Temporal-spatial epidemiology of foot-and-mouth disease outbreaks in Mongolia, 2000 – 2002

Prior to 2000, foot-and-mouth disease (FMD) had not been observed in Mongolia since 1973; however, between April 2000 and July 2002, Mongolia reported 44 FMD outbreaks that affected cattle, sheep, goats, and camels. The objectives of this study were to describe the distributions of the 44 reported FMD outbreaks in Mongolia and to assess their spatial clustering and directions of movement. Official reports were collected to obtain the number and species of animals both affected and at risk, and the date and geographical coordinates of each outbreak. Significant global and local spatial clusters of reported FMD outbreaks were identified. Disease spread during the second epidemic moved 76° northeast and the spread of the disease during the third epidemic moved 110° northwest. FMD outbreaks were clustered intensely close to other FMD-positive counties. These findings can be used in the future to help plan prevention and control measures in high risk areas.     

Prevalence of dental disorders in 483 horses and ponies

Prevalence of dental disorders in 483 horses and ponies Five equine veterinarians working at three equine referral hospitals examined the oral cavity of 483 horses and ponies prior to surgery, to gain information about the prevalence of common dental disorders in the horse. A thorough examination, using hands/fingers, a full-mouth speculum, a dental mirror and a good light source, is essential to detect such disorders. Many horses examined needed dental attention even though there were no problems with mastication or riding. The most detected abnormalities were sharp enamel points on the buccal side of the upper arcade and the lingual side of the lower arcade, and hooks at 106/206 and 311/411. Regular dental care would improve the condition and welfare of horses.     

Meperidine prolongs lidocaine caudal epidural anaesthesia in the horse

The aim of the study was to evaluate and compare the effects of caudal epidural administration of meperidine (MP), lidocaine (LD), and a combination of the two (MPLD) in six mature saddle horses. Horses were randomly assigned to receive three treatments (MP 0.3 mg/kg; LD 0.2 mg/kg; and MPLD: MP 0.3 mg/kg and LD 0.2 mg/kg), with at least 1 week between treatments. Drugs were injected into the epidural space between the first and second coccygeal areas in conscious standing horses. Analgesia, ataxia, sedation, cardiovascular and respiratory effects, and rectal temperature were recorded at different intervals before (baseline) and after administration. Epidural administration of MPLD resulted in a longer duration of analgesia of the tail, perineum, and upper hind limb regions than did administration of MP or LD alone.     

Type and frequency of contacts between Belgian pig herds

Knowledge of the frequency of direct and indirect contacts between pig herds is a requirement for understanding the potential between-herd transmission of pathogens. Our aim was to investigate the different contacts between Belgian pig herds. We obtained data by conducting a postal survey on 421 pig herds in August 2005 and by analysis of available information on livestock movements in the national identification-and-registration database (18-months period in 2004-2006). Direct contacts included transports of pigs by onto-farm, off-farm and between-farm movements. Indirect contacts included vehicles entering the herd and visitors entering the stables. The median number of direct contacts per herd made by onto-farm movements was 0.2/month (Q1: 0; Q3: 0.5). About 1.2% of herds had > or = 3 onto-farm movements/month. We used a zero-inflated negative-binomial regression model to describe differences in the number of onto-farm movements according to herd size and herd type. Piglet multipliers followed by finishing herds were predicted to have the most onto-farm movements. Farrow-to-finishing herds made less movements compared to breeding herds. A median of 3997 between-farm movements/month was made in Belgium; these mainly concerned piglets. The median number of origin herds during an 8-month period for between-farm movements was 4 (Q1: 2; Q3: 8). For a typical 1-month period, we constructed directed graphs of between-farm piglet and replacement stock movements, illustrating potential receivers and distributors of infection. Of these between-farm movements, many were made over a short distance (median straight-line distance 19 km (Q1: 8; Q3: 36)). The median number of vehicles entering a herd and visitors entering the stables was 8/month (Q1: 6; Q3: 13) and 3/month (Q1: 2; Q3: 6) respectively. The number of indirect contacts by vehicles and persons were associated with herd size (Spearman's r: 0.7 and 0.2), herd type and other factors. Skewness of both direct and indirect contacts, illustrated that there was a wide variety in contact structure between pig herds in Belgium. Infection control might benefit by accounting for this variation in contacts and by targeting 'high-risk' herds in case of animal-disease emergencies.     

