Lice in Dogs and Cats 🐶🐱🦠

By Dr Duncan Houston, BVSc

Lice may be uncommon, but they’re not impossible. In shelters, kennels, or situations with low grooming standards, lice can infest dogs or cats—and make life incredibly itchy. Fortunately, treatment is straightforward. In this 2025 guide, I’ll show you how to detect, treat, and prevent lice in pets. 🧴

🔍 What Are Lice?

Lice are flat, six-legged, wingless insects that live on your pet’s skin. They can be seen with the naked eye and move slowly. Unlike fleas, they don’t jump. Each louse lives about 21 days and spends its entire life cycle on the host. They lay eggs (called nits) on hair shafts, which look like small white flakes. 🧬

⚠️ Are Lice Zoonotic?

No—lice are host-specific. That means:

• 🧍‍♂️ Humans get lice only from other humans
• 🐶 Dogs get lice from other dogs
• 🐱 Cats get lice from other cats

Lice might crawl onto another species briefly, but they can’t survive or reproduce on the wrong host. ✅

🔬 Types of Lice in Pets

In Dogs:

• 🦠 Trichodectes canis – chewing louse
• 🦟 Linognathus setosus – sucking louse

Sucking lice cause more irritation and may lead to anemia in puppies. Severe infestations can even cause shock. 🚨

In Cats:

• 🐛 Felicola subrostrata – chewing louse

🧾 Symptoms of Lice Infestation

• 😾 Severe itching and scratching
• 🐾 Dry, scruffy coat with bald patches
• 🔍 Visible white flakes (nits) on hair shafts
• 🦴 Puppies or kittens may become anemic

Lice often gather around the ears, neck, shoulders, and anus—areas with thin skin or longer hair. 🩺

📈 How Do Pets Get Lice?

Lice spread by direct contact with an infested animal or shared contaminated items, like:

• 🪮 Grooming tools
• 🛏️ Beds or blankets
• 🏠 Crowded kennels or shelters

🩺 Diagnosis

Lice are large enough to see without a microscope. A veterinarian will check your pet’s coat and look for adult lice and nits. 🧼

💊 Treatment Options

Lice don’t build resistance easily, so treatment is usually effective. Options include:

• 🧴 Insecticidal baths and sprays
• 💊 Oral or topical medications: fipronil, selamectin, or isoxazolines (e.g., sarolaner, lotilaner, fluralaner, afoxalaner)
• ✂️ Shaving matted coats (if needed)

Treatment is typically repeated every 2 weeks for 3–4 doses. Isoxazolines may need only 1–2 treatments. 🗓️

🧽 Cleaning Your Home

While lice don’t survive long off the host, it’s still smart to clean your environment:

• 🧺 Wash bedding, blankets, and toys
• 🪮 Disinfect grooming tools
• 💨 Use foggers or environmental sprays only if infestation is severe

🛡️ Prevention Tips

• 🔍 Groom and inspect pets regularly
• 🧼 Keep living areas clean
• 🪰 Use year-round parasite preventives
• 🏠 Isolate new or rescued animals until cleared

📱 Ask A Vet App Support

Not sure if your pet has lice—or what product to use? The Ask A Vet app provides:

• 📸 Photo review of suspected lice or nits
• 🧾 Product recommendations (based on weight and species)
• 💬 Live vet chat for treatment protocols
• 🧼 Environmental cleaning advice

🏁 Final Takeaway

Lice are rare but treatable in pets. Don’t confuse them with dandruff or fleas. If your pet has bald patches or constant itching, have your vet examine them. With the right treatment plan and good hygiene, lice infestations can be cleared quickly and safely. 🐶🐱🧼