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Side Effects of Cephalexin for Dogs

Side Effects of Cephalexin for Dogs
Cephalexin is an antibiotic that is used for treating a number of bacterial infections. However, it may have some side effects, especially for dogs that are allergic to penicillin. This DogAppy article lists the cephalexin side effects for dogs.
Parul Solanki
Last Updated: May 31, 2018
Did You Know?

Cephalexin works by interfering with the bacteria's cell wall formation, causing it to rupture, and thereby, killing the bacteria.

A broad spectrum antibiotic that is used to treat bacterial infections of the skin, urinary tract, bones, joints, and the respiratory tract, cephalexin is commonly prescribed by veterinarians to treat the above conditions in dogs. This antibiotic belongs to a class of drugs called cephalosporins, which are known to suppress the growth of microorganisms such as bacteria, fungi, or protozoa. Although the FDA has not approved cephalexin as a veterinarian drug, it is a common practice to prescribe this medication. This antibiotic is available as 250 mg or 500 mg capsules and as liquid medication, and is only administered if the veterinarian has prescribed it. Usually, 10 mg of cephalexin is prescribed for each pound (lb.) of your dog's weight, with the dosage being administered twice a day This affordable medication not only treats bacterial infections, but also prevents secondary infections.

Cephalexin is usually considered safe for dogs, unless the dog is allergic to penicillin mold and medication that function in the same manner as penicillin. Before prescribing this drug, it is important for the veterinarian to check whether the dog nursing or pregnant, or is allergic to penicillin. Here are some unwanted side effects of cephalexin for dogs that can serve as a warning to pet owners who indiscriminately use this medication for treating their dog's health issues.

Adverse Effects of Cephalexin for Dogs

Nausea and Vomiting

The most common side effect of cephalexin includes nausea and vomiting. This can happen due to an allergic reaction to the medication, or due to an overdose. Check the dosage instructions before administering it to the pet. As a general guideline, you should give your pet 10 to 15 mg of the medication per pound of body weight every 12 hours.

Diarrhea and Abdominal Pain

In case of an overdose, the dog may suffer from diarrhea and stomach pain. To ensure that the dog does not suffer from stomach problems, ensure that you administer the cephalexin dosage after a meal, with plenty of water. Some dogs may also suffer from a loss of appetite. If the diarrhea continues, it is best to stop the medication and consult a veterinarian.

Allergic Reaction

Most dogs can handle cephalexin dosage; however, dogs that are allergic to penicillin may suffer from certain side effects. The symptoms of these include:
  • Hives that are characterized by small reddish circular itchy bumps on the skin.
  • Rashes and extreme itching
  • Difficulty in breathing
  • Yeast infection
  • Mucus and blood in stool
  • Fever
  • Swelling of the mouth, tongue, and head
Behavioral Effects

Apart from physical side effects, you may also notice some behavioral changes in the dog. It might appear excitable and hyperactive, which can often aggravate the breathing irregularity. Some dogs may appear to drool excessively as well.

Special Precautions

  • Animals allergic to penicillin or cephalosporins are not to be prescribed this medication.
  • It is advised to use caution in administering cephalexin to nursing and pregnant dogs.
  • Tell your vet about any other medication that the dog may be taking, such as probenecid, or a loop diuretic such as furosemide or warfarin, as this may interact with cephalexin and cause side effects.
  • Never combine this medication with other drugs, especially other antibiotics or over-the-counter medicines, including vitamins, minerals, and herbal products.
  • The oral suspension, after being mixed with water, must be kept in the refrigerator. The unused portion should be discarded after fourteen days.
  • In extreme cases, an overdose of this drug has known to cause seizures and muscle weakness in dogs.
Ensure that you administer the right dosage, and if you forget to give your pet a dose of cephalexin, do not double the amount the next time. In the event of an allergic reaction, stop administering cephalexin, and seek emergency veterinary medical care.

Disclaimer: This article is for informative purposes only and should not be used as a replacement for the advice of a veterinarian.
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