# Convenia Injection (Cefovecin) for Dogs and Cats Convenia is the brand name for cefovecin sodium, a long-acting injectable antibiotic approved for dogs and cats. A single subcutaneous injection at 8 mg/kg provides roughly 14 days of antibacterial coverage for labeled skin infections, which means the pet owner does not have to give pills at home. Cefovecin is a third-generation cephalosporin with very high plasma protein binding in both species, and that binding is the main reason the drug stays in the body far longer than most antibiotics. This article explains how cefovecin works, which infections it is labeled to treat, which bacteria it cannot kill, how it is given, what side effects to watch for, and how it compares with oral antibiotics. It is written for US pet owners who have been offered a Convenia injection or who want to understand the choice their veterinarian is making. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## At a Glance | Feature | Detail | |--|--| | Active ingredient | Cefovecin sodium | | Drug class | Third-generation cephalosporin antibiotic | | Species | Dogs and cats | | How it is given | Subcutaneous injection by a veterinarian | | Labeled dose | 8 mg/kg every 14 days | | Duration per dose | About 14 days for labeled skin infections | | Formulations | Injectable only, no oral version | | Prescription status | Prescription only, administered in clinic | | Not for | Food-producing animals | | Inactive against | Pseudomonas and Enterococcus | ## What Convenia Injection Is Convenia is a sterile injectable antibiotic sold for veterinary use. Its active ingredient, cefovecin sodium, belongs to the cephalosporin family and is classified as a third-generation cephalosporin [1][2]. Third-generation cephalosporins are considered critically important antimicrobials in human and [veterinary medicine](/blog/careers/veterinary-medicine-careers-from-clinical-practice-to-public-health), which is why they are meant to be used carefully rather than as a casual first choice [1]. The drug is supplied as a powder that is reconstituted with a diluent before injection. Once reconstituted, storage conditions matter. A laboratory study found that room temperature storage led to progressive discoloration, rising minimum inhibitory concentrations, and falling drug concentrations over time, while refrigerated storage slowed those changes and frozen storage preserved the drug's physical properties and antibacterial activity across the study period [3]. In practice, this means the reconstituted product should be handled according to the manufacturer's storage instructions and used within the recommended window. Convenia has no oral formulation. It is given only as an injection, which is the entire point of the product. The drug's value is convenience and guaranteed compliance, not superior killing power against every organism. ## How Cefovecin Works Cefovecin kills bacteria by interfering with the bacterial cell wall. Like other beta-lactam antibiotics, it binds to proteins involved in building the peptidoglycan layer that holds a bacterium together. When that layer cannot be built properly, the bacterium ruptures and dies. This is a bactericidal mechanism, meaning the drug actively kills susceptible organisms rather than just stopping their growth. What separates cefovecin from ordinary cephalosporins is its pharmacokinetics, the way the body handles the drug. After a subcutaneous dose of 8 mg/kg, the plasma terminal half-life of cefovecin is about 102 hours in dogs [2]. Other work reports half-lives of roughly 133 hours in dogs and 166 hours in cats [4]. For comparison, the same 8 mg/kg subcutaneous dose produces a half-life of only 2.6 to 8.0 hours in several nonhuman primate species, with total drug exposure 10 to 40 times lower than in dogs [2]. The reason for this species difference is high plasma protein binding. In dogs and cats, cefovecin binds to plasma proteins at more than 97 percent, and in cheetahs the measured binding was approximately 99.9 percent [5][6]. A drug that is tightly bound to plasma proteins is released slowly, and the kidneys appear to actively reabsorb cefovecin in dogs and cats, since plasma clearance is well below the normal glomerular filtration rate [4]. In nonhuman primates, renal clearance approximates plasma clearance, which suggests active reabsorption does not occur and explains the short half-life in those species [4]. Protein binding is not a universal predictor across all animals. A review of 22 nondomestic species found that animals in the order Carnivora showed binding above 98 