Experienced and professional animal trainer provide their insights in answering this question :
A. It can be caused by some pain or unnoticed injury. It can be also fleas infestation, neurological problem…See your vet to check what is going on

How to Identify Common Pet Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced pet care professionals :

Pain and discomfort

Pain: If your dog is in pain, it may remain hidden or become reluctant to interact with the family. Your dog may seem to be panting more than usual or trembling. You may also notice other signs of pain like irritability, restlessness, or aggression.

Separation Anxiety Can Cause Your Dog to Not Leave Your Side

This is triggered when you and your dog are separated for any amount of time, and some dogs can become very agitated when you leave them behind at home, while others seem depressed when they see you getting ready for work or packing your bags.

Dogs who yelp frequently may also be in pain from an illness. They may have arthritis or another medical condition that contributes to chronic pain. Talk to your vet if you suspect your dog could be yelping from chronic pain or from an acute injury.
What are the typical signs of pain in dogs? General behaviour: Shaking, flattened ears, low posture, aggression, grumpy temperament, panting or crying, excessive licking or scratching a specific area, reluctant to play, interact or exercise, lameness (limping), stiffness after rest, loss of appetite.
Some of the signs of parvovirus include lethargy; loss of appetite; abdominal pain and bloating; fever or low body temperature (hypothermia); vomiting; and severe, often bloody, diarrhea. Persistent vomiting and diarrhea can cause rapid dehydration, and damage to the intestines and immune system can cause septic shock.
When our furry friends are in pain they tend to be more vocal. A hurt dog may express their pain either through whining, whimpering, yelping, growling, and even howling.
Your dog has his reasons for acting out. Boredom, restlessness, fear, and separation anxiety are all common reasons that your dog might bark and whine while you`re gone.
When you leave the house your dog cries because it doesn`t want you to leave him alone and wants you to know that. Regardless of breed, all dogs are capable of growing attached to their owners and experiencing sadness in their absence – though some are more vocal about it than others.
Dogs with a pulled muscle will have symptoms similar to those observed with a torn muscle; however, the symptoms will be milder. Things to look for when a muscle is pulled are muscle spasms, weakness, cramping, and immobility, as well as pain, bruising, and swelling.
The last few days before your dog passes you may notice: extreme weight loss, a distant look in their eyes, a lack of interest in anything, restlessness or unusual stillness, a change in the way that your dog smells, and a changed temperament.
Some of the signs indicating that your dog is sad include sleeping more than usual, not wanting to play or exercise, hiding from you, laying around a lot, not eating as much, staying close to your side but not wanting to be petted, pacing, aggression, and whining.
Parvo smell has a unique very bad-smelling poop that is not easy to forget. The smell has been described as metallic, with hints of blood stench since the virus affects the intestinal walls, and a seemingly sweet scent.
Canine influenza is a viral infection that primarily affects dogs, but can sicken cats, too. Currently, two strains have been identified in the United States: H3N8 and H3N2.
Wincing, Whining or Crying

All three of these actions indicate an injury or some kind of pain your dog is experiencing. If you start to pet your dog and they shy away from your hand or whine, you know there is something wrong.

Whining or crying is another way dogs, especially puppies, express their needs. A dog might whine for you to take them outside, feed them, or play fetch. The high-pitched cry is often your dog`s way of expressing what they want or letting you know they`re unhappy.
Here are a few common causes of dog anxiety symptoms: Fear: Everyone has fears and phobias, and dogs are no different. Sometimes dogs are frightened of new situations and stimuli, like a visit to the groomer or vet. Others may have more ingrained phobias, like loud cars or slick flooring.
Following you very closely can be a sign that they`re bored, they want something, they`re feeling scared or are just being nosy. It is also part of their natural social behaviour, to watch and follow what you are doing to help maintain a good relationship with you.
Let the dog cry it out until he`s `used to it`: This often makes the dog`s aversion for being home alone a million times worse. Anti-bark collar (yes, also the one with citronella): This is at best only focusing on the symptoms without addressing the cause and at worst animal abuse. Just don`t go there.
“Ignoring the whining is your best option,” says Dr. Coates. “Any type of attention will just reinforce the behavior.” Campbell says that pet parents should avoid giving attention or taking a puppy out of the crate until he is quiet.
“In my experience, the four most common breeds of dogs that exhibit signs of separation anxiety are typically Labrador Retrievers, Chihuahuas (both mixed breeds and standards), German Shepherds and Cocker Spaniels”, says Dr.
The Science of Dogs Sensing Crying

Actually, psychological research has indicated that it is a combination of both auditory and visual sensory information that allows a dog to not only sense that someone is crying, but make a connection that this is a negative emotion that requires attending to.

