Cefalexin for Dogs: Safe Dosages and Clinical Applications

If your dog has received treatment for a urinary infection or a dermatological condition, they are likely prescribed cephalexin. What exactly is this medication, and how is cephalexin used in dogs? Here you’ll find everything you need to know about cephalexin for dogs, including safe dosages, possible side effects, animals that should not receive it, and whether it is covered by pet insurance.

What is cephalexin and how does it work?

Cephalexin is a prescription antibiotic belonging to the first-generation cephalosporin class, acting similarly to penicillin and amoxicillin. This medication can eliminate a broad spectrum of bacterial infections and is commonly used in canines to treat urinary tract infections.

Cephalexin works on both gram-positive and gram-negative bacteria, making it a broad-spectrum antibiotic. It functions by preventing bacterial cells from forming their cell walls. When you administer cephalexin to your dog, the drug is absorbed into the bloodstream and distributed throughout the body, making it effective against infections anywhere in the body.

The medication is marketed under various brand names, including Keflex, Biocef, Keftab, Rilexine, Vetolexin, Cefadroxil, and Sporidex.

Forms and administration of cephalexin

Cephalexin is generally given orally to dogs, available in capsules, tablets, and chewable tablets. For dogs that refuse tablets, a liquid suspension is also available. Your veterinarian may also choose to administer cephalexin via injection.

Clinical uses of cephalexin in dogs

According to Dr. Danielle Rutherford, D.V.M., associate veterinarian at Westside Veterinary Center in New York, “cephalexin is an excellent choice for pets with skin infections related to underlying allergies or as a prophylactic antibiotic for those undergoing surgical procedures where infection risk exists.”

In addition to skin infections like staph infections, pyoderma, and hot spots, cephalexin in dogs is used for:

• Urinary tract infections
• Ear infections
• Bone infections
• Upper respiratory infections
• Pneumonia
• Abscesses
• Wound infections

Safety of cephalexin in dogs

Cephalexin is approved by the Food and Drug Administration for use in dogs, meaning it has been evaluated and deemed to have benefits that outweigh potential risks in canines. While generally safe, some dogs may experience side effects, and it can interact negatively with certain medications.

Dogs allergic to penicillin should not receive cephalexin. It is essential to inform your veterinarian if your dog has kidney disease, is pregnant, or nursing. Dr. Rutherford warns that “it should be used with caution in pets with certain immune conditions, such as immune-mediated hemolytic anemia.”

Dosage guidelines and safe administration

The typical dose of cephalexin for dogs is 10 to 15 milligrams per pound of body weight. Your veterinarian will prescribe the correct dose based on your dog’s size, weight, and severity of infection. It is crucial to follow the dosing instructions exactly to avoid overdose and ensure your pet receives enough medication to clear the infection.

Cephalexin is a prescription medication that must be prescribed by a veterinarian. If your vet prescribes cephalexin, instructions will include the exact dose and frequency. Carefully follow these instructions and keep a consistent schedule.

If you forget a dose but it’s not yet time for the next one, you can give it. However, if it’s close to the next dose, skip the missed one to prevent overdose. If the medication causes vomiting or diarrhea, you can give it with food or a treat to reduce stomach upset.

Situations in which cephalexin should NOT be given

Do not give cephalexin to pregnant or nursing dogs, or those with allergies or sensitivities to penicillin-based antibiotics. Use with caution in dogs with kidney disease or renal failure.

Although no direct drug interactions have been documented, cephalexin may enhance the effects of anticoagulants and diuretics. “Interactions have been reported in humans when combined with certain acid reducers, hormonal therapy, anticoagulants, and zinc supplements,” notes Dr. Rutherford. “It should be used cautiously in pets receiving any of these medications.”

Always inform your veterinarian of any known health conditions and medications or supplements your dog is taking. Never give your dog cephalexin prescribed for humans or other animals, as it could cause overdose or prevent effective dosing needed to eliminate the infection.

Overdose and emergency situations

An overdose of cephalexin can make your dog sick and worsen side effects. Signs include:

• Severe vomiting and diarrhea
• Excessive salivation
• Watery eyes

Large overdoses can cause kidney or liver damage, as well as blood cell count abnormalities. If you suspect you’ve given too much cephalexin, contact your veterinarian or the pet poison control line immediately.

Duration of treatment with cephalexin

Cephalexin is typically given daily during treatment, which can last from two weeks up to four months depending on infection severity. Even if your pet starts to improve and shows no symptoms before completing the course, it’s important to finish the entire medication to ensure all bacteria are eliminated and prevent recurrence.

Not completing the full course can lead to antibiotic resistance. Unless your veterinarian prescribes another cycle, do not continue giving cephalexin after finishing the initial course.

Side effects and adverse reactions

Most dogs start feeling better within a few days of beginning cephalexin. Side effects are usually mild, with nausea, vomiting, and diarrhea being the most common.

Other possible side effects include:

• Rapid breathing or panting
• Salivation
• Skin rashes
• Hyperactivity
• Lethargy
• Drowsiness
• Itching and scratching
• Increased thirst

Signs of an allergic reaction include ear rash, hives, facial swelling, pale gums, difficulty breathing, or collapse. Seek emergency veterinary care immediately if any of these occur.

For mild side effects, administering cephalexin with food is recommended. “If you notice behavioral changes or any side effects, it’s best to stop the medication and consult your veterinarian immediately to determine if it’s safe to continue treatment,” adds Dr. Rutherford.

Onset of action and how long it stays in the system

Cephalexin begins working on your dog’s infection within the first 90 minutes of administration. However, it may take several days before you see noticeable improvement in symptoms.

Cephalexin remains in your dog’s system for about 24 hours before being eliminated. Any side effects usually resolve as the drug is cleared from the body.

Pet insurance coverage

Most pet accident and illness insurance policies cover prescription medications for infections that are not pre-existing conditions. Check your policy details to see if your insurer has requirements regarding brand-name versus generic drugs, and whether your dog’s health condition is eligible for coverage.

Conclusion

Cephalexin is an effective prescription antibiotic for treating skin and urinary infections in dogs, as well as a wide range of other bacterial infections. It is generally safe at correct doses but should not be given to dogs allergic to penicillin, with kidney disease, or that are pregnant or nursing. Side effects are usually minimal, mainly vomiting and diarrhea, and can be reduced by giving the medication with food. Following your veterinarian’s instructions and maintaining clear communication about your pet’s health will help ensure cephalexin remains a reliable treatment option for many canine infections.