Cefovecin Sodium (Convenia) — Veterinary Vademecum Drug Reference

Dosage & Administration Guidelines

Species	Route	Dose	Frequency	Duration & Clinical Notes
Dog	Subcutaneous (SC)	8 mg/kg	Single dose; may be repeated after 14 days if needed	Duration: Up to 14 days per injection Notes: For skin and soft tissue infections, a single injection is often sufficient. For UTIs, a single injection may be used. Repeat dosing should be based on clinical response and culture results.
Cat	Subcutaneous (SC)	8 mg/kg	Single dose; may be repeated after 14 days if needed	Duration: Up to 14 days per injection Notes: For skin and soft tissue infections, a single injection is often sufficient. For UTIs, a single injection may be used. Repeat dosing should be based on clinical response and culture results.

Clinical Indications & Species Uses

General Indications

Treatment of bacterial infections caused by susceptible organisms in dogs and cats.

Dog (Canine)

Treatment of skin and soft tissue infections (e.g., wounds, abscesses, pyoderma) caused by susceptible strains of Staphylococcus intermedius and Streptococcus canis.
Treatment of urinary tract infections (UTI) caused by susceptible strains of Escherichia coli and Proteus mirabilis.

Cat (Feline)

Treatment of skin and soft tissue infections (e.g., wounds, abscesses) caused by susceptible strains of Pasteurella multocida, Staphylococcus spp., and Streptococcus spp.
Treatment of urinary tract infections (UTI) caused by susceptible strains of Escherichia coli.

Pharmacology & Mechanism of Action

Drug Class: Cephalosporin antibiotic (third-generation) | Pharmacological Group: Beta-lactam antibiotic

Mechanism of Action: Cefovecin is a third-generation cephalosporin that exerts its bactericidal effect by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs) located on the bacterial cell membrane, interfering with the transpeptidation step of peptidoglycan cross-linking. This leads to a weakened cell wall, osmotic instability, and ultimately bacterial cell lysis. Cefovecin has a broad spectrum of activity against Gram-positive and Gram-negative bacteria, including many beta-lactamase-producing strains, due to its stability against various beta-lactamases.

Pharmacodynamics: Cefovecin exhibits time-dependent bactericidal activity. Its efficacy is correlated with the duration of time that the drug concentration exceeds the minimum inhibitory concentration (MIC) for the target pathogen. It has a prolonged half-life in dogs and cats, allowing for sustained plasma concentrations above the MIC for many common pathogens for up to 14 days after a single subcutaneous injection. It is active against Staphylococcus spp., Streptococcus spp., Pasteurella multocida, Escherichia coli, and some anaerobic bacteria. It is not effective against methicillin-resistant staphylococci, Pseudomonas aeruginosa, or Enterococcus spp.

⚡ Pharmacokinetics Summary

Absorption: Cefovecin is administered subcutaneously and is rapidly and completely absorbed. Peak plasma concentrations are achieved within 1-2 hours in dogs and cats. The absolute bioavailability is approximately 100%.

Distribution: Cefovecin is widely distributed in body tissues and fluids. It has a volume of distribution of approximately 0.1-0.2 L/kg in dogs and cats. It penetrates well into skin, soft tissues, and respiratory tract. Protein binding is moderate to high (approximately 85-90% in dogs and cats).

Metabolism: Cefovecin undergoes minimal metabolism. It is primarily eliminated unchanged via renal excretion. Some biliary excretion may occur.

Excretion: Cefovecin is excreted primarily by the kidneys via glomerular filtration and tubular secretion. In dogs, approximately 75% of the dose is recovered in urine unchanged. In cats, approximately 85% is recovered in urine. The prolonged half-life is due to extensive protein binding and slow renal clearance.

Half-Life: Dogs: approximately 5.5 days (range 4.5-6.7 days); Cats: approximately 6.9 days (range 5.5-8.5 days).

Bioavailability: Approximately 100% after subcutaneous administration.

Protein Binding: Approximately 85-90% in dogs and cats.

Available Formulations & Strengths

Injectable Solution (reconstituted) 80 mg/mL after reconstitution (vials containing 10 mL, 20 mL, or 50 mL) (Subcutaneous)

Contraindications & Clinical Warnings

Contraindications:

Known hypersensitivity to cefovecin, other cephalosporins, or beta-lactam antibiotics.
Use in animals with a history of anaphylactic reactions to penicillins or cephalosporins.
Not for use in food-producing animals (cattle, sheep, goats, poultry) due to lack of withdrawal times.
Not for use in horses or other non-target species.