Just like us, dogs tend to be crankier when they are experiencing pain. Here are a few behavioral signs that might indicate that your pet is experiencing pain: Not wanting to be touched.
Avoid speaking in excited, loud tones, and keep your movements slow and calm. Wait to pet and interact with your dog until she`s less excited. It may also help to teach her to do something you`d like her to do instead of whining, such as sitting or hand targeting when she greets you or other people.
If your veterinarian suspects that your dog has pulled a muscle, they will want to prescribe medication to help with the pain and inflammation. Usually, this includes a non-steroidal anti-inflammatory drug, such as carprofen (Rimadyl) or meloxicam (Metacam), and may include a muscle relaxer, such as methocarbamol.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. Why does my dog eat grass?
ANSWER : A. As another user mentioned, dogs can eat grass when they want to vomit. Sometimes, when a dog has an upset tummy, they will eat grass. If you notice your dog eating grass frantically, you can assume vomiting will shortly follow. Grass does not digest and pass normally. If your dog eats too much grass, it can cause serious issues with pooping. Your dogs poop can end up all tangled inside of her, and it can need veterinary assistance to remove it. The same goes for celery, so avoid feeding celery to your dog.

The other day my boyfriend accidentally left the laundry room door open where we were keeping the trash that was filled with cooked chicken bones. She ate one of the chicken bones lightning fast. We had to induce vomiting by feeding her some hydrogen peroxide. After we had fed her the peroxide, she immediately began frantically eating grass because her tummy was upset.

If there is something lacking in your dogs diet, it could be that your dog is eating grass to make up for it. I am sure that my dogs diet is extremely well balanced (I do not only feed her an air-dried raw food-type diet (Ziwipeak), but a wide variety of safe, healthy foods), so when she eats grass, I know that it is because she has an upset tummy.

That is why I think it is important making sure your dog has a very well balanced diet. If your dog is on a low quality kibble, your dog may be trying to let you know by eating grass (or eating poop).

Q. My 9 month old Maltese-Shih eats his own feces. Is there anything i can give him to get him to stop?
ANSWER : A. Coprophagia (or eating stool) is very common in young dogs. Luckily, most dogs will outgrow this behavior as they age. There are several theories as to why dogs do this which range from mimicking the mother dog’s behavior of cleaning the den, nutrient deficiency, boredom or just plain enjoyment of it.

If your dog is eating his own, removing the feces as soon as he deposits them is best in preventing them from being eaten. Keeping your dog on a leash while he potties can also help to catch any stool before he finds it. If he is eating other stool as well, sweeping the area prior to letting him out to go potty can help you identify and remove any left-behind stool.

There is also a product called For-bid that is available to make stool distasteful to pets. This product is sprinkled over every meal for a period of a week. When your dog attempts to eat the stool formed from this product, it becomes distasteful and discourages him from doing so. Most dogs will stop after a week of use, but some may need a few reminders from time to time to completely stop the behavior.

Q. Why do dogs eat grass?
ANSWER : A. Some pet parents get concerned when they see their favorite canine nibbling on grass in the yard. They wonder whether it is because hunger, boredom or an indication of an underlying illness. Often the consumption of grass will result in vomiting because it irritates the stomach and gastrointestinal tract. This is an extremely common problem for dog parents. There is no one reason for why dogs exhibit these behaviors and it is very much dependent on each dog. Here are some of the reasons why our dogs choose to eat grass:

1. Nutritional Issues

Historically speaking, dogs are considered omnivores, which mean they consume a variety of both meat and plant-based food. There is some indication that dogs with a low fiber diet may choose to scavenge in the grass to fulfill this nutritional deficiency. These dogs may also find that grass has an appealing flavor and consistency. If you feel that this may be the reason for your beloved canine consuming grass then consider discussing with your veterinarian on how to incorporate more fiber into your dog’s diet.

