American trypanosomiasis infection in fattening pigs from the south-east of Mexico

American Trypanosomiasis (AT) is an infectious parasitic disease produced by the protozoa Trypanosoma cruzi (T. cruzi). Infection is acquired by vectorial via but can also be transmitted congenitally, by ingestion of an infected host, by transfusion with contaminated blood or transplant of organs from an infected donor. Currently, AT is widely distributed from the South of the United States to South America. In Mexico, the presence of the parasite has been reported throughout the country where several reservoirs such as dogs, opossums, rats and cats have been identified. Yucatan is in the south-east of Mexico where AT is endemic and has been reported since 1940s. There is little information about the role of pigs as reservoirs of T. cruzi. The frequency of specific antibodies against T. cruzi was determined in fattening pigs from Yucatan, Mexico. After sampling in the 3 main areas of pig production in the state, IgG ELISA and Western blot were performed to identify seropositive cases. Association of farm size, farm area and production system with infected pigs was evaluated. From 273 sampled pigs, 5.4% (n = 15) positive cases were found. No association with evaluated factors and infected pigs was found. Pigs are also reservoirs of T. cruzi in the studied area. These findings are considered important to improve vectorial control in the area in order to avoid the parasite infection in animal populations destined for human consumption and avoid further transmission to humans.     

Pharmacokinetics of ruminally dosed sodium [36Cl]chlorate in beef cattle

The recently recognized potential of sodium chlorate as a possible preharvest food safety tool for pathogen reduction in meat animals has spurred interest in the pharmacokinetics of intraruminally dosed chlorate. Six Loala cattle were assigned (one heifer and one steer per treatment) to one of three intraruminal doses of radiolabeled sodium [36Cl]chlorate (21, 42, or 63 mg/kg body weight) administered in four equal aliquots over a 24-h period. Blood and serum were collected (29 samples in 48 h). Total radioactive residues were measured and the radioactive moieties were speciated. Chlorate appeared rapidly in blood and serum after dosing. For animals administered a dose of 42 or 63 mg/kg, the half-life of absorption was estimated at 0.6-0.9 h. Serum chlorate concentrations progressively increased with aliquot administration until peaking at 6-21 parts per million at 26 h. Between aliquot administrations, serum chlorate levels typically peaked in 3.5 h or less. The half-life of chlorate elimination ranged between 6.9 and 11 h, depending on the dose. Ultimately, absorption of chlorate removes it from its desired site of action, the lower gastrointestinal tract, thereby reducing its efficacy. Further research is needed to develop a chlorate formulation that will allow passage to the lower gastrointestinal tract.     

Improved husbandry to control an outbreak of rainbow trout fry syndrome caused by infection with Flavobacterium psychrophilum

CASE DESCRIPTION: A cohort of 35,200, 13-week-old, female rainbow trout at a fish farm was evaluated because of a 2-week history of anorexia and lethargy and a mortality rate of approximately 100 fish/d. CLINICAL FINDINGS: Affected fish were lethargic and thin and had disequilibrium, bilateral exophthalmia, pale red gills and kidneys, red-tinged coelomic fluid, and pale brown livers. Some fish were differentially pigmented bilaterally. The presumptive diagnosis was bacterial or viral septicemia. The definitive diagnosis was rainbow trout fry syndrome caused by infection with Flavobacterium psychrophilum. TREATMENT AND OUTCOME: A strategy for controlling the outbreak based on reducing pathogen numbers in affected tanks and reducing pathogen spread among tanks was developed. The option of treating with antimicrobial-medicated feed was discussed with the farmer, but was declined. After changes were made, mortality rate declined quickly, with no more deaths within 10 days after the initial farm visit. CLINICAL RELEVANCE: Bacterial coldwater disease is the most common manifestation of infection with F psychrophilum in fingerling and adult rainbow trout. However, the organism can also cause rainbow trout fry syndrome. This condition should be included on a list of differential diagnoses for septicemia in hatchery-reared rainbow trout fry.     

Response of healthy dogs to infusions of human serum albumin

OBJECTIVE: To evaluate the clinical and immunologic response in healthy dogs to infusions of human serum albumin (HSA). ANIMALS: 9 healthy purpose-bred mixed-breed dogs. PROCEDURES: Each dog was administered a 25% HSA solution once or twice. Various physical examination and laboratory variables were serially evaluated. Antibody against HSA was assayed before and after infusion by use of an ELISA. Intradermal testing was also conducted. A repeated-measures ANOVA or Friedman repeated-measures ANOVA on ranks was used to compare results for the variables. RESULTS: Adverse clinical reactions were observed after the first or second infusion in 3 dogs. Anaphylactoid reactions were observed in 1 of 9 dogs during the first infusion and in 2 of 2 dogs administered a second infusion. Two dogs developed severe edema and urticaria 6 or 7 days after an initial infusion. All dogs developed anti-HSA antibodies. Positive responses for ID tests were observed in 8 of 9 dogs. Short-term increases were detected in blood protein, total bilirubin, and calcium concentrations after HSA infusion. Serum cholesterol concentrations and platelet counts decreased after HSA infusion. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of HSA resulted in profound reactions in 2 of 9 dogs administered a single infusion and in 2 of 2 dogs administered a second infusion. This indicates that there is risk of life-threatening adverse reactions to HSA infusion in healthy dogs.     

