Swimming and Dog Skin: Chlorine, Saltwater, and Lake Water Effects

By Emiel Maddens  ·  Reviewed in consultation with licensed veterinary professionals  ·  Updated June 2026  ·  10 min read

Photo by Anya Prygunova on Unsplash

Swimming is one of the best forms of exercise for dogs. It provides a full-body workout with minimal joint stress, helps regulate body temperature in hot weather, and most water-loving breeds find it genuinely enjoyable. But while the benefits of swimming are well established, the effects of different water types on your dog's skin, coat, and ears deserve careful attention.

Whether your dog swims in a chlorinated pool, the ocean, a freshwater lake, or a backyard pond, each water environment presents distinct risks to skin health. Chlorine is a powerful chemical disinfectant that does not discriminate between pool contaminants and your dog's natural skin oils. Saltwater is inherently drying and can irritate already sensitive skin. Lake and pond water can harbor bacteria, blue-green algae, and parasites that pose both skin and systemic health risks.

This article covers how each type of water affects your dog's skin and ears, what risks to watch for, and how to develop a post-swim care routine that lets your dog enjoy the water safely throughout the season.

Chlorinated Pool Water and Dog Skin

Pool chlorine serves an essential purpose: it kills bacteria, viruses, and other pathogens that would otherwise make pool water a breeding ground for infectious disease. However, chlorine is a broad-spectrum oxidizer that reacts with organic material, and your dog's skin and coat are organic material. Understanding how chlorine interacts with canine skin helps explain why frequent pool swimming can lead to dermatological problems.

How Chlorine Affects the Skin Barrier

The outermost layer of your dog's skin, the stratum corneum, is protected by a thin film of natural oils (sebum) produced by the sebaceous glands. This lipid layer helps retain moisture, maintains skin pH, and supports the beneficial microbiome. Chlorine dissolves and strips these protective oils with each exposure. A single swim in a properly chlorinated pool may not cause noticeable problems, but repeated exposure, particularly daily swimming during summer months, can progressively deplete the lipid barrier. The result is dry, flaky skin that is more vulnerable to cracking, irritation, and infection.

Chlorine Concentration Matters

Residential pools typically maintain chlorine levels between 1 and 3 parts per million (ppm). Commercial and hotel pools may run higher concentrations. The higher the chlorine level, the more aggressive the effect on your dog's skin and coat. Some pool owners "shock" their pools with high chlorine doses to address algae or contamination, temporarily raising concentrations well above normal levels. Dogs should not swim in recently shocked pools until the chlorine level has returned to the normal range, typically 24 to 48 hours after treatment.

Signs of Chlorine-Related Skin Irritation

Dogs that swim frequently in chlorinated water may develop dry, flaky skin and a dull, brittle coat. The skin may appear pink or mildly red, particularly on the belly and inner thighs where the skin is thinner. Some dogs develop a chlorine contact dermatitis characterized by itching, redness, and small bumps in areas of heaviest exposure. Light-colored dogs may develop a greenish tint to their coat from chlorine absorption. If your dog begins scratching excessively after pool sessions, the chlorine exposure is likely too frequent or the concentration too high.

Saltwater Swimming and Skin Effects

Ocean swimming presents a different set of skin considerations. While saltwater does not contain the chemical irritants found in chlorinated pools, its high salt concentration creates its own challenges for canine skin health.

Drying and Osmotic Effects

Saltwater is hypertonic, meaning it has a higher salt concentration than your dog's skin cells. Through osmosis, contact with saltwater draws moisture out of the skin cells and into the surrounding salty water. This dehydrating effect is temporary during the swim itself, but becomes more significant if salt is left to dry on the skin and coat. Salt crystals that remain in the fur continue to draw moisture from the skin surface for hours after swimming, which is why a freshwater rinse after ocean exposure is so important.

Sand and Salt Abrasion

Beach swimming often combines saltwater exposure with sand contact. Fine sand particles can become trapped in the coat, skin folds, and between the toes. The combination of abrasive sand and drying salt creates significant mechanical irritation, particularly in the interdigital spaces, the groin, and around skin folds. Dogs that enjoy digging or rolling on the beach compound this effect. Thorough rinsing to remove both salt and sand is essential.

Saltwater on Damaged Skin

If your dog has any pre-existing skin wounds, hot spots, or areas of irritation, saltwater exposure will cause significant pain and can worsen the condition. The salt solution irritates open tissue and can delay healing. Dogs with active skin conditions should avoid saltwater swimming until the skin has fully healed. If your dog has known allergic skin disease, saltwater can exacerbate itching and inflammation during flare periods.

