If your puppy is not eating, there could be dozens of reasons behind it and finding the right one is extremely important. If you try giving them a treat or different type of food and they still refuse, there may be a serious problem to deal with, though usually there is a less dramatic reason for lack of appetite in young pups.This article was created in order to give you an idea of why your dog may not be eating and a few things you can try and do for them. If after a couple days you do not see a change in your dog’s appetite, you should take them to a veterinarian to diagnose the problem.Reasons behind anorexia in dogsAnorexia in dogs has a completely different definition than it does for the human condition. In people, anorexia is an eating disorder where the person will starve themselves usually due to a false image of themselves being extremely overweight. In dogs however, anorexia is defined as the total lack of an appetite and refusal to eat any food. There are several reasons your dog or pup may be suffering from anorexia – and in some cases it is not anorexia at all, just a simple case of a picky pup!A few of the most dangerous causes of anorexia in dogs are:CancerInfectionPainOrgan failure (usually in the liver or kidneys)A few less worrisome and more common causes of anorexia in dogs are:Separation anxietyChange in environmentPup may be teethingRecent vaccinationsMany different illnesses can cause your dog or young pup to lose their appetite. This is very common in dogs who suffer from cancer (just like in people suffering from cancer), or even a simple upper respiratory infection. Almost any illness can cause a dog to lose their appetite either temporarily or for a longer period of time.If your dog has already refused to eat for two days then a vet should be consulted immediately as they are the only ones who can properly diagnose if your dog is suffering from an illness. In some cases if may become necessary for them to force feed your dog, otherwise they can die due to lack of food and water.While those situations are very real and quite possible they are not the most common reasons that your dog may not want to eat. If you have recently moved your dog may not want to eat because they are in an unfamiliar place and simply do not feel comfortable there. If this is the case, it will gradually get better the longer you stay in your new home.If you just got back after a long car ride, your dog may suffer motion sickness, which can also lead to a sudden interruption in their usual feeding schedule. Recent vaccinations can also be a potential cause of anorexia in dogs and puppies, though this is not the most common, it is also usually very temporary and appetite returns within 24 hours.If you have a young puppy, then the reason may not be that they are not hungry – they might be teething. Just like a baby, your puppy will grow a primary set of teeth also called milk-teeth. These teeth are like a human child’s baby teeth and around eight to ten weeks old your pup will start to lose their milk-teeth and permanent ones will come in.It can take up to seven months old for your puppy to have all their permanent teeth in. During this teething time, it can be very uncomfortable for the pup, causing them to chew on anything they can, but usually something soft. If they won’t eat, their food may just be too hard for them to chew properly.Another problem could be that rather than your dog not being hungry, he just may not want to eat. This is common when you have two dogs or two pets in the household. If your dog will not eat it may be that the other dog or pet is stealing his food, growling at him while he tries to eat or maybe the other dog just eats faster. Any of these can be reasons for your dog to not want to eat around their companion.What you can do?Whatever the reason, it is always concerning when your puppy or dog just doesn’t seem to want to eat. It is usually an immediate concern when they are not dancing around your feet waiting for you to put the food bowl down for them. If this happens, there are a few ways to go about figuring out whether or not your puppy is sick or just being picky.If your dog has been eating the same food for his whole life, then switching foods may cause an upset in some dogs. Dogs like routines, even as young pups. If you have been giving him the same food since you brought him home and then suddenly change the food, he may be disinclined to eat this new food. Whether it is a different taste or smell is not the concern, getting your pup to eat is.To avoid your dog refusing the new food right away, consider mixing the old food in with the new food for a little bit, until your pup gets used to it. This is a great tactic if you are preparing to switch from a puppy food to adult food. Also, this method works best if you are using a dry food, mixing the kibbles around to blend it well. It will work with wet food, but not as well with a mixture of wet and dry food.If you are looking to figure out whether your dog may just be having a fit and being picky, then here are a few good ideas you can try out:Try tempting your pup with a small bit of meat (like lean chicken or beef). If he will eat this, but not their own food, chances are, you have a picky eater on your hands.Try warming up dry kibbles in the microwave for just 10-20 seconds. This can release the aroma in your dogs’ food and may cause them to become interested again.Try adding warm water or broth to a puppy’s food (or for a senior dog). This will soften the food and make it easier for them to chew if they are teething or having dental issues.If you have a cat, consider mixing just a little cat food into your dog’s food. The cat food kibbles are higher in protein and will often be very appealing to your dog. (I had two dogs that wouldn’t eat their food unless I mixed the cats food into it, this really does work!)Try giving them an option like peanut butter that has a very strong smell and is a food that almost any dog loves.If any of these options work, you may only be dealing with a picky eater. If that is the case, you should reduce your dog’s treat intake, refuse to give table scraps and any other foods other than the dog food you provide for them. This way, they will have no choice but to eat the dog food you are giving them.When you go to feed your pup, leave the food down for only a little while during the time of day