There are growing concerns regarding the rise of antimicrobial-resistant bacteria in companion animals. This study aimed to bring new insights into the current scenario of Portugal’s antimicrobial resistance bacteria isolated from companion animals with urinary tract infections and is the first to be performed during a long period on a large scale. Of a total of 17472 urine samples analyzed, 12,166 (69.6%) (CI 12,200–12,200) were negative for bacterial growth, and 5306 (30.4%) (95% CI 5310–5310) had bacterial growth. Of the culture-positive samples, 5224 (96.6%) (95% CI 5220–5220) were pure cultures and 82 (3.2%) (95% CI 81.9–82.1) had mixed growth. Escherichia coli was the most frequently isolated bacteria (n = 2360, 44.5%) (95% CI 2360–2360), followed by Proteus mirabilis (n = 585, 11%) (95% CI 583–583), Enterococcus faecium (n = 277, 5.2%) (95% CI 277–277) and Staphylococcus pseudintermedius (n = 226, 4.3%) (95% CI 226–226). The overall susceptibility rates were low for erythromycin (45.3%) and clindamycin (51.3%), and high for aminoglycosides (96.3%), carbapenems (92.4%), trimethoprim-sulfamethoxazole (81.2%), and quinolones (79.9%). E. coli also showed considerable resistance to amoxicillin-clavulanic acid. The rates of multidrug-resistant bacteria are still high compared to the northern countries of Europe. This study’s findings show the emergence of antibiotic resistance in the antibiotic agents commonly used in the treatment of UTIs in dogs and cats in Portugal.

Pseudomonas aeruginosa is a pathogenic bacterium that can cause serious infections in both humans and animals, including dogs. Treatment of this bacterium is challenging because some strains have developed multi-drug resistance. This study aimed to evaluate the antimicrobial resistance patterns and biofilm production of clinical isolates of P. aeruginosa obtained from dogs. The study found that resistance to various β-lactam antimicrobials was widespread, with cefovecin and ceftiofur showing resistance in 74% and 59% of the isolates tested, respectively. Among the aminoglycosides, all strains showed susceptibility to amikacin and tobramycin, while gentamicin resistance was observed in 7% of the tested isolates. Furthermore, all isolates carried the oprD gene, which is essential in governing the entry of antibiotics into bacterial cells. The study also investigated the presence of virulence genes and found that all isolates carried exoS, exoA, exoT, exoY, aprA, algD, and plcH genes. This study compared P. aeruginosa resistance patterns worldwide, emphasizing regional understanding and responsible antibiotic use to prevent multi-drug resistance from emerging. In general, the results of this study emphasize the importance of the continued monitoring of antimicrobial resistance in veterinary medicine.

Dermatophytosis, commonly referred to as ringworm, is a common superficial fungal infection in companion animals and humans. Between 2012 and 2023, plucked hair and scraped scale samples from domestic dogs and cats with clinical suspicion of dermatophytosis were collected from 355 veterinary medical centres across mainland Portugal. A total of 4716 animal samples were inoculated onto DERM agar, incubated at 25 °C for up to 4 weeks, and periodically examined macro- and micro-scopically to observe and evaluate fungal growth. Of these, 271 samples were removed due to contaminant fungi. Of the 568 positive cultures, the highest number were from the North (48.1%; 95% CI: 44.0–52.2%) and Centre (32.4%; 95% CI: 28.7–36.4%) regions. Microsporum canis was the most frequently isolated species (63.9%), followed by Trichophyton spp. (20.3%) and Nannizia gypsea (formerly Microsporum gypseum) (8.1%). Felines exhibited a higher frequency (17.4%) compared with dogs (9.1%) (p < 0.001). In dogs, the Yorkshire Terrier, West Highland White Terrier, Miniature Pinscher, Dalmatian and Miniature Schnauzer demonstrated a significant predisposition to dermatophytosis (p < 0.05). In cats, the Persian and Scottish Fold breeds were significantly predisposed (p < 0.05). No significant differences were found between sexes (p > 0.05). These findings underscore dermatophytosis as an increasing public health concern due to its zoonotic and contagious nature, providing comprehensive insights into the epidemiology of dermatophytosis in Portugal.

