Cephalexin for Dogs Dosage
Calculate the correct cephalexin antibiotic dose for your dog by weight. Free veterinary dosage calculator with tablet and liquid measurements and safety warnings.
About This Calculator
The Cephalexin for Dogs Dosage Calculator helps pet owners and veterinarians determine the appropriate antibiotic dose for canine patients. Cephalexin is a first-generation cephalosporin antibiotic commonly prescribed to treat bacterial infections in dogs, including skin infections, urinary tract infections, respiratory infections, wound infections, and bone infections (osteomyelitis).
The standard dosage for cephalexin in dogs is 15 mg per kilogram of body weight, administered twice daily (every 12 hours), based on NOAH (National Office of Animal Health) recommendations. The calculator uses the formula: Single Dose = Dog Weight (kg) × 15 mg/kg. The daily dosage is calculated by multiplying the single dose by 2 for twice-daily administration.
Cephalexin belongs to the beta-lactam class of antibiotics, the same family as penicillin and amoxicillin. It works by interfering with bacterial cell wall formation, causing the bacteria to rupture and die. It is effective against many gram-positive and some gram-negative bacteria, making it a versatile choice for treating common canine infections.
Pharmaceutical companies sell cephalexin under various brand names including Keflex, Lupin, and Rilexine — only Rilexine chewing tablets are registered for oral use in dogs, and only in certain countries. The calculator supports multiple formulations including regular tablets (250 mg, 500 mg), chewable tablets (75 mg, 150 mg, 300 mg, 600 mg), and liquid suspensions (125 mg/5 mL, 250 mg/5 mL).
Important Safety Notes
Never give cephalexin to dogs with known allergies to beta-lactam antibiotics or penicillin. Avoid use in puppies under 1 kg (2.2 lb) and dogs with kidney impairment. Always monitor your dog after the first few doses and contact your veterinarian if you notice any adverse reactions.
This calculator is for informational purposes only and does not replace professional veterinary advice. Always consult your veterinarian for proper diagnosis and treatment recommendations for your dog.
Frequently Asked Questions
How much cephalexin can I give my dog?
The standard cephalexin dosage for dogs is 15 mg per kilogram of body weight, given twice daily (every 12 hours). The total daily dosage is 30 mg/kg. Always consult your veterinarian before administering any medication.
What is cephalexin used for in dogs?
Cephalexin is a first-generation cephalosporin antibiotic used to treat bacterial infections in dogs including skin infections, urinary tract infections (UTIs), respiratory infections, wound infections, and bone infections (osteomyelitis). It works by interfering with bacterial cell wall formation.
Can I give my dog human cephalexin?
Yes, human cephalexin contains the same active ingredient as veterinary formulations. However, only Rilexine chewing tablets are registered for oral use in dogs in certain countries. Always calculate the correct dose by weight and confirm with your veterinarian before giving any human medication to your dog.
What are the side effects of cephalexin in dogs?
Common side effects include vomiting, diarrhea, loss of appetite, and lethargy. Give with food to reduce GI upset. Rare but serious side effects include allergic reactions (skin rashes, difficulty breathing), and some pure breeds may experience weakness or lameness with off-label use. Contact your vet if any severe symptoms occur.
How long should my dog take cephalexin?
Treatment duration depends on the condition. Skin infections typically require 7-14 days, UTIs require 10-14 days, and other infections may require longer. Always complete the full course of antibiotics as prescribed by your veterinarian, even if symptoms improve.
When should cephalexin not be used in dogs?
Cephalexin should not be used in dogs with known allergies to beta-lactams, penicillin, or cephalosporins. It should also be avoided in puppies weighing less than 1 kg (2.2 lb) and in dogs with kidney damage or impairment. Always inform your vet of your dog's full medical history.
Is 500 mg of cephalexin safe for dogs?
500 mg of cephalexin is an appropriate single dose for a dog weighing approximately 33 kg (73.5 lb) at the standard 15 mg/kg dosage. For smaller dogs, 500 mg may be too high and could cause overdose symptoms. Always calculate the correct dose based on your dog's exact weight.
Does cephalexin interact with other medications?
Cephalexin may interact with other medications including anticoagulants, certain diuretics, and other antibiotics. Always inform your veterinarian about any other medications or supplements your dog is taking to avoid potential drug interactions.