Please consult a veterinarian immediately. A bald patch could be a sign of several health issues, some serious.
Here are some possible causes of bald patches in guinea pigs:
* Ringworm: A fungal infection that causes hair loss and skin lesions.
* Mites: Tiny parasites that burrow into the skin and cause itching and irritation.
* Allergies: Guinea pigs can develop allergies to food, bedding, or other environmental factors.
* Stress: Stress can lead to hair loss.
* Nutritional deficiencies: Lack of certain nutrients can affect hair growth.
* Other medical conditions: Such as hypothyroidism, Cushing's disease, and cancer.
A veterinarian can diagnose the cause of the bald patch and recommend the appropriate treatment. This may involve medication, dietary changes, or other therapies.
It's important to act quickly to prevent the condition from worsening and ensure your guinea pig's health and well-being.