Will A Dog Sink If It Drowns?

Drowning occurs when a living organism is deprived of oxygen from submersion or immersion in a liquid. This article will explore whether dogs are able to float and survive after drowning, based on factors like their anatomy, breed traits, buoyancy, and age.

The purpose of this article is to provide a factual and evidence-based analysis of what happens when a dog drowns. There are many myths and misconceptions around this topic, which this content aims to address. By evaluating how a dog’s physical characteristics and swimming abilities relate to drowning survival rates, the goal is to leave readers with a clear understanding of the outcomes.

Dog Anatomy

A dog’s body composition, including fat levels and muscle mass, affects its buoyancy and ability to float (Metroeast Home Veterinary Care). Ideal body fat percentage for dogs ranges from 15-25%, depending on the breed. Overweight dogs with body fat over 30% will be less buoyant and have more difficulty staying afloat (Li et al. 2012). Lean, muscular dogs with less body fat and more dense muscle mass will sink more easily. The ratio of fat to muscle impacts whether a dog floats or sinks when in water.


Buoyancy is the upward force exerted on an object that is immersed in a fluid. This force occurs because of the differences in pressure acting on the top and bottom of the immersed object. According to Archimedes’ principle, the buoyant force on an object is equal to the weight of the fluid displaced by the object. The buoyant force can be calculated using the following formula:

Buoyant force = Density of fluid x Volume of displaced fluid x Gravitational acceleration

An object will float in a fluid if the buoyant force equals the object’s weight. If the buoyant force is greater than the object’s weight, the object will rise until it floats. If the buoyant force is less than the object’s weight, the object will sink. The buoyant force on an object decreases as it sinks deeper because the volume of displaced fluid decreases. Density and volume are key factors that determine an object’s buoyancy.

The density of the fluid also matters – denser fluids like water produce more buoyant force than less dense fluids like air. This is why objects that sink in water can float in air. The volume of fluid displaced by the object determines the magnitude of the buoyant force. Larger volumes displaced lead to greater buoyant forces.

Understanding these principles helps explain why some objects float while others sink when placed in a fluid. The interaction between the object’s weight, the fluid’s density, and the displaced volume determines whether the object will sink or float.

Source: Archimedes’ Principle and Buoyancy

Fat Content

Dogs generally have a higher body fat percentage than humans. The average body fat percentage for an adult dog ranges from 15% to 30%, compared to 21-35% for adult humans 1. This extra fat helps provide energy and insulation for dogs.

A dog’s fat content can significantly affect its buoyancy. Fat is less dense than water, so it increases buoyancy. The more body fat a dog has, the more it will float. Leaner dogs with less fat and more muscle will have a harder time floating. Breeds like Labrador Retrievers tend to have a higher percentage of body fat and are very buoyant swimmers. Sighthounds like Greyhounds have much less fat and tend to sink more when swimming 2.

Muscle Mass

Muscle mass plays a significant role in determining whether a dog will sink or float when in water. Muscle tissue is denser than fat and more dense than water, with a density of about 1.06 g/cm3 compared to 1 g/cm3 for water (https://home.csulb.edu/~emyrw/T3/lessons/Hydrodynamics.html). This means that the more muscular a dog is, the more likely it is to sink rather than float. Dogs with greater muscle mass often have less body fat, which further reduces their buoyancy.

According to Scientific American, “If a substance is less dense than water, it will be buoyant, meaning it will be more likely to float. Density is determined by an object’s mass relative to its volume. Fat is less dense than muscle and bone, so fattier animals and people are more buoyant” (https://www.scientificamerican.com/article/muscle-versus-fat/).

Breeds such as Greyhounds and Whippets with low body fat and heavy muscle mass are more prone to sinking, whereas breeds like Labrador Retrievers with more body fat tend to float more easily. The age of a dog also influences muscle mass, as older dogs lose muscle as they age. With less muscle mass, senior dogs are more buoyant than highly muscular puppies or younger adults.

Dog Breeds

Different dog breeds have different natural buoyancy and swimming abilities based on their anatomy. According to this source, breeds with higher fat content and more muscular builds tend to float better than lean, thin breeds. For example, Labrador Retrievers are excellent swimmers due to their otter-like tails and webbed feet, whereas Greyhounds have lean builds and minimal body fat, making it more difficult for them to stay afloat.