A potentized homeopathic drug, Arsenicum Album 200, can ameliorate genotoxicity induced by repeated injections of arsenic trioxide in mice

Groundwater arsenic contamination has become a menacing global problem. No drug is available until now to combat chronic arsenic poisoning. To examine if a potentized homeopathic remedy, Arsenicum Album-200, can effectively combat chronic arsenic toxicity induced by repeated injections of Arsenic trioxide in mice, the following experimental design was adopted. Mice (Mus musculus) were injected subcutaneously with 0.016% arsenic trioxide at the rate of 1 ml/100 g body weight, at an interval of 7 days until they were killed at day 30, 60, 90 or 120 and were divided into three groups: (i) one receiving a daily dose of Arsenicum Album-200 through oral administration, (ii) one receiving the same dose of diluted succussed alcohol (Alcohol-200) and (iii) another receiving neither drug, nor succussed alcohol. The remedy or the placebo, as the case may be, was fed from the next day onwards after injection until the day before the next injection, and the cycle was repeated until the mice were killed. Two other control groups were also maintained: one receiving only normal diet, and the other receiving normal diet and succussed alcohol. Several toxicity assays, such as cytogenetical (chromosome aberrations, micronuclei, mitotic index, sperm head anomaly) and biochemical (acid and alkaline phosphatases, lipid peroxidation), were periodically made. Compared with controls, the drug fed mice showed reduced toxicity at statistically significant levels in respect of all the parameters studied, thereby indicating protective potentials of the homeopathic drug against chronic arsenic poisoning.     

Thirteen cases of tetanus in dogs

The records of 13 dogs with tetanus were reviewed, 12 of the dogs survived and were discharged, but the other died as a result of the acute onset of hyperthermia. Long-term follow up was available for 10 of the survivors of which nine were reported to be normal. One case was euthanased after a cervical spine fracture four months after it was discharged. Complications encountered during management included aspiration pneumonia in three cases, urinary tract infection in two cases, and upper respiratory tract obstruction, hiatal hernia, coxofemoral luxation, seizures and respiratory arrest in one case each. None of the dogs required ventilatory support, and the complications were managed successfully. The dogs were nursed intensively and monitored carefully.     

Hormonal responses to acute exercise, training and overtraining. A review with emphasis on the horse

Overtraining is an imbalance between training and recovery leading to symptoms associated with a neuroendocrine dysbalance called the overtraining syndrome, a disease characterized by behavioral, emotional and physical symptoms similar with depression. Although the prevalence of overtraining is high in human and equine athletes, at present no sensitive and specific test is available to prevent or diagnose overtraining. Nowadays, it is believed that combination of different (hormonal) parameters appear to be the best indicators of overtraining. Therefore, this review provides a summary of previous literature examining the response of the hypothalamic-pituitary-adrenal (HPA) axis and the growth hormone-insulin-like growth factor-I (GH-IGF-I) axis to acute and chronic exercise as well as overtraining in humans and horses. The exercise induced hormonal responses seem to be equal for the equine as well as the human athlete, which makes comparisons possible. Repeated bouts of exercise are suggested to provide a way to detect subtle changes in hormonal responses in the individual athlete, which may make them an important tool in detecting early overtraining. This should be combined with corticotropin releasing hormone (CRH) stimulation tests and basal ACTH and GH pulsatility determination. Further research is needed to establish the correct training intensity and rest period for the exercise test in equines.     

Determination of Oestrous Cycle of the Rats by Direct Examination: How Reliable?

For determination of the oestrous cycle in rats classical Papanicolaou technique has long been used successfully. Instead of using many stains in Papanicolaou, staining the vaginal secretions with only methylene blue has also been defined. Recently a new technique in which vaginal samples are directly examined under light microscope has been introduced. The aim of this study was to assess the reliability of this new technique by comparing it with the classical staining techniques. From 20 Wistar rats 60 vaginal samples were collected with a micropipette, three from each. Briefly, the vagina was flushed two to three times then the fluid was placed onto a glass slide. The fluid was equally distributed onto three glass slides. The glass slides were coded. Two samples were stained with Papanicolaou and methylene blue while the other one was examined directly. Determination of the phases of the oestrous cycle was made by the same histologist who was blinded to the groups and coding system. After determination of the oestrous phase in all samples, the results were compared and it was found that the results were matching. In conclusion, the same results can be obtained with the direct examination technique and this technique is reliable, so there is no need to use relatively time-consuming, less practical and more expensive techniques such as Papanicolaou or methylene blue.