Evaluation of totally implantable catheters in healthy horses.

BACKGROUND: For horses requiring prolonged daily cephalic intravenous regional limb perfusion (IVRLP), the use of a totally implantable catheter (TIC) could be indicated to reduce complications associated with frequent venipuncture or external catheterization. This study aims to evaluate the implantation technique of the TIC in the cephalic vein of horses for IVRLP, describe the complications associated with the device's placement and use, and assess its viability up to 60 days after implantation. Totally implantable catheters, cut to 15 cm (n = 5) and 46 cm (n = 5) in length, were implanted into one cephalic vein in ten adult horses (n = 10). Twenty-four hours following placement, IVRLP with contrast was performed via the TIC and evaluated with radiography. Physical examinations, lameness evaluation, hematologic assessment, and the catheter patency tests were performed at scheduled intervals for the duration of catheterization (7-60 days). RESULTS: Catheters were implanted without difficulty and allowed for IVRLP 24 h post implantation. Complications resulted in removal of the catheters, with four maintained for 7 days, three in place for 15 days, and three catheters maintained for 60 days. Complications included lameness, limb swelling, catheter kinking, and venous thrombosis. CONCLUSIONS: The implantation technique of the TIC in the cephalic vein of horses is feasible and requires minimal technical effort. Although TIC allows venous access without the need for repeated venipuncture, its long-term use presents complications. For horses requiring prolonged daily cephalic IVRLP, the use of a TIC could be indicated. However, the high incidence of venous thrombosis may limit clinical application.

Evaluation of intravenous regional perfusion with amphotericin B and dimethylsulfoxide to treat horses for pythiosis of a limb.

BACKGROUND: Treatment for horses with pythiosis of a limb is challenging. This study aims to evaluate the effects of administering amphotericin B in a 10 % solution of dimethylsulfoxide by intravenous regional limb perfusion (IRLP) to treat horses for cutaneous pythiosis of a limb. RESULTS: All 15 of the horses treated had complete resolutions of their lesion between 6 to 9 weeks after a single IRLP treatment. No complications were observed at the site of venipuncture for IRLP. Before initiation of treatment, there was anemia and marked leucocytosis which resolved following treatment. Serum biochemistry showed no significant changes. CONCLUSIONS: IRLP administration of amphotericin B in a 10 % DMSO solution was easily performed, relatively inexpensive and an effective treatment for treating horses for pythiosis of a limb and resolved the infection with no complications.

Intra-articular concentration of gentamicin administered by intravenous regional limb perfusion in healthy horses / Concentração intra-articular de gentamicina administrada por perfusão regional intravenosa em membros de equinos sadios

ABSTRACT: Intravenous regional limb perfusion (IRLP) is an efficient method to treat horses with synovial infections. However, information on the dose, volume, and intervals of administration is lacking. The aim of this study was to evaluate the intra-articular concentration of gentamicin administered by IRLP in horses over 24 h post-administration and evaluate the influence of the total perfused volume. Twenty horses were assigned to two treatment groups. Gentamicin 60 group (G60, n=10) and Gentamicin 250 group (G250, n=10) received IRLP of 6.6 mg/kg of gentamicin diluted in Ringer's lactate for a total volume of 60 ml (G60) and 250 ml (G250), respectively. Synovial fluid harvests were performed in the metacarpophalangeal joint before (0) and 4, 8, 12, 16, 20, and 24 hours after IRLP. Agar diffusion was the assay for measuring gentamicin concentrations. Four hours after IRLP, the intra-articular concentration of gentamicin was 47.58±49.21 μg/ml in G60 and 10.92±6.11 μg/ml in G250. During the 24 h of harvest, the intra-articular concentration of gentamicin remained above the minimum inhibitory concentration for horses (MIC; 2 μg/ml) in both experimental groups. In G60, the concentration of gentamicin in synovial fluid reached the maximal concentration and remained 8 to 10-fold higher than the MIC (Cmax: 16 to 20 μg/ml) during 12 h after IRLP. These findings support that IRLP with 6.6 mg/kg of gentamicin diluted to a volume of 60 ml promotes intra-articular concentrations higher than 250 ml, remaining above the MIC for 24 h and at the maximum concentration for 12 h.

