Evaluation of antimicrobial usage in companion animals at a Veterinary Teaching Hospital in Nigeria

This study investigated various qualitative and quantitative indices of antimicrobial use (AMU) in companion animals (CAs) at a Veterinary Teaching Hospital (VTH-A) and its annex (VTH- B) from 2019 to 2021. For 694 documented animals, antimicrobial administrations (AADs) were 5, 278 times, of which 98.8% (5217) and 1.2% (61) were in dogs and cats respectively. At the VTH- A, oxytetracycline (1185 times, 22.5%) was mostly administered in dogs and metronidazole (26 times, 0.5%) in cats. Similarly, at VTH- B, oxytetracycline was administered 895 times (17.0%) in dogs while amoxicillin was given 7 times (0.1%) in cats. The prescription diversity (PD) was estimated at 0.73 and 0.82 in VTH-A and VTH-B respectively. The quantity of antimicrobials (AMs) used was 10.1 kg (A, 6.2 kg and B, 3.9 kg). Oxytetracycline administrations and quantity of metronidazole (P < 0.0001) were higher than other Active Ingredients (AIs). Furthermore, 16.5% of AIs were classified as Critically Important Antibiotics (CIA) with the highest priority, while enrofloxacin, ciprofloxacin, and azithromycin fell under the World Health Organisation (WHO) Watch group. The In-Depth Interview (IDI) indicated that the high frequency of oxytetracycline administrations was linked with being the first choice for blood parasite treatment by the clinicians at the hospital. The quantity of metronidazole used was perceived to be higher due to the clinicians' preference for the treatment of acute gastroenteritis, its wider dose range, and the frequency of administration (bi-daily). The study provides baseline data on AMU indices in CAs, for the development of antimicrobial stewardship (AMS) and communication training, and policy modifications to enhance antimicrobial therapy optimization in tertiary veterinary hospital care in Nigeria.


Study setting
We selected a veterinary teaching hospital and its satellite facility (annex) for this study.The VTH serviced a city in South West Nigeria with a human population of approximately 571,500 people (https:// world popul ation review.com/ world-cities/ abeok uta-popul ation).Nigeria is a sub-Saharan West African country with well over 10 million pet dogs 15 .The hospital under study has an annex and both serve as a referral center for private and government veterinary clinics 16 .The hospital offers services to all varieties of animals such as CAs, food animals, and wildlife, and has board-certified veterinarians who prescribe medications including AMs for various empirical use in animals.Hence, clinical routine data from the hospital can be used to evaluate AMU patterns in CAs, especially dogs and cats.The main VTH was designated VTH-A and the annex was designated VTH-B for this study.

Study design
A mixed methods assessment was conducted as follows: (1) A 3-year retrospective analysis of medical records on AMU from the veterinary tertiary hospital and its annex from 2019 to 2021 was conducted.For this study, AMs were considered "both synthetic and non-synthetic".
(2) An in-depth interview (IDI) was held among the antimicrobial prescribing clinicians (APCs) at the VTH to explore their perceptions towards rational antimicrobial prescriptions, drivers for AMs prescriptions or choices, and AMR.All qualified veterinarians prescribing antibiotics were eligible to participate in the discussion.The interview guide was developed based on the outcomes of analysis of patients' medical records and previous research (Limato et al. 2022), and validated by qualitative research experts.

Data collection and management
For this study, we assumed that all billed drugs were used to treat pets.Information obtained included the patient's case file I.D., sex, breed, species, age, weight at treatment, antimicrobial prescription, and patient category (out-patient, in-patient, or in-house point-of-care administration).For the drugs, data were generated on the total number of antimicrobials administered; treatment date, active ingredients, amount and unit of the preparation; and whether the drug was administered during the visit or dispensed to the owner; whether treatment plans were completed, and route of drug administration.Additionally, the active ingredients in each AM were classified according to the WHO-CIA and AWaRe.

