In some cases, 48 to 72 hours after being bitten, a more severe rash-like irritation may begin to spread across the body.

Symptoms include swelling of the bitten area, erythema, ulcers of the mouth and throat, restlessness, and soreness of the areolae.

[1] In extreme cases, within 1 week after being bitten, the condition may spread through the lymph nodes and begin affecting the central nervous system.

[2]: 450 If they receive an excessive number of bites, pets can also develop flea allergy dermatitis, which can potentially be fatal if no actions are taken.

[citation needed] However, dogs and cats are not the only ones that are at risk.