Cat Health
Hormone Gels and Sprays for People: Hair Loss and Skin Changes in Pets
Many people use hormone medicines that go on the skin, as gels, creams or sprays, for example to ease menopause symptoms [1]. A 2022…
Pet Health
Plain-English guides to dog and cat skin, coat and wound health, with the sources listed at the end of every guide.
154 articles
Cat Health
Prescription Skin Creams for People: Keeping Dogs and Cats Safe
Some prescription medicines that people put on their own skin can harm pets. The U.S. Food and Drug Administration (FDA) has warned about two…
Cat Health
Reactions After Flea and Tick Products in Dogs and Cats: What to Do
Flea and tick products protect pets from bites, but the U.S. Food and Drug Administration (FDA) warns that side effects can happen [1]. This…
Cat Health
Tetanus After a Wound in Dogs and Cats: Stiffness Near the Injury
Tetanus is an illness that can follow a wound. It is caused by a toxin made by the bacterium Clostridium tetani. The toxin acts…
Dog Health
Lagenidiosis in Dogs: Skin Lumps After Standing Water
Lagenidiosis is a deep skin infection caused by a water mold, a fungus-like organism that lives in warm water. Researchers first identified it in…
Dog Health
Perianal Fistula in Dogs: Draining Wounds Around the Anus
Perianal means around the anus, and a fistula is a channel that opens onto the skin. Perianal fistulas, also called anal furunculosis, are painful…
Cat Health
Fungal Mycetomas in Dogs and Cats: Lumps With Grains
A mycetoma is a lump caused by an infection. When a fungus is behind it, vets call it a fungal (eumycotic) mycetoma. The fungi…
Dog Health
Systemic Histiocytosis in Bernese Mountain Dogs: Skin Lumps
Histiocytes are cells of the immune system that live in the tissues. Bernese Mountain Dogs are well known for problems with these cells: a…
Cat Health
Phaeohyphomycosis in Dogs and Cats: Dark Mold Skin Lumps
Phaeohyphomycosis is a skin infection caused by dark-colored molds. A veterinary dermatology handbook from the University of Minnesota describes the cause as a group…
Cat Health
Snakebites on Dogs and Cats: Fang Marks, Swelling and Skin Damage
A bite from a venomous snake is a medical emergency for a dog or cat. Vets in the United States see it often enough…
Cat Health
Skin Cysts in Cats: Keratin Cysts and Dilated Pores
A cyst is a small sac in or under the skin. Some cysts in cats are lined with skin-like cells and slowly fill with…
Cat Health
Skin Flaps and Grafts for Large Wounds in Dogs and Cats
Some wounds are too large to close with stitches alone. In those cases a vet may cover the gap with skin moved from nearby…
Cat Health
Lipomas in Cats: Soft Fatty Lumps on the Belly
A lipoma is a lump made of fat cells. It is a benign tumour, which means it is not cancer and does not spread…
Cat Health
Wound Drains in Dogs and Cats: What the Tube Is For
A wound drain is a tube that a vet places in a wound so fluid can leave it. After surgery, fluid can build up…
Dog Health
Blastomycosis in Dogs: Draining Skin Lumps and Sores
Blastomycosis is an infection caused by a fungus called Blastomyces. The fungus lives in damp, sandy, acidic soil, and rotting plants and animal waste…
Cat Health
Brown Recluse Spider Bites on Dogs and Cats: Blisters and Sores
The brown recluse (Loxosceles reclusa) belongs to a group of spiders called recluse or brown spiders. In North America they are also called violin…
Dog Health
Pythiosis in Dogs: Skin Lumps and Sores That Do Not Heal
Pythiosis is one form of oomycosis, an infection caused by water molds. These organisms look a lot like fungi under the microscope, but they…
Cat Health
Leishmaniosis in Cats: Hair Loss, Scaling and Ear Ulcers
Leishmaniosis, also called leishmaniasis, is a disease caused by a tiny single-celled parasite called Leishmania. The parasite lives inside the body's own cells, and…
Dog Health
Nocardiosis in Dogs: Lumps and Abscesses Under the Skin
Nocardiosis is an infection caused by Nocardia bacteria, which grow in long, thread-like strands. These bacteria live in the environment, in soil, rotting plants,…
Cat Health
Protothecosis in Cats: Firm Skin Lumps on the Nose, Ears and Tail
