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Doxycycline 101: What to Know if Your Veterinarian Prescribes Doxycycline for Your Dog or Cat

Developed in collaboration with Kelly Cairns, DVM, MS, DACVIM | Vice President of Medical Excellence and Education | Thrive Pet Healthcare

Last reviewed: 9/28/2023

What is Doxycycline?

Doxycycline is a prescription antibiotic medication commonly prescribed by veterinarians to treat a wide variety of current and secondary bacterial, viral, and fungal infections. It is generally well-tolerated by both cats and dogs.

In addition to its use as an antibiotic, doxycycline is used in low doses as an anti-inflammatory and adjunct treatment for arthritis and degenerative joint-disease in dogs, for the treatment of heartworm disease in dogs and cats and is FDA-approved for the treatment and management of periodontal disease in dogs, usually in gel form. It is often also used off-label in cats.

Your veterinarian may prescribe doxycycline under the brand names Vibramycin®, Oracea®, Monodox®, Periostat®, Doryx®, or Acticlate®. It is generally given by mouth in the form of a tablet, capsule, liquid/suspension, or oral gel, but may be given intravenously when necessary.

Key Facts
  • Doxycycline is a safe, effective, and commonly prescribed antibiotic for dogs and cats.
  • It is also used to treat viral and fungal infections and has other off-label uses.
  • It is generally well-tolerated by both cats and dogs.
  • Side effects of doxycycline are generally not severe but can cause an upset stomach.
  • It is available in a number of forms, including oral capsules, tablets, and oral suspension.
  • Doxycycline starts working in just a few hours, although it can take several days for symptoms to improve.

Some Conditions Doxycycline is Prescribed to Treat in Dogs and Cats

  • spirochetes (spiral-shaped bacteria)    
  • feline infectious anemia (Mycoplasma hemofelis)    
  • leptospira    
  • canine ehrlichiosis (anaplasmosis)    
  • kennel cough (bordetella bronchiseptica)    
  • toxoplasma (from a single-celled parasite)
  • tick-borne diseases (Lyme Disease, Rocky Mountain Spotted Fever)
  • chlamydia
  • canine parvovirus
  • salmon poisoning (neorickettsia helminthoeca)

How Doxycycline Works in Dogs and Cats

Doxycycline is in the tetracycline class of antibiotics and works by blocking the bacteria’s protein synthesis that they need to live. Without these proteins, the bacteria’s cell wall becomes altered and its ability to properly replicate and grow is compromised

Possible Side Effects of Doxycycline

  • The most-common side effects of doxycycline in dogs and cats are gastrointestinal upset, including nausea, vomiting, diarrhea, anorexia, lethargy, and lack of appetite. Oral antacids may be helpful to decrease gastrointestinal symptoms.
  • Cats may be at increased risk for esophageal strictures (tightening of the throat) after “dry” pilling with doxycycline. In order to minimize this problem, it has been suggested to dose the cat with water after pilling or use a compounded liquid product to minimize esophageal damage.

Additional Precautions for Doxycycline

  • Doxycycline and other tetracycline antibiotics should be avoided during pregnancy because of the risk of skeletal limb abnormalities and discoloration of teeth. Doxycycline may pose less risk than other tetracycline antibiotics, but its use should be avoided unless the benefits outweigh the potential risks.
  • It should be used with caution in pets with significant liver disease or in young pets that are still developing bones and teeth.
  • Doxycycline can cause increased sensitivity to sunlight. Direct or prolonged sun exposure should be avoided.
  • Increases in liver enzymes in bloodwork may occur, more often in dogs than in cats.
  • Doxycycline should not be used in animals with known hypersensitivity or allergy to the drug.

Doxycycline Drug Interactions

  • Giving oral doxycycline should be separated from any oral antacids, calcium supplements, bismuth, kaolin, or pectin-containing products by 1- 2 hours. Iron supplements also interfere with the absorption of doxycycline and should be separated by three hours.
  • Doxycycline and other tetracycline antibiotics are generally not used with bactericidal antibiotics such as penicillin, cephalosporin, and aminoglycosides.
  • Enrofloxacin and doxycycline together can reduce and delay enrofloxacin in vitro activity against escherichia coli.
  • Tetracycline antibiotics may change clotting times. Animals receiving warfarin or another anticoagulant may need additional monitoring and dosage adjustment.
  • Phenobarbital may reduce the half-life of doxycycline.

