Dog Days of Summer-How A Dermatologist’s Best Friend Could Impact Your Skin

Summer in South Jersey means longer walks, backyard afternoons, and a dog who is happy to be part of all of it. What most pet owners never consider is how much of their dog’s summer ends up on their own skin. Fleas, ticks, mites, plant oils, and even the medications sitting on your bathroom counter can all travel between you and your pet in ways that show up in a dermatology exam room.

At HMGS Dermatology, our providers see the results of this every summer at all three of our offices in Camden, Marlton, and Hammonton. Here is what every dog owner should know before the season gets going.

Your Prescription Cream Could Be Dangerous to Your Dog

5-Fluorouracil (5-FU) cream is one of the most effective topical treatments in dermatology for actinic keratoses and certain superficial skin cancers. It is also profoundly toxic to dogs. Extremely small exposures, including a lick of treated skin, a chewed tube, or a discarded applicator or gauze pad, have caused fatal poisoning in dogs. Symptoms can begin within an hour and include vomiting, tremors, and seizures. There is no reliable antidote.

Topical minoxidil, used widely for hair loss, carries a similar warning. Minoxidil is a vasodilator, and in dogs and cats, even small ingested or absorbed amounts can cause a dangerous drop in blood pressure, rapid heart rate, fluid in the lungs, and death.

If you have been prescribed either medication:

• Store the tube in a closed cabinet, never on a nightstand or counter.
• Wash your hands thoroughly after each application.
• Do not let your dog lick, nuzzle, or sleep against treated skin. Cover the area with clothing or a dressing while it dries if your dog is affectionate.
• Discard used gloves, cotton swabs, and gauze in a lidded trash can your dog cannot open.

If you suspect your dog has had any exposure, contact your veterinarian or an animal poison control line immediately. Do not wait for symptoms.

Capnocytophaga: When A Small Bite Becomes a Serious Infection

Capnocytophaga canimorsus is a normal bacterium in the mouths of most healthy dogs and cats. In most people, a minor bite or lick causes nothing at all. In a smaller group of patients, it can cause an aggressive bloodstream infection.

The people at highest risk are those who have had their spleen removed, those with alcohol use disorder or liver disease, and anyone who is immunocompromised, including patients on chemotherapy or long-term immunosuppressive medication.

What makes this relevant to dermatology is that the skin often shows the first clues. Warning signs after a dog bite, scratch, or even a lick over broken skin include:

• Redness, swelling, warmth, or drainage that worsens after the first day or two
• Fever, chills, vomiting, or confusion
• A purple, bruise-like, or blotchy rash, especially on the arms, legs, or trunk
• Skin that turns dusky, black, or begins to break down

Those last two findings can signal sepsis and require emergency evaluation, not an office visit. Any dog bite should be washed immediately with soap and running water, and any bite that breaks the skin deserves a same-day medical assessment, particularly if you fall into one of the higher risk groups above.

Dog Scabies Is Real, But Can You Catch It?

Canine scabies, or sarcoptic mange, is caused by Sarcoptes scabiei var. canis. It is a different variety of mite than the one responsible for human scabies, but it will absolutely bite a person.

The mite cannot complete its life cycle in human skin, so the infestation is usually self-limited. That does not make it comfortable. Patients typically develop intensely itchy red bumps on the forearms, abdomen, chest, and thighs, the areas that contact the dog while holding or petting. The itch often feels worse at night.

Because canine scabies does not burrow and reproduce in people the way human scabies does, the treatment strategy differs. The rash is managed symptomatically while the real fix happens at the veterinarian’s office. If your dog is scratching relentlessly, losing hair around the ears, elbows, and belly, and developing crusted skin, both of you need care. Treating one without the other means the bumps keep coming back.

Flea Bites: The Classic Ankle Rash

Fleas rarely live on people, but they will feed on us readily. The pattern is distinctive enough that we can often identify readily: clusters or lines of small, firm, very itchy red bumps concentrated on the ankles, shins, and lower legs, sometimes with a tiny central puncture.

