How to Tell If Your Puppy Is Underweight—and What to Do

Whether you recently adopted a puppy or you’re fostering a shelter puppy, helping them achieve a healthy weight is an important part of your responsibilities. You want to prevent them from getting too chonky, but you also don’t want them to be too thin. While overweight puppies are usually more common than underweight puppies (it’s hard to resist treating those sweet faces), there are times when a puppy may need to gain weight.

If your puppy is underweight, helping them safely pack on some pounds is crucial for proper growth and development. It also gives them the energy to support all their wild puppy antics.

So, what is a healthy weight for a puppy? And how can you help your puppy safely gain weight if needed? Read on to find the answers to these questions and more.

Is my puppy underweight?

Puppies grow incredibly fast — almost too fast (more puppy time, please). Depending on a puppy’s breed, their growth in height and size will stop between six months and 24 months. 

If you think your puppy is too thin, it’s important to take that concern seriously and assess their condition. Here are some tips to help you determine if your puppy is underweight.

Check their body shape  

• Ribs: You should be able to feel your puppy’s ribs with a light touch, and they should either not be visible or only slightly to moderately visible (depending on the breed). If their ribs are extremely prominent or their spine is visible, your puppy is likely underweight.

• Waist: When viewed from above, your puppy should have a visible waistline. If the waist is too pronounced, they might be underweight. If there’s no discernible waist, they might be overweight.

• Abdomen: When viewed from the side, your puppy’s abdomen should curve upward (aka tuck up) behind the rib cage and before the hind legs. A sagging abdomen may indicate excess weight, while an overly pronounced tuck-up could suggest your puppy is underweight.

Look for behavioral signs

Your puppy’s behavior and development can also provide clues about your puppy’s weight status.

• Energy levels: An underweight puppy may have lower energy levels, and seem lethargic or tired more often than expected.

• Appetite: If your puppy has a poor appetite or struggles to finish their meals, it might contribute to being underweight.

• Development: Delays in hitting developmental milestones, such as teething or motor skills, can be associated with inadequate nutrition.

Consider the breed

Puppies have different growth rates, weights, and body types depending on their breed. For instance, Greyhounds, Azawakhs, and Whippets are naturally lean, so it’s normal for their ribs to be slightly to moderately visible. In contrast, Labrador Retrievers, Golden Retrievers, and Bernese Mountain Dogs have thicker bodies and should not have visible ribs. It’s important to monitor your puppy’s appearance and compare that to breed standards.

Refer to a puppy weight chart

Because each breed has its own unique weight range, there isn’t a universal puppy weight chart that applies to all breeds and mixes. Instead, breed-specific puppy weight charts are available, providing guidance based on the typical growth patterns and size expectations of each breed. These charts can help you monitor your puppy’s growth and keep them on track for healthy development.

Ask your veterinarian

The best, most reliable way to determine if your puppy is underweight is to take them to a veterinarian for a checkup. The vet can weigh your puppy and tell you whether your dog is underweight according to their size and breed. Your vet might also check for underlying health conditions that could contribute to weight loss.

Why is my puppy underweight?

Various factors can contribute to a puppy not gaining weight as expected. Below are some common causes of weight loss in puppies.

Insufficient caloric intake

One of the most straightforward reasons a puppy may be underweight is that they’re not consuming enough calories to support their rapid growth and energy needs. According to Dr. Alex Crow, chief veterinary officer at The Net Vet, this can be due to:

• Incorrect feeding amounts — feeding your puppy too little food or not adhering to feeding guidelines for their breed, size, and age

• Low-calorie diet — giving them a diet that doesn’t provide sufficient calories or nutrients for a growing puppy

• Feeding frequency — not feeding often enough, especially for very young puppies who may need multiple small meals throughout the day

• Being a stray — former strays may have struggled to find enough food to eat, and could require more time to catch up to a healthy weight

Poor nutrition

The quality of the food your puppy eats is as important as the quantity. Crow says poor nutrition can stem from the following issues.

• Inadequate diet: Feeding them a diet that lacks essential nutrients, vitamins, and minerals necessary for healthy growth

• Inappropriate food: Feeding them adult dog food or low-quality puppy food that doesn’t meet the specific nutritional needs of a growing puppy

• Competition for food: In multi-pet households, some puppies may not get their fair share of food if more dominant pets eat their portions

Health issues

Various health problems can prevent a puppy from gaining weight. The following are common issues that may affect a puppy.

• Parasites: “Intestinal worms, such as roundworms, hookworms, or tapeworms, can steal nutrients from the food a puppy consumes, causing them to lose weight,” Crow says.

