Antimicrobial activity and spectrum of cefovecin, a new extended- spectrum cephalosporin, against pathogens collected from dogs and cats in Europe and North America

Evolutionary genomic analyses of canine E. coli infections identify a relic capsular locus associated with resistance to multiple classes of antimicrobials

Infections caused by antimicrobial-resistant Escherichia coli are the leading cause of death attributed to antimicrobial resistance (AMR) worldwide, and the known AMR mechanisms involve a range of functional proteins. Here, we employed a pan-genome wide association study (GWAS) approach on over 1,000 E. coli isolates from sick dogs collected across the US and Canada and identified a strong statistical association (empirical P < 0.01) of AMR, involving a range of antibiotics to a group 1 capsular (CPS) gene cluster. This cluster included genes under relaxed selection pressure, had several loci missing, and had pseudogenes for other key loci. Furthermore, this cluster is widespread in E. coli and Klebsiella clinical isolates across multiple host species. Earlier studies demonstrated that the octameric CPS polysaccharide export protein Wza can transmit macrolide antibiotics into the E. coli periplasm. We suggest that the CPS in question, and its highly divergent Wza, functions as an antibiotic trap, preventing antimicrobial penetration. We also highlight the high diversity of lineages circulating in dogs across all regions studied, the overlap with human lineages, and regional prevalence of resistance to multiple antimicrobial classes.

IMPORTANCE

Much of the human genomic epidemiology data available for E. coli mechanism discovery studies has been heavily biased toward shiga-toxin producing strains from humans and livestock. E. coli occupies many niches and produces a wide variety of other significant pathotypes, including some implicated in chronic disease. We hypothesized that since dogs tend to share similar strains with their owners and are treated with similar antibiotics, their pathogenic isolates will harbor unexplored AMR mechanisms of importance to humans as well as animals. By comparing over 1,000 genomes with in vitro antimicrobial susceptibility data from sick dogs across the US and Canada, we identified a strong multidrug resistance association with an operon that appears to have once conferred a type 1 capsule production system.

Emergence of livestock-associated Mammaliicoccus sciuri ST71 co-harbouring mecA and mecC genes in Brazil

The discovery and tracking of antimicrobial resistance genes are essential for understanding the evolution of bacterial resistance and restraining its dispersion. Mammaliicoccus sciuri (formerly Staphylococcus sciuri) is the most probable evolutionary repository of the mecA gene, that later disseminated to S. aureus. In this study, we describe the first double mecA/mecC homologue-positive non-aureus staphylococci and mammaliicocci (NASM) from the American continent, also representing the first report of mecC-positive NASM in Brazil. Two clonally related methicillin-resistant M. sciuri strains co-carrying mecA and mecC genes were isolated from the teat skin swab and milk sample collected from an ewe's left udder half. Both M. sciuri strains belonged to the sequence type (ST) 71. Besides mecA and mecC genes, the M. sciuri strains carried broad resistomes for clinically important antimicrobial agents, including β-lactams, tetracyclines, lincosamide, streptogramin, streptomycin, and aminoglycosides. Virulome analysis showed the presence of the clumping factor B (clfB), ATP-dependent protease ClpP (ClpP) and serine-aspartate repeat proteins (sdrC and sdrE) virulence-associated genes. Phylogenomic analysis revealed that these M. sciuri strains are part of a globally disseminated branch, associated with farm and companion animals and even with food. Our findings suggest that M. sciuri is likely to emerge as a pathogen of global interest, carrying a broad repertoire of antimicrobial resistance genes with a remarkable co-presence of mecA and mecC genes. Finally, we strongly encourage to monitor M. sciuri under the One Health umbrella since this bacterial species is spreading at the human-animal-environment interface.

CEFOVECIN PROTEIN BINDING AS A PREDICTOR FOR EXTENDED DURATION OF ACTION: A REVIEW OF CURRENT LITERATURE AND IN VITRO ANALYSIS IN MULTIPLE ZOOLOGICAL SPECIES

Cefovecin is a third-generation cephalosporin antibiotic with an efficacy of 2 wk following a single injection in domestic dogs and cats. A high degree of plasma protein binding to cefovecin has been proposed as one of the mechanisms responsible for the long elimination half-life, but protein binding has not been evaluated extensively in nondomestic species. In this study, a review of the current literature was conducted, and pharmacokinetic data were compiled for species in which cefovecin has been evaluated thus far. Additionally, in vitro cefovecin protein binding was evaluated in plasma from 22 nondomestic species representing a broad range of taxa. Animals of the order Carnivora demonstrated protein-binding levels of >98%, which is supportive of the long elimination half-life seen in related species. Protein binding was highly variable in Artiodactyl and Perissodactyl species, with dolphins (Tursiops truncatus) and barasingha (Rucervus duvaucelii) displaying high protein binding (99.12% to >99%), but not gazelles (Eudorcas thomsonii) or equids (91.76-92.70%). Cefovecin was not highly bound in any reptiles or birds, corresponding to short half-lives reported for these taxa. These results suggest that a high percentage of plasma protein binding in vitro may predict in which species cefovecin may exhibit a long half-life and duration of action in vivo. These findings may aid in selecting species for cefovecin pharmacokinetic research and for empirical treatment of infections caused by susceptible bacteria.

A multicenter study of antimicrobial prescriptions for cats diagnosed with bacterial urinary tract disease

Objectives

The aim of this study was to evaluate initial antimicrobial therapy in cats diagnosed with upper or lower bacterial urinary tract infections at veterinary practices in the USA and Canada.

Methods

Electronic medical records from a veterinary practice corporation with clinics in the USA and Canada were queried between 2 January 2016 and 3 December 2018. Feline patient visits with a diagnosis field entry of urinary tract infection, cystitis and pyelonephritis, as well as variation of those names and more colloquial diagnoses such as kidney and bladder infection, and where an antimicrobial was prescribed, were retrieved.

Results

Prescription data for 5724 visits were identified. Sporadic cystitis was the most common diagnosis (n = 5051 [88%]), with 491 (8.6%) cats diagnosed with pyelonephritis and 182 (3.2%) with chronic or recurrent cystitis. Cefovecin was the most commonly prescribed antimicrobial for all conditions, followed by amoxicillin–clavulanic acid. Significant differences in antimicrobial drug class prescribing were noted between practice types and countries, and over the 3-year study period. For sporadic cystitis, prescription of amoxicillin–clavulanic acid increased significantly and cefovecin decreased between 2016 and 2018, and 2017 and 2018, while fluoroquinolone use increased between 2017 and 2018.