Inclusion criteria
Only dogs and cats that were prescribed at least one antimicrobial drug within the study period were considered for inclusion in the study.
www.nature.com/scientificreports/Exclusion criteria Dogs and cats whose files did not have adequate documentation on active ingredients, amount and units of preparation, and at least a veterinarian certifying treatment plans or protocols were excluded from the study.All other animal species were also excluded from the study because the overwhelming number of animal species presenting at the VTHs were dogs and cats.

In-depth interview
The IDI explored results from the retrospective analysis of AMU in dogs and cats from 2019 to 2021.Before the interviews, potential participants were sent invitations and consent forms.Once the participants had signed the form, he or she was enrolled in the discussion.The date and location were agreed on by the interviewers and participants.The interview was continuous and follow-up questions were asked based on the responses of participants.The discussion was in English, audio-recorded, and transcribed verbatim.The IDI questions and guidelines were reviewed by two experts in the field of qualitative research.No personal data from veterinary practitioners were recorded.
The subject of the IDI was grouped into four themes, which addressed AMU practices, drivers, and challenges; Infection control practices; awareness about WHO-CIA and AWaRe; and opinions about AMR and control in veterinary hospitals.

Statistical analyses
Data generated were captured and merged into Microsoft Excel, 2016 (Microsoft Corporation, Redmond, WA) and transferred to Statistical Package for the Social Science version 23.0 (IBM SPSS 23.0, USA) for both descriptive and inferential statistics.The age and weight of patients were subjected to normality testing using Kolmogorov-Smirnov (> 0.05), which informed our use of median or Mean ± SD.Data on antibiotic classes and active ingredient administrations were analysed descriptively as proportions and percentages.According to Schnepf et al. 8,17 , the calculation of the Administered Daily Amount (ADA) was evaluated using the formula: • Administered Daily Amount (ADA) = amount of drug × proportion of active ingredient in the drug • Prescription Diversity (PD) = Where np = number of prescriptions of a particular pharmaceutical class (PC) within a PF.NP = the total number of prescriptions within a PF.Prescription diversity (PD) is defined as "the frequency and variety with which a practice prescribes pharmaceutical classes (PC) within a determined pharmaceutical family (PF)" 18 .
Further comparisons were performed using ordinary-two-way ANOVA and Dunnett's post hoc analyses to test the mean variation in the number of drug administrations and quantity at VTH -A and VTH-B.These comparisons were made only for data retrieved from dogs.Records for cats were few and unanalysable.

Ethical approval
This study was performed in line with the principles of the Declaration of Helsinki

Informed consent
Informed and signed consent was obtained from the VTH's Director to have access to patient files from 2019 to 2021 and to conduct interviews among APCs.Similarly, signed consent was obtained from APCs before the interview commenced.Permission to make audio recordings of the discussions was obtained and the clinicians were aware participation in the discussion was voluntary.Personal identifiers were not collected and information provided by participants was treated confidentially.Every participant was aware of his/her right to discontinue participation at any stage of the study according to the World Medical Association Declaration of Helsinki, 2001.Only authorized persons (the research team) had access to the hospital information used for this research, and none were allowed to keep a personal copy of the records.

Antimicrobial use and prescription diversity in dogs and cats from 2019 to (VTH-A )
Two thousand five hundred and six (2506 antimicrobial administrations (AMAs) were documented, of which 2452 (97.8%) were in dogs and 54 (2.2%) in cats.The outpatient point of care accounted for all AMA (100.0%).
Oxytetracycline was administered 1185 times and followed by metronidazole (435 times) in dogs.The prescription diversity (PD) of AMs used in 2019, 2020, and 2021 were 0.73, 0.73, and 0.67 respectively with 1.0 representing maximal richness and diversity.For cats, metronidazole was most prescribed (26 times; Table 2), and PD for AMAs were 0.49, 0.38, and 0.68 in 2019, 2020, and 2021 respectively.The number of administrations for each AIs for over 3 years is presented in Fig. 2A.

