What Medicine to Give a Cat with a Fever

1 Overview

A fever is an abnormally high body temperature caused by a malfunction in the body’s control system. Fever is thought to be a way to fight infection. The body resets the brain’s temperature-control region to raise temperature—possibly a response to foreign invaders such as bacteria or viruses. Because many invaders cannot thrive in heat, the body raises temperature to destroy them. This differs from hyperthermia, where temperature rises due to external factors like hot weather, inability to pant, or lack of sweating; the brain did not intend the rise.

Fever is usually distinguished by the animal’s recent environment (e.g., if it was in a hot car) and its response to rising temperature. Animals that pant excessively, with increased heart and breathing rates, are usually victims of hyperthermia. A feverish animal does not show obvious distress. A cat’s normal temperature is 100.5–102.5°F.

Causes of fever in cats

1. Infection

2. Inflammation

3. Cancer

4. Medication-related

5. Immune system disease

6. Some undetermined idiopathic causes, also called fever of unknown origin.

Symptoms related to feline fever

1. Lethargy

2. Abnormal behavior

3. Refusing food and water

4. Hiding more

5. Swelling, abscess, or tumor

6. Wound discharge

For more detail on causes and symptoms, see ‘What to Do When Your Cat Has a Fever: Symptoms and Causes.’

How to tell if a cat has a fever

Fever is easily diagnosed by rectal temperature. Above 103°F is considered a fever. Finding the underlying cause, usually an infection, is challenging. Sometimes history and a physical exam point to the cause or source. Unfortunately, if the cause is not obvious, further tests may be needed.

Recommended tests may include:

1. Complete blood count (CBC), which counts white, red, and platelet cells. Many feverish animals have elevated white-cell counts.

2. Blood chemistry panel to assess overall health and detect organ damage.

3. Blood smear to check for blood parasites.

4. Serology for uncommon fever sources such as tick-borne diseases.

5. Blood evaluation for immune disease. 6. Feline leukemia and feline immunodeficiency virus tests.

7. Urinalysis to detect urinary tract infection.

8. X-rays to check for internal masses, pneumonia, or other abnormalities that could cause fever.

9. Abdominal or cardiac ultrasound to find infection sources such as liver, kidneys, or heart valves.

10. Exploratory surgery with organ biopsies for long-standing fever cases with no diagnosis.

Treatment of feline fever

Fever treatment is based on the underlying diagnosis and severity. Some mild fevers need no treatment, as mild fever helps destroy invading bacteria or viruses.

If history and exam are inconclusive, vets commonly try a course of antibiotics before diagnostic tests. For temperatures of 104.5–105°F, the vet will first suggest medication to reduce the fever. Ketoprofen is commonly used to treat fever.

Commonly used antibiotics:

1. Amoxicillin

2. Ampicillin

3. Cephalexin

4. Doxycycline

If fever persists or returns after antibiotics, further diagnostic tests are advised. Once the cause is found, treat it specifically.

Home care

For a mild fever below 104.5°F, you can monitor the pet at home; it may recover on its own. Ensure it keeps eating and drinking. Take its temperature once or twice daily. If it rises above 104.5°F, contact your vet promptly.

Meanwhile, watch for any infected areas—abscesses, skin lumps, bloody or difficult urine, sneezing, or breathing trouble. Also, if it shows loss of appetite or lethargy, take it for examination and treatment promptly.

Fever prevention and care

Many fevers cannot be prevented and are infection-related. Keep the pet and its environment clean and avoid contact with sick animals to reduce the chance of infection and fever.