Conclusions and relevance

The results indicate targets for intervention and some encouraging trends. Understanding how antimicrobials are used is a key component of antimicrobial stewardship and is required to establish benchmarks, identify areas for improvement, aid in the development of interventions and evaluate the impact of interventions or other changes.

Cefovecin pharmacokinetics after single-dose intramuscular administration in cheetahs (Acinonyx jubatus)

Cefovecin is a third-generation cephalosporin with potential value for use in exotic felids due to its long duration of action. A sparse sampling protocol was implemented with 18 zoo-housed cheetahs (Acinonyx jubatus) to evaluate the pharmacokinetics of cefovecin (Convenia^® ) after a single 8 mg/kg intramuscular injection. Blood was collected serially for 15 days following administration, and plasma cefovecin concentrations were determined using high-pressure liquid chromatography with ultraviolet detection. Pharmacokinetic parameters were estimated using population pharmacokinetic methods and non-linear mixed effects modeling (NLME). Cefovecin was well tolerated by all cats, with no adverse effects observed. Peak plasma cefovecin concentration was 84.75 µg/ml, with a mean residence time of 207.9 h and an elimination half-life of 144.1 h (6.00 days). Plasma concentrations of cefovecin were maintained >7 µg/ml in all individuals for the entire study duration (15 days). These concentrations are lower, and the half-life slightly shorter, than the values reported for domestic cats. Cefovecin was highly protein-bound (approximately 99.9%) in cheetah plasma, which is nearly identical to domestic cats. These results indicate that cefovecin is potentially useful as a long-acting antibiotic in cheetahs.

Detection of bla OXA-1, bla TEM-1, and Virulence Factors in E. coli Isolated From Seals

Marine mammals are frequently considered good sentinels for human, animal and environmental health due to their long lifespan, coastal habitat, and characteristics as top chain predators. Using a One Health approach, marine mammals can provide information that helps to enhance the understanding of the health of the marine and coastal environment. Antimicrobial resistance (AMR) is the quintessential One Health problem that poses a well-recognised threat to human, animal, and ecosystem health worldwide. Treated and untreated sewage, hospital waste and agricultural run-off are often responsible for the spread of AMR in marine and freshwater ecosystems. Rescued seals (n = 25) were used as sentinels to investigate the levels of AMR in the Irish coastal ecosystem. Faecal swabs were collected from these animals and bacterial isolates (E. coli and cefotaxime-resistant non-E. coli) from each swab were selected for further investigation. E. coli isolates were characterised in terms of phylogenetic group typing, AMR, and virulence factors. All E. coli isolates investigated in this study (n = 39) were ampicillin resistant while 26 (66.6%) were multi-drug resistant (MDR). Resistance genes bla _OXA-1 and bla _TEM-1 were detected in 16/39 and 6/39 isolates, respectively. Additionally, virulence factors associated with adhesion (sfa, papA, and papC) and siderophores (fyuA and iutA) were identified. An additional 19 faecal cefotaxime-resistant non-E. coli isolates were investigated for the presence of β-lactamase encoding genes. These isolates were identified as presumptive Leclercia, Pantoea and Enterobacter, however, none were positive for the presence of the genes investigated. To the authors knowledge this is the first study reporting the detection of bla _OXA-1 and bla _TEM-1 in phocid faecal E. coli in Europe. These results highlight the importance of marine mammals as sentinels for the presence and spread of AMR in the marine and coastal environment.

The Complex Diseases of Staphylococcus pseudintermedius in Canines: Where to Next?

Staphylococcus pseudintermedius is a pathogenic bacterium of concern within the veterinary sector and is involved in numerous infections in canines, including topical infections such as canine pyoderma and otitis externa, as well as systemic infections within the urinary, respiratory and reproductive tract. The high prevalence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) within such infections is a growing concern. Therefore, it is crucial to understand the involvement of S. pseudintermedius in canine disease pathology to gain better insight into novel treatment avenues. Here, we review the literature focused on S. pseudintermedius infection in multiple anatomic locations in dogs and the role of MRSP in treatment outcomes at these niches. Multiple novel treatment avenues for MRSP have been pioneered in recent years and these are discussed with a specific focus on vaccines and phage therapy as potential therapeutic options. Whilst both undertakings are in their infancy, phage therapy is versatile and has shown high success in both animal and human medical use. It is clear that further research is required to combat the growing problems associated with MRSP in canines.

Controlled, non-inferiority trial of bupivacaine liposome injectable suspension

OBJECTIVES

Recently, a bupivacaine liposome injectable suspension (BLIS) became commercially available in the veterinary market that may provide local analgesia for 72 h. The purpose of this study was to compare a BLIS incisional block with a control protocol in cats after ovariohysterectomy (OHE). The hypothesis was that a BLIS block would provide equivalent pain relief.

METHODS

This study was designed as a randomized, double-blind, non-inferiority trial. Students performed an OHE followed by a two-layer incisional and body wall block with either standard bupivacaine (control) or BLIS. Postoperatively, cats in the control group received robenacoxib, whereas the BLIS cats received saline. All cats were evaluated using the feline Glasgow Composite Measure Pain Scale (GCMPS) at multiple time points postoperatively.

RESULTS

There were 24 control cats and 23 BLIS cats. One cat from each group required rescue medication. The mean GCMPS scores were low and the groups were equivalent at all time points (P <0.05). This study showed that BLIS was equivalent to the control group up to 42 h and pain scores remained low up to 68 h after surgery.

CONCLUSIONS AND RELEVANCE

BLIS incisional block is equivalent to a control pain protocol and reduces the need for continued postoperative drug administration.

Use of cefovecin in dogs and cats attending first-opinion veterinary practices in Australia

BACKGROUND

Cefovecin is a long-acting third-generation cephalosporin commonly used in veterinary medicine. Third-generation cephalosporins are critically important antimicrobials that should only be used after culture and susceptibility testing. The authors describe the common indications for cefovecin use in dogs and cats, and the frequency of culture and susceptibility testing.

MATERIALS AND METHODS

A cross-sectional study was performed using clinical records extracted from VetCompass Australia. A previously described method was used to identify records containing cefovecin. The reason for cefovecin use was annotated in situ in each consultation text.

RESULTS

Over a six-month period (February and September 2018), 5180 (0.4 per cent) consultations involved cefovecin administration, of which 151 were excluded. Cats were administered cefovecin more frequently than dogs (1.9 per cent of cat consultations and 0.1 per cent of dog consultations). The most common reasons for cefovecin administration to cats were cat fight injuries and abscesses (28 per cent) and dermatitis (13 per cent). For dogs, the most common reasons for cefovecin administration were surgical prophylaxis (24 per cent) and dermatitis (19 per cent). Culture and susceptibility testing were reported in 16 cases (0.3 per cent).

