The purpose of the present study was to present the results from a retrospective study on the preva-lence of ear diseases among 5870 dogs referred for examination and treatment at the Small Animal Clinic at the Faculty of Veterinary Medicine, Stara Zagora, Bulgaria from January 1, 2010 to Decem-ber 31, 2014. According to the results, ear diseases were significantly less prevalent in dogs aged up to 1 year (P=0.0012) and between 9–12 years (P=0.0019), but predominated in male dogs (P=0.0206). Ear diseases were more frequently observed in Cocker Spaniels (20.77%; P<0.0001), Bulgarian Shepherd dogs (17.91%; P<0.0001), Shar Pei (15.58%; P<0.0001), Kangals (11.76%; P=0.0240), Dogo Argentino (10.81%; P=0.0351) and French Bulldogs (9.35%; P=0.0041). Dogs from breeds with pendulous ears were more commonly affected. The diseases were more frequently unilateral (63.94%; P<0.0001), with clear effect of the season and higher prevalence during the summer (38.29%). Among all ear diseases, inflammations were the predominating pathology (67.90%).

The aim of the study was to investigate the changes in some rapid, indicative clinical laboratory parameters – white blood cells (WBC), leukogram, erythrocyte sedimentation rate (ESR), total protein (TP), albumin (A), globulins (G), albumin/globulin ratio (A/G) during experimental Pseudomonas aeruginosa skin infection in dogs and to determine their ability to provide information for evaluating such type of infection. Suspension of P.aeruginosa (1×10 cfu/mL) was inoculated at a dose 0.3 mL/kg body weight, in five clinically healthy, dogs, 2–5 years old, weighing 24.3 ± 1.8 kg. The control group (n=5) was injected with the same dose of normal saline. The blood samples were taken in the following dynamics: before infection (0 h) and on 4, 24, 48, 72 hour and on 7, 10 and 14 day after infection. The data presented clearly suggest that ESR was the most sensitive haematological parameter increasing significantly 4 hours after infection (P<0.01), with values remaining high (P<0.001) till the end of experimental period (day 14). WBC increased significantly on hour 72 (P<0.001). The changes in the leukogram demonstrated increase in band neutrophils on hour 48 and 72 (P<0.01), which is indicative for left shift. Eosinopenia was found on hour 24 and 72 (P<0.01). Analysis of biochemical parameters demonstrated that the period within 24 to 72 hour was crucial in progress of P. aeruginosa skin infection. This statement is supported by the significant decrease of albumin concentration (P<0.001), decrease in A/G ratio and hyperglobulinaemia (P<0.001) within this period. These alterations in protein profile did not affect total protein concentration, which remained unchanged during the whole experimental period. The matched analysis of both haematological and biochemical parameters is more accurate and indicative for the progression of bacterial skin infections in dogs. Albumin and globulins concentrations and A/G ratio are sensitive, consistent and reliable parameters, which can be useful for evaluating skin P. aeruginosa infection in dogs.

Summary Dimitrova, D., I. Borissov, Ts. Chaprazov, T. Georgieva, S. Yanev & B. Pandova, 2011. Pharmacokinetics of enrofloxacin in dogs with experimental staphylococcal infection. Bulg. J. Vet. Med. , 14, No 3, 158 −164. The study investigated the effect of experimental Staphylococcus aureus bacterial infection on enro> floxacin pharmacokinetics in dogs. After infection, serum blood enrofloxacin concentrations and the values of AUC 0→∞, C max , Tmax and t 1/2abs were higher. Other pharmacokinetic parameters (t 1/2 β, MRT) exhibited an insignificant decrease. The infection resulted in lower serum concentrations of ciproflo> xacin, the main metabolite of enrofloxacin. Statistically significantly lower biological half>life, lo wer AUC 0→∞, T max , C max and MR were also observed.

The aim of our study was to evaluate nonspecific defense mechanisms (phagocytosis and acute phase response) in dogs during an experimental infection caused by subcutaneous application of Staphylococcus aureus (1x108 CFU/mL). The neutrophils phagocytosis (evaluated by fluorescein isothiocyanate labeled Staphylococcus aureus) is activated at 48 h and the phagocytic number remained high at the 72-nd h of infection. During the early stage of the infection process (between the 2-nd and 24-th h) the absolute segmented neutrophil count, the absolute band count, band-neutrophyl ratio, tend to have high sensitivity, whereas an abnormal leukocyte count is registered at 48 h. Fibrinogen increase is registered the earliest (at 24-th h). Its concentrations remain high till the end of the study. The changes in the blood protein profiles show that the ?2-globulin fraction rises at the 48-th and 72-nd h. Albumin was significantly lower at 72 h compared to the baseline values. There are no statistically significant changes in the total protein, A/G ratio and sialic acid, which we determined. The obtained data about the red blood cell parameters shows that Staphylococcus aureus induces a moderate anaemia when applied in dogs. Deviations are also registered in the mean corpuscular hemoglobin, while the other red blood cell indices - mean corpuscular hemoglobin concentration and mean corpuscular volume, are within normal reference ranges. We conclude that it is always better to combine immunological, hematological and biochemical indices. The key is to choose tests that are frequently used and to ensure more rapid information about the infectious process.

