How does pepper spray affect mice? - briefly
Pepper spray irritates the eyes, nasal passages, and lungs of mice, producing intense burning, tearing, and difficulty breathing that quickly immobilizes them; the effects subside within 30–60 minutes as the irritant is cleared.
How does pepper spray affect mice? - in detail
Pepper spray, containing capsaicinoids such as oleoresin capsicum, acts as a potent irritant when applied to rodents. The active compounds bind to transient receptor potential vanilloid‑1 (TR V1) channels on sensory neurons, triggering a cascade of physiological events.
The immediate response includes intense ocular irritation, tearing, and corneal inflammation. Nasal passages and respiratory tract become inflamed, leading to coughing, sneezing, and bronchoconstriction. These effects are mediated by the release of substance P and calcitonin‑gene‑related peptide, which increase vascular permeability and cause edema.
Systemic consequences follow the acute phase. Elevated heart rate and blood pressure result from sympathetic activation. Stress‑induced hyperglycemia can be detected within minutes. Prolonged exposure may produce hypoxia due to compromised airway function, potentially leading to lethargy, loss of coordination, and, in severe cases, death.
Key factors influencing severity:
- Concentration – commercial formulations range from 0.5 % to 2 % capsaicinoids; higher percentages produce more rapid and severe symptoms.
- Dosage – a single 0.1 ml spray directed at the face can cause full‑scale irritation; larger volumes increase the risk of respiratory failure.
- Exposure route – ocular and nasal contact produce the strongest reactions; dermal exposure alone yields milder effects.
- Animal size and age – juvenile mice exhibit heightened sensitivity due to thinner epithelial layers and higher metabolic rates.
Recovery typically occurs within 30–60 minutes if the animal receives fresh water and a clean environment. Antagonists of TR V1, such as capsazepine, can accelerate symptom resolution when administered promptly.
Experimental studies report mortality rates below 5 % for exposures below the lethal concentration 50 % (LC₅₀) of approximately 0.4 ml of 1 % solution per kilogram body weight. Exceeding this threshold markedly raises fatality risk.
In summary, pepper spray induces acute ocular and respiratory irritation, activates the sympathetic nervous system, and can cause systemic stress responses. Severity depends on concentration, amount applied, exposure site, and the physiological status of the mouse. Proper dosing and immediate post‑exposure care mitigate adverse outcomes.