Overview of Cat Scratch Disease
Cat scratch disease (CSD) is a bacterial infection caused by Bartonella henselae. It is a common zoonotic disease, with cats being the primary reservoir. While CSD is often mild in humans, it can cause serious complications in immunocompromised individuals. In cats, the infection is usually asymptomatic, but some may develop mild illness. The disease is transmitted through scratches, bites, or contact with infected flea feces. Awareness and preventive measures are crucial.
Early Warning Signs and Symptoms
Most infected cats show no symptoms. However, some may exhibit:
- Fever
- Lethargy
- Loss of appetite
- Swollen lymph nodes (lymphadenopathy)
- Red, raised lesion at the site of a scratch or bite (papule)
- Rarely, eye inflammation or neurological signs
In humans, symptoms include a papule at the wound site, swollen lymph nodes, fever, headache, and fatigue. Symptoms usually appear 3-14 days after exposure.
Common Causes and Risk Factors
Bartonella henselae is transmitted among cats by fleas (Ctenocephalides felis). Risk factors include:
- Outdoor access (increased flea exposure)
- Kittens (more likely to scratch and bite)
- Multi-cat households
- Flea infestation
- Immunocompromised cats
Prevention Measures
Vaccination
There is no vaccine available for CSD in cats. Prevention focuses on flea control and scratch prevention.
Hygiene Management
- Keep nails trimmed and filed to reduce injury risk.
- Disinfect any wounds (scratches or bites) promptly with antiseptic.
- Wash hands after playing with cats, especially kittens.
- Cover any scratches with bandages.
Dietary Control
A balanced diet supports a healthy immune system. Ensure high-quality cat food appropriate for age and health status.
Regular Check-ups
Annual veterinary exams help detect underlying issues. Flea prevention is essential year-round.
Diagnostic Process
Veterinarians may perform:
- Physical examination: Check for fever, lymph node enlargement, and skin lesions.
- Blood tests: Complete blood count (CBC) may show mild anemia or elevated white blood cells.
- Serology: Detect antibodies to Bartonella henselae.
- PCR testing: Identify bacterial DNA from blood, lymph node aspirate, or skin biopsy.
- Culture: Specialized culture for Bartonella (insensitive).
In humans, history of cat contact and positive serology often confirm diagnosis.
Treatment Options
Home Care
- Isolate infected cat from immunocompromised individuals.
- Ensure rest and supportive care: fresh water, nutritious food.
- Monitor wounds for signs of secondary infection.
- Administer prescribed antibiotics as directed.
Veterinary Treatment
Symptomatic cats may receive:
- Antibiotics: Doxycycline, azithromycin, or enrofloxacin for 2-4 weeks.
- Supportive therapy: Fluids if dehydrated, appetite stimulants if needed.
- Surgical drainage of abscessed lymph nodes if required.
Common Medications
| Drug | Dosage (Cat) | Duration |
|---|---|---|
| Doxycycline | 5-10 mg/kg PO q12h | 2-4 weeks |
| Azithromycin | 5-10 mg/kg PO q24h | 2-4 weeks |
| Enrofloxacin | 5 mg/kg PO q24h | 2-4 weeks |
Human treatment: Antibiotics for severe cases; mild cases resolve spontaneously.
When to Seek Emergency Care
- If a cat shows severe lethargy, high fever, or seizures.
- If a human develops high fever, severe headache, or swollen lymph nodes that rapidly enlarge.
- If the wound becomes red, swollen, or shows signs of infection (pus, warmth).
- Immunocompromised individuals with exposure should seek medical advice.
Prognosis, Recovery, and Long-Term Management
Prognosis for cats is excellent. Most recover fully with treatment, though some remain carriers. Humans also recover well, but immunocompromised patients may have prolonged illness. Long-term management includes:
- Regular flea control (topical or oral preventives).
- Keep cats indoors to reduce flea exposure and scratching.
- Trim nails regularly.
- Discourage rough play that leads to scratches.
- Educate family members, especially children, on safe interaction.
Recovery time is typically 2-4 weeks. Recurrence is uncommon. With proper care, prevention, and hygiene, the risk of CSD significantly decreases.