Cephalexin Dosage For Cats | Rilexine Dosage Chart by Weight

Cephalexin for cats, also known as Cefalexin, Cephalexin monohydrochloride, or Cephalexin monohydrate,  is a prescription medicine belongs to the cephalosporin class of drugs is a first-generation cephalosporin antibiotic works against gram-negative and anaerobic organisms commonly used to treat bacterial infections in felines include skin infections,  respiratory tract,  urinary tract bones, and joints infections. 

Cephalexin is a prescription medicine for cats. Learning about the safe dosage, safety precautions, uses, side effects, and safe serving tips is essential to prevent your kitty from any adverse reactions. 

There are famous brands of Cephalexin available that you can use for your pet treatment purposes, such as Keflex®, Rilexine®, Keftab®, Ceporex® and  Biocef® etc. 

This blog article is an ultimate and comprehensive guide about Cephalexin for cats. Includes dosage chart by weight and dosage calculator. 

Cephalexin for cats
Medicine NameCephalexin
Group Cephalosporin (Antibiotic)
Popular Brand Names Rilexine®, Keflex®, Keftab® and  Biocef®, Cephaforte®, Rilexine®, Keflex®, Vetolexin®
FDA-Approved For catsYes some brands
Prescription RequiredYes
BrandsRilexine®, Ceporex®, Cephacare®,  Cefaseptin®, Cephorum®, Ceporex®, Cefabactin®, Petalexin®, Therios®  
Available FormsCapsules:250mg+500mg
Tablets:50mg+75 mg+150 mg+200mg+250mg+ 300mg+500mg+ 600 mg+750 mg+1000 mg  Oral suspension:   250mg/5ml+125mg/5ml+500mg/5ml
Safe Form For CatsTablets: 50mg+75 mg+150 mg Oral Suspension: 125mg/5ml+ 250mg/5ml
Storage Requirements: 18-25  °C

How does Cephalexin work?

Cephalexin belongs to the cephalosporin group of antibiotics that usually works against gram-negative and anaerobic organisms. Antibiotics belong to this group limiting the activity of bacteria for forming adequate and protective cell walls in the organism.

These antibiotics cause instability from the bacteria that eventually kill the harmful bacteria and hence help treat the infection. 

Is cephalexin safe for cats?

Yes, giving the safe version of cephalexin in the right dosage is safe for cats. However, overdosing on the medicine and giving it to felines that are not supposed to take the antibiotic can cause health complications.

Uses of Cephalexin for felines

In cats, Rilexine® is mostly used for treating:

  • Skin Infections
  • Wound Infections 
  • Bone Infections
  • Upper Respiratory Tract Infections
  • Mastitis
  • Urinary Tract Infections
  • Joints Infections

Cephalexin Dosage For Cats

According to veterinarians, the safe dosage of Cephalexin for cats is 10-30 mg/kg (5-14 mg/lb) 6 to 12 hours for seven days to one month or as prescribed by the veterinarians. 

The ideal dosage of Cephalexin liquid oral suspension 125mg/5ml (25mg/ml) is 0.4 ml/kg and of 250mg/5ml (50mg/ml) is 0.2ml/kg.

Cephalexin Dosage For Cats

Your vet may increase or decrease the dose depending on the severity of the infection and the overall health performance of your pet. 

Never overdose your cat on Cephalexin; it can be fatal. Self-medication can be fatal for your feline. Ensure to use the drug with the vet’s prescription only. 

If you observe any adverse effects of an overdosing reaction, make sure to contact your nearby vet immediately. 

Dosage Calculator:

For the safety measures, always start with the lower dose and only increase the dose when your vet advises you to.

Cephalexin Dosage Chart for Cats by Weight

Cat Weight in kgCat Weight in lbsCephalexin Dosage
2 kg4 lbs20-60 mg
5 kg11 lbs50-150 mg
8 kg18 lbs80-240 mg
12 kg26 lbs120- 360 mg
15 kg33 lbs150-450 mg
20 kg44 lbs200-600 mg
25 kg55 lbs250-750 mg
30 kg66 lbs300-900 mg
Cat Body WeightCephalexin 50mg DosageCephalexin 75mgCephalexin 150mg Cephalexin 200mg DosageCephalexin 300mg Dosage
2 kg1/2 Tablet1/3 Tablet1/5 Tablet**
5 kg1 Tablet*1/3 tablet1/4 Tablet*
8 kg1+1/2 Tablets1 Tablet1/2 Tablet1/3 tablet*
12 kg2+ 1/2 Tablets1+1/2 Tablet1 Tablet1/2 Tablet*
15 kg3 Tablets2 tablets1 Tablet*1/2 Tablet
20 kg*3 Tablets1, 1/3 Tablets1 Tablet*
25 kg**1,1/2 Tablets1, 1/4 Tablets1 Tablet
30 kg*2 Tabets1,1/2 Tablets1 Tablet
Cat WeightCephalexin (Oral suspension) 125mg/5ml Dosage Cephalexin (Oral suspension) 250mg/5ml
2 kg0.8 ml0.4 ml
5 kg2 ml1 ml
8 kg3.2 ml1.6 ml
12 kg4.8 ml2.4 ml
15 kg6 ml3 ml
20 kg8 ml4 ml
25 kg10 ml5 ml

Cephalexin Side Effects For Cats

Most reported side effects of Cephalexin in felines are:

Minor Side Effects:

  • Allergic reactions
  • Vomiting
  • Diarrhea
  • Drooling
  • Irregular breathing
  • Restlessness
  • Decreased Appetite
  • Lethargy

Overdosing Side Effects:

Which cats should avoid taking Cephalexin?

Cats allergic or hypersensitive to Cephalexin or other cephalosporin class drugs should not take Cephalexin. Pregnant and nursing Felines and, cats having health issues such as kidney,  liver illnesses, seizures, epilepsy, or heart issues should avoid taking Cephalexin without veterinarian advice.

How much time does Cephalexin take to start work on cats?

Cephalexin usually starts its effects once absorbed in the body. You will observe an improvement in the treatment process within 24-48 hours.

However, in certain infections in cats, it may take longer than 7 days to see the result.

If you don’t observe improvement within 7 days, make sure to inform your vet about the situation. 

How to give cephalexin to cats?

  • 1. Use the antibiotic with your vet’s prescription only, and make sure to only give the safe dose of the medicine.
  • 2. Whatever form of medicine you are using, make sure to calculate and administer the safe amount.
  • 3. Pet owners allergic to cephalexin, penicillin, or cephalosporin class drugs avoid giving the antibiotic to the pet. Prefer another household member. 
  • 4. Keep the medicine out of the reach of children and other pets in the house to avoid any complicated or emergency situations.
  • 5. Keep a close eye after administering the medicine to your pet. If you observe any adverse effects in your kitty, immediately take your vet’s help.
  • 6. Make sure to choose the right formulation of the medicine for your kitty. Avoid the product that contains any additional ingredients or any other artificial toxic flavors. 

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Can I give human cephalexin to my cat?

Yes, you can give the human formulation cephalexin (that doesn’t contain any extra ingredients) to your cat in the right dosage. However, the best idea is to choose a pet-friendly formulation of antibiotics for your kitty. 

What is the lethal amount of cephalexin for cats?

A dose high than 40mg/kg can be lethal for cats. A high dose can lead your pet to severe health issues such as kidney, liver, or heart failure. 

Can I use Cephalexin for fungal and viral infections?

No, Cephalexin is not effective medicine for the treatment of fungal and viral infections.
Cephalexin dosage chart by weight for cats

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