А histopathological analysis of 430 specimens of canine skin tumours obtained in the period 2000– 2010, was performed at the Department of General and Clinical Pathology, Faculty of Veterinary Medicine, Trakia University, Bulgaria. The tumours were classified according to the last World Health Organization classification. The incidence of benign and malignant neoplasms was 48.14% and 51.86% respectively. Among the total number of skin tumours, 250 cutaneous growths were diagnosed as epithelial and melanocytic tumours and another 78 – as mesenchymal skin and soft tissue tumours. The most frequently diagnosed tumours from the skin epithelial and melanocytic group were hepatoid gland adenoma (9.3 %), squamous cell carcinoma (8.6 %), hepatoid gland carcinoma (5.34 %) and basalioma (5.11 %). The most frequently diagnosed canine mesenchymal skin and soft tissue tumours were lipoma (5.58 %), fibrosarcoma (4.41 %), haemangiopericytoma (2.32 %) and haemangioma (2.09 %).

Summary Rusenov, A., Y. Nikolov, R. Simeonov, T. Chaprazov, I. Todorova & I. Borissov, 2009. A case of fibrous osteodystrophy in a dog with secondary renal hyperparathyroidism. Bulg. J. Vet. Med., 12, No 3, 212−218. A clinical case of fibrous osteodystrophy in a dog with secondary renal hyperparathyroidism is described. Considerable deviations in blood biochemistry, radiological, ultrasonographic and ECG findings, as well as in histological examination of kidneys were observed. All these changes are considered as relevant and in our view, could be utilized for the proper diagnostics of this pathological state.

Summary Chaprazov, Ts. & I. Borissov, 2009. Time course of blood C-reactive protein and fibrinogen concentrations after experimental Pseudomonas infection in dogs. Bulg. J. Vet. Med., 12, No 4, 240−245. An experimental infection was produced in six mongrel dogs from both genders, at the age of 6–7 years, weighing 16±2 kg, by intravenous injection of 24-hour broth culture of Pseudomonas aeruginosa containing 1.2×10 9 CFU/mL. Another six untreated dogs served as controls. Blood Creactive protein (CRP) was assayed between baseline (hour 0) and post infection hour 24, whereas blood fibrinogen levels were determined between baseline and the 28 th day after infection. It was found out that blood CRP concentrations were statistically significantly higher by the 4 th hour of infection vs baseline (P<0.01), and at hours 6 and 24 vs controls as well (P<0.001). Fibrinogen alterations consisted in increased levels by hour 24 (4.25±0.23 g/L) vs baseline concentrations of 2.73±0.27 (P<0.01) of treated and 2.17±0.55 g/L in control dogs.

Summary

Staphylococcus aureus is the leading pathogenic cause of nosocomial infections, especially in bacteriaemia and sepsis. Phagocytosis is known to be an essential factor of innate immunity. The aim of this study was to evaluate phagocytic activity of leucocytes in experimental bacteriaemia. Bacteriaemia was induced in six adult male mongrel dogs (experimental group) by intravenous injection of Staphylococcus aureus isolate (1.2x109 cells/ml). Phagocytic activity was evaluated before infection (0 h.), and on the 2nd, 6th, 24th, 48th hour, and on the 7th, 14th and 21st day after infection. Six control animals were tested in the same dynamics. Phagocytic activity was evaluated by using the Nitrotetrazolium blue reduction (NBT) test, and the immune fluorescence method (Samnaliev et al., 1995) for detection of phagocytic index and percentage of phagocyting leucocytes (FITC marked Staphylococcus aureus were used). Percentage of phagocyting leucocytes showed an increase in experimental animals, compared to control animals, on the 24th h. Production of reactive oxygen species, evaluated by NBT, showed changes within experimental group as follows: an increase on the 24th h. compared to the 2nd h., 6th h., and the 14th day after infection; and an increase on 48th h., compared to the 2nd h. and 14th day. Comparison of reactive oxygen species production between groups, revealed an increase in the experimental group, as compared to the control group, on the 24th h. and on the 48th h.