CONCLUSION

Cefovecin is used in many scenarios in dogs and cats where antimicrobials may be either not indicated or where an antimicrobial of lower importance to human health is recommended.

42936 pathogens from Canadian hospitals: 10 years of results (2007-16) from the CANWARD surveillance study

OBJECTIVES

The CANWARD surveillance study was established in 2007 to annually assess the in vitro susceptibilities of a variety of antimicrobial agents against bacterial pathogens isolated from patients receiving care in Canadian hospitals.

METHODS

42 936 pathogens were received and CLSI broth microdilution testing was performed on 37 355 bacterial isolates. Limited patient demographic data submitted with each isolate were collated and analysed.

RESULTS

Of the isolates tested, 43.5%, 33.1%, 13.2% and 10.2% were from blood, respiratory, urine and wound specimens, respectively; 29.9%, 24.8%, 19.0%, 18.1% and 8.2% of isolates were from patients in medical wards, emergency rooms, ICUs, hospital clinics and surgical wards. Patient demographics associated with the isolates were: 54.6% male/45.4% female; 13.1% patients aged ≤17 years, 44.3% 18-64 years and 42.7% ≥65 years. The three most common pathogens were Staphylococcus aureus (21.2%, both methicillin-susceptible and MRSA), Escherichia coli (19.6%) and Pseudomonas aeruginosa (9.0%). E. coli were most susceptible to meropenem and tigecycline (99.9%), ertapenem and colistin (99.8%), amikacin (99.7%) and ceftolozane/tazobactam and plazomicin (99.6%). Twenty-three percent of S. aureus were MRSA. MRSA were most susceptible to ceftobiprole, linezolid and telavancin (100%), daptomycin (99.9%), vancomycin (99.8%) and tigecycline (99.2%). P. aeruginosa were most susceptible to ceftolozane/tazobactam (98.3%) and colistin (95.0%).

CONCLUSIONS

The CANWARD surveillance study has provided 10 years of reference antimicrobial susceptibility testing data on pathogens commonly causing infections in patients attending Canadian hospitals.

Characteristics of Extended-Spectrum β-Lactamase-Producing Escherichia coli From Dogs and Cats Admitted to a Veterinary Teaching Hospital in Taipei, Taiwan From 2014 to 2017

Extended-spectrum β-lactamases (ESBLs) are enzymes that mediate resistance to newer β-lactam antibiotics, including extended-spectrum cephalosporins and monobactams. The production of ESBL is primarily plasmid mediated, and such plasmids often comprise the genes that encode resistance to other classes of antimicrobials, such as aminoglycosides and fluoroquinolones. Therefore, ESBL-producing microorganisms leave clinicians with limited therapeutic options in both human and veterinary medicine. Compared with human medicine, information regarding ESBL-producing microorganisms is limited in veterinary medicine. We screened for ESBL-producing Escherichia coli in dogs and cats admitted to National Taiwan University Veterinary Hospital, Taipei, from 2014 to 2017 and further analyzed the genotypes and phylogenetic traits of these ESBL producers. Double disk tests specified by the Clinical and Laboratory Standards Institute were performed on 283 E. coli isolates and revealed a total of 65 E. coli (54 from dogs and 11 from cats) with the ESBL phenotype (22.8%). bla_{CTX−M−1group} and bla_{CTX−M−2group} were the most commonly identified ESBL gene groups. bla_CTX−M−55 was the main ESBL gene within the bla_{CTX−M−1group}, whereas the bla_{CTX−M−2group} contained only bla_{CTX−M−124}. The ESBL-producing E. coli were all resistant to ampicillin. The resistance rate to ceftiofur, doxycycline, enrofloxacin, and ciprofloxacin was 93.8, 73.8, 80, and 78.5%, respectively. Of the antibiotics tested, greater sensitivity to imipenem and gentamicin was noted. Multilocus sequence typing indicated that ST457, ST131, and ST648 were the most common sequence types. Our study identified eight ST131/O25b isolates, which is a global zoonotic clone of public health concern. The major ESBL genes of these clones were bla_{CTX−M−174} and bla_{CTX−M−194}. Because companion animals such as dogs and cats are in close contact with humans, the characterization of ESBL producers originating from them is crucial from the perspective of both public health and veterinary medicine.

In vitro killing of canine strains of Staphylococcus pseudintermedius and Escherichia coli by cefazolin, cefovecin, doxycycline and pradofloxacin over a range of bacterial densities

Background

Bacterial densities likely fluctuate during infection and may exceed the bacterial density used in susceptibility testing. As such, investigation of bacterial killing by antibiotics over a range of varying bacterial densities may provide important differences between compounds and could impact drug selection for therapy.

Hypothesis/Objectives

To measure killing of clinical isolates of Staphylococcus pseudintermedius and Escherichia coli by cefazolin, cefovecin, doxycycline and pradofloxacin at clinically relevant (minimum inhibitory, mutant prevention, maximum serum and maximum tissue) drug concentrations against varying densities of bacteria.

Animals/Materials

Bacterial strains collected from dogs with urinary tract infections were studied.

Methods and materials

High bacterial densities ranging from 10⁶ to 10⁹ colony forming units (cfu)/mL were exposed to minimum inhibitory, mutant prevention, blood and tissue drug concentrations, and the percentages (log₁₀) of viable cells killed following 30 min, 1, 2, 4, 6, 12 and 24 h of drug exposure were quantified.

Results

Doxycycline exhibited bacteriostatic properties with less killing than the other three agents. For example, at a 10⁷ cfu/mL density of S. pseudintermedius, more cells were killed by pradofloxacin (P < 0.0001) and cefovecin (P = 0.0014) but not cefazolin when compared to doxycycline at the maximum serum drug concentration following 12 h of drug exposure.

Conclusions and clinical importance

Differences were seen between some drugs in the speed and extent of bacterial killing; this could be clinically important and may impact drug selection and length of therapy.

Background – Bacterial densities likely fluctuate during infection and may exceed the bacterial density used in susceptibility testing. As such, investigation of bacterial killing by antibiotics over a range of varying bacterial densities may provide important differences between compounds and could impact drug selection for therapy. Hypothesis – To measure killing of clinical isolates of Staphylococcus pseudintermedius and Escherichia coli by cefazolin, cefovecin, doxycycline and pradofloxacin at clinically relevant (minimum inhibitory, mutant prevention, maximum serum and maximum tissue) drug concentrations against varying densities of bacteria. Conclusions and clinical importance – Differences were seen between some drugs in the speed and extent of bacterial killing; this could be clinically important and may impact drug selection and length of therapy.

