt 
It can also be used to induce vomiting so do not allow them to lick or drink. Salt soaks are also useful to reduce swelling or remove foreign bodies.

Antibiotic Ointment
Scrapes, minor cuts can be treated with a broad based antibiotic ointment topically. 

Benedryl liquid
Good for mild allergic reactions to bites or allergens. If stung by a bee, a treatment of benedryl will buy you time to get to a vet especially if it is in the mouth.

Cold/hot pads
Useful if required for shock, injuries etc.

Sanitary pad
This works well as a bandage to put on any open wound to add pressure to stop bleeding. Do not use on a broken bone or exposed bone.

Gauze pads and gauze tape
Used to cover and wrap any wounds to protect them from licking or further infection

Cotton Balls
Used to clean areas 

Tensor or vet wrap
Vet wrap works best to keep the bandages in place

Telfa pads
For covering wounds to prevent sticking

Scissors and tweezers
Dedicated for your dog's use to cut back unwanted hair to see wounds, pick off ticks etc, cut bandaging