Alternatives to Doxycycline for Dogs and Cats

Other broad-spectrum antibiotics may be used in place of doxycycline. These can include other tetracyclines (minocycline), oxytetracycline, amoxicillin, clindamycin, or floxacin antibiotics like enrofloxacin or orbifloxacin.

Doxycycline Dosage Forms and Strengths

Veterinarians prescribe a specific dosage of doxycycline based on the pet’s weight and condition. It is available in a number of forms, including oral capsules, tablets, and oral suspension. 

The most commonly used dosing strengths of doxycycline are 50 mg, 100 mg, and 300 mg. Be sure to follow your veterinarian’s dosing instructions carefully.

When the appropriate dosage form is not available, it may be compounded by a specialty pharmacy. Wedgewood Pharmacy specializes in compounding and provides medication options that help ensure accurate dosing, especially for hard to medicate pets. 

Wedgewood Pharmacy provides medication options that help ensure accurate dosing, especially for hard to medicate pets. Click below for a complete list of Wedgewood’s dosing forms and strengths.


What to Do if You Miss a Dose

If you miss giving your pet a dose of doxycycline, give the next dose to your dog or cat as soon as you remember or, if it is close to the next scheduled dose, return to the regular schedule. Do not give two doses at once (double dose) to catch up. If you are not sure what to do, call your veterinarian and follow their directions.

What to Do in the Case of a Doxycycline

Oral overdose of doxycycline in most instances will cause pronounced GI distress like those listed above.

If you suspect your pet or another animal has overdosed accidentally or has eaten this medication inadvertently, contact your veterinarian or A.S.P.C.A.’s Animal Poison Control Center at 888-426-4435. Always bring the prescription container with you when you take your pet for treatment.

If you or someone else has accidentally ingested this medication, call the National Capital Poison Center at 800-222-1222.


Cost of Doxycycline

Wedgewood Pharmacy’s doxycycline preparations start at $0.12 per dose. However, your veterinarian will prescribe a specific dosage based on the pet’s weight, condition, and other factors. 

Compounded medicines are prepared for the exact strength your veterinarian prescribes. The price of the medication will depend on the dosage and the medication form, with certain dosage forms and higher strengths generally being more expensive. 

In addition, the cost of a medication will depend upon the price of the other active pharmaceutical ingredients and may increase the cost of the finished drug.

Looking for Doxycycline

Looking for Doxycycline?

We can let your veterinarian know that you are interested in our compounded Doxycycline.

Frequently Asked Questions

Frequently Asked Questions for Doxycycline

How Long Does It Take for Doxycycline to Work in Pets?
Doxycycline starts working in just a few hours, but it can take several days for symptoms to improve.
What Does Doxycycline Do for Cats?
Doxycycline is approved by the FDA for use in humans, but not for animals. Veterinarians commonly prescribe this doxycycline for use in cats and dogs. Doxycycline treats a variety of bacterial infections in cats, including urinary tract infections, respiratory infections, and infections caused by a number of organisms like bartonella, hemoplasma, chlamydia felis, ehrlichia, anaplasma, and toxoplasma.
Is Doxycycline a Strong Antibiotic?
It is not that doxycycline is a strong antibiotic, doxycycline is an effective antibiotic that treats a wide range of infections in dogs and cats.
Is Doxycycline for Dogs the Same as the Medication for Humans?
Just because an active ingredient is the same in human and animal formulations doesn't mean they are identical. There is often a difference in dosage and the inactive ingredients.
Veterinarians prescribe a specific dosage of doxycycline based on the pet’s weight and condition. Do not give your pet human formulations of doxycycline and always give the exact dose your veterinarian prescribes.
Is Doxycycline Safe for Pets?
Doxycycline is usually well tolerated, is widely prescribed, and is considered safe for both cats and dogs.
How Does Doxycycline Make Dogs Feel?
The most common side effects include vomiting, diarrhea, and lack of appetite. The effects, however, may be lessened by giving the medication with food.
Should Pets Taking Doxycycline Be Monitored?
No specific monitoring is required for doxycycline, but your veterinarian may recommend routine testing to monitor the condition that initially caused your pet to be prescribed doxycycline or to monitor your pet if it is on multiple medications.


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