Caffeinated drinks / Soda

Symptoms reported in cats

Most serious first.

1. 1
   Severe Neurological Overstimulation 2 to 12 hours (progresses as the caffeine is fully absorbed) · Caffeine blocks cellular adenosine receptors, leading to severe central nervous system overstimulation4. The cat will become extremely agitated, which can rapidly progress to severe muscle tremors, grand mal seizures, and potentially a coma.
2. 2
   Cardiovascular Dysfunction 2 to 12 hours · Caffeine increases intracellular calcium levels, which abnormally enhances the strength and frequency of cardiac muscle contractions4. This results in very rapid, irregular heartbeats and ultimately cardiac arrest in the terminal phase of poisoning.
3. 3
   Respiratory Distress Mid to terminal phases (progressing from 2 to 12 hours) · As the central nervous and cardiovascular systems become overwhelmed by the stimulant, the cat will pant and breathe very rapidly1. In the most extreme cases, this culminates in complete respiratory failure and arrest.
4. 4
   Hyperthermia 6 to 12 hours · The extreme overstimulation of the nervous system, combined with continuous hyperactivity and severe muscle tremors, generates excessive internal heat, causing the cat's core body temperature to spike to dangerous levels12. (Note: If the caffeinated drink or soda is a "diet" or "sugar-free" variety sweetened with xylitol, there is a theoretical risk of a rapid drop in blood sugar (hypoglycemia) and liver injury, though cats appear to be much more resistant to xylitol toxicity than dogs7. Nonetheless, xylitol combined with caffeine makes these beverages strictly contraindicated8.)
5. 5
   Gastrointestinal Upset (Vomiting and Diarrhea) 2 to 4 hours (can be delayed up to 6–12 hours) · These are typically the initial symptoms after a cat ingests caffeinated drinks or sodas1. Early vomiting can actually be beneficial, as it helps remove some of the unabsorbed toxic caffeine from the cat's body before it fully enters the bloodstream.
6. 6
   Increased Thirst and Urination 2 to 4 hours · Caffeine acts as a mild diuretic, which increases fluid loss and causes the cat to pass abnormally large amounts of urine, subsequently driving excessive thirst.

Important notes

Caffeinated beverages — including sodas, energy drinks, tea, and coffee-based drinks — are toxic to cats because of their methylxanthine content (primarily caffeine, and in some cases theobromine). Cats metabolise these compounds far more slowly than humans, allowing dangerous levels to accumulate rapidly. Even a small amount can cause significant harm: just a few sips of energy drink can overwhelm a cat's system. Sugar-free sodas and energy drinks carry an additional risk if they contain xylitol.

• Symptoms: Vomiting, diarrhea, and excessive thirst and urination initially; progressing to extreme agitation, rapid heart rate, rapid breathing, muscle tremors, hyperthermia, cardiac arrhythmias, and seizures.
• Energy drinks are especially dangerous: They contain caffeine in concentrations far higher than soda or tea, and sometimes also taurine and other stimulants that compound the effect.
• Action: Keep all caffeinated beverages out of reach. Seek veterinary care immediately if a cat has ingested any caffeinated drink.