Analysis of the effect of the bovine adenosine triphosphate-binding cassette transporter G2 single nucleotide polymorphism Y581S on transcellular transport of veterinary drugs using new cell culture models

In commercial dairy production, the risk of drug residues and environmental pollutants in milk from ruminants has become an outstanding problem. One of the main determinants of active drug secretion into milk is the ATP-binding cassette transporter G2/breast cancer resistance protein (ABCG2/BCRP). It is located in several organs associated with drug absorption, metabolism, and excretion, and its expression is highly induced during lactation in the mammary gland of ruminants, mice, and humans. As a consequence, potential contamination of milk could expose suckling infants to xenotoxins. In cows, a SNP for this protein affecting quality and quantity of milk production has been described previously (Y581S). In this study, our main purpose was to determine whether this polymorphism has an effect on transcellular transport of veterinary drugs because this could alter substrate pharmacokinetics and milk residues. We stably expressed the wild-type bovine ABCG2 and the Y581S variant in Madin-Darby canine kidney epithelial cells (MDCKII) and MEF3.8 cell lines generating cell models in which the functionality of the bovine transporter could be addressed. Functional studies confirmed the greater functional activity in mitoxantrone accumulation assays for the Y581S variant with a greater relative V(MAX) value (P = 0.040) and showed for the first time that the Y581S variant presents greater transcellular transport of the model ABCG2 substrate nitrofurantoin (P = 0.024) and of 3 veterinary antibiotics, the fluoroquinolone agents enrofloxacin (P = 0.035), danofloxacin (P = 0.001), and difloxacin (P = 0.008), identified as new substrates of the bovine ABCG2. In addition, the inhibitory effect of the macrocyclic lactone ivermectin on the activity of wild-type bovine ABCG2 and the Y581S variant was also confirmed, showing a greater inhibitory potency on the wild-type protein at all the concentrations tested (5 μM, P = 0.017; 10 μM, P = 0.001; 25 μM, P = 0.008; and 50 μM, P = 0.003). Differential transport activity depending on the genotype together with the differential inhibition pattern might have clinical consequences, including changes in substrate pharmacokinetics (and subsequently pharmacodynamics) and more specifically, changes in secretion of ABCG2 substrates into milk, potentially implying important consequences to veterinary therapeutics.     

Quantification of melamine absorption, distribution to tissues, and excretion by sheep

Eight D?hne Merino rams were used to quantify apparent absorption, distribution to tissues, and excretion of dietary melamine in sheep. Two batches of concentrate pellets were made; one (CON) contained corn gluten meal with no detectable melamine and the other (MEL) contained corn gluten meal that was previously found to be highly contaminated with melamine at 15,117 mg/kg. The MEL pellets contained 1,149 mg/kg of melamine. During a 10-d adaptation period, all the animals received a forage-based diet supplemented with 600 g/d of the CON pellets. This was followed by an 8-d collection period during which 6 of the animals received MEL pellets and 2 received CON pellets. Melamine intake of sheep that received MEL pellets was 0.69 g/d. Blood samples were taken before first ingestion of MEL pellets on d 1 and again on d 3, 6, and 8 of the collection period for melamine and serum creatinine analyses. Feces and urine were collected quantitatively over the 8 d for proximate and melamine analyses. All the animals were slaughtered at the end of the trial, and samples of the LM, liver, kidneys, and abdominal fat were taken for melamine analysis. Data of the 2 sheep that received CON pellets for the duration of the trial confirmed that no melamine was detected in any of the samples, and no statistical analyses were performed on these data. The apparent digestibility or efficiency of absorption of ingested melamine was 76.7%. Melamine was detected in the urine, blood, muscle (LM), and fat tissue of all the sheep that received MEL pellets. Serum melamine concentrations reached 5.4 mg/kg on d 8 of the collection period, and the meat (LM) contained 9.6 mg/kg of melamine. Calculations on the partitioning of ingested melamine suggested that urine is the major excretion route accounting for 53.2%, whereas feces accounted for 23.3% of ingested melamine. Approximately 3.5% of the ingested melamine was detected in muscle. It was concluded that ingested melamine is highly absorbable from the small intestine and that a pathway exists for the distribution of dietary melamine to meat.