Antimicrobial use and prescription diversity in dogs and cats from 2019 to (VTH -B)
2772 AMAs were documented from 2019 to 2021 of which 2765 (99.7%) were in dogs' and (0.3%) in cats' treatments.A higher number of AMAs was documented for outpatient care (99.8%), while 0.2% accounted for inpatients.
The common routes of drug administration were intravenous (34.9%), oral (32.5%), intramuscular injections (31.6%), and Intraocular (1.0%).Oxytetracycline (31.3%), enrofloxacin (16.2%), and amoxicillin (13.3%) were most frequently administered IV, IM, and PO drugs respectively.Figure 1B above described the various active ingredients (AIs) and routes of administration.For dogs in the decreasing order, tetracyclines (oxytetracycline, 32.4%), Quinolones (enrofloxacin, 16.8%), and Penicillins (amoxicillin, 16.6%).This was similar to what was documented at VTH-A.In contrast, Penicillins (amoxicillin, 100.0%) were the only AMs used in cats during the study period.Antimicrobial prescriptions were completed in 90.2% of the 370 patients.Metronidazole, amoxicillin, ciprofloxacin, doxycycline, oxytetracycline, tetracyclines, enrofloxacin, and azithromycin tablets were main AMs dispensed for patients especially dogs (41/332, 12.3%) for subsequent administration at home by pet owners.No records of follow-up on pet owners were observed.For dogs, oxytetracyclines were administered 895 times, followed by enrofloxacin (459 times) and amoxicillin (465 times).The least administered AMs were the Macrolides (azithromycin, 12 times).The number of drug administrations for each AI over 3 years is illustrated in Fig. 2B.The PD for dogs in 2019, 2020, and 2021 were 0.79, 0.82, and 0.81 respectively.According to the data, no antimicrobial drug administration was documented in 2019 and 2020 for cats.The PD was estimated at 0.43 in 2021.Table 3 describes the total drug administrations in dogs and cats at VTH-B.Overall there was no significant variation in the number of drug administrations at the VTH, A, and B (P = 0.39).However, oxytetracycline administration was higher (P < 0.0001) than other AIs used in dogs.

Amount of Antimicrobial active ingredients used for dogs and cats at the Veterinary Teaching Hospital (A and B) from 2019 to 2021
The documented amount of AIs used from 2019 to 2021 was 10.1 kg (A, 6.2 kg and B, 3.9 kg respectively, Fig. 3A  and B).The quantity of antimicrobials used at VTH-A and B are presented in Tables 4 and 5.The largest amount of antimicrobial used was in dogs of which metronidazole accounted for (92.0%, 5.7 kg) and 75.9% (3.0 kg) at A and B respectively.Conversely, the lowest amount of AIs was administered to cats during the study period (0.0173 kg).The quantity of antimicrobials administered was similar (P = 0.15) at VTH-A and B, while the quantity of metronidazole administered in dogs was significantly higher (P < 0.0001) than in other AIs.

Antimicrobial classification based on the risk to human health and prioritization for antibiotic stewardship according to the World Health Organization (WHO)
Antimicrobials documented were medically important antimicrobials.AIs were classified as CIAs with highest priority (16.5%), high priority (17.5%), highly important (53.7%), and important (12.2%;Fig. 4).Five out of the AIs fell under the Watch group and included all the CIA's highest priority agents namely enrofloxacin, ciprofloxacin, and azithromycin (Table 6).

In-depth interview responses
Three APCs provided consent to be interviewed.The themes of discussion and responses are presented in Table 7.