• Infections: Bacterial, viral, or fungal infections can affect a puppy’s appetite and overall health.

• Illness: Conditions such as gastrointestinal disorders or liver disease can impact a puppy’s ability to absorb nutrients properly, Crow says.

• Dental issues: Painful teething or dental problems can make eating difficult for puppies.

If your puppy is experiencing any symptoms such as diarrhea, weight loss, or lethargy, take them to the vet ASAP for an evaluation. 

Stress and anxiety

Like humans, puppies can experience stress and anxiety, which may reduce their appetites. Common stressors include:

• Changes in their environment

• Changes in the pet parent’s schedule

• Separation anxiety

• Loud noises (thunder, blaring music, drums, etc.)

Strategies for weight gain in puppies

As tempting as it might be to indulge your underweight puppy with unlimited dog food or scraps from your plate, this approach is neither healthy nor effective. Helping your puppy gain weight requires a strategy that’s controlled and emphasizes nutrition. Let’s take a look at effective feeding methods that can help your puppy achieve a healthy weight.

Consult your veterinarian

“It’s important to start with a vet checkup to find out why the puppy is underweight,” Crow says. They can provide personalized recommendations based on your puppy’s specific needs. They can also create a deworming schedule for your puppy to prevent parasites that may affect your dog’s weight.

Choose high-quality puppy food

Select a high-quality, nutrient-dense dog food. Look for food that’s specifically formulated for puppies, as they contain the essential nutrients, vitamins, and minerals required for growth and development.

Add healthy caloric supplements

With your vet’s approval, you can add high-calorie supplements to your puppy’s diet to help them gain weight.

• Nutrient-dense treats: High-quality treats designed for puppies can offer a calorie boost. Just be sure they complement the main diet rather than replace meals.

• High-calorie gel: These concentrated gels are formulated to provide a quick and easy way to increase your puppy’s caloric intake. They are often palatable and easy to administer.

• Specialized puppy foods: Some brands offer high-calorie formulations specifically designed for underweight puppies or those with higher energy needs.

Monitor portion sizes

Adjust the portion sizes according to your puppy’s needs. Start with the recommended serving size on the puppy food packaging and increase gradually if necessary. Monitor your puppy’s weight and adjust portions accordingly.

Ensure palatability

Make sure the food is appealing to your puppy. If they are not eating enough, try different flavors or textures to find what they enjoy the most. Warming up wet food slightly or adding a bit of warm water to dry kibble can also make the food more enticing.

If your puppy isn’t eating at all (or very little) despite being offered plenty of healthy puppy food, call your vet ASAP for advice. 

Provide a stress-free feeding environment

Stress or anxiety can reduce your puppy’s appetite. Strive to create a calm, quiet environment in your home to help your puppy feel secure and comfortable. Here are some tips to reduce stress and anxiety for your puppy.

• Consistent routine: Establish a regular feeding, play, and sleep schedule to provide a sense of stability and predictability.

• Safe space: Create a designated area to where your puppy can retreat when feeling overwhelmed. A cozy bed or crate can serve as a safe haven.

• Positive reinforcement: Use positive reinforcement techniques to encourage good behavior and create positive associations. This entails immediately rewarding good behavior with something desirable, such as a treat or praise.

• Gradual socialization: Gradually introduce your puppy to new people, animals, and environments to build confidence and reduce anxiety.

• Calm interactions: Handle your puppy gently and speak to them with kindness to create a relaxed atmosphere.

• Mental stimulation: Provide toys, puzzles, and activities that engage your puppy’s mind and help reduce boredom and stress.

Track progress

Check your puppy’s weight once a week. Use a growth chart to monitor progress, and make sure they’re on the right track.

Commonly asked questions

What should you expect during your puppy’s first vet visit?

During your puppy’s first vet visit, the vet will weigh your puppy, perform a thorough physical exam, check for any signs of illness, administer vaccines if needed, discuss vaccination schedules, and provide guidance on nutrition and care.

What should I feed my puppy?

Feed your puppy high-quality, puppy-specific food, and follow the recommended feeding guidelines on the package. Consult your vet if you have any concerns about your puppy’s diet.

How often should I feed my puppy?

Puppies need more frequent meals than adult dogs. Typically, from about six weeks to six months, puppies should be fed three to four times per day. After that, you can switch them to a twice-daily feeding schedule. 

References 

Breed Weight Chart 

Feeding Growing Puppies 

Puppy Feeding Fundamentals 

Puppy Growth Chart: When Does My Puppy Finish Growing?