Experienced and professional animal trainer provide their insights in answering this question :
A. Change the food back to the original food and if it continues to happen there might be something stuck like a foreign body that is causing it. It could just be the new food too but you have to rule it out.

How to Identify Common Pet Problems ?

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

Switching your dog`s food abruptly can cause gastrointestinal upset such as vomiting, diarrhea, and a decreased appetite. Any time you decide to change your dog`s food, you should transition to the new diet gradually in order to give your dog`s system time to adjust to the change.
Sudden changes to your dog`s food may result in gastrointestinal issues, so switching dog food (varieties or brands) too quickly can upset his stomach. Above all, it`s important to transition to a new dog food slowly, typically over 7-10 days.
Usually, it`s regurgitation. Your dog may have eaten too much, too fast, or they may be suffering from stress. Megaesophagus is also a possibility, so you`ll want to check with your vet to be sure. If your dog is vomiting, it usually happens at least a few minutes after your dog has eaten.
Long-term dog owners know that vomiting is not uncommon. Occasionally, healthy dogs will get sick for no apparent reason and then continue with their day as if nothing happened. Your dog could have eaten too quickly, swallowed something disagreeable, or merely snacked on too much grass.
Most pet`s suffering from diarrhoea due to a change in food will recover within 1-3 days.
If your dog is throwing up, but still acting otherwise normal, it`s possible that your pet has either chronic gastritis (inflammation of the stomach) or food indiscretion.
Stress and anxiety: Your pet`s stomach can get upset when it is stressed out or has anxiety, causing it to have diarrhea or vomit.
The first and most common reason your dog may be throwing up undigested food is that they`re eating too fast. It`s common for dogs to eat fast. Some dogs seem to inhale food without even chewing, and this is a habit you`ll want to work to break because eating too fast can lead to more than just regurgitation.
Gastric hypomotility typically occurs in older dogs, and results in vomiting undigested or partially digested food hours after eating. This cluster of diseases can be primary or secondary, meaning it is caused by a stomach issue vs something outside of the gastrointestinal tract, respectively.
While all dogs can have or develop an issue to a food, Labrador Retrievers are especially prone to food allergies and sensitivity because their bodies react more frequently and intensely to the food in their diets. They have a genetic tendency for these conditions.
Dog vomiting treatment

A lot of dog vomiting is caused by inflammation of the stomach, so one of the most common treatments includes feeding a bland diet (boiled chicken or white fish and white rice or sweet potato or a veterinary-prescribed gastrointestinal diet), alongside some anti-nausea medication.

Gastric Dilatation and Volvulus, also known as GDV or Bloat, usually occurs in dogs with deep, narrow chests. This means your Labrador is more at risk than other breeds. When a dog bloats, the stomach twists on itself and fills with gas. The twisting cuts off blood supply to the stomach, and sometimes the spleen.
Withhold food for 12 to 24 hours

Withholding food for a time gives your pup`s digestive tract a chance to calm down and reset itself.

Signs of an upset stomach should disappear within 24-48 hours. If your dog`s symptoms continue for more than a couple of days. it`s time to see the vet.
After a dog vomits, it`s generally best to withhold food for several hours and observe, but don`t withhold water. 2 If your dog vomits one time and then acts completely normal, you can probably resume your normal feeding routine within six to 12 hours or when the next meal is due.
Pancreatitis in dogs is usually caused by a new food or treat being introduced into the diet, or by an accidental ingestion of something unknown to the owner like when the garbage gets raided. There are also cases that occur from non-dietary reasons that remain a mystery to owner and veterinarian alike.
There is a higher prevalence of pancreatitis in Miniature Schnauzers, Yorkshire Terriers, Cocker Spaniels, Dachshunds, Poodles, sled dogs, or other breeds. Some infections, such as Babesia canis or Leishmania, may also contribute to the development of pancreatitis.
The most common scenario in which a dog develops pancreatitis is after eating a relatively high-fat meal, such as barbecue meat or a holiday ham. The clinical symptoms typically begin within the next 12 to 24 hours.
Putting food into an upset tummy is irritating and makes it more likely that vomiting will continue. Take your dog`s food away for 12–24 hours, and don`t give them any treats or table scraps.
Once your dog vomits, he may feel nauseous which prevents him from wanting to drink. This, along with vomiting up fluid, can cause dehydration if the amount of fluid he loses is greater than the amount of fluid he`s taking in.
If your dog`s symptoms of depression are accompanied by any other signs, like vomiting, diarrhea, severe lethargy, significant aggression, peeing or pooping more often, and so on, take your dog to the vet right away.
They have an empty stomach

