Azithromycin For Cats Dosage Chart | 100mg/5ml-200mg/5ml

Azithromycin (Zithromax®) is a macrolide antibiotic used off-label for cats to treat certain feline health issues, including upper respiratory infections, pneumonia, fever, congestion, dermatological infections and urogenital infections.

Azithromycin is not an FDA Approved medicine for cats; however, this can be legally prescribed by the veterinarian off-label. According to the veterinarian, Azithromycin is a safe alternative for felines allergic to penicillin or issues not well-treated with penicillin.

Azithromycin is a prescription medicine for cats and should only be used with a licensed veterinarian’s prescription. Self-medication can be toxic and even fatal. 

Feline health should be a priority for every cat owner; therefore, learning the essential requirements of the medicine for pet use to avoid any overdosing or other severe complications is essential.

This blog post is a comprehensive and ultimate guide about Azithromycin dosage for dogs, dose chart, benefits, side effects, safety precautions, dose calculator and more. 

Azithromycin For Cats

When to use Azithromycin for Cats?

Azithromycin (Zithromax® ) is a prescription medicine for cats and only be used with the veterinarian’s advice for the treatment of upper respiratory infections, pneumonia, fever, congestion, oral infections, middle ear infections, dermatological infections, Intestinal Infections, rickettsia, urogenital infections, and Urinary Tract Infections.

Remember, long-term use of Azithromycin can increase the risk of antibiotic resistance, so don’t use the medicine as a first treatment option. 

The ideal form of Azithromycin for cats is the liquid form. Tablets usually come in a high dose, and maintaining a safe dose in the tablet form can be difficult. 

Serve Cats Disclaimer: This article is compiled for the good well of our readers. All the information is for guidance purposes and will never replace your vet’s advice at any stage.

Azithromycin Dosage For Cats

Azithromycin Dosage For Cats

According to veterinarians, the recommended Azithromycin dosage for cats is 5-10mg/kg (2.5-4.5 mg/lb) once daily for 3-6 days or as directed by the veterinarian. The dosage of Zithromax® liquid 100mg /5ml (20 mg/ml) for felines is 0.25 ml/kg, and 200 mg/ml (40 mg/ml) is 0.125 ml/kg.

The dose can be increased, decreased or stopped depending on the health condition of the pet. 

Azithromycin Dosage Calculator For Cats

Azithromycin For Cats Dosage Chart By Weight

#Kg Cat Weight#lbs Cat WeightAzithromycin Dosage
5-10mg/kg (2.5-4.5 mg/lb)
3 kg7 lbs15-30 mg
5 kg11 lbs25-50 mg
8 kg18 lbs40-80 mg
10 kg22 lbs50-100 mg
15 kg33 lbs75-150 mg
20 kg44 lbs100-200 mg
25 kg55 lbs125-250 mg
30 kg66 lbs150-300 mg

For safety precautions, always go with the less dosage. For a high safe dose, first, take advice from your veterinarian.

Zithromax 100mg/5ml, 200 mg/5ml Dosage Chart For Cats

Cat #Kg Weight Cat #lbs WeightZithromax 100mg/5ml (20mg/ml) Dosage
(0.25 ml/kg)
Zithromax 100mg/5ml (40mg/ml) Dosage
(0.125 ml/kg)
3 kg7 lbs0.75 ml0.37 ml
5 kg11 lbs1.25 ml0.62 ml
8 kg18 lbs2 ml1 ml
10 kg22 lbs2.5 ml1.25 ml
15 kg33 lbs3.75 ml1.8 ml
20 kg44 lbs5 ml2.5 ml
25 kg55 lbs6.25 ml3.12 ml
30 kg66 lbs7.5 ml3.75 ml

Azithromycin Side Effects in Cats

The commonly reported side effects of Azithromycin in cats are:

  • Vomiting
  • Diarrhea
  • Foaming Mouth
  • Irregular Urination
  • Kidney and liver illnesses
  • Anaphylaxis
  • Facial swelling or hives
  • Allergic Reactions

Which cats should not take Azithromycin?


For felines, use Azithromycin with precautions. The medicine is not safe for all cats.

Felines with certain health issues include liver or renal problems, heart issues, pets allergic to antibiotics, and pregnant and lactating cats should avoid taking Azithromycin until your veterinarian advises. 

Newborn kitties should not take Azithromycin without the supervision of a licensed veterinarian. 

Which drugs can interact with Azithromycin (Zithromax®)?

Be very careful before administering Azithromycin to your kitty. The drug may interact with certain medicines that can compel your feline friend to have health complications.

Drugs that can interact with Azithromycin are:

  • Antacids
  • digoxin
  • Cyclosporine
  • Cisapride
  • warfarin
  • Phenytoin
  • Pimozide

Is Azithromycin safe for kittens?

Newborn kittens and kitties weight less than 2 kg should not take Azithromycin without the prescription and supervision of a licensed veterinarian. 

Can I use Azithromycin for cats’ upper respiratory infections?

Yes,  Azithromycin is a treatment medicine for cats’ upper respiratory infections. For the treatment of upper respiratory infection, a dose of 5-10mg/kg (2.5-4.5 mg/lb) can be given to felines for 3-6 days, depending on the severity of the illness.


Give only a safe and ideal dose according to your pet’s body weight and health condition with the vet’s prescription only.

Azithromycin for cats should never be used without a vet prescription

In certain health issues, your vet may prescribe the treatment twice a day, so make sure to keep a gap of 12 hours between the doses.

Try to use the liquid form of the Azithromycin for cats. If you are using the tablet form, make sure to follow the dosing instruction to avoid overdosing. 

After administering Azithromycin to your feline, observe your pet for about 1 hour. If you notice any adverse reactions and symptoms, contact your vet immediately for help. 

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