Here are some signs to indicate a stressed pet.
Itching. Most of the time, this isn't a symptom of stress. There are other more obvious reasons for itching like ticks, fleas, lice, rashes, skin allergies, etc. But if these reasons aren't present or they are scratching more than normal then stress becomes a troubling possibility.
Shedding. A bit of shedding is normal. A lot of shedding isn't. Most instances of shedding are due to a poor diet or the animal isn't getting enough sun. Sometimes it's a genetic trait. But it's also a sign of increased stress levels. Remember your teacher complaining that the trouble you made could cause them to grow bald. Well stress does this to all animals.
Lethargy. If your pet doesn't want to do anything, then something is wrong. Pets are active creatures. If they're not, then they could be depressed, unhealthy, unhappy or completely stressed out.
Aggression. Most pets are not aggressive to their owners. If they are, they are usually sick or injured. They simply don't want to deal with an owner that's pushing them to play when they can't. However, this aggression also points to stress as a reason.
No appetite. Pets that are not in prime condition will not eat much. This usually means they are sick or stressed.
Lacking interest. Is your pet just sitting there when something that made him jump up and down appeared? This is troubling for any pet owner. If he's not actually sick then stress may have gotten hold.
Passivity. Stress can make animals not just care about anything.
Negativity. Stressed pets will send out negativity in droves. It can lead to a display of bad behavior like barking constantly or chewing anything.
Changed potty habits. You could have the most well trained pet in existence. But once stress hits, it could turn them into careless, uncaring animals who does his 'business' in the wrong place. Stress or depressed animals do this.
Sounds. If your animal is making a sound then that could be a sign of stress. Dogs will bark and cats will purr. Listen to your pets and hear what they have to communicate.
Body language. If your pets suddenly change their body language then stress could be heavily affecting them. Humans slouch when stress hits and this behavior has counterparts in the animal kingdom.
Article Source: http://EzineArticles.com/?expert=Jonathan_J_Russell