RESUMO: A perfusão regional intravenosa (PRI) em membros de equinos é um método comprovadamente eficiente para o tratamento de infecções sinoviais, porém ainda existem lacunas quanto à dose, volume e intervalos de administração a serem utilizados. Neste estudo, objetivou-se avaliar a concentração intra-articular da gentamicina administrada por PRI em equinos, ao longo de 24 horas pós-administração, bem como avaliar a influência do volume total perfundido. Vinte equinos foram distribuídos em dois grupos experimentais, Grupo Gentamicina 60 (G60) e Grupo Gentamicina 250 (G250), representados por 10 equinos em cada grupo que receberam, por PRI, 6,6 mg/kg de gentamicina diluída em Ringer lactato para um total de 60 ml (G60) ou 250 ml (G250). As colheitas de líquido sinovial foram realizadas, na articulação metacarpo-falangeana, antes do início do experimento e após 4, 8, 12, 16, 20, e 24 horas. Difusão em ágar foi o método para doseamento das concentrações de gentamicina. Quatro horas após a PRI, a concentração intra-articular da gentamicina era de 47,58±49,21 µg/ml no G60 e 10,92±6,11 µg/ml no G250. Durante as 24 horas de colheita, a concentração intra-articular de gentamicina permaneceu acima da concentração inibitória mínima (CIM) (2 μg/ml) em ambos os grupos experimentais. No G60, as concentrações de gentamicina no líquido sinovial atingiram a concentração máxima e mantiveram-se 8 a 10 vezes mais elevadas que a CIM (Cmáx: 16 a 20 μg/ml) durante 12 horas após a PRI. Conclui-se que a PRI em membros, com 6,6 mg/kg de gentamicina diluída para o volume de 60 ml, promove concentrações intra-articulares mais elevadas que o volume de 250 ml, permanecendo acima da CIM durante 24 horas e em concentração máxima durante 12 horas.

Investigação clínica e comparação do esfregaço sanguíneo e PCR para diagnóstico de hemoparasitas em equinos de esporte e tração (carroceiros) / Clinical investigation and comparison of blood smear and PCR to diagnose haemoparasites in Sports Horses and Traction Horses (Cart Horses)

Na clínica médica de equinos, explora-se o perfil hematológico do animal, geralmente, com a finalidade de encontrar alterações que não foram constatadas ao exame clínico. A pesquisa de hematozoários em equinos, muitas vezes, apresenta resultados conflitantes entre o quadro clínico apresentado pelo animal e o resultado laboratorial, levantando a hipótese de que a técnica de pesquisa de hematozoários seja a responsável por falhas diagnósticas. Este estudo visa comparar os valores obtidos em exames hematológicos de 15 equinos de esporte e 15 equinos de tração (carroceiros), levando-se em consideração diferenças como características nutricionais, estado de higidez e tipo de atividade realizada, e comparar as diferentes técnicas de pesquisa de hematozoários, como esfregaço sanguíneo e PCR. Verificou-se que apenas os equinos de tração apresentaram valores médios de hemácias, hematócrito e hemoglobina abaixo do considerado fisiológico para a espécie, embora 100% dos animais, de ambos os grupos experimentais, tenham sido considerados positivos para hemoparasitoses por PCR. Verifica-se a superioridade do método de pesquisa de hemoparasitas por PCR, em comparação com esfregaço sanguíneo, realizado por diferentes técnicas, visto que apenas 33,3% dos animais foram considerados positivos para Theileria equi por esta técnica, enquanto que o PCR revelou 100% de positividade, para Theileria equi, Babesia caballi e infecção mista. Nenhum dos animais estudados foi diagnosticado com Anaplasma phagocytophilum (Ehrlichia equi) e Ehrlichia risticcii (Neoricketsia risticii). Verifica-se, então, que muitos dos diagnósticos de ausência de hemoparasitose por exame hematológico e ou esfregaço sanguíneo são errôneos, devido à baixa sensibilidade da técnica e podem repercutir em falha no tratamento ou disseminação dos hemoparasitos e das hemoparasitoses. Ressalta-se, então, a importância de exames como o PCR na elaboração de diagnóstico definitivo.(AU)

The blood profile is usually explored in equine medicine to find changes not detected through clinical examination. The haematozoa search in horses, often presents conflicting results between the clinical picture presented by the animal and the laboratory result, raising the hypothesis that the hematozoa search technique is responsible for diagnostic failures. Thus, this study aims to compare the values obtained from blood tests in 15 sports horses and 15 traction horses (cart horses), taking into account differences such as nutritional characteristics, state of health and type of activity performed, and to compare the different techniques with hematozoa search, as blood smear and PCR. It was found that only the traction horses showed mean values of red blood cells, hematocrit and hemoglobin below the considered physiological for the species, although 100% of the animals of both experimental groups were considered positive for hemoparasitoses by PCR. It was verified the superiority of hemoparasites search method by PCR, compared with blood smear performed by different techniques, since only 33.3% of the horses were considered positive for Theileria equi by this technique, while the PCR showed 100% positive for Theileria equi, Babesia caballi and mixed infection. None of the animals studied was diagnosed with Anaplasma phagocytophilum (Ehrlichia equi) and Ehrlichia risticcii (Neoricketsia risticii). It is shown that many cases of hemoparasitosis absence of diagnostic by hematological exams and or blood smears are erroneous due to the low sensitivity of the technique and may impact on treatment failure or spread of blood parasites and hemoparasitoses. It is noteworthy to stres the importance of tests such as PCR for the definitive diagnosis.(AU)