what is the best antibiotic for feline upper respiratory infection | Important Points

Upper respiratory infections (URIs) are common in felines and can be caused by a variety of viruses, bacteria, and other pathogens. The symptoms of a URI can be quite severe, including sneezing, coughing, nasal discharge, conjunctivitis, fever, loss of appetite, and difficulty breathing. Fortunately, many feline URIs can be treated with antibiotics, which are medications that kill or inhibit the growth of bacteria. However, determining the best antibiotic for feline upper respiratory infection depends on various factors that the veterinarian will consider before prescribing the medicine. This article will discuss some of these factors and help cat owners understand the best antibiotic to treat their cat’s URI.

Common bacterial causes of feline URIs include Mycoplasma, Chlamydia, and Bordetella. The severity of the illness and the cat’s overall health condition will determine the antibiotic administered. However, it is essential to note that not all cases require antibiotic treatment. Some URI’s may be caused by viruses, which are not treatable with antibiotics. Therefore, the veterinarian will have to determine whether the cat’s URI is due to a bacterial or viral pathogen before prescribing antibiotics. They will do this by performing a diagnostic test or evaluation. They may take a sample from the cat’s nasal discharge or blood to help diagnose the underlying bacteria.

Nonetheless, the following are the commonly prescribed antibiotics by veterinarians to treat feline URIs.


Azithromycin is one of the preferred antibiotics used to treat feline URIs caused by Mycoplasma and Chlamydia. It belongs to the macrolide antibiotic family and works by blocking bacterial protein synthesis, thereby preventing the bacteria from multiplying. It is also effective against certain gram-negative bacteria, but it is less effective against gram-positive bacteria. Azithromycin is available in tablet, oral liquid, and injection form. It is also available in a long-acting form that can be administered once by injection, thus reducing the number of clinic visits for the cat.

One of the advantages of azithromycin over some other antibiotics is that it has a long half-life, which means it stays active in the cat’s body for a longer time. This may lead to fewer dosages for the treatment. Also, research suggests that if given promptly, azithromycin can significantly reduce the severity of the cat’s upper respiratory infection, shorten the duration of signs, and prevent the spread of organisms to other cats.

Do note that azithromycin can cause some side effects in cats, the most common being gastrointestinal problems such as vomiting, diarrhea, and loss in appetite. Other less common side effects can include lethargy, changes in liver and kidney function, and certain neurological disorders. Therefore, it is crucial to follow the veterinarian’s instructions when administering the medication to the cat.


Clindamycin is another broad-spectrum antibiotic used to treat feline upper respiratory infections. It belongs to the lincosamide class of antibiotics and works by inhibiting bacterial protein synthesis. It is beneficial against gram-positive bacteria such as Streptococcus and Staphylococcus. Clindamycin is available in tablet, liquid, and injection form and is usually given twice a day.

Like other antibiotics, clindamycin can cause side effects in cats, and the most common are gastrointestinal related. Cats may experience vomiting, diarrhea, and loss of appetite. If any of these side effects occur, it is necessary to contact the veterinarian immediately. Clindamycin can also lead to a decrease in the number of beneficial bacteria in the cat’s intestines, leading to an overgrowth of harmful bacteria.


Doxycycline is another tetracycline-type antibiotic that is effective against feline upper respiratory infections. It works by inhibiting bacterial protein synthesis and is effective against a wide range of bacteria, including gram-positive and gram-negative bacteria. Doxycycline also has an anti-inflammatory property that may help relieve some of the inflammation and swelling associated with feline URIs.

Doxycycline is available in tablet form and is usually given orally once or twice a day depending on the severity of the infection. Like other antibiotics, doxycycline can cause gastrointestinal problems, so the veterinarian will advise on how to reduce the likelihood of side effects.

Other factors to consider when treating feline URIs

Besides the type of bacteria present, there are other factors that the veterinarian will consider when treating a feline upper respiratory infection. These include the cat’s overall health, age, weight, and any underlying medical conditions. Cat owners should bring their pets to the vet as soon as they become symptomatic. If the cat is not eating or drinking, the veterinarian may recommend hospitalization. Also, the cat may be prescribed additional medication for symptom relief, such as anti-inflammatory medication for congestion and antiviral medication to reduce the severity and duration of the symptoms.

Feline URIs are highly contagious, and infected cats should be isolated from other cats to prevent the spread. Also, cat owners should practice good hygiene to prevent the disease’s transmission to other pets and humans.


Antibiotic treatment can be helpful in treating feline upper respiratory infections caused by bacteria. Azithromycin, Clindamycin, and Doxycycline are some of the antibiotics that veterinarians use to treat these infections. Instead of selecting random antibiotics from the drugstore, it is crucial to get your cat examined by a veterinarian. They are better equipped to determine the best possible treatment and dosage. However, despite the effectiveness of antibiotics, it is essential to note that not all feline URIs require antibiotic treatment. As usual, practice good hygiene and watch out for your pet’s symptoms to seek prompt medical care.

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