The retrospective histopathological study of 468 samples of tumour material obtained from dogs, referred to the Faculty of Veterinary Medicine, Trakia University, Stara Zagora during the period 1991-2000 showed that 29 specimens (6.19%) were epulides. According to their histogenesis, the lesions were classified in two primary groups: reactive lesions – 37.94% and peripheral odontogenic tumours – 62.06%. Epulides were most commonly encountered in males (68.96%) compared to females (31.04%). The average age of affected dogs was 4 years for both genders. In 18 cases (62.06%), the lesions were mandibular whereas in 11 (37.94%) – maxillar. The highest predilection to epulides was observed in German Shepherds – 27.58%.

Microbiological and laboratory studies have been performed in 2-3 month old piglets weighing 15-18 kg with clinically manifested arthritis. Seven healthy animals, housed and fed uniformly, have been used as controls. Twenty eight synovial punctate specimens were microbiologically studied and 11 strains (8 Staphylococcus hyicus and 3 Streptococcus suis) were isolated. The sensitivity of isolates towards antimicrobial drugs was evaluated via he disk diffusion methods of Bauer-Kirby. Laboratory studies, both haematological and biochemical (erythrocytes, haemoglobin, haematocrit, leukocytes, total protein, sialic acid, fibrinogen) showed statistically significant decrease in leucocyte counts and total protein concentrations. A tendency towards elevation in sialic acid and fibrinogen was observed. The data suggested the development of infectious staphylococcal arthritis.

The changes in some factors of the innate immunity (phagocytosis, complement, lysozyme); haematological parameters-leukocytes, erythrocytes, differential white blood cell counts, haemoglobin, haematocrit and the serum concentrations of the microelements zinc and iron in six 2- to 3-months-old female piglets after the intravenous administration of lipopolysaccharide from Escherichia coli 0111:B4 were determined. It was found out that 1 h after the administration of lipopolysaccharide at the dosage rate of 10 microg/kg body weight resulted in a decrease in the phagocytic parameters, i.e. the phagocytic number and the index of phagocytic activity, which was followed by an increase in their values between post treatment hours 2 and 4. The leukocyte counts had decreased by hour 2 after the injection, but thereafter increased, and at post treatment hour 72, a leukocytosis was observed. The differential white blood cell counts were characterized by a shift to the left between hours 2 and 4 and a statistically significant increase in lymphocyte counts at hour 48 of the experiment. The serum zinc concentrations were increased an hour after the lipopolysaccharide application; after which their average values were lower. The haemolytic activities (CH50) of the classical and the alternative pathways of complement activation decreased. The haemolytic activity (CH50) for the classical pathway began to increase at hour 48 following the treatment. Significant changes were not observed in lysozyme activity, serum iron concentrations or the related haematological parameters (erythrocytes and haemoglobin).

During the last few years a significant increase in the number of dogs with traumatic dental problems has been observed, particularly those with fractured canine teeth. In the period 1994-1998, 12 dogs of different breeds (German Shepherd, Dobermann, Pit Bull and Bull Terrier) were referred with complete fractures of a total of 34 canine teeth. After endodontic treatment, preparation of teeth and taking of dental imprints according to routine methods, the fractured teeth were reconstructed using moulded metal crowns and parapulpar pins. The length of the latter was 16-22 mm according to the depth of the pulpa channel. The metal crowns were fixed to the remaining tooth with chemopolymers. All reconstructed teeth were observed for 36 months. Complications occurred only in 2 teeth (new fractures and removal of crown). The method of reconstruction of fractured teeth with moulded metal crowns and pulpar pins is relatively easy to perform and can be done in two stages. Efficacy was about 96% and is found to be practical for application in veterinary dental practice in Bulgaria.

SUMMARY In six female piglets aged 2-3 months weighing 28 ± 3 kg, an experimental infection has been provoked via the intravenous application of Escherichia coli 0111:B4 lipopolysaccharide (LPS) at a dose of 10 ∝g/kg b.w. The changes in clinical and laboratory parameters were followed out up to hour 72 following the treatment. It was determined that the first clinical signs, manifested with hyperthermia, anorexia and decreased activity appeared as early as 40 min after the LPS application. The infection was characterized with an initial leukopenia, followed by leukocytosis. The most prominent biochemical changes were expressed in hyperproteinemia, disproteinemia, increased serum sialic acid and urea levels and increased serum alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) activities.

A clinical case of mandibular canine tooth retention and secondary fibrous epulis in a dog was described. Clinical, paraclinical and radiological studies, as well as rostral mandibulectomy, were performed. The histological study of gingival and bone tissue cross-sections of the affected mandibular part revealed dystrophic, necrotic, inflammatory and reparatory-compensatory changes, characteristic of that type of lesion. The performance of mandibulectomy was found to be justified in cases of permanent and irreversible changes In both solid and soft peridental tissues, accompanied by destructive changes in the mandible in young and valuable animals.