A thorough freshwater rinse after swimming is the most important step in protecting your dog's skin

Photo by Karsten Winegeart on Unsplash

Lake, Pond, and River Water Risks

Freshwater bodies present the most diverse and potentially serious risks to your dog's skin and overall health. Unlike chlorinated pools, natural freshwater is not treated to control microbial populations. Lakes, ponds, rivers, and streams can harbor a variety of organisms that affect canine health.

Bacterial Contamination

Stagnant or slow-moving freshwater, particularly warm ponds and lakes during summer months, can contain elevated levels of bacteria including Leptospira, E. coli, and Pseudomonas species. Leptospirosis is a serious bacterial infection transmitted through contaminated water that can affect the kidneys, liver, and other organ systems. While leptospirosis vaccination is available and recommended for dogs that swim in natural water, it does not cover all serovars. Pseudomonas bacteria, commonly found in warm freshwater environments, are a frequent cause of swimmer's ear (otitis externa) in dogs.

Blue-Green Algae (Cyanobacteria)

One of the most dangerous hazards in freshwater environments is blue-green algae, technically a type of cyanobacteria that can produce potent toxins. Cyanobacterial blooms typically occur in warm, nutrient-rich, stagnant water during late summer and early fall. The toxins produced by certain cyanobacteria can cause severe illness or death in dogs within hours of exposure, and there is no specific antidote. Signs include vomiting, diarrhea, weakness, seizures, and respiratory distress. Always check for local blue-green algae advisories before allowing your dog to swim in natural water, and avoid any water that appears scummy, has a pea-soup green color, or has visible algal mats floating on the surface.

Parasites and Other Organisms

Freshwater environments can harbor parasites including Giardia and various cercariae (larval forms of parasitic flatworms) that cause swimmer's itch. While swimmer's itch is more commonly reported in humans, dogs can also be affected. Additionally, freshwater ponds and marshy areas may have higher populations of mosquitoes (which transmit heartworm) and ticks along the shoreline. A comprehensive parasite prevention program is essential for dogs that swim in natural water bodies.

Ear Infections and Swimming: A Common Combination

Of all the skin-related complications associated with swimming, ear infections are by far the most common. The canine ear canal is L-shaped, which means water that enters during swimming can become trapped in the horizontal portion of the canal. This trapped moisture creates a warm, dark, humid environment that is ideal for bacterial and yeast overgrowth.

Why Some Breeds Are at Higher Risk

Breeds with long, pendulous ears (Cocker Spaniels, Basset Hounds, Labrador Retrievers) are at elevated risk because the ear flap covers the canal opening, preventing air circulation and trapping moisture. Breeds with hairy ear canals (Poodles, Bichon Frises, Schnauzers) face similar problems because the hair retains water within the canal. Dogs with narrow or stenotic (narrowed) ear canals also have reduced air flow, making them more susceptible to moisture-related infections.

Post-Swim Ear Care

The most effective prevention for swimmer's ear is thorough ear drying after every swim. Use a soft, absorbent towel or cotton ball to gently dry the outer ear canal and the inner surface of the ear flap. Tilt your dog's head to each side and gently massage the base of the ear to encourage trapped water to drain out. Your veterinarian may recommend an ear drying solution containing a drying agent (often a mild acidifying solution) designed to evaporate residual moisture and maintain an acidic pH that inhibits bacterial growth. Never insert cotton swabs or any object deep into the ear canal, as this risks damaging the eardrum and pushing debris further inside.

Signs of Post-Swimming Ear Infection

Watch for head shaking, ear scratching, redness or swelling of the ear flap or canal opening, discharge (yellow, brown, or dark in color), odor from the ears, and pain when the ear area is touched. These signs can appear within one to three days after water exposure and warrant veterinary evaluation. Early treatment of swimmer's ear is important because untreated infections can progress to involve the middle or inner ear, leading to more serious complications including hearing loss and vestibular (balance) problems.

Building a Post-Swim Care Routine

The single most important thing you can do to protect your dog's skin and ears after swimming is to establish a consistent post-swim care routine. This routine takes only a few minutes but dramatically reduces the risk of skin irritation, ear infections, and other water-related problems.

The Freshwater Rinse

After every swim, regardless of the water type, rinse your dog thoroughly with clean, fresh water. For pool swimming, this removes chlorine residue. For ocean swimming, it removes salt and sand. For lake swimming, it removes bacteria and organic material. Use a garden hose, outdoor shower, or even large buckets of clean water. Pay special attention to the belly, groin, underarms, and between the toes, areas where contaminants tend to concentrate. A brief rinse is better than no rinse, but a thorough five-minute rinse is ideal.