Some patients react far more strongly than others. In sensitized individuals, the bumps can become large, swollen, and blistered, a reaction called papular urticaria, and scratching can lead to a secondary bacterial infection that needs antibiotics.

Signs your home has a flea problem rather than a mosquito problem include bites clustered below the knee, itchy bumps that appear overnight indoors, and a dog who is scratching at the base of the tail. Year-round flea prevention for every pet in the household, along with vacuuming and washing pet bedding in hot water, is the only durable solution. Topical steroids and antihistamines calm your skin, but they will not empty your carpet.

Poison Ivy Rides in on Fur

Dogs almost never develop a rash from poison ivy, oak, or sumac. Their coat protects their skin. What their coat does very well, however, is carry urushiol, the oil responsible for the rash, straight into your living room.

Urushiol can stay active on fur, leashes, collars, and toys for a long time. A dog who ran through a patch of poison ivy at the edge of the yard can transfer enough oil to cause a full-blown reaction in someone who never went near a plant, which is why so many of these cases are so puzzling to the patient.

The rash appears as intensely itchy red streaks, patches, or blisters, usually 12 to 72 hours after contact, often on the forearms, hands, and anywhere a dog leaned or slept against you.

To prevent it:

• Learn to recognize the plants in your yard and along your walking route. Poison ivy has three leaflets with a longer center stalk.
• If your dog may have contacted a patch, bathe them with pet shampoo while wearing gloves and long sleeves.
• Wash leashes, collars, harnesses, and bedding.
• Wash your own skin with soap and cool water within a couple of hours of exposure when possible.

Widespread rash, facial or eye involvement, significant swelling, or blistering that covers a large area should be evaluated by a dermatologist. These cases often require an oral steroid taper rather than a cream.

Ticks: Watch The Bite Site and The Calendar

New Jersey is a high-burden state for tick-borne illness, and dogs are efficient at bringing ticks indoors. Deer ticks, dog ticks, and lone star ticks are all present in our region.

For dermatology, the skin findings matter enormously because they are frequently the earliest sign of disease:

• Erythema migrans, the rash of early Lyme disease, appears in a majority of cases roughly 3 to 30 days after a bite. It is an expanding pink or red patch, sometimes but not always with a clearer center that gives it a target appearance. It is usually warm and not especially itchy or painful, which is exactly why it gets ignored.
• Rocky Mountain spotted fever can produce small pink spots that begin on the wrists and ankles and spread inward. This illness moves quickly with fevers, headaches and is a medical emergency.
• STARI, associated with the lone star tick, produces an expanding rash.
• A small, itchy red bump at the bite site alone is usually just a local reaction and not a sign of infection.

Remove an attached tick promptly with fine-tipped tweezers, grasping as close to the skin as possible and pulling straight up with steady pressure. Do not use petroleum jelly, nail polish, or a hot match. Clean the area, then note the date.

Any expanding rash, fever, headache, joint pain, or flu-like illness in the weeks after a tick bite warrants prompt evaluation. Keep your dog on veterinarian-recommended tick prevention and run your hands over their coat after every walk, checking the ears, neck, armpits, and between the toes.

When To Call HMGS Dermatology

Don’t worry, your dog will bring much joy, and the potential skin issues just come with the territory. Most of what we have described is easy to prevent and very treatable when caught early.

Reach out to us if you notice:

• An itchy rash that will not resolve with over-the-counter treatment
• Clusters of bites that keep appearing
• Any expanding rash after a tick bite
• A rash after contact with a pet who may have been in poison ivy
• Any dog bite wound
• New, changing, or non-healing spots on your skin, which deserve attention no matter what your dog is up to

Contact Us Today

Our board-certified dermatologists and clinical team see patients at three convenient South Jersey locations: Camden, Marlton, and Hammonton. We evaluate rashes, bites, infections, and skin cancer concerns for the whole family, and we are happy to answer questions about safely storing and using your topical medications around pets.

Call HMGS Dermatology or request an appointment online to be seen at our Camden, Marlton, or Hammonton office.