Doxycycline for Dogs: Safe Dosages, Uses, and Everything You Need to Know About This Medication

If your dog contracts Lyme disease or develops heartworms, your veterinarian is likely to include doxycycline in their treatment regimen. Doxycycline is known by several brand names and is a safe and effective medication for treating a variety of infections in most dogs. To understand what this medication is used for, it is essential to also review information about dosing, possible side effects, drug interactions, and what to expect after your dog starts taking it.

What Is Doxycycline and What Is This Medication Used For?

Doxycycline is a broad-spectrum antibiotic. In addition to targeting a wide range of bacteria, this medication also has antimicrobial properties that act against various microorganisms, making it effective against adult heartworms in dogs. Doxycycline is marketed under the following brand names:

• Vibramycin
• Periostat
• Doryx
• Acticlate
• Oracea
• Monodox

How Does This Antibiotic Work in Dogs?

Tetracycline drugs like doxycycline work by inhibiting protein synthesis and altering the permeability of the cytoplasmic membrane in bacterial and microbial cells. This mechanism blocks bacterial growth, allowing the dog’s immune system to destroy the infection.

Doxycycline Formulations for Dogs

Doxycycline for dogs is an oral antibiotic that can be given as a tablet or liquid. It is also available as a gel for treating periodontal disease in dogs. Doxycycline is the generic name of this medication, sold under the aforementioned brand names.

Is Doxycycline for Dogs the Same as for Humans?

Oral doxycycline is a medication for humans that is sometimes used to treat diseases in dogs. Except for the gel formulation, which is approved by the U.S. Food and Drug Administration (FDA) for treating periodontal disease in dogs, doxycycline is not FDA-approved for use in canines. For this reason, veterinarians typically prescribe compounded formulations of doxycycline for dogs. These compounded versions are specially formulated to provide the correct dose and potency for the specific dog being treated. Human-prescribed doxycycline should never be given to dogs, just as you should not take doxycycline formulated for your pet.

Is Doxycycline Safe for Dogs?

Most dogs can take doxycycline without issues, but some may experience mild side effects. Rarely, this medication can cause liver disease or liver failure. Some dogs might also have an allergic reaction.

“Use this medication with caution in puppies, as dental and bone abnormalities are possible in growing pets,” says Dr. Danielle Rutherford, DVM, associate veterinarian at Westside Veterinary Center in New York City. For this reason, doxycycline should not be given to pregnant or nursing dogs.

Main Uses of Doxycycline in Dogs

Doxycycline is commonly used to treat these conditions:

• Tick-borne diseases, including:
  • Lyme disease
  • Rocky Mountain spotted fever
  • Rickettsia
  • Anaplasma
  • Ehrlichia
• Kennel cough
• Respiratory infections
• Urinary tract infections
• Dental disease
• Leptospirosis
• Heartworm disease

Doxycycline is also sometimes used alongside other medications to treat autoimmune skin diseases in dogs, such as discoid lupus erythematosus.

When Can Owners Give Doxycycline to Their Dogs?

Doxycycline should only be given to your dog when prescribed by a veterinarian. Your vet will provide instructions on how often to give doxycycline and how long to continue treatment.

It’s best to give this medication with meals, advises Rutherford, as giving doxycycline with food helps prevent stomach upset. This is especially important to minimize adverse effects.

When NOT to Give Doxycycline to Dogs

Doxycycline should not be given to pregnant, nursing, or puppy dogs, as it could cause deformities or dental abnormalities in developing puppies. It should also not be given to dogs with liver disease.

Inform your veterinarian if your dog is taking any of the following medications, which could cause drug interactions that reduce doxycycline’s effectiveness:

• Acid reducers
• Anticoagulants
• Penicillin or other antibiotics
• Anticonvulsants

Additionally, dogs on doxycycline should avoid dairy products or iron-rich foods, as these can interfere with absorption of the medication.

Safe Dosing of Doxycycline for Dogs

According to the Merck Veterinary Manual, the typical dose of doxycycline for dogs is generally 5 to 10 mg per kilogram of body weight. Depending on the condition being treated and its severity, it may be given once every 12 to 24 hours for up to 45 days. To ensure safety and effectiveness, it’s important to follow your veterinarian’s instructions for administering the correct dose.

Can Dogs Overdose on Doxycycline?

While overdose in dogs is rare, it can happen. Symptoms of overdose include vomiting, diarrhea, and loss of appetite. You can prevent overdose by carefully following your veterinarian’s dosing instructions and storing the medication out of your dog’s reach. If you forget to give a dose and it’s almost time for the next one, do not double the dose—just skip the missed dose and resume the normal schedule.

If you suspect your dog has ingested too much doxycycline, contact your veterinarian or an animal poison control center like ASPCA Animal Poison Control immediately. Consultation fees may apply.

Can I Give My Dog Doxycycline Daily?

Follow your veterinarian’s instructions for giving doxycycline. It is usually administered once or twice daily for a specified period of up to 45 days. Unless your vet advises otherwise, there is generally no need to continue giving doxycycline after completing the prescribed course.

Side Effects and Precautions of Doxycycline

The most common side effects in dogs are gastrointestinal symptoms, often caused by giving the medication on an empty stomach. These include:

• Vomiting
• Diarrhea
• Loss of appetite

Less common but more serious side effects can include:

• Lethargy
• Increased sensitivity to sunlight
• Elevated liver enzymes

Rarely, doxycycline can cause liver disease or failure. Symptoms include:

• Yellowing of skin, gums, and eyes
• Abnormal bleeding
• Vomiting and diarrhea
• Low energy
• Seizures

Some dogs may also be allergic to doxycycline. Signs of an allergic reaction include:

• Rash or redness
• Swelling
• Difficulty breathing

If your dog shows any of these severe symptoms or if gastrointestinal issues persist despite giving doxycycline with food, stop administering the medication and contact your veterinarian immediately. Signs of allergy or liver failure should be treated as emergencies—seek emergency veterinary care.

How Long Does Doxycycline Take to Work?

Doxycycline generally starts working within two hours of the first dose in dogs. However, it may take several days before your dog shows visible signs of improvement.

How Long Does Doxycycline Stay in a Dog’s System?

According to VCA Animal Hospitals, doxycycline remains in a dog’s system for about 24 hours. However, dosing is typically every 12 to 24 hours to maintain therapeutic blood levels.

Conclusion

Doxycycline for dogs is a prescription antibiotic from the tetracycline family used to treat Lyme disease, kennel cough, and heartworms. While generally safe, it should not be given to pregnant, nursing, puppy, or dogs with liver disease. Common side effects include vomiting or diarrhea, which can often be prevented by giving the medication with food. Understanding what this medication is for and how to use it properly is crucial for your pet’s health and safety.