Many people consider hyperactivity normal for Chihuahuas, as if it is impossible for a tiny dog to control himself. Hyperactivity is never normal in any dog, except for very young puppies, who are normally curious and boisterous. True hyperactivity is rare and can only be diagnosed by a veterinarian.
Hyperactivity could be a sign that your dog is bored. Dogs are intelligent animals that like to be active and productive. If your Chihuahua does not have your companionship or at least a toy to play with, he will try to amuse himself -- or will try to get your attention -- by getting into mischief. This kind of hyperactivity can be cured by giving your dog an interactive toy or simply by playing games with him yourself. Taking your dog for a walk is a simple and inexpensive cure for your Chihuahua’s boredom.
Obedience and Trick Training
Many Chihuahuas are hyperactive because they lack obedience training. Instead of being taught control over their behavior by learning to sit, lie down or stay, many Chihuahuas are carried everywhere or, worse, are given leniency for their bad behavior because they are small. Even basic or “pet” obedience training gives your Chihuahua a chance to use his mind, and trick training can be fun for both of you. Don’t be surprised if your dog starts offering you the behaviors you’ve taught him if he wants to get your attention -- he is signaling you that he wants to learn even more.
Dogs are more likely to have hypothyroidism -- too little production of the hormone thyroxine -- than they are to have hyperthyroidism. However, if your Chihuahua develops a tumor on his thyroid, he may also develop hyperthyroidism. Hyperthyroidism may also occur if your dog is taking medication for hypothyroidism, as an inappropriate dosage can stimulate excessive thyroxine production. Hyperthyroidism is usually evident even before diagnosis through his inability to maintain his weight despite an increased appetite, an abnormally fast heartbeat and persistent activity. If you think your Chihuahua has these symptoms, take him to the veterinarian for testing. If your dog has hyperthyroidism, it can be treated; however, the condition will have to be managed throughout his lifetime. Treatment includes surgery and lifetime hormone management.
Physical Pain or Discomfort
Dogs are typically reluctant to show pain or discomfort. If your Chihuahua seems to be unusually active, he may be in distress from fleas, internal parasites or an unseen injury that does not allow him to be comfortable. Take your dog to your veterinarian to determine what might be distressing your dog. Many things that might cause your dog to be uncomfortable are easily treated if they are diagnosed.
Barking is Not “Hyperactivity”
Barking, no matter how persistent, is not a hyperactive behavior. Rather, it is a symptom that something is wrong with your dog or that he perceives that something is wrong in his environment. Your Chihuahua might bark simply because he is bored and barking gets your attention -- and even negative attention may seem better than no attention at all. If your dog does not stop barking after increased activity or play or if he seems to be in distress, he might have a physical problem causing him to bark.