Protothecosis is an infection caused by Prototheca, a group of tiny, colourless algae that behave a bit like fungi [3]. These algae live almost…
Cat Health
Valley Fever in Cats: Draining Skin Sores, Lumps and Abscesses
Valley fever, also called coccidioidomycosis, is an infection caused by a fungus named Coccidioides. The fungus lives in the soil of dry regions, and…
Cat Health
Cryptococcosis in Cats: Swelling Over the Nose and Skin Lumps
Cryptococcosis is an infection caused by a yeast-like fungus called Cryptococcus. It is the most common deep (systemic) fungal infection reported in cats [1].…
Dog Health
Actinomycosis in Dogs: Skin Abscesses After Bites and Wounds
Actinomycosis is a bacterial infection. The germs behind it, Actinomyces species, belong to a group of thread-like bacteria that can look a lot like…
Cat Health
Nocardiosis in Cats: Skin Abscesses and Draining Wounds
Nocardiosis is a bacterial infection. The Nocardia bacteria behind it live in soil all over the world and feed on dead plant matter [1].…
Dog Health
Leishmaniosis in Dogs: Skin Signs, Hair Loss, Sores and Long Nails
Leishmaniosis, also called leishmaniasis, is a disease caused by a tiny single-celled parasite, Leishmania infantum. It can pass between animals and people, so vets…
Dog Health
Skin Signs of Cushing’s Disease in Dogs: Thin Skin and Blackheads
Cushing's disease, also called hyperadrenocorticism, is a hormone disease in which the body has too much of the steroid hormone cortisol in the blood…
Dog Health
Skin Signs of an Underactive Thyroid (Hypothyroidism) in Dogs
Hypothyroidism means the thyroid gland, in the neck, does not make enough of its hormone. The University of Minnesota dermatology handbook calls it perhaps…
Dog Health
Post-Grooming Furunculosis in Dogs: Painful Sores After a Bath
Post-grooming furunculosis is a deep bacterial skin infection that can follow a bath or grooming. A University of Minnesota veterinary dermatology handbook lists it…
Cat Health
Urticaria Pigmentosa in Cats: Mast Cell Skin Rash in Sphynx Cats
Feline maculopapular cutaneous mastocytosis, also called urticaria pigmentosa, is a rare skin disease of cats. Under the microscope, the affected skin holds clusters of…
Dog Health
Impetigo in Dogs: Puppy Pyoderma and Pustules on Hairless Skin
Impetigo is one form of bacterial skin infection, or pyoderma. It comes in two forms: a juvenile form in dogs under one year old,…
Dog Health
Exfoliative Cutaneous Lupus in German Shorthaired Pointers
Exfoliative cutaneous lupus erythematosus (ECLE) is a rare, inherited skin disease. It is a severe, widespread form of cutaneous lupus, and it is seen…
Dog Health
Golden Hair on a Miniature Schnauzer’s Back: Acquired Aurotrichia
Acquired aurotrichia is a change in coat colour in which some of a dog's hair turns golden. It has been described mainly in Miniature…
Cat Health
Cancer That Spreads to the Skin in Dogs and Cats
Some cancers start in one part of the body and spread to the skin. This is called skin (cutaneous) metastasis. In dogs and cats…
Dog Health
Calcinosis Cutis in Dogs: Calcium Deposits in the Skin
Calcinosis cutis means calcium builds up in the skin. It is not common in dogs. It usually shows up when a dog's body has…
Dog Health
Fungal Nose Infections in Dogs: Swelling, Deep Sores and Discharge
Fungi can infect the skin of a dog's nose and the passages inside it. Fungi are living things such as moulds and yeasts. Several…
Dog Health
Mucocutaneous Pyoderma in Dogs: Crusty Sores on Lips and Nostrils
Pyoderma is a bacterial skin infection. Mucocutaneous pyoderma is a form that settles where haired skin meets the moist lining of the body, most…
Dog Health
Bleeding From the Groove Under a Dog’s Nose: Philtrum Arteritis
The nasal philtrum is the groove that runs down the middle of a dog's nose to the upper lip. Arteritis of the nasal philtrum…
Dog Health
Nasal Hyperkeratosis in Dogs: A Thick, Crusty Top of the Nose
Nasal hyperkeratosis means extra hard skin builds up on a dog's nose. Keratin, the tough protein that forms the outer layer of skin, piles…
Cat Health
Bite Wounds in Dogs and Cats: What Your Vet Looks For Under the Skin
Bite wounds are a common reason dogs and cats need a vet, and pets that go outdoors on their own get into more fights…