2. Boredom

Many dogs who are not receiving adequate exercise will be become bored and search out activities to occupy their time, including eating grass. Evaluate how much exercise your dog is getting on a daily basis and consider more walks or other fun activities, such as playing fetch or tug of war.

3. Upset Stomach

There is a belief that dogs with an upset or gassy stomach will self-medicate by consuming grass. Vomiting often follows this grass eating activity eliminating the contents of the stomach or changing the gas distension within the gastrointestinal tract. However, there is not much scientific evidence to back up this theory. If you are concerned about too much gastric acid in your dog’s stomach or any other underlying medical issue that could be the reason for their grass eating, consult with your veterinarian.

Overall, grass eating is usually not toxic to your dogs unless your lawn contains chemicals, including pesticides or herbicides. Monitor your dog’s behavior along with his diet and exercise to determine if there is a reason for the inappropriate grass snacking.

Q. My dog doesn’t eat, what should I do?
ANSWER : A. If this is a puppy, see a veterinarian immediately. Puppies should want to eat. Common causes for anorexia in puppies include viruses (parvo is a big one), parasitism, and foreign bodies. They need immediate care – go to an emergency vet if yours isn’t open. Puppies can get low blood sugar and dehydration very quickly.

If this is an adult dog and you observe other concerning signs, such as diarrhea or decreased energy, you should see a veterinarian.

If the dog seems otherwise bright and stable, try offering different types of food: wet food, canned tripe, or cooked chicken and rice. Some dogs will go for canned baby food: chicken, turkey, or beef as the main ingredient. Make sure there are no garlic or onions in the ingredients!

Causes of anorexia in adult dogs can range from less serious to severe. Younger dogs are more likely to get into trouble- they tend to eat things they shouldn’t, and can get foreign bodies from eating things like socks, or stomach upset from getting in the trash. Any dog may stop eating due to stress, or just being a picky eater. Middle aged dogs can stop eating when they’re stressed and also have Addison’s disease, which can be fatal. Older dogs tend to stop eating when they develop cancer or renal disease.

There is no one-size-fits-all recipe to know when the right time is to take your dog to the vet. The moral of this story is, if it’s not getting better, your pup feels bad, or you’re worried – go see the vet!

Read Full Q/A … : My Dog Won’t Eat

Q. Rescued a dog almost two weeks ago, and now that her kennel cough is gone her personality shines!! No previous training, how should I start?
ANSWER : A. POST FOUR:

After your dog is familiar with the behavior you lured from scratch, and taught to your dog, you can start to use the “no-reward marker” I talked about. What you do is ask the dog to perform the behavior, and if the dog does not perform the behavior, you simply say your no-reward marker (choose one: eh-eh, hey, uh-oh, oops) show them the treat, put it behind your back, and BRIEFLY ignore your dog. Just turn your back for a second or two, before turning back to your dog and saying, “let’s try that again.” When you’re ready to start over with your dog, make sure you move around. If you are repeating the same cue while in the same position, while your dog is in the same position, you are likely to receive the same results. The more you move around, and start fresh, the better your chances are of having your dog listen to your cue the second time around. BIG rewards when they dog it successfully! Lots of praise and treats.

My no-reward marker is “hey.” When my dog does something wrong I say, “hey” and she immediately understands that she needs to offer a different behavior. This is clear to her. I don’t have to say it in a mean way, I simply say, “hey” in a normal tone of voice and she understands what the word means.