Drying Protocol

After rinsing, towel-dry your dog as thoroughly as possible. Focus on the ears, skin folds, interdigital spaces, and the groin area. These are the areas most prone to moisture-related problems. If your dog tolerates it, a blow dryer on a cool or low-heat setting can help remove residual moisture from the coat and skin. Avoid leaving your dog damp for extended periods, especially in humid conditions where air drying is slow.

Skin and Ear Inspection

Make it a habit to briefly inspect your dog's skin and ears after every swim. Look for redness, bumps, scratches, or any changes from normal. Check for ticks, especially after swimming in natural water where shoreline vegetation may harbor them. Look inside the ears for redness, excess moisture, or discharge. Early detection of problems allows for prompt treatment before minor irritation becomes a significant infection.

Moisturizing and Protection

Dogs that swim frequently may benefit from a moisturizing conditioner or coat spray applied after rinsing to help replace natural oils stripped by chlorine or saltwater. For dogs with sensitive skin or a history of post-swim irritation, applying a topical skin protectant before swimming can reduce direct chemical contact with the skin. Consult your veterinarian for product recommendations specific to your dog's skin type and swimming habits.

Swimming and Dog Skin FAQ

Q: Is pool chlorine bad for dogs' skin?

Occasional pool swimming is generally safe for most dogs. However, frequent exposure to chlorinated water strips the natural protective oils from your dog's skin and coat, leading to dryness, flaking, and potential irritation. Dogs that swim in pools daily during summer are at highest risk. A thorough freshwater rinse after every pool session and limiting the frequency of exposure can significantly reduce these effects.

Q: Can my dog get an ear infection from swimming?

Yes, ear infections are one of the most common health problems associated with swimming in dogs. Water trapped in the L-shaped ear canal creates a warm, moist environment ideal for bacterial and yeast overgrowth. Breeds with floppy ears, hairy ear canals, or narrow ear canals are at highest risk. Thorough ear drying after every swim is the best prevention.

Q: Is lake water safe for dogs to swim in?

Lake water can carry bacteria, parasites, and potentially toxic blue-green algae. Always check for local water quality advisories before swimming. Avoid water that looks scummy, bright green, or has visible algae on the surface. Ensure your dog is current on vaccinations, especially leptospirosis, and rinse thoroughly after every lake swim. Have your dog vaccinated and on a comprehensive parasite prevention program.

Q: How do I rinse my dog after swimming?

Use clean, fresh water from a garden hose, outdoor shower, or buckets. Rinse the entire body thoroughly, paying special attention to the belly, groin, underarms, and between the toes. For ocean swimming, ensure all salt and sand are removed. Follow the rinse with towel drying, especially the ears, skin folds, and interdigital spaces.

Q: Can saltwater irritate my dog's skin?

Yes. Saltwater is hypertonic and draws moisture from skin cells, causing a drying effect. Salt crystals left in the coat continue to dehydrate the skin after swimming. Dogs with pre-existing skin conditions, wounds, or allergic dermatitis may experience worsened irritation from saltwater exposure. A thorough freshwater rinse after every ocean swim prevents most salt-related skin problems.

Sources

Rosychuk, R.A.W. & Luttgen, P. (2000). Diseases of the ear. In Ettinger, S.J. & Feldman, E.C. (Eds.), Textbook of Veterinary Internal Medicine. Saunders.

Miller, W.H., Griffin, C.E., & Campbell, K.L. (2013). Muller and Kirk's Small Animal Dermatology, 7th Edition. Elsevier.

Backer, L.C., et al. (2013). Recreational exposure to microcystins during algal blooms in two California lakes. Toxicon, 76, 103-109.

Cole, L.K. (2004). Otoscopic evaluation of the ear canal. Veterinary Clinics of North America: Small Animal Practice, 34(2), 397-410.

Paterson, S. (2016). Discovering the causes of otitis externa. In Practice, 38(Suppl 2), 7-11.

Related Reading

• Dog Ear Infections: Complete Guide, Understanding causes, symptoms, and treatment of canine ear infections
• Seasonal Dog Skin Problems: Summer, Common skin issues during warm weather and how to prevent them
• Hot Spots in Dogs, Recognizing and treating acute moist dermatitis
• Dog Skin Barrier Function, How the skin barrier protects your dog and what damages it

Emiel Maddens

Founder of Vetified. Develops topical antifungal and antimicrobial formulations for companion animals. Vetified products are listed on DailyMed and manufactured through FDA-registered facilities in the United States.