Antimicrobial resistance, multilocus sequence types and virulence profiles of ESBL producing and non-ESBL producing uropathogenic Escherichia coli isolated from cats and dogs in Switzerland

Among 64 uropathogenic Escherichia coli (UPEC) isolated from 13 cats and 51 dogs, 35 were extended-spectrum beta-lactamase (ESBL) producers, and 29 were non-ESBL producers. Forty-six (71.9%) of the isolates were multidrug resistant (MDR). Among the ESBL producers, bla_CTX-M-15 (n = 17/48.6% of the bla_ESBLs), bla_CTX-M-1 (n = 10/28.6%), bla_CTX-M-55 (n = 4/11.4%), bla_CTX-M-14 (n = 3/8.6%), and bla_CTX-M-27 (n = 1/2.9%) were identified. The plasmid-mediated fluoroquinolone resistance genes aac(6')-Ib-cr, qnrB and the azithromycin resistance gene mph(A) were detected in 17 (26.6% of all isolates), one (1.6%) and in 13 (20.3%) respectively. The most frequent phylogenetic groups were C (n = 19) and B2 (n = 15). Twenty-six different sequence types (STs) were identified, with two being novel. The most frequent STs were ST410 (n = 16/25%), ST131, and ST73 (both n = 5/7.8%), and ST361 (n = 4/6.3%). Ten (15.6%) of the STs have been associated with urinary tract infection (UTI) in humans, suggesting zoonotic potential. Among seven virulence-associated genes, fyuA was the most prevalent. The overall aggregate virulence factor (VF) score was highest for isolates belonging to phylogenetic group B2 (median aggregate VF score 6, mean score 5,5, range 3-7), and lowest for isolates belonging to phylogenetic group C (0/ 0.5/0-3). The most frequent ST in this study, ST410, harboured the lowest number of VF (0/0,3/0-2). VF scores were higher in NDR (4/3.8/3-4) than in MDR (1/1,9/0-7), and higher in non-ESBL producing isolates (3/3/0-7) than in ESBL producers (1/1,7/0-7). Our data advance our knowledge of the phenotypic and genotypic characteristics of UPEC in companion animals and their potential for infection, zoonotic transmission and dissemination of antimicrobial resistance determinants.

Cephalexin susceptibility breakpoint for veterinary isolates: Clinical Laboratory Standards Institute revision

The Clinical and Laboratory Standards Institute (CLSI) uses cephalothin as the class representative for testing veterinary isolates for susceptibility to other first-generation cephalosporins, including cephalexin. We examined replacing cephalothin with cephalexin because cephalexin is used more often clinically. Bacterial isolates were obtained from dogs and cats from a national surveillance program. CLSI testing methods were used to determine the MIC for 4 cephalosporins used in veterinary medicine. Cephalexin clinical breakpoints for canine isolates were established by using published pharmacokinetic data and Monte Carlo simulations to calculate the probability of target attainment (PTA). For 1,112 Staphylococcus pseudintermedius isolates, the mode, MIC₅₀, and MIC₉₀ were 1, 2, and 64 µg/mL, respectively, for cephalexin, and ≤0.06, 0.12, and 2 µg/mL for cephalothin. Susceptibility of S. pseudintermedius from 2011 to 2014 did not change for the 4 cephalosporins tested. Only 4.3% of the penicillin-binding protein 2a-positive S. pseudintermedius isolates had MIC values ≤2 µg/mL for cephalexin, but 66.3% of these isolates had MIC values ≤2 µg/mL for cephalothin. There were also discrepancies between cephalexin and cephalothin for other bacteria tested, but the largest difference was for S. pseudintermedius, with a MIC difference of 4 doubling dilutions. Cephalexin interpretive categories (breakpoints) of ≤2 μg/mL (susceptible), 4 μg/mL (intermediate), and ≥8 μg/mL (resistant) were established for isolates obtained from dogs. Cephalothin should not be used for susceptibility testing of cephalexin for veterinary bacterial pathogens, and canine-specific breakpoints should be used for testing susceptibility. Breakpoints determined using the methods described herein for the interpretive categories will be added to future CLSI tables to reflect this recommendation.

Pharmacokinetics of Single-bolus Subcutaneous Cefovecin in C57BL/6 Mice

Because of its extended half-life, cefovecin is a broad-spectrum cephalosporin antibiotic commonly used to treat dermatitis in dogs and cats. A single injection in dogs can yield an effective plasma concentration for as long as 14 d, depending on the strain of Staphylococcus and for as long as 7 d in cats for the treatment of Pasteurella multocida. In the laboratory animal setting, C57BL/6 mice are commonly affected with dermatologic conditions that make these animals unsuitable for experiments. Therefore, we performed this pharmacokinetic study to determine whether cefovecin would be of benefit in mice. Plasma levels of the drug were determined by HPLC. For this study, single-bolus subcutaneous dosages of 8 and 40 mg/kg were assessed. The results showed that the dosage of 40 mg/kg achieved a maximal plasma concentration of 411.54 μg/mL with a half-life of 0.84 h, whereas 8 mg/kg yielded 78.18 μg/mL and 1.07 h respectively. The pharmacokinetic results suggest that cefovecin is not suitable as a long-acting antibiotic after a single subcutaneous bolus injection in mice for the treatment of dermatitis or any other bacteria sensitive to this medication.

Characterisation of extended-spectrum β-lactamase and AmpC β-lactamase-producing Enterobacteriaceae isolated from companion animals in New Zealand

AIMS

To assess the occurrence of, and characterise, extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase (AmpC)-producing Enterobacteriaceae isolated by veterinary diagnostic laboratories from infection sites in companion animals in New Zealand.

METHODS

Selected Enterobacteriaceae isolates were submitted by seven New Zealand veterinary diagnostic laboratories. They were isolated from infection sites in companion animals between June 2012 and June 2013, and were resistant to amoxicillin-clavulanic acid, fluoroquinolones, or any combination of two or more antimicrobials. Based on disk diffusion test results, the isolates were phenotypically categorised according to production of ESBL and AmpC. Genes for ESBL and AmpC production were amplified by PCR and sequenced. Escherichia coli isolates were also typed by multilocus sequence typing.