Theme 1: perceptions about antimicrobial use, prescribing drivers, and challenges
The clinicians who participated in the in-depth interview reported that the choice of antimicrobials is fundamentally determined by the case presentation, formal knowledge and experiences, clients' willingness to persist in presenting their pets to complete antibiotic therapy regime, availability of the drugs and cost, and laboratory results if available.Also, APCs provided the reason for the higher administrations and quantity of oxytetracycline and metronidazole respectively compared with other active ingredients.Oxytetracycline is considered the first line of treatment for blood parasitism especially babesiosis (aside from bacterial infections), which is an endemic blood parasitic infection in animals in Nigeria.For metronidazole, the higher consumption was attributed to APC's preference to treat acute gastroenteritis, the dosage range, the safety of the drug, and the severity of the case presented.No documentation of antimicrobial policy or standardized treatment protocols was available.
A few strengths that impact the discriminate use of antimicrobials were identified by participating clinicians.These included having well-trained veterinary personnel, who ensure that proper diagnosis is carried out based on their good knowledge and experiences of disease presentation, and laboratory confirmation.The practice carries out patient-centered approach investigations and treatments as well.
Several gaps identified as promoting indiscriminate use of antimicrobials in CAs in Nigeria were discussed and reported.Factors such as lack of antimicrobial sensitivity tests and materials, inadequate veterinary laboratories, poor funding, quackery, and lack of structure for capacity building or on-the-job training especially on antimicrobial stewardship were discussed.APCs agreed antimicrobials are indiscriminately used in CAs most especially as a result of quackery.Clients (especially dog breeders) are reported to self-administer drugs to their pets promoting AMR in animals.APCs recommendations to combat indiscriminate use of antimicrobials included target-specific training and awareness creation, control of quackery in the veterinary profession, effective surveillance of AMU, prescriptions, and drug handling.The teaching hospital has infection control policies and practices but not officially documented or available to workers.

Theme 3: awareness about WHO-CIA and AWaRe
APCs were aware of the WHO-CIA groups and unaware of AWaRe classifications of antimicrobials of CIA in human medicine.APCs agree that there is a need to amplify efforts in the training of staff especially in the responsible use of these antimicrobials.In the clinicians' opinion making antimicrobial susceptibility tests mandatory in companion animal practice may not be practicable due to limited funding for such procedures, and clients' inability to pay for such services.The APCs pointed out that overuse and misuse of antimicrobials by non-vets especially quacks make the Antimicrobial Susceptibility Test (AST) unhelpful especially where resistance (100%) to all antimicrobials is reported.

