Treatment of peritonitis.

In summary, peritonitis in the horse is a potentially life-threatening disease that must be treated promptly and aggressively. Therapy should be aimed at reducing systemic shock and hypovolemia, correction of the primary cause, antibiotic and anti-inflammatory therapy, and abdominal drainage and lavage. The prognosis depends on the ability to diagnose and treat the underlying cause and prevent the development of complications. Mortality rates can be as high as 59.7%, with horses developing postoperative peritonitis having a 56% mortality rate. Long-term complications like adhesion formation or internal abscesses may further reduce the survival rate. The prognosis is best determined by an early and quick response to aggressive treatment.     

Integration of soil, crop and weed management in low-external-input farming systems

Greater adoption and refinement of low-external-input (LEI) farming systems have been proposed as ways to ameliorate economic, environmental and health problems associated with conventional farming systems. Organic soil amendments and crop diversification are basic components of LEI systems. Weed scientists can improve the use of these practices for weed management by improving knowledge of four relevant ecological mechanisms. First, multispecies crop rotations, intercrops and cover crops may reduce opportunities for weed growth and regeneration through resource competition and niche disruption. Secondly, weed species appear to be more susceptible to phytotoxic effects of crop residues and other organic soil amendments than crop species, possibly because of differences in seed mass. Thirdly, delayed patterns of N availability in LEI systems may favour large-seeded crops over small-seeded weeds. Finally, additions of organic materials can change the incidence and severity of soil-borne diseases affecting weeds and crops. Our research on LEI sweetcorn and potato production systems in central and northern Maine (USA) suggests that these mechanisms can reduce weed density and growth while maintaining crop yields. Low-external-input farming systems will advance most quickly through the application of interdisciplinary research focused on these and other ecological mechanisms.     

Temporal patterns of growth hormone in blood and seminal plasma of mature dairy bulls

This study was conducted to determine if growth hormone (GH) concentration in bovine seminal plasma would be proportional to but less variable than blood plasma GH. The relationship between GH in blood and seminal plasma was also examined critically. Blood samples were collected at 15-min intervals for 5.75 h, while semen was collected at 30-min intervals over the same time period. Average seminal plasma GH concentrations were 3.2 times higher (P less than .05) than blood plasma GH concentrations (40.4 +/- 15.8 ng/ml vs 12.6 +/- 1.2 ng/ml, respectively). The within animal correlation between blood and seminal plasma was consistently low and nonsignificant (P greater than .05). Overall blood plasma GH and seminal plasma GH concentrations were weakly correlated (r = .418; P greater than .05) among bulls. A predictable relationship between blood and seminal plasma GH concentration does not exist under the conditions of this study.     

Effects of thyroxine and growth hormone treatment of dairy cows on milk yield, cardiac output and mammary blood flow

Four cows received thyroxine injections (T4; 20 mg/d) and three cows received growth hormone injections (GH; 44 mg/d) for 4 d during successive 16-d experimental periods. Measurement was made of milk yield, protein yield, mammary tyrosine and phenylalanine uptake, blood plasma hormone concentrations, mammary blood flow and cardiac output. Milk yield increased by 25% with T4 and 21% with GH treatment. Milk protein content tended to decline during T4 treatment and increase following GH treatment. Cardiac output increased by 8.9 liter/min (20%) and 4.6 liter/min (10%) with T4 and GH injection. Mammary blood flow (half-udder) increased from 3.6 to 4.9 liter/min (35%) and from 3.3 to 4.4 liter/min (33%) with T4 and GH treatment, respectively. These increases calculated on a whole-udder basis, accounted for 28% (T4) and 48% (GH) of the increases in cardiac output. The proportion of cardiac output perfusing the (whole) udder increased to 19.1% (T4) and 18.7% (GH), increases of 17 and 30%, respectively. Heart rate increased with T4 (but not GH treatment) from 80 to 115/min. Ratio of blood flow to milk yield was not changed by either treatment. The proportion of cardiac output perfusing the udder likely plays a major role in facilitating the partitioning of nutrients for milk synthesis.     

Ocular distribution and toxicity of intravitreal injection of triamcinolone acetonide in normal equine eyes

Objective  To determine ocular distribution and toxicity of a single injection of intravitreal triamcinolone acetonide (TA) in normal horses.
Animals studied  Six adult horses, donated to North Carolina State University.
Procedures  Six horses were injected intravitreally with either 10, 20, or 40 mg ( n  = 2 each) of TA. The opposite eye of each horse was injected with balanced salt solution (BSS). Ocular toxicity was assessed by biomicroscopy, tonometry, indirect ophthalmoscopy, and electroretinogram. Aqueous humor (AH), vitreous humor (VH), and plasma samples were collected. Horses were euthanized 7 or 21 days after injection and eyes enucleated for histopathology. TA concentrations in AH, VH, and plasma were measured by HPLC.
Results  Three control eyes and one TA eye developed inflammation after injection or collection of AH. Positive bacterial cultures ( Corynebacterium spp., Staphylococcus spp., and Streptococcus spp.) were obtained from three of these eyes. Other than transient corneal edema in TA injected eyes, which resolved by 7 days after injection, no other changes were observed. TA crystals were visible within the vitreous body. No evidence of TA toxic effect was noted on histopathology. TA was detected in all AH and VH samples from treated eyes following injection. Drug was not detected in the plasma.
Conclusions  There was no evidence of overt toxicity from intravitreal TA in normal horses and a single intravitreal injection resulted in TA ocular levels for 21 days. However, the risk for bacterial infections with intravitreal injection or anterior chamber aspirations in horses is high. Use of topical and systemic antibiotics after injection is recommended.     

Pinch-induced behavioral inhibition ('clipnosis') in domestic cats

Research has documented immobilization of rodents, rabbits, guinea pigs and dogs by mechanical means, typically using neck clips or inversion ('animal hypnosis'). In contrast, only a few studies of mechanical immobilization of cats are available, although some success has been reported in the literature. Domestic cats may be effectively immobilized by clips placed along the animal's dorsum. We use the term 'pinch-induced behavioral inhibition' (PIBI) for this behavior because it describes both the method and the response, while avoiding the more anthropomorphic term 'hypnosis'. We investigated the effectiveness of PIBI and its neurological and habituation effects in healthy cats and cats with idiopathic cystitis (IC). Although not all cats were susceptible to PIBI and effectiveness varied among individuals, PIBI was useful for gentle restraint in most cats.