1) Separation Anxiety
Whether it's a dog or a cat, every time you head out the door, they start acting up. This is especially true with puppies or a newly adopted pet. Certain signs like you grabbing your keys or putting on your shoes can trigger stressful behavior in them. This anxiety can cause them to chew on furniture or shoes, excessive barking, or even harming themselves.
The best thing to do is not respond to their behavior. Act like your pet is invisible and never say things like "Don't worry, I will be right back", this will just cause them to be more anxious. The way to desensitize them about you leaving, is to sometimes go out and come back in, or pick up your purse or keys and then put it away or start your car, turn it off and come back in.
This way they will realize that your comings and goings are natural. You can also try giving them treats when you are about to leave, so they will associate you leaving with something positive.
2) Fear of Thunderstorms or Fireworks
This is the most common fear in any pet, be it a cat or dog or even a horse. It is usually the booming sounds added with flashes of lightning that can scare them. To desensitize them to thunder or lightning, try playing a CD with thunder sounds. Start at a low volume and play with him throughout this process, cuddle them or give them treats while you slowly increase the volume.
As for lightning, you can take their pictures with a camera that has flash. They will soon realize that the noises and flashes are harmless. However, thunder and lightning are caused by a change in weather or biometric pressure. This can really set a dog off. In this case you can help him relax or try a pheromone collar like D.A.P collar that has dog appeasing pheromones to keep them calm or a new item called Thundershirt that helps them feel more secure.
3) Fear of Vacuums or Household Appliances Like Blenders
Vacuums and blenders or food processors are especially menacing to small breeds, because they seem big to them. This is an easy fear to overcome, just put them in a different part of the house when you vacuum so he is not exposed to the sound or the whirring of a vacuum.
But if you want to train your dog out of hating the hoover, play a CD of vacuum sounds at a volume your dog can handle, and give him his favorite treat or play his favorite game with him. Do this for 10 or 15 minutes; then, when the sound stops, the fun stops. Do this repeatedly over the course of a week, slowly turning up the volume each time. Once your dog gets used to this routine, every time you vacuum, you can give him a treat, and he will relate vacuuming as a normal experience.
4) Fear of Strangers
This fear stems from puppyhood, usually to puppies who don't meet lots of people between the age of 3 weeks to three months. However, it is not just lack of socialization that causes fear of strangers. Sometimes dogs are afraid of people because they might have been mistreated in the past or someone accidently scared it when it was young. This fear should be addressed right away as dogs become aggressive and bite strangers or refuse to go out at all.
Keep your dog somewhere safe but at a visible distance when you have a visitor in your house. Next step would be to slowly bring him out on a leash when he is ready and calm. Make sure that your visitor or guests know not to look or touch your dog, because that can aggravate him. If your dog does not react right away, you can try bringing him closer to the visitor but don't force interaction otherwise the dog might lose trust in you. If your guest is comfortable, you can even have them give your dog a treat, that way they associate visitors with a positive experience.
5) Fear of Other Dogs
Just like fear of strangers, your dog could be afraid of other dogs, big or small. It's the same theory, if they are not socialized early on or if they have had a bad experience with bigger dogs when they were puppy, they learn to distrust them.
If your dog lunges or barks at other dogs, when they want to greet other dogs, it's called barrier frustration. The solution is simple, when you encounter another dog or pet, just turn your pet's back to them and give them a treat. This not only serves as distraction but also acts as a reward for keeping calm.
6) Fear of the Vet or Groomer
Majority of people don't like going to the dentist, it's the same with your pet. All those unpleasant medicinal scents or grooming equipments can act on their nerves. He may also notice that other dogs in the waiting room are afraid from their body language and barking.
You need to show him that not every trip to the vet or groomer will be uncomfortable. Try taking him in when you don't have an appointment, reward him and leave. At times you can try handling your dog like a vet or a groomer might, so he doesn't view being held down horrible.
7) Fear of Travel or Car
Your dog may not fear your vehicle so much as where you're going, especially if your dog hops in the car only to visit the vet or the groomer. You can start making your dog comfortable by pulling in into a fenced area and opening all the doors. Let them off the leash and throw in some of their favorite toys. This will help them get rid of their claustrophobia, and also show them that a car is a safe place.
If your pet has another pet friend, you can invite him along, this helps your pet in trusting the car as a safe place. Keep travel distances short in the beginning, and take them to the dog park or other fun places. Soon they will start associating travel as going to a fun place, even if it's not always the dog park.