Why Your Cat May Sleep More or Pass Gas After Deworming
📝 Summary
House cats are usually dewormed every 2-3 months, and most show no reaction, but a cat with a heavy parasite load or a weak constitution can have mild side effects. Frequent passing of gas comes from the drug speeding gut movement and fermenting food; if the cat acts normal it eases within an hour, and a pet probiotic can help. Mild vomiting or diarrhea, drowsiness, or lowered appetite are also usually normal and pass in 1-2 days, though severe cases need a vet to rule out toxicity or fatty liver.
1 Gas and Digestive Upset
Normally a cat is dewormed at least every 2-3 months. Most show few side effects, but if the parasite load is high a few mild reactions can appear.
1. Frequent passing of gas. Some cats break wind repeatedly after a dewormer because the drug mildly irritates the gut, speeding intestinal movement and increasing gas from fermenting food. If the cat’s mood and appetite are normal, don’t worry, it usually eases in under an hour.
You can give a pet probiotic to balance the gut flora and, to some extent, reduce gas production.
2 Other Side Effects
2. Vomiting and diarrhea. Cats with sensitive guts may have mild vomiting or diarrhea from the drug; if it’s not severe it’s normal, the medicine is working, and it clears in 1-2 days. A probiotic soothes the gut. But if vomiting and diarrhea are severe, consider acute gastroenteritis or accidental overdose and see a vet.
3. Drowsiness and lethargy. Some cats become withdrawn and sleepy, either from a mild drug side effect or from weakness due to a heavy parasite load needing rest to recover; this also eases after a few hours.
4. Lowered appetite. This shares the same cause as vomiting and diarrhea and is normal, but if a cat stops eating for long it risks fatty liver, so syringe a little liquid food to meet energy needs, or get intravenous fluids at a clinic.
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