Leishmaniosis is a vector-borne disease caused by protozoan parasites of the genus Leishmania, which are zoonotic and have an important impact on animal and public health globally. Between 2009 and 2023, blood samples from domestic dogs with clinical suspicion of leishmaniosis were received from 286 veterinary medical centres throughout mainland Portugal. An enzyme-linked immunosorbent assay (ELISA) was utilised to detect antibodies against Leishmania infantum antigens. Additionally, a complete blood count and tests for total proteins, urea, creatinine and alanine aminotransferase, as well as protein electrophoresis, were also performed. No significant relationship between sex and breed was observed. The age distribution was bimodal, with the highest prevalence of disease occurring at 2–5 years of age and a secondary peak occurring at 6 years or over (p < 0.001). No statistical correlation was observed between creatinine and urea across the ELISA serological groups. In contrast, both the gamma globulin levels (r = 0.45; p < 0.001) and the albumin/globulin ratio (r = −0.36; p < 0.001) exhibited moderate correlations with the ELISA. These findings support recent seroprevalence studies in dogs, with some geographical areas in Northern Portugal exhibiting the highest values, which may be the result of geographical shifts in parasite circulation due to climate change.

Cytology is an exam frequently used as a diagnostic technique to evaluate animal oral lesions. However, the retrospective studies published comparing cytology and histology in oral pathology are scarce. This study aimed to determining the association between diagnostic cytology and histopathology in neoplastic and non-neoplastic samples from oral cavity lesions of dogs and cats. Cytological and histological samples (n = 103) of oral lesions from 70 dogs and 33 cats collected over 12 years were compared in terms of agreement, considering the histopathology as the gold standard. Of 103 specimens, 78 were classified as neoplastic, and 25 were non-neoplastic. The sensitivity, specificity, and accuracy of cytology in neoplastic and non-neoplastic lesions were 84.6%, 96.0%, and 87.4%. Of the overall 103 cases, 75.7% (n = 78) were neoplastic and revealed an agreement that was complete in 64.1% (n = 50) and partial in 17.9% (n = 14) samples, and the remaining 17.9% (n = 14) revealed disagreement; regarding the non-neoplastic diagnoses (24.3%, n = 25) the agreement was complete in 68.0% (n = 17), partial for 20.0% (n = 5) samples, and the remaining 12.0% (n = 3) revealed disagreement. A statistical association between neoplastic cases and agreement was obtained (p < 0.0001). The high agreement verified between the cytological and histopathological diagnoses emphasizes the role of cytology as the first approach method to an oral lesion in dogs and cats.

This study evaluated diagnostic trends and the overall utility of cytology in feline patients through the analysis of a large, multicentric dataset from Portugal. A retrospective review of 3068 cytological cases from 130 veterinary practices was conducted, with samples categorised by anatomical location and lesion type. Diagnostic outcomes were statistically assessed, revealing an overall success rate of 66.20%. The highest diagnostic yields occurred in fluid samples (83.48%), glandular tissues (76.67%), and mucous membranes (75.81%), followed by organ-based samples (67.79%), miscellaneous tissues (66.98%), cutaneous/subcutaneous nodules (62.16%), and lymph nodes (57.93%). Neoplastic lesions showed age-associated prevalence, being more common in older cats, with epithelial and melanocytic lesions more frequent in females and round cell/mesenchymal lesions predominating in males. Non-diagnostic samples (33.80%) primarily resulted from insufficient cellularity or suboptimal quality, though no significant correlation existed between diagnostic success and clinical setting. This study underscores that cytology remains a fundamental diagnostic tool in feline medicine, particularly when combined with proper sampling techniques and complementary diagnostic methods, and reinforces its value in clinical decision-making, thereby supporting its broader utilisation in routine veterinary practice.