Whenever there is an obvious change in how a dog is acting, one of the first things to look at is possible medical issues that may be causing the dog to act differently. Many conditions include behavioral changes, which can be interpreted as being moody as one of the symptoms. This includes:
In general, worms can make a dog act lethargic and this may be accompanied by a lack of appetite. This alone can make a Chihuahua seem depressed and not quite like himself. In the case of tapeworms, another symptom is restlessness; and therefore there may be mood swings of both feeling down and showing agitation.
Other signs do include evidence of the worms in the stools, coughing, vomiting, possible changes to the skin or coat and in some cases, diarrhea.
Along with weight changes and skin changes, a Chihuahua with abnormal thyroid levels can behave very moody by displaying both signs of fearfulness and aggression.
Arthritis: When an older, senior dog gradually acts more moody, this can point to arthritis which worsens over time. A senior Chihuahua may have dealt with minor discomfort, but as the disease progresses, he is struggling more and having a hard time coping.
Signs of this are difficult getting up from a down position, trouble going up or down steps, inability to keep up on walks as before and/or favoring a certain limb. Since arthritis is a degenerative disease, moodiness may gradually creep in.
Any medical condition ranging from allergies
to cancer all have the ability to rob a dog of his otherwise happy state can cause him to be moody. Any issue that makes a dog feel uncomfortable or suffer from discomfort will affect his moods.
Dogs that are not feeling well will act down in the dumps, often retreating to be alone, will have trouble acting happy and some may show aggressiveness when approached.
Just a 1.5% loss of normal water levels in the body, which would be considered to be slight dehydration can cause several issues with a dog including loss of enthusiasm, being more tired that normal and a range of minor mood changes.
For this possible issue, you'll want to access if your Chihuahua has been drinking enough water. Offering flavored ice cubes (water mixed with apple or orange juice) can help bring levels up to normal.
What to do:
Whenever there are severe mood changes, making sure that your Chihuahua has a full health checkup is recommended. Even if your dog just recently had a vet visit, a health issue
could have developed from that time to now.
The veterinarian should perform a full physical that includes examining all body parts, checking the ears, nose, eyes, throat and pulse, a complete blood count (CBC), urinalysis, thyroid hormone testing and usually a stool check (you will be asked to bring in a stool sample).
Many disorders are much easily treated when caught early and for some including heartworms, early detection is vital for successful recovery.