The anticoagulant rodenticides are the most commonly used toxicants to control rodents nowadays. Therefore, developing resistance to them is an issue of great importance for pest control. The aim of this study was to investigate the sensitivity of synanthropic rodents in the Stara Zagora region, Bulgaria to some of the most significant first (warfarin and coumatetralyl) and second (bromadiolone and brodifacoum) generation anticoagulants. Resistance tests were carried out by a standard protocol using lethal feeding period tests and blood clotting response tests according to the European and Mediterranean Plant Protection Organization (Paris, France) standard. Studies were performed on 278 wild synanthropic rodents -67 house mice (Mus musculus), 153 roof rats (Rattus rattus) and 58 brown rats (Rattus norvegicus). The rodents belonged to 11 populations inhabiting 9 animal farms in the region of Stara Zagora, Southern Bulgaria. High-level resistance to warfarinwas established in 100% of surveyed house mice and 92.1% of roof rats. Resistance to coumatetralyl was registered in 62.5% of the tested roof rats. Low-level resistance to bromadiolone was found in 38.5% of the surveyed roof rats and 23.1% of house mice. There was no resistance registered in brown rats. The sensitivity of all three rodent species to the strategic anticoagulant brodifacoum was high, and there were no signs of resistance. The results proved the resistance among synanthropic rodents and led to the conclusion that the resistance in house mice and roof rats to warfarin and coumatetralyl tends to be the main issue in pest control.

A case of co-infection due to Demodex cati and feline immunodeficiency virus in a cat is described. A 5 year-old neutered male cat was presented to the Small Animal Clinic at the Faculty of Veterinary Medicine, Trakia University with lethargy, diarrhoea, pyrexia, anorexia, adipsia, skin lesions, intense itching and alopecia. Parasitological, mycological and serological examinations were carried out. Adult D. cati mites and antibodies against FIV were detected. A proper therapy with an endectocide, antibiotic and antihistamine drug was prescribed. The improvement of the general condition was observed after a month of treatment. Later, the disease recurred twice and the animal was humanely euthanased for medical reasons and at the owner’s request.

The aim of the present study was to compare the prevalence of microbial agents involved in canine otitis externa and their sensitivity to antibacterial drugs in two periods: 2007–2011 and 2013–2017. For 2013–2017, coagulase-positive staphylococci were the dominating bacterial species (186 isolates), followed by Pseudomonas aeruginosa (82 strains). The rate of isolated yeasts (mainly Malassezia pachydermatis) was substantially high (152 isolates). Compared to the earlier period (2007–2011) a tendency to more frequent occurrence of co-infections was noted – 61.7% and more than 80% of co-infections involved yeasts. Antibacterial resistance patterns showed a clear trend to increased resistance of coagulase-positive staphylococci and β-haemolytic streptococci to amoxicillin/clavulanic acid (42% and 50% respectively) and gentamicin (29%, 40%). Increased resistance of P. aeruginosa was established to gentamicin (16%) and amikacin (18%). The prevalence of pseudomonads resistant to enrofloxacin was lower (27%).

During the last years, the significance of diseases associated etiologically to Shiga-toxin producing Escherichia coli (STEC) is continuously increasing at a global scale, while the O157 serotype is considered as one of the most important pathogens of animal origin. Large ruminants play a key role in the epidemiology of E. coli diseases among men. Bovine faeces are a primary source of contamination of the environment and foods with this agent. The purpose of this study was to test a specific, microbiological algorithm for primary identification of STEC isolates from bovine faeces using sorbitol McConkey agar supplemented with cefixime and tellurite. The attempts were focused not only on increasing the sensitivity and specificity of serotype identification, but also on optimisation of labour and analysis costs. From May 2013 to October 2014, a total number of 1104 faecal swab samples from calves 3 to 6 months of age were collected from 19 farms in different administrative and geographical regions of Bulgaria. Thirty six sorbitol-negative E. coli isolates (3.26%) were detected as belonging to the O157 serotype after slide agglutination test.

The hatcheries may become contaminated with pathogenic bacteria which could spread in the hatchery through the air. That is why the implementation of an effective cleaning and disinfection program and the maintenance of good hygiene are extremely important for the normal course of production and for reducing the spread of infectious agents. In this study, data on the degree and dynamics of bacterial contamination in a poultry hatchery are presented. In the incubation sector, bacterial contamination on the surfaces was found to be low-level ranging from 0.25 to 4.43x101 CFU/ cm2 but in the air it was strongly influenced by the hatching. In the hatchery sector, bacterial contamination on the surface and in the air was high, with the highest values found on the egg shells (1.77x106 CFU/cm2), on the floor (3.2x104 CFU/cm2) and in the air (1.77x105 CFU/cm3) of hatcher cabinets during hatching. The results obtained show that the most important source of microbial contamination in the hatchery is the hatchery sector, especially during hatching, when highly contaminated materials as fluff, shells and dried secretions are released. In case of poor organization of working process, the bacteria could spread by air and contaminate the other sectors of the hatchery. The study confirms the importance of a different approach in the development of preventive measures, depending on the degree of risk in different zones in the hatchery, which is the basis for the effective management practice aimed at decreasing microbiological hazards in hatcheries.

A clinical case of co-infection with Trichophyton menthagrophytes and Microsporum canis in a Siberian tiger (Panthera tigris altaicа) is described. Clinical and laboratory mycological examinations were carried out. Two dermatophytic species were isolated from hairs, crusts and swab samples from different parts of the cage. A systemic oral therapy with itraconazole (Sporanox, Janssen) at a dose of 10 mg/kg with food was initiated and body surface was treated with 0.2% enilconazole solution (Imaverol, Janssen). The skin lesions of the tiger healed after the treatments, but recurred a month later. We recommended a thourough disinfection of the cage area inhabited by tigers and inventory in it. The therapeutic protocol was repeated. Clinical signs disappeared. Information about disease recurrence was obtained.

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Deratisation is one of the basic anti-epidemic measures, directed to protect the health of humans and animals. Nowadays, anticoagulants are still the most commonly used rodenticides. In recent years, the problem of development of resistant synanthropic rodents to these agents is becoming more serious. This is the reason for increasing interest in discovering alternative methods for controlling the resistant populations. It is known that some non-steroidal anti-inflammatory drugs (NSAIDs) act as synergists and significantly increase the toxicity of anticoagulant rodenticides, but convincing information on their effectiveness in anticoagulant-resistant rodents is still missing. The aim of the present research is to contribute to solve this problem, by studying the effectiveness of 0.025% indomethacin baits, administered alone and combined with warfarin, in warfarin-resistant wild synanthropic rodents. In the conducted laboratory food tests 36 roof rats (Rattus rattus) and 60 house mice (Mus musculus) were included. A very high toxicity of indomethacin baits in resistant rodents, leading up to 100% mortality, occurring between 24 to 48 hours post acceptance were found. NSAIDs mechanism of action, clinical signs and pathological findings in the intoxicated rodents are discussed. Based on the laboratory conducted tests and scientific data analysis, we conclude that 0.025% indomethacin baits have high effectiveness in anticoagulant-resistant synanthropic rodents and could be used as an alternative method for control of resistant populations.