Pet scratch infection prevention

Overview

A pet scratch infection is an infection that can occur when a cat or dog scratches you and bacteria enter the wound. The most common one is cat scratch disease, caused by bacteria called Bartonella henselae. It usually causes a mild skin infection and swollen lymph nodes, but in rare cases it can lead to more serious illness.

Yes, pet scratch infections are fairly common, especially in households with cats. Cat scratch disease affects about 12,000 people per year in the United States, and many more cases go unreported. Most cases occur in children and young adults.

Anyone can get a pet scratch infection, but it is most common in children under 15 years old, people who own kittens, and those with weakened immune systems (such as people on chemotherapy or with HIV).

Symptoms

Common symptoms

• A small bump or blister at the scratch site (often appears 3 to 14 days after the scratch)
• Swelling and redness around the scratch
• Swollen lymph nodes near the scratch (for example, in the armpit if scratched on the arm)
• Mild fever
• Fatigue

Symptoms in children

• Same symptoms as adults, but children may also have a high fever, headache, or loss of appetite
• Swollen lymph nodes can be more noticeable
• Rarely, eye redness or vision changes if the infection affects the eye (Parinaud's oculoglandular syndrome)

Symptoms in older adults

• Similar symptoms but may take longer to heal
• Older adults with weaker immune systems can have more severe symptoms, such as high fever, severe fatigue, or infection spreading to other parts of the body

Causes

Main causes

• Bacteria from a cat's or dog's mouth or claws entering the skin through a scratch or bite
• The most common cause is Bartonella henselae, carried by fleas in cats
• Less commonly, other bacteria like Pasteurella multocida or Staphylococcus can cause infection

Risk factors

• Owning or handling cats, especially kittens under one year old
• Being scratched or bitten by a cat
• Having a weakened immune system (e.g., from chemotherapy, organ transplant, or HIV)
• Living in warm, humid climates where fleas are more common

When to see a doctor

See a doctor urgently if:

• The scratch looks infected – red, hot, swollen, or oozing pus
• You have a fever above 101°F (38.3°C)
• Lymph nodes are very swollen or painful
• You have a weakened immune system and were scratched

Book a routine appointment if:

• The scratch has not healed after a few days
• You have mild swelling or a small bump that worries you
• You have had a scratch and now feel tired or have body aches

Diagnosis

Your healthcare provider will ask about your symptoms and how you got the scratch. They may examine the wound and feel for swollen lymph nodes. In most cases, the diagnosis is based on your history and a physical exam.

Tests that may be done

• Blood test to check for antibodies to Bartonella henselae (shows if your body has fought the infection)
• Polymerase chain reaction (PCR) test on fluid from a lymph node or wound – this can detect the bacteria's DNA
• Sometimes a biopsy (taking a small sample) of a lymph node is needed if the diagnosis is unclear

What to expect at your appointment

If your provider suspects cat scratch disease, they may recommend a blood test. Results usually come back in a few days. You may not need any treatment if symptoms are mild. If tests are needed, they are generally simple and low-risk. Your provider will explain what each test involves.

Treatment

Treatment depends on how severe the infection is. Most people with mild cases get better on their own within a few weeks, even without medicine. For more serious cases, doctors may prescribe antibiotics to help clear the infection. Always follow your healthcare provider's advice.

Self-care at home

• Wash the scratch gently with soap and warm water as soon as it happens
• Apply an over-the-counter antibiotic cream (like bacitracin) to the cleaned wound
• Cover the scratch with a clean bandage until it heals
• Take over-the-counter pain relievers (such as paracetamol or ibuprofen) if needed for pain or fever – follow the package instructions
• Apply a warm compress to swollen lymph nodes to ease discomfort

Medical treatments

If the infection is more than mild, your doctor may prescribe antibiotics. This might be a course of pills taken by mouth for 5 to 14 days. Common types include macrolides (like azithromycin) or fluoroquinolones, but your doctor will choose the best one based on your health. In some cases, the doctor may drain a very swollen lymph node to relieve pain.

When is surgery considered?

Surgery is rarely needed. It may be considered if an abscess (a pocket of pus) does not drain on its own or if a lymph node becomes very large and painful. In such cases, a small incision to drain the fluid might be done. Most infections resolve without surgery.

Living with this condition

If you have a pet scratch infection, rest and take care of your wound. Most people feel back to normal within 2 to 4 weeks. Avoid scratching the wound or picking at scabs. Keep the area clean and dry. If you have swollen lymph nodes, they may take several weeks to return to normal size.

Lifestyle tips

• Wash your hands often, especially after touching pets
• Trim your pet's nails to prevent deep scratches
• Avoid rough play with cats and kittens
• Keep your pet on flea prevention medicine (ask your veterinarian)

Diet and exercise

There are no specific dietary restrictions. Eat a balanced diet to support your immune system. You can continue normal activities as long as you feel well. If you have fever or fatigue, rest until you recover.

Mental health and emotional wellbeing

Having an infection can be stressful, especially if symptoms last longer than expected. It is normal to feel worried about your health. Talk to friends, family, or your healthcare provider about any concerns. Most pet scratch infections are not serious and will resolve.

Prevention

Yes, you can reduce your risk of getting a pet scratch infection. The most important step is to wash any scratch or bite immediately with soap and water. You can also avoid rough play with cats, especially kittens, and keep your pet's claws trimmed. Using flea prevention for your cat also helps reduce the bacteria that cause cat scratch disease.

Vaccines

There is no vaccine to prevent pet scratch infections.

Screening programmes

There is no routine screening for pet scratch infections. Prevention focuses on avoiding scratches and keeping pets healthy.

Complications

If left untreated

• The infection may spread to the liver, spleen, or brain (rare)
• Endocarditis – an infection of the heart valves (very rare)
• Swollen lymph nodes that become very painful or form abscesses
• Long-lasting fever and fatigue
• In people with weakened immune systems, the infection can be severe and harder to treat

Long-term outlook

Most people with a pet scratch infection recover fully without any long-term problems. Even without treatment, mild cases often get better in a few weeks. With proper care and possibly antibiotics, even moderate infections have an excellent outlook. Serious complications are very rare.

Find support

External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.