Discussion
The indiscriminate use of antimicrobials and the consequent impact on AMR in livestock animals have received more attention and monitoring by public health agencies than in CAs.Many countries still lack regulations on AMU in CAs and recommendations for responsible and prudent use, especially in African countries.Although antimicrobial quantity and misuse may be lesser in CAs, it is still crucial to monitor and report AMU considering the potential of dogs and cats to cross-transfer resistant microbes to humans through close-contact".Furthermore, we must preserve and prioritize antimicrobial treatment possibilities as CAs share some classes of antimicrobials including medically important drugs with humans.Presently, only a few studies have provided information about AMU, the classes, active ingredients, prescribing patterns, and quantity in companion animals 17,[20][21][22] .In Nigeria, the systematic collection and evaluation of AMU data in companion animals are unavailable.There is no current data that demonstrates how much of these drugs have been used for dogs and cats in Nigeria.Hence, from a clinical context, we investigated for the first time qualitative and quantitative indices to describe different ACs, AIs, and quantity usage in dogs and cats presented at a VTH in Nigeria from 2019 to 2021.
The demographic characteristics of pets in the country indicated that dogs are kept as household pets more than cats are in Nigerian culture.This finding was in line with studies conducted on occupational hazards among veterinary students in southwest Nigeria who reported more contact with dogs than cats 23 .Cats are rarely kept as pets in Nigerian homes because of cultural and traditional myths that associate "terrible luck" with them 23 .Furthermore, the Alsatian/German Shepherd is the most common breed of dog reported to have visited the veterinary teaching hospital from 2019 to 2021.This finding is similar to Adekoya et al. 16 who documented Alsatians (German Shepherd Dogs) as the most presented breeds of dogs at the veterinary teaching hospital.The result is not surprising because Alsatian/German shepherd is the most popular breed of dogs in Nigeria.This breed is loved for its strength, intelligence, and ability to be obedient and is often employed for security and protection by many families and individuals in the country.The overall number of antimicrobial administrations was estimated and observed to be lower than reports from other recent studies conducted in Germany 17,18 , Denmark 24,25 , Italy 20 and Japan 22 .The lower drug administrations reported in this study may be attributed to environmental and socio-economic variables impacting dog keeping and the number of dog owners in the country (estimated at about 10 million) as compared with the US (90 million), Europe (92.9 million), or China (136 million).
The main antimicrobial drugs used belonged to the classes of Tetracyclines (oxytetracycline, tetracycline, and doxycycline), Penicillin (amoxicillin and ampicillin), Quinolones (enrofloxacin and ciprofloxacin) and Nitroimidazoles (metronidazole).Presently, there are limited studies on AMU in companion animals in West Africa including Nigeria.However, our results were corroborated by a recent retrospective study, which investigated the trends in the clinical use and misuse of antibiotics in animals (companion animals, ruminants, and wildlife) at a veterinary hospital in Nigeria from 2013 to 2017 26 .The authors documented penicillin, streptomycin, oxytetracycline, gentamicin, and sulphadimidine as the most common antibiotics used.Furthermore, the frequent use of oxytetracycline was observed to increase during the study period.In another study conducted in Chile, penicillins, cephalosporins, quinolones, and tetracyclines were commonly prescribed drugs for Chilean CAs 21 .On the contrary, other studies 18,20,24,27 showed that penicillins with extended-spectrum/beta-lactamase inhibitors, 1st and 2nd generation cephalosporins were frequently prescribed in CAs in the UK and EU.Similarly, in Japan, www.nature.com/scientificreports/ the most common were 1st generation cephalosporin and extended-spectrum penicillins 22 .Due to the high cost and unavailability of cephalosporins, cheaper AMs such as previously described are presently and frequently prescribed in CAs at the veterinary hospital.Furthermore, the high usage/ administration of oxytetracyclines may be attributed to its broad spectrum mode of action against Gram-positive and Gram-negative bacterial infections as well as for the treatment of canine babesiosis (an endemic blood-borne parasitic animal disease in Nigeria).These were corroborated by clinicians during the IDI who indicated that the high oxytet administration was due to its use in the treatment of blood parasite infections.Data on diseases that informed the type of antimicrobials prescribed for the treatment of companion animal diseases was not collected making this difficult to support why oxytetracycline was most prescribed at the VTH.It is likely the prescription of oxytetracycline could be linked to the treatment of babesiosis, which is the first line of management for the blood