percent, consistent with the long half-life seen in dogs and cats, while binding was highly variable in other groups and not high in reptiles or birds [6]. This is why cefovecin's 14-day duration is a dog and cat phenomenon, not a general rule for all species. The practical result is a single injection that maintains effective plasma concentrations for about two weeks. In one study, the mean plasma cefovecin concentration in treated dogs was 9.59 micrograms per milliliter on day 14 after a single 8 mg/kg subcutaneous dose [7]. ## Labeled Uses in Dogs and Cats Cefovecin is licensed for the treatment of skin infections in cats and dogs [2]. The FDA label specifies a subcutaneous dose of 8 mg/kg every 14 days. ### Dogs The labeled use in dogs centers on bacterial skin infections. A multicenter randomized trial compared a single subcutaneous cefovecin injection at 8 mg/kg, repeatable once after 14 days, against oral cefadroxil given twice daily for 14 or 28 days in 235 dogs with secondary superficial pyoderma, abscesses, or infected wounds [8]. At the final assessment 14 days after treatment ended, 92.4 percent of the cefovecin group and 92.3 percent of the cefadroxil group were treatment successes, and there were no serious adverse events or deaths related to treatment [8]. A separate set of three studies enrolled 354 dogs with superficial or deep pyoderma or wounds and abscesses, comparing cefovecin injections at 14-day intervals against oral amoxicillin/clavulanic acid twice daily for 14 days [9]. Cefovecin was statistically non-inferior to the oral comparator across all three diagnoses, with efficacy up to 96.9 percent for cefovecin versus 92.5 percent for amoxicillin/clavulanic acid [9]. The authors noted that cefovecin offers the added benefit of removing owner non-compliance from the equation [9]. ### Cats Cats receive cefovecin more often than dogs in real-world practice. In a six-month Australian study of first-opinion records, cefovecin was administered in 1.9 percent of cat consultations versus 0.1 percent of dog consultations [1]. The most common reasons in cats were cat fight injuries and abscesses at 28 percent, followed by dermatitis at 13 percent [1]. For dogs, the leading reasons were surgical prophylaxis at 24 percent and dermatitis at 19 percent [1]. A UK electronic health record study of 1,148 feline consultations involving cefovecin found the skin was the most common body system treated at 48.2 percent, followed by urinary at 13.7 percent and respiratory at 9.8 percent [10]. Microbiological evaluation was recorded in only 16.8 percent of entries [10]. The most frequently cited reason for choosing Convenia over an alternative antibiotic was an inability to give the cat oral medication, noted in 77 entries [10]. That last point is central to how cefovecin is used in cats. Many veterinarians report feeling pressure to prescribe antimicrobials, and 41 percent of cat owners in one survey reported requesting them [11]. Veterinarians estimated that about 20 percent of cat owners could not give oral medications, while fewer than 10 percent of owners reported having a cat that was impossible to medicate [11]. That gap between what veterinarians assume and what owners can actually do is one driver of cefovecin use [11]. ## What Cefovecin Does Not Cover Cefovecin is not a broad-spectrum cure-all. Two important gaps matter for clinical decisions. Cefovecin is inactive against Pseudomonas species. Pseudomonas is a common opportunistic bacterium in chronic ear infections, deep wounds, and hospital-associated infections, and it is intrinsically resistant to cefovecin. If a veterinarian suspects Pseudomonas, cefovecin is the wrong drug. Cefovecin is also inactive against Enterococcus. Enterococci are gram-positive bacteria that appear in urinary tract infections, wound infections, and sometimes as secondary invaders. Because cefovecin does not cover them, a culture that grows Enterococcus should steer treatment elsewhere. These gaps are one reason third-generation cephalosporins should be reserved for situations where they are actually indicated. The Australian study authors noted that cefovecin is used in many scenarios where antimicrobials may not be indicated at all or where another antimicrobial would be a better choice, and that culture and susceptibility testing was reported in only 16 cases out of more than 5,000 consultations [1]. ## How Convenia Is Given Convenia is administered by a veterinarian as a subcutaneous injection, typically in the scruff or another loose-skinned area. The labeled dose is 8 mg/kg every 14 days. A