The right toys are vital.
Toys filled with peanut butter or toys that hold kibble but are designed to make a dog really work to retrieve it can be incredible helpful. Many dogs will whine as an owner prepares to leave, however once the toy is 'discovered' it can keep a Chihuahua busy for hours.
Additionally, a SnugglePet - a soft stuffed animal that emits a soothing heartbeat - has been proven to help many dogs with anxiety issues. It becomes a 'mothering' toy - both both males and females alike- and a companion that makes a dog feel that he is not truly alone.
Plan your arrival approach.
As mentioned above, leaving should be a calm event in which an owner behaves as if it is "no big deal", however arriving back home should be planned out for dogs that suffer from separation stress. Some dogs will work themselves up into a frenzy as soon as they hear their owners car pull up to the driveway.
As the front door opens, the dog may have little control. Helping a Chihuahua cope with being home alone will include teaching him to control his behavior both before and afterward.
If an owner rushes over to a dog as soon as arriving back home, this gives confirmation to a dog that thought being alone was the worst thing in the world. Unless it is clear that an immediate trip outside is needed, it can help to enter and not approach or speak to a puppy or dog for 4 to 5 minutes.
Casually checking the mail, getting a drink of water, straightening off the kitchen table, etc. and then calming approaching a dog can give the message that leaving and arriving was an acceptable part of daily life.
Gradually desensitizing a dog to your absence can work with some dogs.
This is best done on weekends or other days on which the dog has not endure a bout of Separation Anxiety. This method involves leaving for short amounts of time that the dog can handle. For some this many be 5 minutes, for others a full hour. With all chew, teething, treat and cuddle toys in place and the dog in his designated area, the owner calmly departs.
While it may be tempting to stand by the front door, for some Chihuahuas, it is the sound of the car's engine that triggers the fear of isolation. An owner may circle the block or park down the street to quietly walk back and spy on how things are going.
Once it has been established that a dog does alright for a certain amount of time, the owner then adds on 5 to 10 minutes to that set time. Arrival back home should be as described earlier, without a lot a big fuss and a delayed greeting.
In this way, a Chihuahua can slowly gain self-confidence. When a dog realizes that all is fine during short duration, he can often handle incrementally longer periods without stress or fear settling in.
Calming Collars -
These have been found to help for some puppies and dogs. These are an over-the-counter accessory that uses pheromone technology.
These have mixed reviews and the ones that seem to work best use a lavender and chamomile fragrance that does calm down some dogs. The most highly ranked collar is by Sentry and can be adjusted to fit toy sized dogs. The price is relatively inexpensive and these can be found in a 3-pack, with each collar lasting 30 days.
Supplements and Treats for Separation Anxiety -
Specialized treats - especially those with colostrum calming Complex, L Theanine, and Thiamine (Vitamin B1) have been found to help some dogs calm down and relax without interfering with cognitive ability or changing the dog's core behavior. They are said to promote relaxation and calm irritability.