Did You Ever Hear the One About the Horse that Could Count?

Did You Ever Hear the One About the Horse that Could Count?

Front Psychol. 2012;3:357

Authors: Beran MJ

PMID: 23049522 [PubMed – as supplied by publisher]

A questionnaire study on parasite control practices on UK breeding Thoroughbred studs.

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A questionnaire study on parasite control practices on UK breeding Thoroughbred studs.

Equine Vet J. 2012 Jul;44(4):466-71

Authors: Relf VE, Morgan ER, Hodgkinson JE, Matthews JB

Abstract
REASONS FOR PERFORMING STUDY: Improved education of veterinarians and equine owners/managers is essential in implementing parasite control strategies that are less reliant on chemicals.
METHODS: This questionnaire study, conducted on 61 UK Thoroughbred (TB) establishments during 2009 and 2010, was designed to obtain an understanding of current helminth control practices on studs. To our knowledge, this is the first occasion that statements obtained from TB studs via questionnaire have been supported by statistical analysis.
RESULTS: Despite many respondents indicating high levels of concern regarding anthelmintic resistance, 56% of these establishments that received visiting equines co-grazed these animals with permanent stock and <74% administered anthelmintics prior to integration. In the 12 months preceding the study, most respondents administered frequent macrocyclic lactone (ML) treatments, with none appearing to leave any animals in groups untreated at each administration. Indiscriminate whole group treatments with MLs and movement of animals to 'clean grazing' post treatment (reported by >25% of respondents), indicates that many stud owners/managers are not aware of the strong risk factors for the development of anthelmintic resistance. Few studs had conducted faecal egg count (FEC) analysis in the past and only 22% indicated that they considered this form of analysis beneficial in determining anthelmintic choice.
CONCLUSIONS AND POTENTIAL RELEVANCE: The challenge now is to convince stud owners/managers to deviate from their current practices to control strategies that are more likely to preserve anthelmintic efficacy. Veterinarians need to get more involved in implementing these control strategies, with better emphasis placed on the role of diagnostic tests in facilitating targeted treatments and in investigating anthelmintic sensitivity in the associated nematode populations.

PMID: 22050130 [PubMed – indexed for MEDLINE]

Mating behavior increases workload of the heart in Thoroughbred stallions.

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Mating behavior increases workload of the heart in Thoroughbred stallions.

J Vet Med Sci. 2012 Apr;74(4):423-8

Authors: Hatazoe T, Kubota C, Fujiki M, Misumi K

Abstract
To evaluate the influence of mating behavior on cardiac function, changes in heart rate (HR), electrocardiogram (ECG), hematocrit (Hct) and serum concentration of alpha-atrial natriuretic peptide (alpha-ANP) were evaluated in 10 clinically sound Thoroughbred stallions before and after mating behavior. The stallions were submitted twice to experimental pseudomating in the same month in 2009 and 2010. Measurements and blood samples were collected at a stable before mating (baseline) and at a covering yard before and after mating. ECG was recorded by a Holter-ECG system. Arrhythmias were detected in 5 stallions before or after mating behavior. Minimum HR (HRmin), maximum HR (HRmax) and HR recorded when the stallions entered into yard (HRent) and ejaculated (HRejc) were 34.2 ± 3.7, 168.9 ± 14.2, 141.8 ± 35.3 and 142.6 ± 27.3 beats/min, respectively. Time from entrance into the yard to ejaculation (mating time; MT) ranged from 30 to 2,103 sec and was highly correlated with HRent (r=-0.82) and the time required for attaining HRmax after entrance into the yard (dT HRmax) (r=0.87). Hct and serum alpha-ANP concentration significantly increased after ejaculation (60.0 ± 3.2%, P<0.0001, and 1.54 ± 0.61 ng/ml, P=0.0353) compared with the baselines values (46.9 ± 4.4%, 1.40 ± 0.60 ng/ml). HRent and Hct were significantly higher in the stallions with an MT of less than 5 min (n=5) compared with those (n=5) with an MT of more than 5 min (P=0.0324 and P=0.0082). Mating behavior increases the workload of the heart in Thoroughbred stallions.

PMID: 22123303 [PubMed – indexed for MEDLINE]

Complex dental structure and wear biomechanics in hadrosaurid dinosaurs.

Complex dental structure and wear biomechanics in hadrosaurid dinosaurs.

Science. 2012 Oct 5;338(6103):98-101

Authors: Erickson GM, Krick BA, Hamilton M, Bourne GR, Norell MA, Lilleodden E, Sawyer WG

Abstract
Mammalian grinding dentitions are composed of four major tissues that wear differentially, creating coarse surfaces for pulverizing tough plants and liberating nutrients. Although such dentition evolved repeatedly in mammals (such as horses, bison, and elephants), a similar innovation occurred much earlier (~85 million years ago) within the duck-billed dinosaur group Hadrosauridae, fueling their 35-million-year occupation of Laurasian megaherbivorous niches. How this complexity was achieved is unknown, as reptilian teeth are generally two-tissue structures presumably lacking biomechanical attributes for grinding. Here we show that hadrosaurids broke from the primitive reptilian archetype and evolved a six-tissue dental composition that is among the most sophisticated known. Three-dimensional wear models incorporating fossilized wear properties reveal how these tissues interacted for grinding and ecological specialization.

