Cefovecin
Cefovecin sodium
Also known as: Convenia · UK-287074-02 · cefovecina sodica · céfovécine sodique · natrii cefovecinum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Audited v13 dosing evidence
Structured calculator evidenceUTI and severe infections of the gingival and periodontal tissues (extra-label)
Verified clinician required
- once
NA
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Cefovecin is a long-acting, injectable third-generation cephalosporin antibiotic specifically labeled for use in dogs and cats.
Key Clinical Features:
- Compliance Solution: Its primary clinical benefit is for patients whose owners have difficulty adhering to an oral dosing regimen, or when oral antibiotics are poorly tolerated or absorbed.
- Spectrum of Activity: As a 3rd-generation cephalosporin, it has broad-spectrum activity. It is highly effective against common skin pathogens including Staphylococcus pseudintermedius, Streptococcus canis (Group G), and Pasteurella multocida.
- Limitations: It is not active against Pseudomonas spp. or enterococci. Furthermore, because it is highly protein-bound, it does not achieve effective serum levels to treat systemic (non-urinary tract) E. coli infections at standard labeled doses.
- Pharmacokinetic Profile: Its exceptionally long half-life is due to its high affinity for plasma proteins and slow dissociation rate, allowing for a single injection to provide days to weeks of therapeutic antibacterial concentrations depending on the target organism's MIC.
Mechanism of action
Cefovecin is a time-dependent, bactericidal beta-lactam antibiotic.
- Mechanism: Like other cephalosporins, cefovecin mimics the D-alanyl-D-alanine terminal of the peptidoglycan chain. It binds to and irreversibly inhibits bacterial Penicillin-Binding Proteins (PBPs), specifically transpeptidases and carboxypeptidases.
- Pathway: Inhibition of PBPs → Prevents cross-linking of peptidoglycan chains → Weakens the bacterial cell wall → Osmotic instability → Bacterial cell lysis and death.
- Efficacy: Because it is a time-dependent antibiotic, maintaining free (unbound) drug concentrations above the Minimum Inhibitory Concentration (MIC) of the target pathogen for a significant portion of the dosing interval is critical for its bactericidal efficacy.
Safety & warnings
Contraindications
- Known allergy or hypersensitivity to cefovecin, other cephalosporins, or penicillins (beta-lactams)
- Small herbivores (e.g., guinea pigs, rabbits) due to risk of fatal dysbiosis
- Dogs or cats less than 4 months of age (USA label) or less than 8 weeks of age (UK label)
Adverse effects
- Lethargy and depression
- Anorexia
- Vomiting
- Mild to moderate increases in liver enzymes (ALT, GGT)
- Increases in BUN and moderately elevated serum creatinine (observed in cats)
- Injection site irritation, vocalization, and transient edema
- Hypersensitivity reactions and anaphylaxis (rare but potentially fatal)
- Myelotoxicity creating toxic neutropenia (rare class effect)
- Anemia, thrombocytopenia, and prolonged coagulation times (rare class effect)
Precautions
Prolonged Duration Warning: Because cefovecin can persist in the body for up to 65 days, any adverse reactions (such as hypersensitivity or gastrointestinal upset) may require prolonged symptomatic and supportive treatment.
- Renal Impairment: Cefovecin is primarily eliminated via renal mechanisms. Use with caution in animals with severe renal dysfunction.
- Breeding/Lactation: Safe use in breeding or lactating animals has not been definitively established, though cephalosporins are generally considered safe. Weigh risks vs. benefits.
- Laboratory Interference: May cause false-positive urine glucose (copper reduction methods), falsely elevated creatinine (Jaffe reaction at high doses), falsely lowered albumin, and false-positive direct Coombs' tests.
Drug interactions
May compete for plasma protein binding sites, potentially increasing the free (active) concentrations of either drug.
May compete for plasma protein binding sites.
May compete for plasma protein binding sites.
May compete for plasma protein binding sites.
Concurrent use of highly protein-bound drugs may compete with cefovecin binding and cause adverse reactions, though actual clinical significance is not fully established.
Competition for plasma protein binding, potentially altering free drug concentrations
Monitoring
- Clinical efficacy (resolution of clinical signs of infection)
- Adverse effects (e.g., gastrointestinal upset, lethargy, injection site reactions)
- Renal and hepatic parameters in patients with pre-existing organ dysfunction
Pharmacokinetics
Half-life
Absorption
Completely absorbed after subcutaneous injection. Peak plasma levels occur approximately 6 hours post-dose in dogs, and 2 hours post-dose in cats. Exhibits non-linear kinetics; increasing the dose does not proportionally increase plasma concentration.
Distribution
Highly bound to plasma proteins (98.5% in dogs; 99.8% in cats). The slow dissociation from these proteins is responsible for its long elimination half-life. Volume of distribution (steady-state): 0.122 ± 0.011 L/kg (dog), 0.09 ± 0.01 L/kg (cat).
Metabolism
Not extensively metabolized.
Elimination
Primarily eliminated via renal mechanisms, with the majority of the dose excreted unchanged in the urine. A small amount is excreted unchanged in the bile. Total body clearance: 0.76 ± 0.13 mL/hr/kg (dog), 0.350 ± 0.40 mL/kg/hr (cat). The drug may persist in the body for up to 65 days.
Overdose
Acute overdoses are generally well tolerated and relatively safe.
- Dogs: Administered SC up to 180 mg/kg (22.5X the labeled dose) showed only injection site irritation, vocalization, and transient edema (which resolved within 8-24 hours).
- Cats: Administered the same 22.5X dose showed similar injection site signs. However, 10 days post-injection, treated cats had lower mean white blood cell counts compared to controls, and one cat exhibited a small amount of bilirubinuria on day 10.
- Treatment: If massive overdose occurs or severe adverse effects are noted, treatment is symptomatic and supportive. Due to the long half-life, prolonged monitoring may be required.
Available products
Formulations
- Injectable lyophilized powder (reconstitutes to 80 mg/mL)
Veterinary
- Cefovecin Sodium (lyophilized) 800 mg (of cefovecin) per 10 mL multidose vial (80 mg/mL when reconstituted); Convenia® (Pfizer); Rx
Regulatory status
POM-V classification. Highest priority critically important antibiotic.
POM-V classification.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store the lyophilized powder and the reconstituted product in the original carton, refrigerated at 2°-8°C (36°-46°F). Protect from light. Use the entire contents of the vial within 28 days of reconstitution. The color of the solution may vary from clear to amber upon reconstitution and may darken over time; if stored properly, this color change does not adversely affect potency.
Client information
What is Cefovecin (Convenia)? Cefovecin is a long-acting antibiotic given by injection at the veterinary clinic. It is highly effective for treating certain skin and soft tissue infections.
Key Points for Pet Owners:
- Convenience: A single injection provides days to weeks of antibiotic therapy, eliminating the need for you to give daily pills or liquids at home.
- Long-Lasting: This drug stays in your pet's body for approximately 2 months (up to 65 days) after the injection.
- Side Effects: While generally very safe, some pets may experience tiredness, decreased appetite, or vomiting. Because the drug stays in the system for a long time, if your pet has an allergic reaction or severe side effect, they may require veterinary care for an extended period.
- Action Required: Contact your veterinarian immediately if you notice any facial swelling, hives, severe vomiting, diarrhea, or extreme lethargy after your pet receives this injection.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.