RESULTS

A total of 115 isolates matching the inclusion criteria were obtained from the participating laboratories, of which 74 (64%) originated from dogs and 29 (25%) from cats. Seven bacterial species were identified, of which E. coli was the most common (87/115, 76%). Of the 115 isolates, 10 (9%) expressed the ESBL phenotype, 43 (37%) the AmpC phenotype, and seven (6%) both ESBL and AmpC phenotypes. Of the 60 ESBL and AmpC-producing isolates, 36 (60%) were E. coli. Amongst these isolates, 27/60 (45%) were classified as multidrug resistant, compared with 15/55 (27%) non-ESBL or AmpC-producing isolates (p<0.01). Ninety five isolates were resistant to amoxicillin-clavulanic acid and 58 (61%) of these were ESBL or AmpC-producing. The predominant ESBL genes were bla_CTX-M-14 and bla_CTX-M-15, and the dominant plasmid-encoded AmpC gene was bla_CMY-2. Thirty-eight E. coli multilocus sequence types (ST) were identified, and the most prevalent were ST12 (12/89, 13%), ST131 (6/89, 7%) and ST648 (6/89, 7%). ESBL and AmpC-producing isolates accounted for 35/1,082 (3.2%) of the Enterobacteriaceae isolated by one laboratory network over the study period.

CONCLUSIONS AND CLINICAL RELEVANCE

ESBL and AmpC-producing Enterobacteriaceae were associated with clinical infections in companion animals in New Zealand, and were often multidrug resistant. In this study, these organisms accounted for <5% of all Enterobacteriaceae isolated from infection sites by one laboratory network, but their prevalence among isolates resistant to amoxicillin-clavulanic acid was 61%. Therefore routine secondary testing for ESBL and AmpC production by Enterobacteriaceae that are resistant to amoxicillin-clavulanic acid in primary testing could improve the accuracy of definitive antimicrobial therapy in companion animals in New Zealand.

Pharmacokinetics and local tolerance of cefovecin sodium after intra-articular administration in horses

Searching for new therapeutic options against septic arthritis in horses, this research was focused on the study of the kinetics and local side effects after the intra-articular treatment of horses with cefovecin sodium. A single dose (240 mg) of the drug (Convenia^® ) was administered into the radiocarpal joint of adult healthy horses (n = 6), and drug concentrations in plasma and synovial fluid were determined by high-performance liquid chromatography (HPLC). Local tolerance was also studied based on the modification of different joint physiopathological parameters (pH, cellular, and protein concentration in synovial fluid). Although no clinically relevant joint damage was noticed, significant increases in the protein concentrations at 5 min and in the cellular concentration at 30 min after cefovecin administration were observed in the treated radiocarpal joints. The duration of the cefovecin above the minimal inhibitory concentration (MIC) ≤1 μg/mL was 28.80 ± 2.58 h in the radiocarpal joint and 16.00 ± 2.86 h in plasma. The results of this study showed that intra-articular administration of cefovecin sodium in horses could be considered in the future to manage septic arthritis in horses, as it offers a good pharmacokinetic behavior and good local tolerance.

Pharmacokinetics of long-acting cefovecin in copper rockfish (Sebastes caurinus)

OBJECTIVE

To assess the pharmacokinetic properties of cefovecin in a cold-water teleost species.

ANIMALS

10 healthy adult copper rockfish (Sebastes caurinus), sex unknown.

PROCEDURES

Cefovecin (16 mg/kg) was administered SC to the rockfish. Blood samples were collected at predetermined points for measurement of plasma cefovecin concentrations (3 samples/fish). Plasma cefovecin concentrations were measured via liquid chromatography with mass spectrometry. Pharmacokinetic analysis was performed by means of naïve pooled analysis and compartmental modeling. Plasma protein binding of cefovecin was determined by ultrafiltration.

RESULTS

Cefovecin administration appeared to be well tolerated by the rockfish. Pharmacokinetic analysis resulted in a maximum plasma concentration of 104.8 μg/mL at 2.07 hours after administration. Plasma terminal half-life was 32.5 hours, and area under the curve was 5,132 h·g/mL. Plasma protein binding was low (< 10%) for plasma concentrations of 10 and 100 μg of cefovecin/mL when assessed at 7.8° and 20°C. Plasma concentrations > 1 μg/mL persisted for the full 7-day follow-up period.

CONCLUSIONS AND CLINICAL RELEVANCE

SC administration of cefovecin to copper rockfish at a dose of 16 mg/kg yielded plasma concentrations > 1 μg/mL that persisted to 7 days, but some interindividual variability was observed. The low degree of plasma protein binding but high circulating concentration of free drug may allow an extended administration interval in rockfish. Studies are needed to assess the efficacy and safety of this dose in rockfish.

Effect of proximal versus distal 50% enterectomy on nutritional parameters in rats preconditioned with a high-fat diet or regular chow

Obesity may protect against the nutritional consequences of short bowel syndrome. We hypothesized that rats preconditioned with an obesogenic diet would have better outcomes after surgical induction of short bowel syndrome compared to rats on regular chow. Rats were fed a high-fat diet or regular rat chow for six months, and then underwent 50% proximal, 50% distal, or sham enterectomy. Food intake, weight, and body composition were monitored before and for 4 weeks after surgery. The high-fat diet consistently produced obesity (>25% body fat). All procedures induced weight loss, but there was no discernable difference between resection vs. sham resection. Rats on the high-fat diet had a greater post-resection loss of body fat compared to rats on chow (36 vs. 26 g, respectively). There was a nonsignificant trend of less lean mass loss in the former compared to the latter rats (16 vs. 33 g, respectively). Enterectomy moderated serum ghrelin, GIP, PPY, insulin, and leptin. Intestinal adaptation was not different between obese vs. non-obese rats. Rats preconditioned with the high-fat diet may have had better retention of lean body mass after a surgical procedure compared to rats on chow. The effect of 50% enterectomy was less than expected.

Comparison of effectiveness of cefovecin, doxycycline, and amoxicillin for the treatment of experimentally induced early Lyme borreliosis in dogs

Background

While Koch’s postulates have been fulfilled for Lyme disease; causing transient fever, anorexia and arthritis in young dogs; treatment of sero-positive dogs, especially asymptomatic animals, remains a topic of debate. To complicate this matter the currently recommended antibiotic treatments of Lyme Disease in dogs caused by Borrelia burgdorferi require daily oral administrations for 31 days or longer, which makes non-compliance a concern. Additionally, there is no approved veterinary antimicrobial for the treatment of Lyme Disease in dogs in the USA and few recommended treatments have been robustly tested.