Dog Health
Psoriasiform-Lichenoid Dermatosis in English Springer Spaniels
Psoriasiform-lichenoid dermatosis is a rare skin disease first described in English Springer Spaniels. A 1986 report followed three unrelated Springers whose skin trouble started…
Cat Health
Gunshot Injuries in Dogs and Cats: Why Small Wounds Can Be Serious
A gunshot wound on a dog or cat can look small. The skin may show only a pinpoint hole while the real damage sits…
Cat Health
Bandages on Dogs and Cats: Why Vets Use Them and What to Watch
Vets use bandages on many kinds of wounds. A bandage protects the wound surface, holds dressings in place and helps control the fluid a…
Cat Health
Stitched or Left Open: How Vets Decide for Dog and Cat Wounds
Some wounds are closed by a vet, and others are left open to heal. Once a wound has been checked and cleaned, the vet…
Cat Health
How Wounds Heal in Dogs and Cats: The Three Stages Explained
A wound is any break in the normal structure of living tissue, such as a cut, scrape, tear or puncture [1]. Skin heals by…
Cat Health
How Vets Use Shampoos and Other Topical Care for Skin Problems
Many treatments for dog and cat skin problems go directly on the skin. For bacterial infections that stay near the surface of a dog's…
Dog Health
Ear Margin Seborrhea in Dogs: Waxy, Scaly Ear Edges
Ear margin seborrhea (also called ear margin dermatosis) is a skin problem along the edges of a dog's ear flaps. The skin at the…
Cat Health
Albinism and White Coats in Dogs and Cats: Skin and Sun Risks
Albinism and very white coats are differences in skin and coat color. Some of them come with a higher risk of skin problems. In…
Dog Health
Skin Signs of Nerve Disorders in Dogs: Air Scratching and Self-Injury
Now and then, a problem in a dog's nerves or spinal cord looks like a skin problem. The dog scratches, licks, chews or even…
Dog Health
Familial Vasculopathy in German Shepherd and Parson Russell Puppies
Familial vasculopathy is a skin disease that runs in families of some dog breeds. Vasculopathy means a problem of the blood vessels. It was…
Dog Health
Sex Hormone Skin Problems in Dogs: Hair Loss, Itch and Rash
Sex hormones can affect a dog's skin and coat. A veterinary dermatology handbook from the University of Minnesota groups these problems as sex hormone…
Cat Health
Epitheliogenesis Imperfecta (Missing Skin) in Kittens and Puppies
Epitheliogenesis imperfecta is a skin problem a kitten or puppy is born with. Some patches of the body never grow a proper skin covering,…
Cat Health
Hives (Urticaria) in Cats: Signs, Causes and When It Is an Emergency
Hives (urticaria) are raised, red, puffy patches that appear on the skin, often suddenly, and they may itch. They are part of an allergic…
Dog Health
Wart-Like Skin Growths in Dogs That Are Not Warts
Not every growth on a dog that looks like a wart is a wart. True warts (papillomas) are caused by a virus. Some other…
Cat Health
Malignant Fibrous Histiocytoma (Soft Tissue Giant Cell Tumor) in Cats
Malignant fibrous histiocytoma is a cancer of the skin and the soft tissues under it. Pathologists now usually call it pleomorphic sarcoma (or undifferentiated…
Cat Health
How Dog and Cat Skin Works: Layers, Hair Coat and Glands
Skin is the biggest organ of the body. A US National Institutes of Health (NIH) lesson on skin lists its jobs: it covers and…
Cat Health
Skin Tags, Collagenous Nevi and Fibromas in Dogs and Cats
Skin tags, collagenous nevi and fibromas are lumps made mostly of fibrous tissue. In a lab report from a skin sample, a skin tag…
Cat Health
How Vets Diagnose Skin Problems in Dogs and Cats: Scrapings, Tape, Cultures and Biopsy
Finding the cause of a skin problem usually takes three things: the story of the problem (the history), a careful look at the whole…
Cat Health
Nerve Sheath Tumors of the Skin in Dogs and Cats (Neurofibromas and Neurofibrosarcomas)
Every nerve runs inside a wrapping of connective tissue called the nerve sheath. Tumors can grow from the cells of this wrapping. Vets group…
Dog Health
Cutaneous Mucinosis in Shar-Pei Dogs: Bubbles and Blisters in the Skin
Mucin is a jelly-like material in the dermis, the layer just under the skin surface. In dogs it is made mostly of hyaluronic acid…