single injection covers the labeled skin infection indication for about two weeks, and a second injection 14 days later can be given if the veterinarian judges it necessary [8]. Because the injection is given in the clinic, there is no at-home dosing schedule to follow and no risk of missed doses. This is the drug's main practical advantage. A modeling study estimated that when non-compliance with oral medication is factored in as a cause of treatment failure, the long-acting injectable was more effective than oral amoxicillin/clavulanic acid, with 162 versus 158 days without clinical signs, and mean total treatment costs were lower with cefovecin at 376.74 US dollars versus 382.34 US dollars in dogs weighing 25 kg [12]. Cefovecin remained cost-saving up to a body weight of 31 kg, and in larger dogs total therapy costs were less than 6 percent higher than the oral comparator [12]. Body weight matters for cost because the dose is calculated per kilogram. Small dogs and cats are relatively inexpensive to treat with cefovecin, while large dogs require more drug and the cost advantage shifts. ## Side Effects and What to Do Cefovecin has a favorable safety profile in the studies that supported its approval. In the 235-dog comparative trial, there were no serious adverse events or deaths related to treatment [8]. The three-study canine program comparing cefovecin with amoxicillin/clavulanic acid likewise reported no safety concerns that changed the risk-benefit assessment [9]. Gastrointestinal upset is the most common class effect of any antibiotic and can occur with cefovecin. Vomiting, soft stool, or diarrhea after an injection should be reported to the veterinarian. Because the drug cannot be withdrawn once injected, management is supportive rather than stopping the drug. Injection site reactions are possible with any subcutaneous product. Swelling, tenderness, or a lump at the injection site should be examined if it persists or grows. A less obvious but important effect is on the gut microbiome. A study of 14 healthy Beagles found that the absolute number of E. coli in feces was lower in treated dogs on day 3, and the number of cefovecin-resistant E. coli was higher in treated dogs on days 7, 14, and 28 compared with untreated dogs [7]. Enterococci increased and were higher in the treatment group on day 7 [7]. Beta-lactam resistance was more common in fecal E. coli from treated dogs than untreated dogs [7]. This is a reminder that antibiotics affect bacterial populations beyond the infection site, and it is a reason to use cefovecin only when a bacterial infection is genuinely present. Any sign of an allergic reaction, including facial swelling, hives, difficulty breathing, or collapse, is an emergency and requires immediate veterinary care. ## Which Animals Should Not Receive Convenia Cefovecin is approved for dogs and cats only. It is not approved for use in food-producing animals, which matters for regulatory reasons and for residue concerns. If a pet is part of a food animal operation, cefovecin is not an appropriate choice. Species outside dogs and cats behave very differently with this drug. The 14-day duration depends on the high protein binding and renal reabsorption seen in dogs and cats, and those properties do not carry over to many other species [4][6]. Nonhuman primates clear the drug rapidly, with half-lives of roughly 2.6 to 8.0 hours and total exposure 10 to 40 times lower than dogs, which means the dog and cat dosing schedule would be ineffective in those species [2]. Alpacas show a half-life of about 16.9 hours after subcutaneous dosing, far shorter than dogs or cats [13]. Mice clear the drug with a half-life of about one hour, making it unsuitable as a long-acting antibiotic in that species [14]. Sea otters show an elimination half-life of about 41.6 hours, longer than primates but still shorter than dogs and cats [15]. Cefovecin should not be used in animals with a known hypersensitivity to cephalosporins or penicillins. Because the drug is eliminated largely through the kidneys, pets with significant kidney disease need a conversation with the veterinarian about whether cefovecin is appropriate. Pregnant or nursing pets, very young animals, and pets with serious concurrent illness should be evaluated individually. The published efficacy and safety trials enrolled client-owned dogs with skin infections, and the label defines the approved population. ## Interactions With Other Medications Cefovecin has no significant drug interactions that change its use in routine practice, but a few points matter. Because cefovecin