In vitro testing of cefovecin, a novel extended-spectrum cephalosporin, demonstrated inhibition of spirochete growth. A small pilot study in dogs indicated that two cefovecin injections two weeks apart would be as efficacious against B. burgdorferi sensu stricto as the recommended treatments using doxycycline or amoxicillin daily for 31 days.

This hypothesis was tested in 17–18 week old Beagle dogs, experimentally infected with B. burgdorferi sensu stricto, using wild caught ticks, 75 days prior to antimicrobial administration.

Results

Clinical observations for lameness were performed daily but were inconclusive as this characteristic sign of Lyme Disease rarely develops in the standard laboratory models of experimentally induced infection. However, each antibiotic tested was efficacious against B. burgdorferi as measured by a rapid elimination of spirochetes from the skin and reduced levels of circulating antibodies to B. burgdorferi. In addition, significantly less cefovecin treated animals had Lyme Disease associated histopathological changes compared to untreated dogs.

Conclusions

Convenia was efficacious against B. burgdorferi sensu stricto infection in dogs as determined by serological testing, PCR and histopathology results. Convenia provides an additional and effective treatment option for Lyme Disease in dogs.

Update in feline therapeutics: clinical use of 10 emerging therapies

PRACTICAL RELEVANCE

The field of veterinary medicine is constantly evolving. New medications are being introduced into clinical practice, and novel uses for established medications are frequently being discovered as new information comes to light.

CLINICAL CHALLENGES

Therapeutic options for our feline patients can be restricted based on inadequate clinical evidence, adverse effects and patient compliance concerns. Additionally, with the reduced availability of commonly used medications in some regions, clinicians are forced to utilize alternatives with which they may have limited experience.

AUDIENCE

This review article is directed towards primary care veterinarians working with feline patients. The selection of medications discussed is based on many of the clinical challenges commonly encountered in practice.

EVIDENCE BASE

The evidence for use of some of these medications is limited due to their novelty. Known mechanisms of action, pharmacokinetic and pharmacodynamics data, adverse effects and clinical uses are reviewed where possible, with clinical recommendations made based on the evidence of data available.

Bacterial species isolated from cats with lower urinary tract infection and their susceptibilities to cefovecin

Background

The aim of this study was to determine the bacterial species recovered from 61 cats with lower urinary tract infection (LUTI), and their susceptibility to cefovecin in vitro.

Results

The clinical signs and final clinical diagnosis for cats with confirmed LUTI were also reported. After physical examination of the cats, urine samples including ≥5-6 leucocytes in microscopic evaluation were cultured using bacteriological techniques. The isolates were identified by conventional microbiological methods and tested for in vitro susceptibility using the Kirby-Bauer disc diffusion method recommended by the Clinical Laboratory Standards Institute. Bacterial growth was observed in 16 of 61 urine samples. Antimicrobial susceptibility tests showed that 13 of 16 (81%) isolates were susceptible to cefovecin. The most frequently isolated bacterium from cats with signs of lower urinary tract infection, was Escherichia coli.

Conclusion

Cefovecin was found to be effective in cats with LUTI. Because cefovecin is a new antimicrobial agent in veterinary medicine, there are only few studies about urine culture of cats with LUTI. It is the first study on in vitro activity of cefovecin against bacterial isolates from cats with lower urinary infections in Istanbul, Turkey.

Canine superficial bacterial pyoderma: evaluation of skin surface sampling methods and antimicrobial susceptibility of causal Staphylococcus isolates

OBJECTIVE

To evaluate three easily performed methods of skin surface sampling for bacterial culture of Staphylococcus isolates obtained from dogs with superficial bacterial pyoderma (SBP) presenting to two veterinary teaching hospitals in Sydney, Australia, and to determine the antimicrobial susceptibility of isolates.

DESIGN

Prospective study of 27 dogs with SBP. Cytologically confirmed SBP lesions were sampled for bacterial culture using a dry cotton swab, a saline-moistened cotton swab and a skin surface scraping. Isolates were identified by standard discriminatory phenotypic and biochemical analyses, and confirmed using matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-TOF MS). Susceptibilities to 14 antimicrobials were determined by disk diffusion and by detection of the mecA gene using PCR. Sampling methods were compared according to bacterial yield, antibiograms and bacterial phenotypic analysis. Location of causative bacteria was evaluated via 8-mm punch skin biopsies using haematoxylin and eosin, Gram-Twort and Giemsa staining, and fluorescence in situ hybridisation (FISH).

RESULTS

Staphylococcus sp. were isolated from lesions in all dogs, either S. pseudintermedius (24 dogs) or S. schleiferi (3 dogs). Susceptibility was highest to cephalexin (96%) and amoxycillin clavulanate (96%). Methicillin resistance assessed by mecA real-time PCR and phenotypic oxacillin resistance was found in one dog (4.3%). Routine histology and FISH revealed bacteria within superficial stratum corneum.

CONCLUSION

Staphylococcal isolates from canine SBP demonstrated high susceptibility to common empirical antimicrobials. Histological techniques confirmed presence of bacteria at superficial sites, likely to be accessed by the sampling techniques. The three techniques afforded similar results and may be equally suitable for obtaining samples for culture.

In vitro efficacy of cefovecin against anaerobic bacteria isolated from subgingival plaque of dogs and cats with periodontal disease

Periodontal disease is a common disease of dogs and cats often requiring antimicrobial treatment as an adjunct to mechanical debridement. However, correct compliance with oral antimicrobial therapy in companion animals is often difficult. Cefovecin is a recently introduced veterinary cephalosporin that has demonstrated prolonged concentrations in extracellular fluid, allowing for dosing intervals of up to 14 days. Subgingival samples were collected from the oral cavity of 29 dogs and eight cats exhibiting grade 2 or grade 3 periodontal disease. Samples were cultivated on Wilkin Chalgrens agar and incubated in an anaerobic chamber for seven days. Selected anaerobic bacteria were isolated and identified to species level using 16S rRNA gene sequence analysis. Minimum inhibitory concentrations were determined for cefovecin and six additional antimicrobials using the agar dilution methodology recommended by the Clinical and Laboratory Standards Institute. The 65 clinical isolates were identified as Porphyromonas gulae (n = 45), Porphyromonas crevioricanis (n = 12), Porphyromonas macacae (n = 1), Porphyromonas cangingivalis (n = 1) Fusobacterium nucleatum (n = 2), Fusobacterium russii (n = 1) and Solobacterium moorei (n = 3). This is the first report of S. moorei being isolated from companion animals with periodontal disease. All isolates were highly susceptible to cefovecin, with a MIC90 of ≤0.125 μg/ml. Conversely, different resistance rates to ampicillin, amoxicillin and erythromycin between isolates were detected. Cefovecin is thus shown to be effective in vitro against anaerobic bacteria isolated from dogs and cats with periodontal disease.