Once you’ve built up that connection and communication with your new dog, you can work on all kinds of fun behaviors! I personally enjoy the more zen-like behaviors: https://www.youtube.com/watch?v=ruy9UMcuGh8

I like to teach my dog fun tricks that offer her a “job” to do of sorts like object retrieval: https://www.youtube.com/watch?v=I4iertZSva8

(object retrieval training completed; what it looks like: https://www.youtube.com/watch?v=jx0Dml28FGY)

Scent-games are fun too! Very confidence building. Hide a REALLY smelly treat in a box, and place that box in a line of boxes. Let your dog go in the room while saying something like “search!” or “find it!” and watch them hunt for that smelly treat! Lots of rewards when they find it!

Q. My Bulldog puppy growls, barks and even tries to bite me when I say “no” to him. What can I do?
ANSWER : A. First, avoid scolding him and acting aggressively towards him if you don’t want him to be acting aggressively towards you. There are other methods you can use to communicate to your dog that you don’t want him to continue doing what he is doing. I recommend you stop telling him “no”, scolding him, or raising your voice at him. Everything coming from you should be 100% positive and 100% calm.

Try to figure out ways to clearly communicate what you want to your dog. If you want your dog to leave something or someone alone, I strongly suggest teaching your dog commands like “leave it”. Here is a link to a video in which I explain how to do it:

www.youtube.com/watch?v=R1TS5nA7z5Q

Another thing I suggest you use is a no-reward marker. This clearly communicates when your dog has done something wrong. No-reward markers have to be introduced during your training sessions. You should be doing at least three training sessions per day, that are something like 3-10 minutes long (working on different things each training session). If you are teaching your dog something BRAND NEW, do not use the no-reward marker, as you do not want to discourage your dog from performing behaviors for you. Use the no-reward marker for known behaviors only. Here is another helpful video about this:

www.youtube.com/watch?v=sdU5a6fXKlg

Lure each new behavior (as shown in the video) using high value treats. Let’s say you’re working on “down” which is a behavior your dog knows fairly well. Present the treat to your dog. Ask your dog to “down” (only ask once). If he does not go “down” immediately, say, “uh-oh” or “eh-eh” in a gentle tone, and then place the treat behind your back. This communicates to your dog that they did something to make the treat go away.

After you place the treat behind your back to show your pup “that was wrong” you need to communicate to your pup “let’s try again” by getting your pup to walk around for a second, and then start the behavior all over again. If your puppy is very young, chances are you haven’t taught him a solid “down” behavior yet. So, as I said, do not use this method until you have lured each new behavior as shown in the video.

This is the order in which you should teach behaviors: Lure using a high value treat as shown in the video. After a few successful food lures, lure with an empty hand. If the pup is successful with the empty hand lure, reward with lots of treats. If the pup is unsuccessful, then go back to food-luring a couple more times. After a few successful empty-hand lures, you can begin to add the cue. Say “sit”, then lure with an empty hand, and then reward. Once your pup understands the cue, begin to work on the no-reward marker.

Q. Whenever I take my dog on walks he always barks at people and others dogs in my neighborhood. What should I do to resolve the problem
ANSWER : A. The very first thing to do is to make sure your dog is getting sufficient physical and mental exercise every day. A tired dog is a good, happy dog and one who is less likely to bark from boredom or frustration. Depending on his breed, age, and health, your dog may require several long walks as well as a good game of chasing the ball and playing with some interactive toys.

Figure out what he gets out of barking and remove it. Don’t give your dog the opportunity to continue the barking behavior.

Ignore your dog’s barking for as long as it takes him to stop. That means don’t give him attention at all while he’s barking. Your attention only rewards him for being noisy. Don’t talk to, don’t touch, or even look at him. When he finally quiets, even to take a breath, reward him with a treat. To be successful with this method, you must wait as long as it takes for him to stop barking. Yelling at him is the equivalent of barking with him.

Get your dog accustomed to whatever causes him to bark. Start with whatever makes him bark at a distance. It must be far enough away that he doesn’t bark when he sees it. Feed him lots of good treats. Move the stimulus a little closer (perhaps as little as a few inches or a few feet to start) and feed treats. If the stimulus moves out of sight, stop giving your dog treats. You want your dog to learn that the appearance of the stimulus leads to good things.