parasitic infection at the VTH.Other non-antibiotic therapeutic options for babesiosis exist and are strongly recommended.On the other hand, tetracyclines are used commonly in food animals in developed countries 22 , which could be a reflection of the difference between policies of antimicrobial drug use for food animals and policies for CAs.The quantity of metronidazole used at the VTH was the highest compared with other AMs.Metronidazole (Flagyl®) is an antibacterial and antiprotozoal agent used in the treatment of certain anaerobic bacterial and protozoal infections.This drug has been in use since 1950.It inhibits several diarrheic agents making it many veterinarians' choice for diarrhea in general even for nonspecific diarrhea 9 .But in some cases, it may not be the best prescription based on several studies that have shown metronidazole does not address Giardia infection, inflammatory bowel disease, or acute diarrhea in dogs 28,29 .Current evidence-based research suggests that metronidazole is much less effective for some gastrointestinal conditions than previously thought and could make diarrhea worse by altering the intestinal mucus.It has been linked to causing unhealthy long-term changes in a pet's gut microbiome 30,31 .A recent nonrandomized controlled study showed metronidazole significantly changed the gut microbiome composition, and decreased important beneficial bacteria, such as Fusobacterial (one of the dominant phyla of bacteria in the gut microbiomes of dogs and cats) that did not fully resolve 4 weeks post metronidazole treatment.The study also observed that it reduced overall richness (the number of different Table 6.Classification of Antimicrobial class and active ingredients according to World Health Organization (WHO) critically important antimicrobials in humans, and AWaRE groups (Access, Watch, Reserve).*CIA, critically important antibiotics in human medicine; Access, this group includes antibiotics that have activity against a wide range of commonly encountered susceptible pathogens and show lower resistance potential than antibiotics in the other groups; Watch, group includes antibiotic classes that have higher resistance potential and includes most of the CIA highest priority agents; Reserve, antimicrobial group that should be reserved for treatment of confirmed or suspected infections due to multi-drug-resistant organisms (last resort when all alternatives have failed).Reasons why higher quantities of metronidazole are used compared with other antimicrobials in the hospital and its annex APCs said that the large quantity of metronidazole consumption may be associated with its dosage range, safety, and severity of disease "Metronidazole has a higher dosage range of 10-30 mg/kg compared to Oxytet that has dosage range of 5-10mg/kg" "Severity of the case also influences the clinician's choice to use the higher dose rate of the drug" "Three factors affect the high dose of met-severity of infection, weight of animal, and the drug dosage.If the severity is low, they use low dosage range (10mg/kg) and if severity is high someone will take the higher dosage (30mg/kg).If we have more of them having severe infection, the clinicians will naturally take 30 mg/kg.Also, the frequency of administration of Metronidazole is a factor.It is administered more frequently like bi-daily" Written standard operating guidelines or antimicrobial use policy for CAs in the practice Used to have documents available "We have it in our head.It is not written or documented" "We used to have them documented" Antimicrobial administration and duration APCs indicated antimicrobials are used according to the manufacturer's guideline "Usually 5-7 days " Clients' compliance to antimicrobial therapy plan for their pets?
Clinicians indicate that they follow up with clients to ensure compliance with antimicrobial therapy plans for their pets  31 .Alternative options to metronidazole and a more cautious approach to prescribing this antimicrobial to dogs are now being recommended 31 .Alternative approaches to metronidazole recommended in dogs and cats may include Rifaximin, a synthetic drug, that is as efficient as metronidazole in treating gastroenteritis,the use of probiotics; and natural options such as Diagel 32 .
The frequent routes of antimicrobial administration at the VTH were the intravenous (IV) and intramuscular (IM) site (especially for oxytetracyclines and enrofloxacin), and less oral (tetracycline, metronidazole, and amoxicillin) or intraocular (ciprofloxacin) However, this contradicts findings from other studies conducted in the United Kingdom 33 , Denmark 25 , and other European countries such as Finland 34 , Norway 35 , Sweden 36 , Italy 20 and the Netherlands 37 , which have shown oral route of AMs administrations prevailed over those for parenteral in dogs and cats.Drug administration via the oral route may be common and more attractive because How about making antimicrobial sensitivity testing mandatory?
