Biocompatibility of hydrogel derived from equine tendon extracellular matrix in horses subcutaneous tissue.

Tendinopathies account for a substantial proportion of musculoskeletal injuries. To improve treatment outcomes for partial and total tendon ruptures, new therapies are under investigation. These include the application of mesenchymal stem cells (MSCs) and biocompatible scaffolds derived from the Extracellular Matrix (ECM). Synthetic polymer hydrogels have not demonstrated results as promising as those achieved with ECM hydrogels sourced from the original tissue. This study aimed to evaluate the biocompatibility of a hydrogel formulated from equine tendon ECM. Six horses were administered three subcutaneous doses of the hydrogel, with a saline solution serving as a control. Biopsies were conducted on days 7, 14, and 56 post-application to gauge the hydrogel's impact. Throughout the experiment, the horse's physical condition remained stable. Thermographic analyses revealed a temperature increase in the treated groups compared to the control group within the initial 12 h. The von Frey test, used to measure the mechanical nociceptive threshold, also showed significant differences between the treated group and the control group at 6 h, 21 days, and 28 days. Histopathological analyses identified an inflammatory response on day 7, which was absent on days 14 and 56. Transmission electron microscopy indicated a decrease in inflammatory cellularity, while immunohistochemistry staining suggested an increased presence of inflammatory factors on day 14. In summary, the hydrogel is easily injectable, triggers a temporary local inflammatory response, and integrates into the adjacent tissue from day 14 onwards.

Outbreak of equine pythiosis in a southeastern region of Brazil: Environmental isolation and phylogeny.

Pythiosis is a disease caused by the oomycete Pythium insidiosum, mainly reported in equines, dogs and humans and directly transmitted through contaminant zoospores in aquatic environments. We report the first outbreak of equine pythiosis in five equines. Wound samples were submitted for diagnostic testing including mycological culture and nested PCR. Treatment approaches consisted of conventional and alternative therapies. Microbiological analyses were performed using water samples from the riverbanks close to where the animals had grazed. All animals were positive for P. insidiosum cultures, and two animals responded successfully to alternative therapy (ozone therapy). After culture and molecular analysis of environmental samples, the presence of P. insidiosum in one section of the Tietê River was confirmed through a 99% sequence identity. Phylogenetic analyses using the cytochrome oxidase II gene showed that the animal isolates clustered in clade I and the environmental isolates clustered in clade III. Although the environmental and wound isolates belonged to different genetic clades, we concluded that the Tietê River is an important source of infection by P. insidiosum and that research concerning environmental isolation of P. insidiosum from rivers and lakes should be strongly facilitated in Brazil.

Association of intraperitoneal ceftriaxone, intravenous gentamicin and oral metronidazole in the treatment of an abdominal abscess and peritonitis in a horse: case report / Associação da ceftriaxona intraperitoneal, gentamicina intravenosa e do metronidazol oral no tratamento de abscesso abdominal e peritonite em equino: relato de um caso

Medical management of abdominal abscesses in horses requires prolonged antibiotic therapy and presents varied success rates. A 6-year-old male horse with a history of colic and multiple abdominal punctures to relieve gas was attended. At admission, tachycardia, tachypnea, hyperthermia, mucosal congestion, dehydration, and rigid gait were observed. The association of physical examination, laboratory and ultrasonographic findings allowed the diagnoses of peritonitis and abdominal abscess. Supporting treatment plus broad spectrum antibiotic therapy was performed: daily intraperitoneal ceftriaxone (25 mg/kg, 7 days); daily intravenous gentamicin (6.6 mg/kg, 7 days); per os metronidazole three times a day (15 mg/kg 12 days), followed by the same dose twice a day (15 mg/kg 33 days), totaling 45 days of treatment. Plasma fibrinogen and ultrasonographic examination were the most effective tools to evaluate abscess evolution. There was normalization of the physical examination 24 h after beginning the treatment, consecutive regression of the nucleated cell count in the peritoneal fluid, and regression of plasma fibrinogen and size of the abscess. On the 10th treatment day, the animal was discharged from the hospital, maintaining oral therapy with metronidazole every 12 h (15 mg / kg). When the animal returned on the 30th day, an abscess size regression was observed. However, there was no resolution, and therapy with metronidazole was maintained. On the 45th day of treatment, a new hospital evaluation was performed, where the abscess resolved, and metronidazole was suspended. It is highlighted that the therapeutic association used in the treatment of abdominal infection and abscess resulted in a rapid clinical response.(AU)

O tratamento conservativo dos abscessos abdominais em equinos requer antibioticoterapia prolongada e apresenta variadas taxas de sucesso. Foi atendido um cavalo de seis anos de idade, com histórico de cólica e múltiplas punções abdominais por agulha para esvaziamento de gás. Na admissão, foram observados taquicardia, taquipnéia, hipertermia, congestão mucosa, desidratação e marcha rígida. A associação do exame físico, achados laboratoriais e ultrassonográficos permitiu o diagnóstico de peritonite e abscesso abdominal. Foi realizado tratamento suporte e antibioticoterapia de amplo espectro: ceftriaxona intraperitoneal diária (25 mg/kg, 7 dias); gentamicina intravenosa diária (6,6 mg/kg, 7 dias); metronidazol oral três vezes ao dia (15 mg/kg, 12 dias), seguido de mesma dose duas vezes ao dia, por mais 33 dias, totalizando 45 dias de tratamento. O fibrinogênio plasmático e o exame ultrassonográfico foram os recursos mais eficazes para a avaliação da evolução do abscesso. Após 24 horas do início do tratamento foi constatada a normalização do exame fisico, regressão progressiva da contagem de células nucleadas no líquido peritoneal, do fibrinogênio plasmático e do tamanho do abscesso. No 10° dia de tratamento o animal recebeu alta hospitalar, mantendo-se a terapia oral com metronidazol a cada 12 horas (15 mg/Kg). Em retorno, ao 30° dia, observou-se regressão do tamanho do abscesso, entretanto, não houve resolução, tendo sido mantida a terapia com metronidazol. No 45º dia de tratamento, realizou-se nova avaliação hospitalar, onde foi observada a resolução do abscesso e a admnistração do metronidazol foi suspensa. Destaca-se, que a associação terapêutica utilizada no tratamento de infecção abdominal e abscesso resultou em rápida resposta clínica.(AU)