Staphylococcus pseudintermedius and Staphylococcus schleiferi Subspecies coagulans from Canine Pyoderma Cases in Grenada, West Indies, and Their Susceptibility to Beta-Lactam Drugs

Over a 2-year period 66 cases of canine pyoderma in Grenada, West Indies, were examined by aerobic culture in order to ascertain the bacteria involved and their antimicrobial resistance patterns. Of the 116 total bacterial isolates obtained, the majority belonged to Gram-positive species, and the most common organism identified through biochemical and molecular methods was Staphylococcus pseudintermedius. Additionally, identification of a Staphylococcus schleiferi subspecies coagulans isolate was confirmed by molecular methods. All isolates of staphylococci were susceptible to beta-lactam drugs: amoxicillin-clavulanic acid, cefovecin, cefoxitin, cefpodoxime, and cephalothin. They were also susceptible to chloramphenicol and enrofloxacin. Resistance was highest to tetracycline. Methicillin resistance was not detected in any isolate of S. pseudintermedius or in S. schleiferi. Among the Gram-negative bacteria, the most common species was Klebsiella pneumoniae, followed by Acinetobacter baumannii/calcoaceticus. The only drug to which all Gram-negative isolates were susceptible was enrofloxacin. This report is the first to confirm the presence of S. pseudintermedius and S. schleiferi subspecies coagulans, in dogs with pyoderma in Grenada, and the susceptibility of staphylococcal isolates to the majority of beta-lactam drugs used in veterinary practice.

Antimicrobial resistance and pharmacodynamics of canine and feline pathogenic E. coli in the United States

Percent resistance and minimum inhibitory concentrations (MIC) were described for canine (n = 301) and feline (n = 75) pathogenic Escherichia coli (E. coli) isolates solicited during May 2005 to Sep 2005 from the Clinical Pharmacology Laboratory at Auburn University (n = 165) or commercial diagnostic laboratories ([CDL]; n = 211) from four regions in the USA. Drugs tested were amoxicillin (AMX), amoxicillin trihydrate/clavulanate potassium (AMXC), cefpodoxime (CFP), doxycycline (DXY), enrofloxacin (ENR), gentamicin (GM) and trimethoprim-sulfamethoxazole (TMS). Urinary isolates were most common (n = 174). Percent resistance was greatest for isolates from the respiratory tract, urine, and skin compared with the ear. Resistance was also greatest for samples sent from the south and central states compared with the western states (P ≤ 0.001). Percent resistance by drug was AMX (46 ± 2.6%) > AMXC (37 ± 2.5%) > CFP (21.8 ± 2%) = DXY (22 ± 2.1%) = ENR (20 ± 2.1%) = TMS (19 ± 2%) > GM (12 ± 1.7%). There was a significant difference in resistance between the different antibiotic drugs (P ≤ 0.001). Population MIC distributions were bimodal, and MICs were highest in samples from the southern states (P ≤ 0.001). E. coli resistance may limit its empirical treatment. For susceptible isolates, AMX and AMXC may be least effective and TMS most effective.

Pharmacokinetics of cefovecin in cynomolgus macaques (Macaca fascicularis), olive baboons (Papio anubis), and rhesus macaques (Macaca mulatta)

Cefovecin sodium is a long-acting, third-generation, cephalosporin antibiotic approved for the treatment of skin infections in dogs and cats. The pharmacokinetic properties of cefovecin were evaluated in cynomolgus macaques (Macaca fascicularis), olive baboons (Papio anubis), and rhesus macaques (Macaca mulatta) by using a single-dose (8 mg/kg SC) dosing regimen. Plasma cefovecin concentrations were determined by using ultra-performance liquid chromatography with tandem mass spectrometry, and a noncompartmental model was used to determine pharmacokinetic parameters. The half-life of cefovecin was 4.95 ± 1.47 h in cynomolgus macaques, 9.17 ± 1.84 h in olive baboons, and 8.40 ± 2.53 h in rhesus macaques. These values are considerably lower than the half-lives previously published for dogs (133 h) and cats (166 h). The extended half-life of cefovecin in dogs and cats is speculated to be due to active reabsorption of drug in the kidney tubules because plasma clearance is well below the normal glomerular filtration rate. In nonhuman primates, renal clearance rates approximated plasma clearance rates, suggesting that active renal reabsorption of cefovecin does not occur in these species. The pharmacokinetic properties of cefovecin in nonhuman primates are vastly different from the pharmacokinetic properties in dogs and cats, precluding its use as a long-acting antibiotic in nonhuman primates. This study highlights the importance of performing pharmacokinetic studies prior to extralabel drug usage.

Pharmacokinetics of Cefovecin in squirrel monkey (Saimiri sciureus), rhesus macaques (Macaca mulatta), and cynomolgus macaques (Macaca fascicularis)

Cefovecin sodium is a third-generation broad-spectrum cephalosporin antibiotic licensed for the treatment of skin infections in cats and dogs. The objective of our study was to assess whether its pharmacokinetic profile in squirrel monkey, rhesus macaques, and cynomolgus macaques was similar to that of dogs. Plasma levels were determined by using protein precipitation followed by liquid chromatography tandem mass spectrometry. After subcutaneous dosing at 8 mg/kg, the plasma terminal half-life of cefovecin was substantially shorter in the nonhuman primates (2.6 to 8.0 h) than in dogs (102 h). The total plasma exposure (AUC(0-96h)) was 10- to 40-fold lower in nonhuman primate species. In cynomolgus macaques, cefovecin showed a similar subcutaneous bioavailability (82% compared with 100%) and volume of distribution (0.16 compared with 0.12 L/kg) as compared to dogs; however, the plasma clearance of cefovecin was 20-fold higher. Cefovecin susceptibility testing and minimum inhibitory concentrations were not established for clinical isolates in nonhuman primates. However, if the minimum inhibitory concentrations of cefovecin for various nonhuman primates pathogens are in the same range as those observed for canine pathogens, our results suggest that cefovecin used at the same dosing regimen and frequency prescribed for the dogs will be ineffective and that increases in dose or frequency (or both) may be required.

Interpreting culture and susceptibility data in critical care: perks and pitfalls

PROBLEM

The need for immediate, effective antimicrobial therapy in the critical care patient must be tempered by approaches which simultaneously minimize emergence of antimicrobial resistance. Ideally, therapy will successfully resolve clinical signs of infection, while eradicating infecting pathogens such that the risk of resistance is avoided. Increasing limitations associated with empirical antimicrobial choices direct the need for culture and susceptibility data as a basis of therapy. Even so, such in vitro data should be utilized within its limitations.