The clinicians perceive this will be difficult due to limited funding for such procedures and on the part of the clients who may not be ready to pay for such services.Also, the overuse and abuse of antimicrobials by non-vets make AST very unhelpful especially where resistance (100%) to all antimicrobials is reported "That will be a little bit difficult because of funds.Then this means the clients have to pay anytime we do that.So, if we have to do AST for every patient, some of these clients themselves even abuse these drugs so even if we have to do AST, it may not really help us" "Yes, AST will help us know that okay certain drugs have been abused by the client but some AST that has been done, we have had results where we've seen resistance all through.When we have resistance all through, and the dog is coming to us for the first time, we know that either quacks have been treating or they have been treating themselves.Where do you start from when all antibiotics are highly resistant?""We may not be able to enforce par say but as much as possible we can encourage our clients.So that the learned ones, we can start with them and tell them about the need for AST.We could create awareness on AMR" www.nature.com/scientificreports/ it is non-invasive, painless, easy to perform though an essential skill requirement for all veterinarians, and well tolerated by patients 38 .Also, variation in antimicrobial protocol or policies across countries, or veterinary practices may contribute to this route being preferred.On the other hand, the efficacy, ease, and frequency of administration may support the use of IV oxytetracycline at the VTH in most cases.Furthermore, oral oxytetracycline is administered 3 times daily for 5-7 days in capsules and not all pet owners have the skill to administer oral medications.However, the success rate over the years has been good with IV oxytet based on clinicians' experiences at the VTH.
For the prescription diversity (PD) finding, our study described higher PD values for dogs than cats.Current research conducted in Germany 17 also corroborated our report, whichdocumented a significant increase in PD for AMs in dogs compared with cats.The PDs estimated were lower than those reported by Schnepf et al. 17 and may be attributed to the frequency of dog and cat visits and the antimicrobial prescription protocols of the various veterinary care facilities.
For the critically important antimicrobials, drugs with the highest priority such as quinolones (e.g.enrofloxacin) were the most prescribed and the least being the macrolides (azithromycin).Ampicillin, which belongs to the CIA high priority was most administered.No drugs under the reserve group (last resort antimicrobials when all alternatives have failed) are used in CAs at the VTH unlike in the developed countries where fluoroquinolones and cephalosporins are mostly prescribed to treat infections 17,20,39,40 .
The researched veterinary care is a multispecialty university teaching hospital in Nigeria, and the present study was a small-scale project describing antibiotic use based on data extracted from the clinical or prescribing records.Though the study addressed AMU in companion animals for a period of three years, the study results may not be representative or generalizable to the other veterinary hospitals and clinics in the country.However, the work has created the first picture of qualitative and quantitative indices of antibiotic use in Nigerian CAs.Also, the study has generated data that could serve as a baseline for AMU negotiations, and the development of guidelines and strategies to promote antimicrobial stewardship in CAs in Nigeria.Another limitation is that it omitted critical information on pet diseases and microbiological laboratory tests performed, which made it difficult to link the motives for antimicrobial choice by clinicians.Further work may be needed to expand the period of evaluation of AMU retrospectively, describe common companion animal diseases, and the rationale for antimicrobial therapy in Nigeria.
In light of our result, the qualitative and quantitative assessments of antimicrobial usage in CAs showed that the most frequently used antimicrobial was oxytetracycline, while metronidazole had the highest administered amount.There was diversity in the prescription pattern of AMs especially in dogs.However, this may not be representative of the larger population of veterinary practices in the country.Hence, justifying the need for a broader national-based study to assess AMU in CAs in Nigeria.It is crucial to develop programmes or frameworks for the effective monitoring of antimicrobial prescriptions and usage/resistance in CAs in the country, and a national reporting system for veterinary practitioners which may contain detailed information, such as animal species, the reason for prescription, and dosage on each prescription.Also, there is the need to join efforts to control AMR development and focus on performing proper diagnosis, increasing the use of standardized microbiological laboratory tests to support diagnosis and appropriate treatment, developing antimicrobial protocol and infection control, creating awareness of AMU and AMR among stakeholders, and promoting staff training on antimicrobial stewardship within veterinary care facilities in Nigeria. https://doi.org/10.1038/s41598-023-44485-wwww.nature.com/scientificreports/

