Veterinary Research Forum

Abstract Biofilm formation is a key virulence factor in Staphylococcus aureus, contributing to bacterial persistence, antimicrobial resistance, and chronic infections. This study aimed to investigate the presence of biofilm-associated genes (fib, fnbA, fnbB, clfA, and clfB) in S. aureus isolates from dogs in Ilam, Iran. From December 2022 to September 2023, 250 swab samples were collected from nasal, oral, and rectal sites of dogs, yielding 81 S. aureus isolates confirmed by PCR amplification of the nuc gene. The prevalence of biofilm-associated genes varied, with clfA, clfB, and fnbA detected in 98.80% of isolates, fib in 63.00%, and fnbB in 16.00%. Notably, fnbA, clfA, and clfB were present in all rectal isolates, while fnbB was absent in this group. The findings highlighted the widespread presence of biofilm-related genes in S. aureus from dogs, suggesting their potential role in colonization and zoonotic transmission. The high prevalence of adhesion-associated genes underscored the need for monitoring biofilm-forming S. aureus in companion animals to mitigate antimicrobial resistance and public health risks.

Abstract Cranial cruciate ligament rupture is one of the most common causes of osteoarthritis in dogs. Surgical stabilization is obligatory and tibial plateau levelling osteotomy (TPLO) is the most commonly used surgical technique. Studies on the long-term monitoring of matrix metallo-proteinases (MMPs) and acute-phase proteins are limited, especially those with parallel monitoring of changes in the serum, synovial fluid (SF) and urine. We aimed to describe long-term changes in 1) MMPs: gelatinases and caseinases, 2) APPs: ceruloplasmin, haptoglobin and paraoxonase-1, and 3) the correlation of MMPs in the serum, SF and urine with lameness in dogs 2 and 6 months undergoing TPLO. From 17 dogs diagnosed with cranial cruciate ligament rupture, sera, SF and urine samples were collected preoperative 2 and 6 months after the surgery. Relative activity (RA) of MMPs was measured in all samples using zymography. Acute-phase proteins were measured in the serum and SF using spectrophotometry and agarose gel electrophoresis. Relative activity of MMPs in serum was not change at different sampling points. In SF, a marked decrease in MMPs RA was evident, however, only RA of caseinases was significantly reduced during the recovery period. In urine, RA of caseinases was positively correlated with the lameness score with decreasing activity trend during time. Serum and synovial acute-phase proteins were not changed after surgery, which was consistent with the agarose gel analyses. Decreased activity of caseinases pointed to reduced degradation of extracellular matrix after TPLO. Synovial and urine caseinases are potential biomarkers in predicting the recovery outcome following stifle stabilization.

Abstract Cardiovascular and respiratory alterations during anesthesia are of major concern in canines. Thus, it is essential to understand the potential depressant effects of anesthetic drugs on cardio-vascular system; so that, anesthetic procedures are conducted in the best possible way. The objective of the study was to assess and compare the echocardiographic indices during dex-medetomidine and midazolam anesthesia in dogs undergoing elective ovariohysterectomy. Twenty-eight female dogs brought to the department for elective ovariohysterectomy were randomly divided into two groups comprising of 14 each. Sedation was achieved with dex-medetomidine and G_MID. Physiological parameters and echocardiographic indices were evaluated before drug administration (T₀), after 10 min of sedation (T₁), after induction (T₂) and at the end of surgery (T₃) in both groups. Heart rate was significantly higher at T₁, T₂ and T₃; while, rectal temperature was significantly lower at T₃ in G_MID compared to the G_DEX. There was a significant decrease in stroke volume and cardiac output values at T₁ and then, a significant increase at T₂; whereas, there was a non-significant decrease at T₃ in both groups. Ejection fraction and fractional shortening values decreased significantly at T₁, increased significantly at T₂ and then, decreased significantly at the end of surgery (T₃). Dexmedetomidine-ketamine and midazolam-ketamine combinations provide better hemodynamic and respiratory stability in the dogs undergoing elective ovariohysterectomy. Systolic functions were minimally altered with G_MID compared to G_DEX. Thus, G_MID is more cardio stable compared to G_DEX.