Dog Health
Cutaneous Histiocytosis in Dogs: Many Skin Bumps That Come and Go
Cutaneous histiocytosis is a skin disease in which many firm bumps and raised patches form in the deeper layers of a dog's skin and…
Cat Health
Electrical Cord Burns in Dogs and Cats: Mouth Burns and Electric Shock
Electrical injury happens when electric current passes through a pet's body. It is not common in dogs and cats, and when it does happen,…
Cat Health
Epidermolysis Bullosa in Dogs and Cats: Fragile Skin That Blisters
Epidermolysis bullosa is an inherited disease that makes the skin so fragile that it blisters from minor rubbing. It is a group of related…
Cat Health
Black Spots on an Orange Cat’s Lips and Nose: Lentigo in Cats
Lentigo is a pigment change in which small dark spots, like freckles, appear on a cat's skin. Under the microscope it is an extra…
Cat Health
Slow-Healing Wounds in Dogs and Cats: What Can Hold Healing Back
Wounds heal in steps, and many things can slow them down. A 2026 review of wound care in small animals describes repair as a…
Cat Health
Degloving Injuries in Dogs and Cats: When the Skin Is Torn Away
A degloving injury is a wound where the skin is torn away from the tissue below it, the way a glove is pulled off…
Cat Health
Pressure Sores (Bed Sores) in Dogs and Cats: Who Gets Them and How to Prevent Them
A pressure sore is a wound that forms where the body presses on the same spot for too long. The US National Library of…
Cat Health
Food Allergy in Dogs and Cats: The Skin Signs and How Vets Confirm It
A food allergy is an immune reaction to something a pet eats. In dogs and cats it shows up mostly on the skin, and…
Cat Health
Injection-Site Sarcoma in Cats: Lumps Where Vaccines Are Given
An injection-site sarcoma is a malignant tumor that grows under the skin of cats, in places where vaccines or other injections are given. Around…
Cat Health
Chiggers (Trombiculosis) in Dogs and Cats: Orange-Red Dots and Itchy Skin
Chiggers, also called harvest mites, are the larval stage of tiny mites in the family Trombiculidae. The adults live freely outdoors and lay their…
Cat Health
Sweat Gland (Apocrine) Tumors in Dogs and Cats: Adenomas and Adenocarcinomas
Dogs have two kinds of sweat glands. Apocrine glands sit in the deeper skin across the body, while eccrine glands are found only in…
Dog Health
Cutaneous Plasmacytoma in Dogs: Small Skin Lumps on the Head, Ears and Legs
A cutaneous plasmacytoma is a skin tumor made of plasma cells, a type of white blood cell. Vets also call it an extramedullary plasma…
Cat Health
Squamous Cell Carcinoma of the Skin in Dogs and Cats: Sun, Sores and Toes
Squamous cell carcinoma (SCC) is a cancer that starts in the cells of the outer skin layer [6]. It is one of the skin…
Dog Health
Perianal (Hepatoid) Gland Tumors in Dogs
Perianal gland tumors start in small oil glands in the skin around a dog's anus. These glands are a modified kind of sebaceous (oil)…
Dog Health
Demodectic Mange in Dogs
Demodectic mange, or demodicosis, is a skin disease caused by Demodex mites. Healthy dogs carry a few of these mites in their hair follicles,…
Cat Health
Ceruminous Gland Tumors in Dogs and Cats
Ceruminous glands are the glands that make earwax in the ear canal. They are a special kind of sweat gland [1]. A ceruminous gland…
Dog Health
Interdigital Furunculosis in Dogs
An interdigital furuncle is a painful bump in the skin between a dog's toes. It forms when a hair follicle there becomes infected, swells…
Dog Health
Lipomas in Dogs
A lipoma is a lump made of fat. These benign fatty tumors grow slowly, and most sit between the skin and the muscle below…
Cat Health
Hereditary Hair Loss (Hypotrichosis) in Dogs and Cats
Alopecia means hair loss of any degree, and hypotrichosis means a coat with less hair than normal [2]. In a small number of dogs…
Cat Health
Mast Cell Tumors of the Skin in Dogs and Cats
Mast cells are immune cells found in the skin and other tissues. They take part in allergic and inflammatory reactions [2]. A mast cell…
Cat Health
Sebaceous Gland Tumors in Dogs and Cats
Sebaceous glands sit next to the hair follicles. They make an oily substance called sebum, which keeps the skin surface and the hairs supple…