you normally feed them. If you notice that after 20 minutes or so that they have not touched it, put the food back up. Out of sight and out of mind. Sometimes, staring at the food will actually make them less hungry – especially if they have a tummy bug (which can happen from just about anything but most commonly from vaccinations, medications or from eating something they shouldn’t have).Return your dog’s food dish only when it is the appropriate time for their next meal. Usually, if your dog or pup has an upset tummy, then they will be over it after one or two missed meals and will gladly chow down on the next meal. If they hit their second meal without even taking a bite, then try one of the above methods. If none of those work, it may be time to consult your vet.Your dog relies on routine. Remember that. They may not be able to tell the time on the clock on the wall, but their internal clock knows very well what time you feed them, walk them, wake up and go to bed every day. They know when you will leave for work and when you will be home. Any change in this usual routine can be upsetting to your dog and he may be skipping the meal out of nerves. Again, this is a case where you should give you dog the chance to make up for their lost appetite at the next meal.If you do not notice any changes in your dog other than the lack of appetite, then taking them for an extra-long walk before dinner time is the way to go. They will work up an appetite after all the exercise, and even more so if you make sure they “go” before you head back home. If you take your dog on a walk before dinner time on a daily basis and have skipped it due to weather or other circumstances, then maybe they just haven’t had enough exercise to be hungry!If you have recently brought a second pet into the home, whether it is the pup who won’t eat or not, it could be the reason behind their lack of eating. If you think your dog may be uncomfortable eating around other pets then you should try feeding them in separate rooms (or at least in separate crates/kennels/etc.) Keeping them separated could give your dog the chance to relax and enjoy his meal like he wants to.When to go to the vet?If you have tried any or all of the methods mentioned above, then it may be time to consider going to the vet. If your dog has refused to eat for more than 24 hours, there could be a more serious underlying problem than just a loss of appetite. There are dozens of illnesses that affect dogs that could make them refuse to eat. Just like people, when your dog doesn’t feel good he is not going to try and put more food in him.With an adult dog you can usually decide within 24-48 hours whether or not your dog’s lack of appetite is due to a situation you can control. Your dog could be stressed or picky – in which case one of the above mentioned methods should work. If those methods did not help you see a change in your dog’s appetite but your vet cannot find anything medically wrong, they may have to force feed your dog. There are a few ways to go about this but only your vet should try to force feed a dog.If your dog presents other symptoms along with their lack of appetite it may be a more immediate reason for concern. If your dog has diarrhea and/or is vomiting regularly then you should take them to the vet immediately as it could be more serious than a simple case of anorexia. If your dog has only one episode of diarrhea or vomit and no blood is present in either then wait just a little bit – they may have just eaten something they shouldn’t have when you weren’t paying attention.After all, dogs are carnivore but they are also scavengers as well and they will eat almost anything they can get into.Other symptoms to look for that may point to illness:FeverConstipationRefusing to drink waterSigns of pain or discomfortIf your dog has a fever or refuses to drink water, those are two of the bigger causes for concern. A high fever can be just as bad for your dog as it is for you or your children – possibly worse.If you do not have a thermometer to check your dog’s temperature (which should be between 101 F and 102.5 F when your dog is healthy) then you can usually tell from other symptoms such as vomiting, nasal discharge or shivering. Serious complications can occur if your dog’s temperature reaches 106 F, so if your dog has a fever that comes close to this, you should take them to a vet immediately.Refusing to drink water is just as much of a reason to worry as a fever. If your dog will not eat and also will not drink water for 12-24 hours, you should take them to the vet as soon as possible. Without water your pet will not be able to survive which means you should not let them go for long without taking a drink.Fresh water should be available to your dog at all times, no matter if you are at home, a friend’s house or the park. Dehydration can cause serious problems for your dog, so if he will not drink along with his loss of appetite, don’t hesitate to call or visit your vet immediately.If you notice that your puppy or dog will not eat, there are plenty of methods you can try in order to bring their appetite back. You should try one or more of these techniques within the first 24 hours that you notice your dog lacking in appetite.If after 24 hours your puppy or dog will not eat, it is probably time to take them to the vet to see if there is further underlying cause for the anorexia. In some cases, your vet may notice that there is nothing physically wrong with your dog. In these cases it may just require time after a stressful situation or change in environment for your dog to be ready to eat again.If your dog continues to refuse to eat for too long though, he may become sick which can lead to worse outcomes. You should talk to your vet about different possibilities, medications that may stimulate appetite or force feeding if necessary. Nobody wants to see their dog feeling unwell, so getting to the bottom of the problem right away is important. If none of your attempts to pique your dog’s appetite are working, try checking their temperature to see if there may be something more serious going on.All in all, usually, the cause of anorexia is temporary and should not be a cause for immediate alarm. If your dog is not hungry there could be a hundred different possibilities. Try to wait until their next meal and see if they are making up for it later before you worry too much!