OBJECTIVES

To demonstrate the attributes and limitations of patient and population culture and susceptibility (pharmacodynamic) data in the selection of antimicrobial drugs and to demonstrate the design of individualized dosing regimens based on integration of pharmacodynamic (PD) and pharmacokinetic (PK) data.

DIAGNOSIS

Limitations in culture and susceptibility testing begin with sample collection and continue through drug selection and dose design. Among the challenges in interpretation is discrimination between pathogens and commensals. Properly collected samples are critical for generation of data relevant to the patient's infection. Data are presented as minimum inhibitory concentrations (MICs). The MIC facilitate selection of the most appropriate drug, particularly when considered in the context of antimicrobial concentrations achieved in the patient at a chosen dose. Integration of MIC data with key PK data yields the C(max):MIC important to efficacy of concentration-dependent drugs and T>MIC, which guides use of time-dependent drugs. These indices are then used to design dosing regimens that are more likely to kill all infecting pathogens. In the absence of patient MIC data, population data (eg, MIC(90)) may serve as a reasonable surrogate.

CONCLUSIONS

Properly collected, performed, and interpreted culture and susceptibility data are increasingly important in the selection of and design of dosing regimens for antimicrobial drugs. Integration of PK and PD data as modified by host and microbial factors supports a hit hard, exit fast approach to therapy that will facilitate efficacy while minimizing resistance.

Feline bacterial urinary tract infections: An update on an evolving clinical problem

Although feline urine is increasingly submitted for bacterial culture and susceptibility testing as part of a more general diagnostic work-up for a range of presentations in veterinary practice, bacterial urinary tract infections (UTIs) are relatively uncommon due to a variety of physical and immunological barriers to infection. Culture positive urine is most often obtained from older female cats and the clinical history may include hematuria, dysuria and pollakiuria, or the infection may be occult. Urinalysis usually reveals hematuria and pyuria, and Escherichia coli and Gram-positive cocci are cultured most frequently. Most feline UTIs can be successfully treated using oral amoxicillin or amoxicillin/clavulanic acid administered for at least 14days, but the prevalence of antimicrobial resistance amongst infecting bacterial species is a growing concern. There is currently no conclusive information on the safety and efficacy of alternative therapeutic agents for the treatment of feline UTIs.

Effectiveness and safety of cefovecin sodium, an extended-spectrum injectable cephalosporin, in the treatment of cats with abscesses and infected wounds

OBJECTIVE

To evaluate the effectiveness and safety of cefovecin sodium in the treatment of cats with naturally occurring skin infections (abscesses and infected wounds).

DESIGN

Multicenter (26 sites), randomized, double-blind, controlled clinical trial.

ANIMALS

Client-owned cats of any breed with naturally occurring skin infections with associated clinical signs and confirmatory bacteriologic culture results.

PROCEDURES

Cats with clinical signs of skin and soft tissue infection were randomly allocated to receive a single dose of cefovecin (8 mg/kg [3.6 mg/lb], SC) followed by placebo drops administered orally once daily for 14 days or 1 SC placebo injection followed by cefadroxil (22 mg/kg [10 mg/lb], PO, once daily for 14 days). Only one 14-day treatment course was permitted.

RESULTS

Effectiveness of cefovecin in the treatment of cats with abscesses and infected wounds was similar to that of cefadroxil. At the final assessment on day 28, 97% (86/89) of cefovecin-treated cats and 91% (80/88) of cefadroxil-treated cats were considered treatment successes. There were no serious adverse events or deaths related to treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

1 SC injection of 8 mg of cefovecin/kg for the treatment of cats with naturally occurring skin infections (wounds and abscesses) was safe and as effective as cefadroxil administered orally at 22 mg/kg, once daily for 14 days.

Efficacy and safety of cefovecin in treating bacterial folliculitis, abscesses, or infected wounds in dogs

OBJECTIVE

To evaluate the efficacy and safety of administration of cefovecin, compared with cefadroxil, for treatment of naturally occurring secondary superficial pyoderma, abscesses, and infected wounds in dogs.

DESIGN

Multicenter, randomized, positive-controlled clinical trial.

ANIMALS

235 client-owned dogs.

PROCEDURES

Dogs with clinical signs of skin infection confirmed via bacteriologic culture were randomly allocated to receive a single SC injection of cefovecin (8 mg/kg [3.6 mg/lb]) followed by placebo administered PO twice daily for 14 days or cefadroxil (22 mg/kg [10 mg/lb]) administered PO twice daily for 14 days following a placebo injection. Two 14-day treatment courses were permitted. Treatment success was defined as reduction of clinical signs to mild or absent at the final assessment.

RESULTS

Clinical efficacy achieved with cefovecin in dogs was equivalent to that observed with cefadroxil. At the final assessment, 14 days following the completion of treatment (on day 28 or 42), 92.4% (109/118) of the cefovecin group and 92.3% (108/117) of the cefadroxil group were treatment successes. There were no serious adverse events or deaths related to treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

A single cefovecin injection (8 mg/kg) administered SC, which could be repeated once after 14 days, was safe and effective against naturally occurring skin infections in dogs and as effective as cefadroxil administered PO twice daily for 14 or 28 days.

The efficacy and safety of cefovecin in the treatment of feline abscesses and infected wounds

OBJECTIVES

To determine the efficacy and safety of cefovecin for the treatment of bacterial abscesses and wounds in cats at clinics in Germany, France, Spain and the UK.

METHOD

Cats with abscesses or wounds were enrolled. Cats (217) were randomised to treatment with either cefovecin administered by subcutaneous injection at 14 day intervals or amoxicillin/clavulanic acid as twice-daily oral tablets for 14 days. Treatment courses were repeated at 14 day intervals, when deemed necessary. Clinicians assessing lesions were masked to treatment allocation. Only animals with a confirmed pretreatment bacterial pathogen were included in the efficacy analysis. Cases were evaluated 28 days after initiation of the final course of treatment.

RESULTS

Cefovecin was as efficacious as amoxicillin/clavulanic acid, and efficacy was 100 per cent for both treatments.

CLINICAL SIGNIFICANCE

Cefovecin, administered as a single subcutaneous injection repeated at 14 day intervals as required, was shown to be as efficacious as oral amoxicillin/clavulanic acid in the treatment of abscesses/wounds in cats.