Cat Health
Dermatophilosis in Dogs and Cats
Dermatophilosis is a skin infection caused by the bacterium Dermatophilus congolensis [1][2]. It used to go by names such as rain rot and rain…
Dog Health
Histiocytoma in Dogs
A histiocytoma is a skin lump that grows from immune cells in the skin. Researchers describe it as a common, benign tumour in dogs…
Cat Health
Flea Allergy Dermatitis in Dogs and Cats
Flea allergy dermatitis, or FAD, is an itchy skin allergy to flea bites. When a flea bites, it leaves saliva in the skin. Some…
Cat Health
Hair Follicle and Basal Cell Tumors in Dogs and Cats
Basal cell tumors and hair follicle tumors are growths that start in the skin and the hair follicles, the small pockets that each hair…
Cat Health
Feline Atopic Skin Syndrome: Environmental Allergies in Cats
Feline atopic skin syndrome, or FASS, is an itchy skin allergy to things in a cat's surroundings, such as house dust mites or pollen.…
Cat Health
Vitiligo in Dogs and Cats: Why Skin and Hair Lose Their Color
Vitiligo is a condition in which patches of skin, and sometimes hair and claws, lose their color. It is acquired, not present from birth:…
Dog Health
Ear Flap Hair Loss in Dogs (Pinnal Alopecia): Pattern Baldness and Other Causes
Pinnal alopecia means hair loss on the ear flaps (the pinnae). In many dogs it is a form of pattern baldness, a fairly common…
Cat Health
Proliferative and Necrotizing Otitis Externa in Cats: Thick Ear Crusts Explained
Proliferative and necrotizing otitis externa is a rare disease that causes thick crusts on the inside of a cat's ear flaps and at the…
Cat Health
Contact Dermatitis in Dogs and Cats: Skin Reactions to Ear Medicines and Other Products
Contact dermatitis is inflammation of the skin caused by something that touches it. A University of Minnesota veterinary dermatology handbook describes it as an…
Cat Health
Auricular Chondritis in Dogs and Cats: Painful, Misshapen Ear Flaps
Auricular chondritis is inflammation of the cartilage inside the ear flap. A 2025 review of feline immune-mediated skin disease describes it as a rare…
Cat Health
Solar Dermatitis in Cats: Sunburned Ear Tips, Skin Cancer Risk and Vet Care
Solar dermatitis is skin damage caused by the sun. Fur shields the skin from ultraviolet (UV) light, so the damage turns up mostly on…
Cat Health
Aural Hematoma in Dogs and Cats: Swollen Ear Flap Causes and Vet Care
An aural hematoma is a swelling of the ear flap (pinna) filled with blood-tinged fluid. It forms when tiny blood vessels inside the ear…
Dog Health
Ear-Tip Sores in Dogs: Vasculitis, Ear-Edge Necrosis and When to See a Vet
Sores at the tips of a dog's ears usually point to damage in the tiny blood vessels that feed the ear edge. Vets sometimes…
Cat Health
Skin Signs of Internal Cancer in Cats: Paraneoplastic Alopecia and Exfoliative Dermatitis
Sometimes a change in a cat's skin is a sign of a disease inside the body. Skin signs can point to internal disease, and…
Cat Health
Frostbite in Dogs and Cats: Signs, First Steps and When to See a Vet
Frostbite is damage to the skin and the tissue under it caused by cold. In dogs and cats the parts most at risk are…
Dog Health
Lethal Acrodermatitis in Bull Terriers
Lethal acrodermatitis is a rare inherited disease of Bull Terriers and Miniature Bull Terriers. Affected puppies grow poorly, develop skin disease on the face…
Cat Health
Sporotrichosis in Cats and Dogs: A Fungal Skin Infection People Can Catch
Sporotrichosis is a long-lasting fungal infection of the skin. It causes lumps and open, draining sores that do not heal. Cats get it more…
Dog Health
Juvenile Cellulitis (Puppy Strangles) in Dogs
Juvenile cellulitis, often called puppy strangles, is an uncommon skin and lymph node disease of young puppies. It causes a swollen face, pimple-like bumps…
Dog Health
Familial Footpad Hyperkeratosis in Dogs: Thick, Cracked Paw Pads
Familial footpad hyperkeratosis is an inherited condition in which a dog's paw pads grow too thick and hard. It starts at a young age…
Dog Health
Skin Cysts in Dogs: Follicular and “Sebaceous” Cysts
A skin cyst is a small pocket in or under the skin that fills up with material. In dogs, most of them start in…