Teach your dog the ‘quiet’ command. Oddly, the first step is to teach your dog to bark on command. Give your dog the command to “speak,” wait for him to bark two or three times, and then stick a tasty treat in front of his nose. When he stops barking to sniff the treat, praise him and give him the treat. Repeat until he starts barking as soon as you say “speak.” Once your dog can reliably bark on command, teach him the “quiet” command. In a calm environment with no distractions, tell him to “speak.” When he starts barking, say “quiet” and stick a treat in front of his nose. Praise him for being quiet and give him the treat.

As in all training, always end training on a good note, even if it is just for obeying something very simple, like the ‘sit’ command. If you dog regresses in training, go back to the last thing he did successfully and reinforce that before moving on again. Keep sessions short, 15-20 minutes max, and do this several times a day.

Q. How do I determine how much my overweight pet should weigh?
ANSWER : A. There are many tools to determine overweight and obesity levels in pets. A new tool, morphometric measurements and body fat index, are available to accurately determine a pet’s ideal weight; this will allow an accurate determination of the amount of food a pet should receive to achieve weight loss. Feeding the correct amount will lead to greater weight loss success.

There are many weight loss food options to help pets reach their ideal weight. Your veterinarian can help make a ideal weight recommendation. Here are some tips to help your dog lose weight in a healthy and safe way:

1. Diet: Providing a healthy and well balanced diet is essential to your pet’s overall health. Finding the right food for your dog can be a challenging process. For those overweight animals many commercial dog companies offer weight loss diets, but it is important to evaluate food labels for adequate nutritional content.

You want to ensure you are not missing other essential vitamin or mineral content. Volume of food is also important and the amount of food that works for one breed of dog may not be the same for another breed of dog. Portion control as opposed to free-choice feeding can help your dog to drop a few unnecessary pounds.

There are also prescription weight loss foods designed by veterinary nutritionists, such as Hill’s r/d (http://bit.ly/1AoENSd). Some pet owners find that home cooking is the best option for helping to provide a well-balanced and realistic diet plan. There are websites such as balanceit.com that offers recipes to fit your dog’s specific needs. Consulting with your veterinarian or a veterinary nutritionist to find the appropriate diet is a great way to help your dog be as healthy as possible.

2. Exercise: Another great tactic for weight loss for your dog is exercise. Whether this is through running, walking or playing with a favorite toy all of these are wonderful types of exercise to help keep your dog at a lean and healthy weight.

For those pet owners with busy schedules utilizing professional dog walking services or playtime through dog daycare services is another option. It has been shown that those pet owners that exercise regularly with their pets generally live a healthier lifestyle.

3. Physical therapy: As animals age pet owners offer encounter their favorite canine having more difficulty walking and have a dwindling desire to play with toys. Physical therapy, specifically hydrotherapy is a wonderful way to help older and arthritic animals gain more mobility and lose weight. Hydrotherapy has been proven to have several therapeutic effects on the body including, muscle strengthening, relief of swelling, decreased joint pain, less stiffness in limbs, improved circulation, weight loss, and increased tissue healing to name a few. For more information on the benefits of hydrotherapy:
http://bit.ly/1w1qqoy

4. Veterinary visit and blood work: Weight gain can also be related to underlying health concerns such as hypothyroidism or other endocrine disorders. Scheduling a veterinary evaluation and routine blood work can be another important component in increasing the longevity of your dog’s life. Conditions such as hypothyroidism that predispose dogs to gain weight can be treated with a daily medication to improve hormonal balance. If feel that your dog is unnecessarily overweight there can be an underlying health condition that needs to be addressed.

5. Healthy treats: Pet owners love the chance to reward their favorite canine companion with treats and most dogs jump at the chance to consume these delicious products. The problem is many treats, which can include commercial dog treats or table scrapes can add many unnecessary calories to your dog’s daily intake. Reading labels and making note of the calories in these treats is an important component of understanding your dog’s overall health. Treats should not exceed more than 10 percent of your pet’s daily calories. There are healthier treats that can be offered to your pet to keep calories lower yet provide a fuller sensation. A pet owner can add steamed or pureed vegetables, such as carrots, green beans or sweet potato to add more fiber and thus a fuller feeling for your dog.