IV injection of buprenorphine caused a dose-dependent increase in SLA, but only the dose of 10 microg/kg induced analgesia on the basis of results for the experimental method used.

Buprenorphine induced excitement and hemodynamic stimulation with minimal changes in arterial blood gas tensions. These effects may impact the clinical use of buprenorphine in horses. Further studies are indicated to investigate the effects of buprenorphine on gastrointestinal motility and fecal output.

ResumoA identificação de injúrias renais é uma medida importante que tem como objetivo evitar a instalação de alterações irreversíveis, tal como a doença renal crônica, problema de incidência elevada em cães e gatos. As concentrações séricas de ureia e de creatinina são os parâmetros rotineiramente avaliados, quando se busca a identificação de insuficiência renal. Porém, estes valores só se encontram alterados quando 66 a 75% dos néfrons apresentam incapacidade de função excretora. Em muitas situações, uma agressão desta magnitude pode ser suficiente para causar a morte do animal. Avaliações que identifiquem a agressão, antes mesmo que as funções encontrem-se alteradas vêm sendo estudadas, mostrando serem importantes avaliadores precoces de possíveis danos irreversíveis. A quantificação das enzimas urinárias, proteína urinária, fração de excreção de eletrólitos, taxa de filtração glomerular e a observação do sedimento urinário têm grande valor como exames sensíveis de injúria renal precoce. Há a necessidade do emprego de testes que auxiliem, não somente na identificação precoce, mas também na determinação da progressão da doença e da eficácia do tratamento. A presente revisão objetiva descrever os testes laboratoriais que podem ser realizados para a avaliação precoce de injúria renal de cães e gatos. Palavras-chave: Injúria renal, diagnóstico precoce, taxa de filtração glomerular, proteinúria AbstractThe identification of kidney injury is an important measure that aims to prevent the installation of irreversible changes, such as chronic kidney disease, seen most frequently in dogs and cats. Serum urea and creatinine parameters are routinely assessed, when searching renal failure. However, these values are only changed when 66 to 75% of glomerular filtration rate has been lost. In many situations, an attack of this magnitude may be enough to cause the animal's death. Evaluations that identify the aggression, even before the functions themselves are altered, have been studied and shown to be important early evaluators, signaling prior to possible irreversible damage. The quantification of urinary enzymes, urinary protein, fractional excretion of electrolytes, glomerular filtration rate and urinary sediment, have shown great value as sensitive tests of renal injury. There is the need of the use of tests that assists in early diagnosis and also determines the progression of disease and efficacy of the treatment. The present review aims to describe the laboratory tests that may be performed to evaluate early kidney injury in dogs and cats.

BackgroundContinuous-rate infusion (CRI) of drugs results in more stable plasma drug concentrations than administration of intermittent boluses, thus providing greater stability of physiological parameters. The aim of this study was to evaluate the physiologic and analgesic effects of the administration of morphine, butorphanol, tramadol or methadone by CRI in horses with induced synovitis of the radiocarpal joint.ResultsIncreased values of cardiorespiratory parameters and body temperature were observed in all groups after initiation of opioid administration, and these increases were sustained throughout the CRI period. Morphine, butorphanol and methadone each caused a reduction in gut sounds, and this effect was greatest in animals that received morphine. Administration of morphine or methadone reduced the degree of lameness after the end of intravenous infusion. Administration of tramadol did not alter the degree of lameness in the animals.ConclusionsCRI of morphine or methadone, but not butorphanol or tramadol, provided analgesia in horses with carpal synovitis. All of these opioids increased cardiovascular and respiratory parameters and reduced gut sounds during CRI.

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Amitraz, an acaricide used to control ectoparasites in animals has a complex pharmacological activity, including alpha2-adrenergic agonist action. The purpose of this research was to investigate the possible antinociceptive and/or sedative effect of amitraz in horses. The sedative effect of the intravenous (i.v.) injection of dimethylformamide (DMF, 5 mL, control) or amitraz (0.05, 0.10, 0.15 mg/kg), was investigated on the head ptosis test. The participation of alpha2-adrenergic receptors in the sedative effect provoked by amitraz was studied by dosing yohimbine (0.12 mg/kg, i.v.). To measure the antinociception, xylazine hydrochloride (1 mg/kg, i.v., positive control) and the same doses of amitraz and DMF were used. A focused radiant light/heat directed onto the fetlock and withers of a horse were used as a noxious stimulus to measure the hoof withdrawal reflex latency (HWRL) and the skin twitch reflex latency (STRL). The three doses of amitraz used (0.05, 0.10 and 0.15 mg/kg) provoked a dose-dependent relaxation of the cervical muscles. The experiments with amitraz and xylazine on the HWRL showed that after i.v. administration of all doses of amitraz there was a significant increase of HWRL up to 150 min after the injections. Additionally, there was a significant difference between control (DMF) and positive control (xylazine) values up to 30 min after drug injection. On the other hand, the experiments on the STRL show that after administration of amitraz at the dose of 0.15 mg/kg, a significant increase in STRL was observed when compared with the control group. This effect lasted up to 120 min after injection. However, no significant antinociceptive effect was observed with the 0.05 and 0.10 mg/kg doses of amitraz or at the 1.0 mg/kg dose of xylazine.