This is a very common cause of yellow vomit in dogs and is referred to as bilious vomiting syndrome (BVS). Some dogs can tolerate an empty stomach for longer than others but either way, bilious vomiting tends to occur overnight or early in the morning before a dog eats breakfast.

A problem that can be confused with vomiting is regurgitation. Vomiting is the ejection of contents of the stomach and upper intestine; regurgitation is the ejection of contents of the esophagus. Regurgitation often, but not always, happens right after eating and the pet will try to eat the regurgitated food.
But if your pup is throwing up undigested food — meaning it appears almost exactly as when they ate it — that could be a sign of an underlying condition like an obstruction or a bacterial infection. In any case, if your pup is vomiting up their food more than two or three times in one day, it`s time to call the vet.

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 cocker spaniel is 9 years old. He has involuntary bowel movements (little drops) very frequently, especially when he is asleep.
ANSWER : A. Is your dog on a senior dog food? I would get your dog on a high quality high protien dog food. Ask a pet store assosicate or your regular vet for a food recommendation. When you buy a better food the dog will have to eat less to get the same amount of energy from the food. The dog has to eat more of the cheaper foods to get the energy it needs from it. Meaning more poop and buying more food. So the cost really evens out. So the lessen your dogs bowel movements get on a better senior dog food. Next talk to your vet they may have a recommendation. If you switch dogs do it slowly by mixing the foods. Start with 10% new 90% old mixed for at least a week until you have switched to 100% new 0% old. Senior foods have more fiber to help with bowel movements. Take the dog outside to go potty more frequently, right before bed time.

Read Full Q/A … : Symptoms Questions & Answers

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.

Q. My 20 month Cavalier doesn’t eat unless I let him eat from my finger, then he eats. Sometimes he will only eat once a day and leave his food.
ANSWER : A. It is possible that your dog is just not satisfied with his current food, or may be a picky eater. There are several things you can try to encourage your dog to eat.

The first step is to remove any additional treats or people food that may be more enticing to your dog than his own meal. If you feel you must give him some form of treat, be sure to place them directly in his food bowl and mixed with his regular diet. This allows him to get some snacks while also “forcing” him to try out his current meal to get the reward.

Enticing your dog to try his food by adding a pet-safe gravy or even a few treats of plain boiled chicken mixed in can help. Be sure to mix the foods thoroughly so he must explore his own food before getting the treat.

Some small breed dogs may also have a hard time with certain bowls and their collars. If there is a metal name tag on the collar and a metal bowl, the clinking sound can sometimes scare off dogs and make them not want to eat from their bowl. Using a bowl of a different material, or removing the collar prior to a meal may help with this issue.

Your dog may also just not be into his current food and may like another variety better. You can try a new variety by gradually switching over a period of 7-9 days, slowly adding in more new food and removing old until it is switched. This change may encourage him to try out meals again, and the slow changeover will allow his body to adjust to the new diet without digestive upset.

Q. Which common foods are poisonous to pets?
ANSWER : A. That’s a great question. As responsible pet owners we need to be aware of food items that can be harmful to our canine or feline companions. Here are some of the most common foods proven to cause illness in our animals at home:

Chocolate: A favorite and irresistible treat amongst most humans, chocolate is considered toxic to dogs. In very small amounts it is usually not a huge issue, but with larger volumes and with darker chocolates pet owners should be concerned. Chocolate contains methylxanthine theobromine, which is similar to caffeine. Chocolate ingestion can cause vomiting, diarrhea, hyperactivity, issues with normal heartbeats, seizures, and in some severe cases, death. It is best to keep your favorite chocolate treats in a good hiding spot and out of reach of your dog or cat.