is highly protein bound, there is a theoretical concern that it could displace or be displaced by other highly protein-bound drugs. In practice, this has not been a reported clinical problem in dogs and cats at labeled doses. Concurrent use of other antibiotics can create redundant or conflicting coverage. If a pet is already on an oral antibiotic for the same infection, adding cefovecin rarely helps and can increase the risk of resistance. Any pet receiving other medications, including NSAIDs, steroids, or seizure medications, should have the full medication list reviewed before the injection is given. The veterinarian needs to know about every product, including supplements. ## How Convenia Compares With Alternatives The main alternatives for bacterial skin infections in dogs and cats are oral antibiotics. The two comparators in the pivotal cefovecin trials were cefadroxil and amoxicillin/clavulanic acid. Cefadroxil is a first-generation cephalosporin given orally twice daily. In the 235-dog trial, cefovecin matched cefadroxil for treatment success at 92.4 percent versus 92.3 percent [8]. Amoxicillin/clavulanic acid is a broad-spectrum oral penicillin given twice daily. In the 354-dog program, cefovecin was non-inferior across superficial pyoderma, deep pyoderma, and wounds or abscesses, with efficacy up to 96.9 percent versus 92.5 percent [9]. The trade-off is straightforward. Oral antibiotics require the owner to give pills or liquid every day for one to four weeks, and missed doses reduce efficacy. Cefovecin removes that variable entirely. A modeling study estimated treatment failure due to oral antimicrobial non-compliance at 13.6 percent, and when that failure rate was included, the injectable was more effective and cost-competitive in dogs up to about 31 kg [12]. The counterargument is antimicrobial stewardship. Third-generation cephalosporins are critically important drugs, and using them when a narrower antibiotic would work contributes to resistance [1]. Culture and susceptibility testing is recommended before using a critically important antimicrobial, yet it was performed in a small minority of real-world cefovecin cases [1][10]. The right choice depends on the individual infection, the owner's ability to medicate, and whether the bacteria involved are likely to be susceptible. For some infections, cefovecin has been studied beyond the skin label. A pilot study in experimentally infected Beagles found that two cefovecin injections two weeks apart were as efficacious against Borrelia burgdorferi as doxycycline or amoxicillin given daily for 31 days [16]. This is not an approved indication, and it does not change the labeled use, but it illustrates the drug's potential reach when oral compliance is a barrier. ## Monitoring After a Convenia Injection Monitoring after cefovecin is mostly clinical. The veterinarian will want to see the infection improving within the expected timeframe and will schedule a recheck based on the diagnosis. For labeled skin infections, the pivotal trials assessed outcome 14 days after the final treatment course, which means a recheck roughly two to four weeks after the injection is typical [8][9]. If the infection is not clearly improving by the expected time, the plan should be reassessed. Key monitoring points include: 1. Clinical response. Reduction in redness, swelling, discharge, odor, and pain at the infection site. 2. Recheck timing. Typically 14 days after the injection for skin infections, with a final assessment about 14 days after treatment ends [8]. 3. Gastrointestinal signs. Appetite, vomiting, and stool quality. 4. Injection site. Any swelling, pain, or lump. 5. Culture and susceptibility. If the infection is not responding, or if it recurs, testing guides the next antibiotic choice [1]. 6. Underlying cause. Skin infections in dogs and cats often have an underlying allergy, parasite, or endocrine problem that must be managed or the infection will return. | Species | Labeled indication | Dose interval | Key monitoring | |--|--|--|--| | Dog | Bacterial skin infections (pyoderma, abscesses, infected wounds) | 8 mg/kg SC every 14 days | Clinical response at recheck, GI signs, injection site, culture if not improving | | Cat | Bacterial skin infections (abscesses, fight wounds, dermatitis) | 8 mg/kg SC every 14 days | Clinical response at recheck, GI signs, injection site, oral medication ability for future episodes | ## Limitations and When to Contact a Veterinarian Cefovecin is a prescription antibiotic, and individual cases need a veterinarian's assessment. The following situations