Figure 1 .
Figure 1.The various antimicrobial active ingredients and routes of administration for dogs and cats at the (A).VTH-A and (B).VTH-B, from 2019 to 2021.IV, Intravenous; IM, intramuscular; PO, Oral or Per Os; IO, intraocular and TP, topical.

Figure 2 .
Figure 2. The mean number of antimicrobial administrations from 2019 to 2021 for (A) VTH-A and (B) VTH-B.Error bars are SEM of data sets for three years.

Figure 3 .
Figure 3.The mean quantity of antimicrobial ingredients administered at (A) VTH-A, and (B) VTH-B.Error bars are SEM of data sets for three years.

Figure 4 .
Figure 4. Proportion of documented antimicrobial drug administrations at the Veterinary Teaching Hospital and its annex from 2019 to 2021 and classification according to the WHO critically important antimicrobials (CIA) and AWaRe (Access, Watch, and Reserve). 19 . Ethical Approval (Reference number FUNAAB/COLVET/CREC/2021/10/01) was obtained from the College of Veterinary Medicine Research Ethics (CREC), Federal University of Agriculture Abeokuta, Ogun State Nigeria.

Table 2 .
Number of antimicrobial active ingredients administered in dogs and cats in 2019, 2020, and 2021documented at the VTH-A.Bold-Summary of drug administration per antimicrobial group, the corresponding active ingredients are indicated below.0 observed zero i.e. not administered during the period of study.

Table 3 .
Number of antimicrobial active ingredients administered in dogs and cats in 2019, 2020, and 2021 documented at VTH-B.Bold-Summary of drug administration per antimicrobial group, the corresponding active ingredients are indicated below.0 observed zero i.e. not administered during the period of study.

Table 4 .
Documented amount of antimicrobial active ingredients used in dogs and cats in 2019, 2020, and 2021 at the Veterinary Teaching Hospital-A.Significant values are in [bold].

Table 5 .
Documented amount of antimicrobial active ingredients used in dogs and cats in 2019, 2020, and 2021 at the annex, VTH-B.Significant values are in [bold].

Antimicrobial group Active ingredient WHO classification (Critically important in Humans) Access Watch Reserve
Theme 1: Perceptions about antimicrobial use practices, prescribing, abuse, and challenges Drivers of choice of the antimicrobials used in the VTH APCs reported that the choice of antimicrobials is fundamentally determined by the case presentation, formal knowledge and experiences, clients' willingness to comply with the prescribed antibiotic therapy regimen, availability of the drug and cost, and laboratory results where available "Antimicrobial choice is dependent on the nature of the case.Different cases have different protocols to follow in handling the cases.Drug availability and cost, availability of the clients to persist in presenting their pets to complete antibiotic therapy regime, temperament of the patient are also factors" "The clinical signs, those are the evidence before me, and lab results, if available from the labs.If I strongly feel that I should use a particular antibiotic, then I use it.Then the availability of the drug and the client may likely be influenced.So if we do not have a particular drug then we may need to switch to another drug.We work based on clinical signs, severity of infection, and laboratory diagnosis.The years of experience and the knowledge of the use of the drug also determines our decision on what antibiotics to use" I would love to say that Berenil is actually the first drug of choice for babesiosis on paper.It is not as if it is not effective, it is excellent but it causes liver toxicity.There are sometimes that it causes cerebral involvement.That is why we don't want to go there.It has a very thin, I mean low margin of safety whereas oxy has a very wide margin of safety.So we would rather take the one with a wide margin of safety than take the one that has low margin of safety and we have more mortalities.Not everybody is familiar with the use of Berenil" Vol:.(1234567890) Scientific Reports | (2023) 13:18195 | https://doi.org/10.1038/s41598-023-44485-wwww.nature.com/scientificreports/"I and another researcher had a paper on diminazene toxicity in dogs, and this is what opened our eyes to see that we can't keep on using Berenil, we have to check other safer options.So that is why I said actually in book, Berenil is the drug of choice but in practice, it is not" "In my own opinion, oxytetracyclines have been working not only for babesiosis but for other blood parasites.We have also used doxy especially when it's in a combination of babesiosis and ehrlichiosis" We do follow-up few times by phones.We usually start all over again if clients break the therapy and then follow up to ensure compliance"

Table 7 .
Responses and summary of the In-depth Interview (IDI) held among clinicians at the VTH and Its annex.