Abstract Melanocytoma and malignant melanoma are the most typical eye tumors in dogs and cats. Due to the presence of melanin, the general appearance is often highly pigmented in a nodular formation with well-defined borders. Electrochemotherapy (ECT) is a therapy combining reversible electroporation and anti-neoplastic drugs to enhance their cytotoxic effects through increasing cellular uptake by the electroporated tumor cells. In this article, the use of adjuvant ECT for the treatment of canine ocular melanoma is reported. The pre-surgical exams (blood count, renal and liver functions, echocardiogram, and electrocardiogram) were within the normal range, as were the chest radiography and abdominal ultrasound without signs of metastases. On the day of the surgery, an excisional biopsy of the tumor was performed without safety margins by keratectomy associated with conjunctivectomy and adjuvant ECT in the surgical site and peri-tumoral region. The animal was followed for approximately 7 months and remained without evidence of tumor recurrence. A complete resolution of corneal opacification was also observed. To our knowledge, this is the first report of the use of ECT in an ocular neoplasm. From a comparative oncology perspective, this report opens the way for future therapeutic approaches in superficial ocular cancers in veterinary and human medicine.

Abstract In a prospective, randomized, experimental non-blinded study, the continuous infusions rates of propofol required to prevent swallowing (P-SR) or pedal withdrawal reflex (P-WR) were evaluated in healthy premedicated dogs. Dogs were randomly assigned to one of two treatments at weekly intervals. Following premedication with a combination of acepromazine and methadone, anesthesia was induced with propofol (4.00 mg kg^-1 per min) and was maintained for 90 min. The propofol infusion rate was increased or decreased by 0.05 mg kg^-1 per min based on positive or negative swallowing (P-SR) or pedal withdrawal reflexes (P-WR). Propofol induction doses were 2.12 ± 0.43 mg kg^-1 (P-SR) and 2.14 ± 0.31 mg kg^-1 (P-WR), which were not significantly different. The mean (±SD) propofol infusion rate was significantly higher for P-WR (0.26 ± 0.10 mg kg^-1 per min) when compared to P-SR (0.22 ± 0.12 mg kg^-1 per min). During the last 30 min, the mean propofol infusion rates were 0.09 ± 0.02 and 0.18 ± 0.03 mg kg^-1 per min for P-SR and P-WR, respectively. There were no significant differences between treatments with respect to heart rate (HR), respiratory rate, arterial blood pressure, end-tidal CO₂ partial pressure, hemoglobin oxygen saturation, partial pressures of oxygen or pH. Transient apnea lasting up to three minutes was observed in three dogs with each treatment. Propofol infusion rate of 0.22 ± 0.12 mg kg^-1 per min can be used in premedicated dogs requiring tracheal intubation and undergoing mechanical ventilation, non-painful procedures or painful procedures with local anesthetic techniques.

Abstract Genus Brachyspira,as Gram negative anaerobic bacteria, colonize in dogs intestine. The aim of the current study was to determine the prevalence of Brachyspira spp. for the first time in Iran and rapid identification of Brachyspira spp. in dogs by a new designment of a species-specific primer set for B. canis. One hundred fifty-one fecal samples were obtained from dogs by rectal swab. Twenty dogs suffered from diarrhea and 131 of them were healthy. In 9.27% (14/151) of samples, spirochaetes were detected on primary cultures by weak hemolysis and positive Gram staining and then Brachyspira genus was confirmed by NADH oxidase (nox) gene via polymerase chain reaction. Among 14 isolates, twelve isolates were B. canis, one isolate was B. intermedia and another one was non-typeable. From 12 B. canis, only eight isolates were detected by designed specific primers. Ten Brachyspira spp. were isolated from dogs ≤ 1 year old (10/67, 14.92%) and 4 isolates were from > 1 year old dogs (4/84, 4.76%). The isolation rates from healthy and diarrheic dogs were (12/131, 9.16%) and (2/20, 10.00%), respectively. A statistically significant association was observed between the presence of Brachyspira spp. and the age under one year. Based on our findings, the nox gene in B. canis might have more sequence variability compared to other Brachyspira spp.