Breeds like Dachshunds with long bodies and short legs tend to have more trouble swimming and floating, according to this source. Their anatomy prevents them from having good buoyancy control. On the other hand, Newfoundlands and other water dog breeds have adaptations like water-repellent coats and greater lung capacity that allow them to swim well and maintain buoyancy.

In general, heavier, more muscular dogs with higher fat content tend to be more buoyant than lean, thin breeds when in water. But with life jackets and proper supervision, even dogs not bred for swimming can usually float safely.

Coat Type

A dog’s coat type can significantly impact its buoyancy in water. The fur of most dogs has specialized properties that increase buoyancy. According to research studies, the water-repellent fur traps air, which provides insulation and buoyancy. The higher the fur density, the more air it can retain, increasing overall buoyancy.

Specifically, the undercoat layer of fur is most important for buoyancy. The undercoat helps retain a layer of air near the dog’s body. Longer outer coat hairs can also help trap air. Breeds with very dense, thick fur like Newfoundlands and Samoyeds tend to be more buoyant.

In contrast, breeds with shorter, less dense fur may not retain as much air. Their coats allow water to penetrate more easily to the skin. Short-haired breeds like Labrador Retrievers may initially sink more when jumping into water compared to long-haired dogs. However, muscle mass and body fat percentage also factor into overall buoyancy.

Age & Size

A puppy’s age and size play an important role in determining its buoyancy and ability to float. Puppies have higher body fat percentages and less muscle mass compared to adult dogs, which affects their buoyancy.

According to research, buoyancy is correlated with age and body size (https://www.researchgate.net/figure/Buoyancy-in-relation-to-age-for-bottlenose-dolphins-Tursiops-truncatus-Points_fig1_250068304). Younger, smaller puppies tend to be more buoyant than older, larger adult dogs.

Puppy fat helps them float better. As puppies grow into adulthood, they lose some of that fat which reduces their natural buoyancy. Their muscle mass also increases as they mature, making them denser and less likely to float.

So while puppies may initially float more easily, adult dogs with less fat content and more muscle mass tend to have greater difficulty staying afloat and are at higher risk of sinking if they end up in water. Their size and density work against their buoyancy.

Swimming Ability

There is a common misconception that strong swimmers do not drown. However, research shows there is not necessarily a direct correlation between swimming ability and drowning risk. In fact, many competent swimmers still drown each year. According to Hard to Believe, But Even Good Swimmers Drown, overconfident swimmers can underestimate the risks involved and put themselves in dangerous situations. Additionally, strong swimmers tend to receive less supervision, which paradoxically increases their drowning risk. As explained in Yes, Even Strong Swimmers Can Drown | 5 Essential Water Safety Tips, even highly skilled swimmers can still experience muscle cramps, exhaustion, or sudden medical events that lead to drowning. While swimming ability reduces risk, it does not make someone “drown-proof.” Ultimately, swimmers of all skill levels must exercise caution and follow water safety principles to avoid tragedy.


In summary, whether a dog will sink or float when drowning depends on several key factors related to the dog’s physical characteristics and swimming abilities.

A dog’s natural buoyancy is determined by its body fat percentage and muscle mass. Dogs with higher body fat ratios tend to float more easily, while lean, muscular dogs are more likely to sink. Breeds that typically have higher fat content and more buoyancy include Labrador Retrievers, Corgis, and Basset Hounds. Slim, athletic breeds like Greyhounds tend to have less natural buoyancy.

The type and length of a dog’s coat also affects buoyancy. Thick, long coats trap air which helps keeps dogs afloat. Short-haired breeds sink more easily. A dog’s size and age impacts buoyancy as well, with larger, older dogs having more difficulty staying above water.

While some dogs have natural advantages, swimming ability is another key factor. Dogs that are comfortable and capable swimmers can better keep themselves above water by paddling. Nervous or inexperienced dogs may panic and be unable to swim effectively.

Safety precautions like dog life jackets provide added buoyancy and flotation assistance. However, without the ability to actively swim, a life jacket may not prevent sinking entirely.

In an emergency, a dog’s survival often depends on both its natural buoyancy and its swimming skills. Proper preparation through training and use of flotation devices can help reduce drowning risks.

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