Effects of ketamine, diazepam, and their combination on intraocular pressures in clinically normal dogs

OBJECTIVE: To evaluate the effects of ketamine, diazepam, and the combination of ketamine and diazepam on intraocular pressures (IOPs) in clinically normal dogs in which premedication was not administered. ANIMALS: 50 dogs. PROCEDURES: Dogs were randomly allocated to 1 of 5 groups. Dogs received ketamine alone (5 mg/kg [KET5] or 10 mg/kg [KET10], IV), ketamine (10 mg/kg) with diazepam (0.5 mg/kg, IV; KETVAL), diazepam alone (0.5 mg/kg, IV; VAL), or saline (0.9% NaCl) solution (0.1 mL/kg, IV; SAL). Intraocular pressures were measured immediately before and after injection and at 5, 10, 15, and 20 minutes after injection. RESULTS: IOP was increased over baseline values immediately after injection and at 5 and 10 minutes in the KET5 group and immediately after injection in the KETVAL group. Compared with the SAL group, the mean change in IOP was greater immediately after injection and at 5 and 10 minutes in the KET5 group. The mean IOP increased to 5.7, 3.2, 3.1, 0.8, and 0.8 mm Hg over mean baseline values in the KET5, KET10, KETVAL, SAL, and VAL groups, respectively. All dogs in the KET5 and most dogs in the KETVAL and KET10 groups had an overall increase in IOP over baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with baseline values and values obtained from dogs in the SAL group, ketamine administered at a dose of 5 mg/kg, IV, caused a significant and clinically important increase in IOP in dogs in which premedication was not administered. Ketamine should not be used in dogs with corneal trauma or glaucoma or in those undergoing intraocular surgery.     

Clinical observations surrounding an increased incidence of postanesthetic myopathy in halothane-anesthetized horses

BACKGROUND: During an 8-year period of clinic improvements, an increased incidence of postanesthetic myopathy (PAM) was observed in horses undergoing anesthesia. A request was made for an independent anesthesiologist to examine possible reasons for this increase. Routine methods used for anesthesia were then compared with new methods introduced by the anesthesiologist. OBSERVATIONS: Investigative observations were conducted from October 1999 to April 2000. Following premedication with xylazine or detomidine, anesthesia was induced with diazepam or guiaifenesin followed by ketamine. Maintenance of anesthesia was with halothane/O(2) with mechanical ventilation. Information was gathered from observing routine anesthetics. Seventeen horses were designated group A (October-December 1999) for which hypotension was defined as mean arterial pressure (MAP) <60 mmHg and managed using low-volume crystalloid fluid therapy, etilefrine, or dopamine. In the next 18 horses (group B), hypotension was redefined as MAP <70 mmHg, and was managed using high-volume fluid therapy and dobutamine (January-April 2000). No other changes were made. In both groups, creatine kinase (CK) and aspartate transaminase (AST) concentrations were measured before induction, 1 and 25 hours after standing. Occurrence of PAM was defined as CK and/or AST concentrations above 1000 IU L(-1) and analyzed with Fisher's exact test between groups. Muscle enzymes increased in five horses in group A (two with clinical signs) and in one horse in group B (difference between groups: p = 0.088). CONCLUSIONS: Maintaining MAP >70 mmHg with high-volume fluid therapy and dobutamine may help to reduce the severity of myopathy.     

Seeing below the surface: making soil processes visible to Ugandan smallholder farmers through a constructivist and experiential extension approach

Ugandan smallholder farmers need to feed a growing population, but their efforts are hampered by declining soil fertility rates. Agricultural extension can facilitate farmers’ access to new practices and technologies, yet farmers are understandably often hesitant to adopt new behaviors. New knowledge assimilation is an important component of behavior change that is often overlooked or poorly addressed by current extension efforts. We implemented a Fertility Management Education Program (FMEP) in central Uganda to investigate smallholder farmers’ existing soil knowledge and their assimilation of new scientific concepts into their knowledge framework. Qualitative data were collected through participant observation, farmer interviews, and focus groups, and coded for using a priori and emergent themes. Our exploration revealed some notable similarities between farmers’ soil knowledge and scientific concepts, particularly in regards to soil health concepts, a discovery that could facilitate communication between extension agents and farmers. However, certain scientific concepts are either unknown to farmers or discordant with existing soil knowledge; these concepts are unlikely to be assimilated by farmers without convincing and concerted extension efforts. Importantly, we found that the combination of new scientific knowledge and hands-on experimentation with novel practices gave farmers far greater confidence in implementing improved soil management practices. Our study provides evidence that extension programs should engage directly with farmers’ existing soil knowledge to develop their understanding of key biological concepts and confidence in implementing improved practices.     

On (not) knowing where your food comes from: meat,mothering and ethical eating

Knowledge is a presumed motivator for changed consumption practices in ethical eating discourse: the consumer learns more about where their food comes from and makes different consumption choices. Despite intuitive appeal, scholars are beginning to illuminate the limits of knowledge-focused praxis for ethical eating. In this paper, we draw from qualitative interviews and focus groups with Toronto mothers to explore the role of knowledge in conceptions of ethical foodwork. While the goal of educating children about their food has become central to Canadian and American discourses of “good” mothering, we identify a paradoxical maternal expectation surrounding meat consumption: (1) to raise informed child consumers who know where their food comes from, and (2) to protect children from the harsh realities of animal slaughter. Rather than revealing the story behind the meat on a child’s plate, mothers seek to shield children from knowledge of meat production. Our analysis of the child consumer contributes to ethical eating scholarship and illuminates a larger paradox surrounding knowledge of meat in an industrialized food system. In the practice of feeding children, mothers confront the visceral discomforts of meat consumption; their reactions speak to discordant feelings involved with eating meat in a setting far-removed from the lives and deaths of animals. Ultimately, the paper illustrates the limits of consumer-focused strategies for food-system change that call on individual mothers to educate young consumers and protect childhood innocence, all while getting ethically-sourced meals on the table.     

The efficacy and tolerability of levetiracetam in pharmacoresistant epileptic dogs

Twenty-two dogs with idiopathic epilepsy which were pharmacoresistant to phenobarbitone and bromide were treated with levetiracetam as an add-on medication. Records of eight dogs were used retrospectively to determine a safe, efficient levetiracetam dosage. Fourteen dogs were entered into a prospective, open label, non-comparative study. After 2 months of levetiracetam oral treatment (10 mg/kg TID), 8/14 dogs responded significantly to the treatment and seizure frequency was reduced by 50%. In dogs that remained refractory, the dosage was increased to 20 mg/kg TID for 2 months. One further dog responded to levetiracetam treatment. Levetiracetam responders had a significant decrease in seizure frequency of 77% (7.9+/-5.2 to 1.8+/-1.7 seizures/month) and a decrease in seizure days per month of 68% (3.8+/-1.7 to 1.2+/-1.1 seizure days/month). However, 6/9 responders experienced an increase in seizure frequency and seizure days after 4-8 months continuing with the levetiracetam treatment at the last effective dosage. Levetiracetam was well tolerated by all dogs and sedation was the only side-effect reported in just one of the 14 dogs.