Warnings & Clinical Precautions:

Use with caution in animals with a history of allergic reactions to drugs, especially beta-lactams.
Use with caution in animals with renal impairment; dose adjustment may be necessary.
Safety in pregnant, lactating, or breeding animals has not been fully established; use only when clearly needed.
Prolonged use may result in overgrowth of non-susceptible organisms (e.g., Pseudomonas, Enterococcus).
Subcutaneous injection may cause transient pain or local reaction at the injection site.
Do not use in animals with known gastrointestinal disease (e.g., colitis) due to potential disruption of gut flora.
In cats, use with caution in those with chronic kidney disease; monitor renal function.

Adverse Effects & Reactions

Common:

Transient pain or swelling at injection site
Mild gastrointestinal upset (vomiting, diarrhea)
Lethargy or decreased appetite

Serious / Severe:

Anaphylaxis (rare but possible)
Acute renal failure (especially in cats with pre-existing renal disease)
Clostridioides difficile-associated diarrhea
Blood dyscrasias (neutropenia, thrombocytopenia)

Rare:

Hepatotoxicity
Neurological signs (seizures) in overdose
Allergic skin reactions (urticaria, pruritus)

Key Drug Interactions

Interacting Drug / Class	Clinical Effect & Mechanism	Severity
Aminoglycosides (e.g., gentamicin)	Potential for additive nephrotoxicity; monitor renal function.	Moderate
Loop diuretics (e.g., furosemide)	May increase risk of nephrotoxicity.	Moderate
Probenecid	May decrease renal excretion of cefovecin, increasing plasma concentrations and risk of toxicity.	Moderate
Bacteriostatic antibiotics (e.g., tetracyclines, macrolides)	Potential antagonism of bactericidal activity; avoid concurrent use.	Mild

Overdose & Toxicity Management

Signs of Toxicity:

Vomiting
Diarrhea
Lethargy
Ataxia
Seizures (in severe cases)
Renal toxicity (elevated BUN/creatinine)

Emergency Treatment Protocol: There is no specific antidote. Treatment is symptomatic and supportive. Induce emesis if recent oral ingestion (not applicable for SC). For SC overdose, monitor for signs of toxicity. Provide intravenous fluids to maintain hydration and renal perfusion. Consider activated charcoal if oral ingestion (not typical). In severe cases, hemodialysis may be considered, but its efficacy is unknown. Discontinue drug and provide supportive care.

Food Animal Withdrawal Times

Cefovecin is not approved for use in food-producing animals. Extra-label use in food animals is prohibited in the United States and many other countries due to lack of established withdrawal times. Do not use in animals intended for human consumption.

Storage, Handling & Regulatory Information

Storage Temperature: Store unreconstituted vials at controlled room temperature 20-25°C (68-77°F). After reconstitution, the solution is stable for 7 days when refrigerated at 2-8°C (36-46°F) and protected from light.

Light Sensitivity: Light-sensitive — protect from direct exposure.

Handling & Special Conditions: Protect from light. Do not freeze. Reconstituted solution should be used within 7 days if refrigerated. Discard any unused portion after 7 days.

Dispensing Status: Prescription Required (Rx Only)

Approval Status: Approved by the FDA for use in dogs and cats for the treatment of skin and soft tissue infections and urinary tract infections (Convenia).

Extra-Label (Off-Label) Use: In the United States, extra-label use of cefovecin in food-producing animals is prohibited by the FDA because it is a cephalosporin of importance in human medicine. In dogs and cats, extra-label use may be considered under AMDUCA, but it is not recommended for non-approved species.

Clinical Pearls & Practice Notes

💡 Clinical Insights: Cefovecin (Convenia) is a convenient long-acting injectable cephalosporin for dogs and cats, providing up to 14 days of antibiotic coverage with a single subcutaneous injection. It is particularly useful for treating skin and soft tissue infections and UTIs caused by susceptible organisms. Its prolonged half-life allows for less frequent dosing, improving owner compliance. However, it should be used judiciously to minimize the development of antimicrobial resistance. Culture and susceptibility testing are recommended before use, especially in recurrent or severe infections. Monitor renal function in cats, especially those with chronic kidney disease. Do not use in food animals. Adverse effects are generally mild, but anaphylaxis can occur. Always have epinephrine available when administering any beta-lactam antibiotic.

References & Literature

📚 Plumb's Veterinary Drug Handbook
📚 Papich Veterinary Pharmacology and Therapeutics
📚 Compendium of Veterinary Products (CVP)