7 Reasons Your Dog is Gaining Weight You’ve tried everything from increasing the activity levels to reducing the calorie intake but nothing seems to work. Here are some reasons why.

7 Reasons Your Dog is Gaining Weight

You’ve noticed that your dog has gained quite some pounds and now you’re concerned. You’ve tried everything from increasing the activity levels to reducing the calorie intake but nothing seems to work. Here are some reasons why your dog could be gaining weight.


While this may sound like the most obvious reason, it is also the one that's often overlooked. If your female dog is not spayed, there's a good chance that those extra pounds are extra puppies. Many dog owners are often unaware of their pet's pregnancy status and in most cases, it's pretty obvious. It only takes a few unattended minutes for pregnancy to be a valid reason for the sudden weight gain.

You're Feeding The Wrong Food

Sometimes, it has little to do with how much you’re feeding the dog, but it’s more about what you’re feeding. Every dog has a different nutritional requirement and it is often difficult to get it right from the get-go. Not only does the requirement differ from breed to breed, but it also depends on the life cycle of the dog. The requirements of a senior dog are going to be vastly different from that of a growing puppy. Apart from the life stage, it also depends on the activity level. For instance, the nutritional requirement of a senior dog that’s active will be different from that of an inactive senior dog. It is always wise to consult with a vet to decide on the nutritional requirements of your dog. Feeding the wrong food can significantly impact your dog's weight, leading to potential health issues.

Prescription Drugs

There are quite a few medications that cause weight gain in dogs. This often happens when they’re consumed for a long time. If your dog is on medication and is also experiencing weight gain that is not being controlled even after diet and exercise, the reason could be the medication being consumed, leading to your dog's weight gain. In such cases, you should visit your vet, and they might suggest a different medication.


Internal parasites can be the reason behind unexplained weight gain. Many parasites tend to latch onto abdominal walls and intestines, thus causing fluid build-up in the infected area. This fluid buildup causes a potbellied look in your pet. Parasites can be a hidden reason why pets gain weight, as they cause fluid buildup and a potbellied appearance. This condition is more common in puppies and younger dogs as they have a developing immune system and are more prone to parasitic infestation.

To identify the cause, the vet will carry out many tests, like blood and stool samples in order to determine the presence of parasites in your pet’s body. After they’ve established the presence and determined the specific type of parasite, they will carry out the necessary treatment.

Fluid Retention

Fluid buildup is one of the reasons that can trigger weight gain in your dog or at least make it appear so. Fluid retention is one of the side effects of heart disease in pets. This results in a potbellied appearance that has no correlation to the eating or exercise habits of your pet. Apart from heart diseases, there are many other conditions that could cause your pet to have an obese appearance. These include the growth of a tumor or other diseases in any of their internal organs.

Undiagnosed Hypothyroidism

Thyroid glands are the glands that produce thyroid hormones in the body. These hormones are responsible for allocating energy that decides the speed at which the food gets digested and the metabolism speed. If this hormone is not produced in the required quantity and there's too much energy in the body, it affects the overall metabolism, which leads to an increase in weight. This condition is called ‘hypothyroidism'. For pet owners, it can be a little confusing to see that their pet is gaining weight despite eating normally or even less than usual. If they are suffering from hypothyroidism, then whatever little food energy they consume is being stored and not released.

Other symptoms of hypothyroidism include coarse hair, fatigue, dry skin, and a slow heart rate. In such cases, it's best to visit a vet to carry out further tests and medication if required.


Many dogs have a habit of chewing down their food rapidly. This is due to a number of reasons, such as their health, personality, living environment, etc. This type of behavior is often called “wolfing down.” Pet owners often notice this behavior, and it often looks as if the dog is not even chewing the food but swallowing it. When this happens, the dog is also taking in a large amount of air.

This leads to a stomach that deals with excess air as well as unchewed food and a condition known as gastric dilatation or bloat. One of the symptoms of bloat is an enlarged belly as well as symptoms like trouble breathing, pain if the abdomen is touched, fast heartbeat, drooling, or even collapse. For dogs, this is a critical condition and one that needs medical attention at the earliest. Bloat is more common in large breeds like German Shepherds and Great Danes. Similar to bloating, Cushing's disease can also cause an enlarged belly and weight gain in dogs.

How to Prevent Your Dog From Gaining Weight During Winter

We all struggle with weight gain during the winter months. Whether your struggle lies in preventing it or shedding the weight afterward, you need to understand that weight gain in winter is a fact of life that even a lot of the animals living in seasonal climates have to contend with. As the temperatures drop, their level of activity and metabolism rate drop with it, and they go into hibernation mode. This is not just limited to the animals living out in the wild. Even though we have come up with a lot of ways to stay active and warm, our bodies tend to react with evolutionary preservation methods. This is true for humans and domesticated pets and that’s where the struggle lies. If an active dog starts going outside just for speedy breaks, then it is a sign that the food he is consuming is not getting converted to energy. Meanwhile, you make hardier and larger meals at home, stocking up the leftovers from your holiday meals. Also, a lot of you tend to include your pets in most of your household activities, and that includes sharing your food with them. All the extra eating might cause your canine friend to pack a few extra pounds. Pet parents need to be vigilant about their dog's diet and exercise routine during the winter months to prevent weight gain. So, what can you do to keep the issue at bay?