warrant a call or visit. Contact a veterinarian if the infection is not improving within the expected timeframe, if it worsens, or if it returns after treatment. Contact a veterinarian if the pet develops vomiting, diarrhea, lethargy, or loss of appetite after the injection. Contact a veterinarian immediately if there is facial swelling, hives, difficulty breathing, or collapse, since these suggest a serious allergic reaction. Contact a veterinarian if a lump or swelling appears at the injection site and does not resolve. Contact a veterinarian if the pet has known kidney disease, is pregnant or nursing, or is receiving other medications, so the choice can be reassessed. Contact a veterinarian if the infection involves the ear canal, a deep wound, or the urinary tract, because cefovecin does not cover Pseudomonas or Enterococcus and those sites often involve organisms that require different drugs. Ask the veterinarian whether a culture was taken, whether the infection has an underlying cause such as allergies, and whether a narrower antibiotic would work just as well. These questions support both the pet's recovery and responsible antibiotic use. ## Frequently Asked Questions ### What is Convenia injection used for in dogs and cats? Convenia injection is a long-acting antibiotic used to treat bacterial skin infections in dogs and cats. In dogs the labeled use covers pyoderma, abscesses, and infected wounds, and in cats it is commonly used for fight wounds, abscesses, and dermatitis. ### How long does a Convenia injection last? A single Convenia injection provides about 14 days of antibacterial coverage for labeled skin infections. The labeled dosing interval is 8 mg/kg every 14 days, and a second injection can be given at that interval if the veterinarian decides it is needed. ### Why does cefovecin last so long compared with other antibiotics? Cefovecin binds to plasma proteins at more than 97 percent in dogs and cats, and the kidneys appear to reabsorb it actively. That combination keeps the drug in the body far longer than most antibiotics, producing a half-life of about 102 to 166 hours in these species. ### Does Convenia work against all bacteria? No. Cefovecin is inactive against Pseudomonas and Enterococcus. It also does not cover every possible skin pathogen, which is why culture and susceptibility testing is recommended when an infection is severe, recurrent, or not responding. ### Can I give Convenia at home? No. Convenia is an injectable prescription antibiotic that must be given by a veterinarian. There is no oral version of cefovecin, which is one reason it is chosen for pets that are difficult to medicate. ### What are the side effects of Convenia in dogs and cats? The most common side effects are gastrointestinal, including vomiting, soft stool, or diarrhea. Injection site reactions and, rarely, allergic reactions can occur. Serious adverse events were not reported in the pivotal canine trials that supported approval. ### Is Convenia safe for puppies and kittens? The published efficacy and safety trials enrolled client-owned dogs with naturally occurring skin infections, and the label defines the approved population. Very young animals should be evaluated individually by a veterinarian before cefovecin is used. ### Can Convenia be used in animals other than dogs and cats? Cefovecin is approved for dogs and cats only and is not approved for food-producing animals. Other species clear the drug much faster, so the 14-day duration does not apply to them. ## Related Articles - [What Are the Side Effects of Steroid Injections for Dogs?](/knowledge/veterinary-medicine/pet-medication-guide/steroid-injection-side-effects-dogs) - [Adequan Polysulfated Glycosaminoglycan: Joint Injection Protocol](/knowledge/veterinary-medicine/calculators-clinical-tools/adequan-polysulfated-glycosaminoglycan-joint-injection-protocol) - [Cytopoint Injection: Monoclonal Antibody Schedule and Duration](/knowledge/veterinary-medicine/calculators-clinical-tools/cytopoint-injection-monoclonal-antibody-schedule-and-duration) - [How to Give Your Dog a Subcutaneous Fluid Injection at Home](/knowledge/veterinary-medicine/senior-and-chronic-care/give-dog-subcutaneous-fluids-home) - [How to Give Your Cat Subcutaneous Fluid Injections at Home](/knowledge/veterinary-medicine/senior-and-chronic-care/give-cat-subcutaneous-fluids-home) - [How to Give Your Dog a Shot at Home: Insulin and Other Injections](/knowledge/veterinary-medicine/pet-medication-guide/give-dog-injection-at-home-insulin) ## Sources 1. 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