Use of Liposomal Gentamicin for Treatment of 5 Foals with Experimentally Induced Rhodococcus equi Pneumonia.

BACKGROUND: Adverse effects of, and bacterial resistance to, macrolides used to treat Rhodococcus equi infections have prompted search for clinically effective alternative antimicrobials. Liposomal gentamicin (LG) is effective against R. equi in vitro and decreases tissue concentrations of R. equi in experimentally infected mice. Effectiveness of LG treatment of foals with R. equi pneumonia, however, has not been described. HYPOTHESIS: Liposomal gentamicin is safe and effective for treating foals with R. equi pneumonia. ANIMALS: Ten foals with experimentally induced R. equi pneumonia. METHODS: Pilot treatment trial. Foals with pneumonia induced by intrabronchial instillation of R. equi were randomly allocated to receive either clarithromycin combined with rifampin (CLR + RIF) PO or LG IV, and followed by daily physical examinations and weekly thoracic ultrasonography and serum creatinine concentration determinations until the resolution of clinical signs. Treatment success was defined as the resolution of clinical signs and ultrasonographically identified pulmonary abscesses. RESULTS: All 10 foals were successfully treated. Two of 5 foals treated with LG developed azotemia within 1 week; LG was discontinued and treatment switched to CLR + RIF for these foals. None of the CLR + RIF treated foals developed azotemia. CONCLUSIONS AND CLINICAL IMPORTANCE: Liposomal gentamicin IV can be effective for treatment of R. equi pneumonia, but nephrotoxicity indicates that an alternative dosing interval or route (such as nebulization) will be needed before LG is adequately safe for clinical use. Larger comparative trials will be needed to evaluate the relative efficacy of a safer LG dosage regimen.

Efeitos da solução salina hipertônica a 7,5 por cento em glicose a 5 por cento nas concentrações séricas de sódio, cloreto e potássio de eqüinos com hipovolemia induzida / Effects of 7,5 percent hypertonic saline in 5 percent glucose on serum levels of sodium, chloride and potassium in induced hypovolemic horses

Estudaram-se os efeitos de soluções salinas isotônica e hipertônica em eqüinos hipovolêmicos sobre as concentrações séricas de sódio, cloreto e potássio e freqüências cardíaca (FC) e respiratória (FR). Quinze eqüinos machos com peso entre 390 e 475kg e idades entre quatro e 18 anos foram submetidos à retirada de sangue correspondente a 2 por cento do peso corporal e distribuídos em três grupos de igual número: o grupo GSH recebeu solução hipertônica de NaCl a 7,5 por cento em glicose a 5 por cento; o GSI, solução isotônica de NaCl a 0,9 por cento; e o GC não foi tratado. Os eletrólitos séricos foram avaliados antes (T0), após a retirada de sangue (T1) e após a infusão das soluções, entre 20 e 30 minutos (T2), entre 60 e 70 minutos (T3) e entre 120 e 130 minutos (T4). Após T0, houve elevação da FC e da FR, e as concentrações séricas de Na, Cl, K permaneceram inalteradas. Após a infusão, houve melhora das variáveis clínicas em GSI e GSH, em relação ao GC. Quanto a T3 e T4, os valores de Na em T2 do GSH foram maiores, e os de Cl e de K não se alteraram. As soluções hipertônica e isotônica são seguras na correção da hipovolemia induzida e não produzem alteração eletrolítica significativa.

The effect of isotonic and hypertonic solutions on serum levels of sodium, chloride and potassium and cardiac (CR) and respiratory rates (RR) of hypovolemic horses were studied. Fifteen horses weighting from 390 to 475kg, aging from four to 18-years-old were submitted to bleeding of 2 percent of body weight and divided in three groups: 7.5 percent NaCl hypertonic saline in 5 percent glucose (GSH), 0.9 percent NaCl isotonic saline and control group (GC). Serum electrolytes were evaluated before (T0) and after bleeding (T1) and after the administration of the solutions between 20 and 30 minutes (T2), 60 and 70 minutes (T3) and 120 and 130 minutes (T4). After T0, CR and RR increased while serum sodium, chloride, potassium were not affected. After the treatment, the clinical variables improved in GSI and GSH as compared to GC. The Na levels increased in GSH at T2 being higher than T3 and T4 while chloride and potassium concentrations did not change. The hypertonic and isotonic solutions safely corrected the hypovolemia of the horses, without altering significantly the electrolyte balance.

Uretrostomia para colheita seriada de urina em bezerros / Urethrostomy for serial sampling of urine in calves

Urethrostomy for serial sampling of urine was used due to the necessity of one technique that allowed the total urinary collection in definite time periods. Twenty-seven male Holstein calves from 8 to 16-days-age having a mean weight 39.50±4.80kg were used. Urethrostomy was carried out with the use of urethral sounding lead that was made for this purpose. In agreement with the clinical examinations, including seric biochemical, urinalysis and blood test and postmortem examination, the technique achieved 81.5 percent of satisfactory results.

Implantaçäo de homoenxerto heterotópico na artéria femoral de cäes / Arterial heterotopic homograft in the femoral artery of dogs

A presente pesquisa visou estudar a interposiçäo de um segmento de carótida homógena, preservada em glicerina, na artéria femoral de cäes. Foram utilizados 18 cäes mestiços, adultos, separados em três grupos, e observados por 15 dias (grupo I), 30 dias (grupo II) e 45 dias (grupo III). Três outros cäes foram observados por 75 dias (grupo IV). Os enxertos foram preservados em glicerina 98 por cento, por período de 60-180 dias. As artérias foram implantadas com auxílio de microscópio cirúrgico em magnificaçäo de 6x e foram avaliadas por inspeçäo clínica, arteriográfica e histopatológica. Foi observada invasäo mononuclear da adventícia, ausência de células na média e progressiva diminuiçäo nas células musculares lisas, com deposiçäo de fibras colágenas. Näo foram evidenciados sinais clínicos ou histopatológicos de reaçäo imunológica