Grapes and raisins: Dogs should not consume grapes and raisins because of the risk of acute kidney failure. Most dogs experiencing grape or raisin toxicity will begin to have vomiting and/or diarrhea within 6-12 hours of ingestion. Other abnormal clinical signs include lethargy, abdominal pain, dehydration, and tremors. Kidney failure develops within 24-72 hours of the initial ingestion. There are some dogs that do not experience these devastating side effects. It is best to contact your veterinarian or veterinary emergency facility if you believe your pet has ingested grapes or raisins.

Garlic and onions: We often forget that our meals contain these two popular ingredients and will allow our furry companions a few bites or licks. Onion and garlic both can cause a type of poisoning that results in damage to red blood cells, making them more likely to rupture. They can also cause stomach upset and mouth irritation. Look for pale gums, increased breathing or drooling or any vomiting or diarrhea.

Bread dough: Unbaked bread dough is considered poisonous to our pets. The bread dough, when ingested, expands in the stomach because of the warm and moist environment. This can lead to a bloated or even twisted stomach. In addition yeast is often added to our baking products to help get bread to rise, and when this yeast is fermented it produces both carbon dioxide and alcohol. The alcohol produced can be absorbed into the bloodstream and causes dangerous drops in blood sugar, blood pressure and body temperature. Common clinical signs include vomiting or retching, distension of the stomach, weakness and collapse.

Macadamia nuts: Ingestion of these nuts are not proven to be fatal in dogs but can cause them to experience uncomfortable clinical sings, including fever, joint stiffness, vomiting, tremors and difficulty walking, especially in their hind legs. Often your pet will start to feel better after about 48 hours, but supportive veterinary care (such as pain medication) may help ease their discomfort.

Xylitol: The most common ingredient used in sugar-free gum is xylitol, which is a non-caloric sweetener. It is also found in some oral rinses, toothpastes and vitamins. Xylitol and dogs do not mix – it can cause a dangerous drop in blood sugars levels. Dogs will often display signs of disorientation, black tarry stool, tremors and seizures. If severe enough some dogs have developed liver failure. Keep your gum away from your canine companion.

Avocados: Avocados are not actually poisonous to dogs or cats but as many veterinarians can tell you the avocado pits can cause a foreign body obstruction. Avocados contain persin, which is actually toxic to the majority of pet birds. The abnormal clinical signs associated with avocado ingestion in birds include, respiratory distress, inability to perch, liver and kidney failure and sudden death.

Go forth and enjoy your favorite foods, but keep in mind which foods you should avoid sharing with your furry family members. Whenever in doubt, contact your veterinarian for healthy and safe food suggestions.

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. 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. Why does my dog eat grass? He throws up afterwards!
ANSWER : A. There is much debate over why dogs eat grass and then vomit afterwards. One theory is that the dog may have an upset stomach, and so eats the grass blades which then irritate the digestive system and causing vomiting to happen. Another theory is that the dogs are eating grass to mimic a “lost nutrient” of their ancestors found usually by hunting and then eating the contents of the stomachs of herbivores. A third theory is that dogs just do it because to them, it’s fun and they can.

If your dog has been vomiting a lot recently, either related to or unrelated to eating grass, then it is always a good idea to schedule a wellness exam with your vet to make sure there are not any issues causing illness. Grass, especially in areas where livestock may graze can also be a host for parasite eggs, which can in turn infect your dog with an internal parasite (and thus cause vomiting and diarrhea).

If your dog is not eating at all, this is more concerning and points further to some digestive upset causing his or her symptoms. Making an appointment with your vet as well as bringing in a sample of his or her stool is best for helping your pet feel better.