If your pet is in good shape and is normally active, create an exercise regimen for the winter months so that he can continue to stay active. Incorporate dog training treats as a tool for positive reinforcement during indoor activities. These might include games like indoor fetch, a romp through the backyard snow, or a brisk hike around the neighborhood when it isn’t snowing a lot. Make sure that your dog gets out as much as possible so that he can burn off those extra calories. It is quite difficult to maintain a daily exercise routine during the peak winter months. In such cases, you must think about cutting back on the calorie intake to account for the lowered metabolic and physical activity. Fewer treats should make all the difference.

Weight loss regimen

If your pet is overweight, you will need to plan it out a bit more as you have to maintain his current weight, even if it is more than his ideal body weight. Unless the vet recommends a specific plan, you need to be careful with how much you exercise your pet and reduce his intake. Treats must be eliminated, but you shouldn't cut down on food dramatically. Before you embark on an exercise or weight loss plan, you need to check for underlying conditions that might be contributing to the weight gain. Only then you and your vet come up with a sensible diet and a structured exercise program.

If your dog is gaining weight and you've tried reducing the calorie intake or increasing their activity levels, you may want to explore the plausibility of a medical condition. This type of weight gain is often a telltale sign of some abnormality, and timely intervention can make all the difference for your pooch. With the help of a medical professional, you can choose the best possible treatment for your dog and find the right reason behind their weight gain.

What foods cause weight gain in dogs?

Like humans, dogs gain weight when they consume more calories than they burn through physical activity. However, some foods are more likely to contribute to weight gain in dogs than others. Feeding your dog scraps from the table or high-calorie treats can quickly add up and contribute to weight gain. Foods that are high in fat, such as bacon, sausage, cheese, and fried foods, are also high in calories and can lead to weight gain. Foods that are high in carbohydrates, such as bread, pasta, rice, and potatoes, can also contribute to weight gain if not balanced with adequate exercise. Some commercial dog foods are high in calories and fat, so it's important to read the label and choose a product that is appropriate for your dog's size and activity level. All dogs have different calorie needs based on their age, size, and activity level. Consult with your veterinarian to determine the appropriate amount of food to feed your dog to help maintain a healthy weight.

What food is best for dogs to lose weight?

If your dog needs to lose weight, it's important to feed them a balanced and nutritious diet that is low in calories. Foods that are high in lean protein, such as chicken, turkey, fish, and lean cuts of beef, can help your dog feel full while providing essential nutrients. Many vegetables, such as green beans, carrots, and broccoli, are low in calories and can help your dog feel full. Some fruits, such as apples, bananas, and blueberries, are low in calories and high in fiber, making them a good choice for weight loss. There are many commercially available dog foods that are designed to help dogs lose weight. These foods are usually lower in calories and higher in fiber than regular dog food. Hill's Science Diet Perfect Weight is designed to help dogs achieve and maintain a healthy weight. It's lower in calories than many other dog foods and contains high-quality protein and fiber to help dogs feel full. Blue Buffalo Life Protection Healthy Weight is made with high-quality protein and whole grains and is lower in calories than many other dog foods. It also contains fruits and vegetables for added nutrition. Purina Pro Plan Weight Management is formulated to help dogs maintain a healthy weight while still getting all the essential nutrients they need. It's lower in calories and fat than many other dog foods but still contains high-quality protein. Wellness Complete Health Healthy Weight is made with lean protein, whole grains, and fruits and vegetables and is lower in calories than many other dog foods. It also contains added vitamins and minerals for optimal nutrition.

What diseases cause rapid weight gain?

There are several diseases and conditions that can cause rapid weight gain in dogs. Hypothyroidism occurs when the thyroid gland doesn’t produce enough thyroid hormone, which can cause weight gain and other symptoms. Cushing’s disease, also known as hyperadrenocorticism, is a condition that occurs when the adrenal glands produce too much cortisol. Symptoms can include weight gain, increased appetite, and increased thirst and urination. Some types of heart disease, such as dilated cardiomyopathy, can cause fluid buildup in the body, leading to rapid weight gain. Dogs with diabetes may experience weight gain, especially if their blood sugar levels are not well controlled. Dogs with kidney disease may experience weight gain due to fluid retention. Some types of tumors, such as those in the liver or pancreas, can cause weight gain. Obese dogs are at a higher risk for various health issues, including joint problems, heart disease, and diabetes.

Can liver problems cause weight gain?

Liver problems in dogs can sometimes cause weight gain, although it depends on the specific type of liver problem. If the liver is not functioning properly, it can lead to a buildup of toxins in the body, which can cause a variety of symptoms, including weight gain. Hepatitis is an inflammation of the liver that can be caused by a variety of factors, including infections, toxins, and immune system disorders. Dogs with hepatitis may experience weight gain, as well as other symptoms such as vomiting, diarrhea, and lethargy. A portosystemic shunt is a condition in which blood bypasses the liver, leading to a buildup of toxins in the body. Dogs with this condition may experience weight gain, as well as other symptoms such as vomiting, diarrhea, and seizures. There are several other types of liver diseases that can affect dogs, including cirrhosis, fatty liver disease, and liver cancer. These conditions can cause a variety of symptoms, including weight gain, decreased appetite, and vomiting.

Can a dog lose weight by walking?

Yes, walking is an excellent form of exercise that can help dogs lose weight. Regular exercise can help dogs burn calories and improve their overall health and fitness. Walking is a low-impact form of exercise that can be easily incorporated into a dog's daily routine. The amount of weight a dog can lose by walking depends on several factors, including their current weight, diet, and activity level. Start slowly and gradually increase the amount of walking to avoid injury or exhaustion. Also, make sure that the dog is getting enough water and is not walking in extreme temperatures or on hot pavement, which can be harmful to their health. In addition to walking, it's necessary to provide a balanced and nutritious diet for your dog if they need to lose weight.

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