cat-cephalexin-dosage-calculator
Calculate cephalexin dosage for cats from body weight in pounds or kilograms, using the standard veterinary rate of 10 mg per pound given twice daily.
Cat Cephalexin Dosage Calculator
Dosage formula: 10 mg/lb
How it's calculated
Formula
5 lb × 10 mg/lb = 50 mg
Administer this dosage twice daily (every 12 hours) or as directed by your veterinarian. Complete the full prescribed course.
This calculator provides dosage estimates based on standard veterinary guidelines. Always consult with your veterinarian before administering medication.
Documentation
Cat Cephalexin Dosage Calculator
The cat cephalexin dosage calculator estimates how many milligrams of cephalexin to give a cat, based on the cat's body weight. It follows the standard veterinary dosing rate of 10 mg per pound (22 mg per kilogram), given twice a day.
What Is Cephalexin?
Cephalexin is an antibiotic in the cephalosporin family. It is sold under brand names such as Keflex for human use. Veterinarians prescribe it for cats to treat bacterial infections of the skin, urinary tract, and respiratory system. It works by stopping bacteria from building new cell walls, which kills the bacteria or stops them from multiplying.
Cephalexin only works against bacteria. It does not treat infections caused by viruses or fungi. A cat needs a prescription from a veterinarian to get it; there is no over-the-counter version made for pets.
How to Calculate Cephalexin Dosage for Cats
- Weigh the cat, or find its most recent weight from a vet visit.
- Enter the weight into the calculator.
- Choose the weight unit: pounds (lb) or kilograms (kg).
- Read the dosage shown. This is the amount for one dose, given twice a day.
Cephalexin Dosage Formula
The calculator uses one of two fixed rates, depending on the unit chosen:
- 10 mg per pound of body weight (lb)
- 22 mg per kilogram of body weight (kg)
Both rates are meant to describe roughly the same dosing standard; 22 mg/kg works out to about 9.98 mg per pound, close enough to the 10 mg/lb figure that they are treated as equivalent in practice.
The dose is given twice daily, about 12 hours apart. That schedule is often written as "BID," short for the Latin phrase bis in die.
Formula:
1Dose per administration = body weight × rate
2Worked Example
A cat weighs 10 lb. Using the pound rate:
110 lb × 10 mg/lb = 100 mg per dose
2The cat receives 100 mg in the morning and 100 mg in the evening, for a total of 200 mg per day.
A second example in metric units: a cat weighs 4 kg.
14 kg × 22 mg/kg = 88 mg per dose
2That cat receives 88 mg twice a day, for a total of 176 mg per day.
Cephalexin Dosage Chart by Weight
| Cat weight (lb) | Cat weight (kg) | Dose per administration | Daily total |
|---|---|---|---|
| 5 lb | 2.3 kg | 50 mg | 100 mg |
| 8 lb | 3.6 kg | 80 mg | 160 mg |
| 10 lb | 4.5 kg | 100 mg | 200 mg |
| 12 lb | 5.4 kg | 120 mg | 240 mg |
| 15 lb | 6.8 kg | 150 mg | 300 mg |
These figures use the 10 mg/lb rate. A veterinarian may prescribe a different amount depending on the type and severity of the infection.
What Cephalexin Treats in Cats
Veterinarians commonly prescribe cephalexin for:
- Skin and soft-tissue infections, including wounds and abscesses
- Urinary tract infections
- Respiratory infections
- Infections following surgery
Giving Cephalexin Safely
- Give cephalexin only on a veterinarian's instructions. Do not give a cat medication made for humans, or leftover medication from another animal, without checking with a vet first.
- Finish the full course of doses, even if the cat seems better partway through. Stopping early can let surviving bacteria multiply again.
- If a dose is missed, give it as soon as it is remembered. If it is almost time for the next dose, skip the missed one; do not give a double dose.
- Store the medication as the label directs. Some liquid forms need refrigeration.
- Common side effects are mild stomach upset, such as vomiting, diarrhea, or reduced appetite. Contact a veterinarian if side effects are severe or do not go away.
Frequently Asked Questions
How much cephalexin should a 10-pound cat get?
At the standard rate of 10 mg per pound, a 10 lb cat gets 100 mg per dose, twice a day, for a total of 200 mg daily. A veterinarian may adjust this based on the infection being treated.
Is cephalexin the same as amoxicillin?
No. Cephalexin is a cephalosporin, and amoxicillin is a penicillin. They belong to different classes of antibiotic and are not interchangeable without a veterinarian's guidance.
Can a cat take human cephalexin?
Only under a veterinarian's direction. The active drug is the same, but tablet strengths, flavorings, and other ingredients in human products are not made with a cat's needs in mind. A veterinarian will prescribe a form and strength suited to the cat.
What happens if a dose is missed?
Give the missed dose as soon as it is noticed. If it is close to the time for the next dose, skip the missed one and continue on the normal schedule. Never give two doses at once to make up for a missed one.
What are the side effects of cephalexin in cats?
The most common side effects are digestive: vomiting, diarrhea, or loss of appetite. Allergic reactions are possible but less common. A cat showing swelling, hives, or difficulty breathing needs urgent veterinary care.
Does cephalexin treat every kind of infection?
No. It works only against bacteria. It has no effect on viral infections, such as most upper respiratory infections in cats, or on fungal infections like ringworm.
When to Contact a Veterinarian
Contact a veterinarian promptly if a cat taking cephalexin shows severe vomiting or diarrhea, signs of an allergic reaction, or no improvement after two to three days of treatment.
This calculator gives a general estimate based on a standard veterinary dosing rate. It is not a substitute for a veterinarian's prescription or advice. Always follow the dose and schedule a veterinarian provides.