PMID: 23042891 [PubMed – in process]

Prevalence, intensity and seasonality of gastrointestinal parasites in abattoir horses in Germany.

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Prevalence, intensity and seasonality of gastrointestinal parasites in abattoir horses in Germany.

Parasitol Res. 2012 Oct 11;

Authors: Rehbein S, Visser M, Winter R

Abstract
Prevalence and intensity of gastrointestinal parasites were studied through a longitudinal survey in 400 horses over a 17-month period in an abattoir in Germany. Three hundred and ten horses (77.5 %) were demonstrated harbouring endoparasites either by direct recovery of parasites from the digestive tract and/or in terms of faecal egg counts (strongyles). The following parasites were found (percentage prevalence, range of counts): Gasterophilus intestinalis larvae (2.25 %, 1-154), Gasterophilus nasalis larvae (0.25 %, 44), Trichostrongylus axei (11.0 %, 1-3,620), Habronema majus (8.0 %; 1-422), Habronema muscae (26.5 %, 1-3,563), Habronema spp. fourth-stage larvae (5.5 %; 1-1,365), Parascaris equorum (total prevalence 11.3 %; adults 8.8 %, 1-178; fourth-stage larvae 2.5 %, 5-2,320), Anoplocephala perfoliata (28.5 %, 1-2,013) and Paranoplocephala mamillana (1.0 %, 1-11). Strongyle eggs (≥10 eggs per gram of faeces) were recorded in 60.8 % of the horses (10-6,450 eggs per gram of faeces).Prevalences of infection with T. axei, P. equorum and strongyles did not show a correlation to specific seasons. In contrast, a significant variation among seasons of collection was shown for the infection rates of Habronema spp. (p < 0.05) and A. perfoliata (p < 0.001). Seasonal prevalence of Habronema spp. infection was significantly (p < 0.01) higher in summer (39.0 %), autumn (34.8 %) and winter (36.5 %) than in spring (18.7 %), and A. perfoliata were significantly (p < 0.001) more often recorded during autumn (36.1 %) and winter (36.5 %) than in spring (17.3 %) and summer (15.9 %). Prevalences of T. axei, Habronema spp., strongyles and A. perfoliata in male and female horses were almost alike, but ascarids were significantly (p = 0.025) more often recorded in male than in female horses.

PMID: 23052780 [PubMed – as supplied by publisher]

Gastric emptying and intestinal absorption of electrolytes,and exercise performance in electrolyte supplemented horses.

Gastric emptying and intestinal absorption of electrolytes,and exercise performance in electrolyte supplemented horses.

Exp Physiol. 2012 May 11;

Authors: Lindinger MI, Ecker GL

Abstract
Horses lose considerably more electrolytes through sweating during prolonged exercise than can be readily replaced through feeds. The present study tested an oral electrolyte supplement (ES) designed to replace sweat electrolyte losses. We measured gastric emptying of 3L of ES (using gamma imaging of 99Tc- sulfide colloid), the absorption of Na+ and K+ from the g.i. tract using 24Na+ and 42K+, and the distribution of these ions in the body by measuring radioactivity within plasma and sweat during exercise. Three L of ES emptied from the stomach as fast as water, with a half time of 47 minutes, and appeared in plasma by 10 minutes after administration (n = 4 horses). Peak values of plasma 24Na+ and 42K+ radioactivity occurred at 20-40 minutes and a more rapid disappearance of K+ radioactivity from plasma was indicative of movement of K+ into cells (n = 3 horses). In a randomized crossover experiment (n = 4 horses), 1h after administration of placebo (water), 1 L or 3 L of ES containing 24Na+, horses exercised on a treadmill at 30% of peak VO2 until voluntary fatigue. 24Na+ appeared in sweat at 10 minutes of exercise, and when horses received 3L of ES the duration to voluntary fatigue was increased in all horses by 33+10 %. It is concluded that an oral ES designed to replace sweat ion losses was rapidly emptied from the g.i. tract, was rapidly absorbed in the upper intestinal tract and rapidly distributed within the body. The ES clearly served as a reservoir to replace sweat ion losses during exercise, and administration of ES prior to exercise resulted in increased duration of submaximal exercise.

PMID: 22581743 [PubMed – as supplied by publisher]

Sublingual administration of detomidine in horses: Sedative effect, analgesia and detection time.

Sublingual administration of detomidine in horses: Sedative effect, analgesia and detection time.

Vet J. 2012 Oct 10;

Authors: L’ami JJ, Vermunt LE, van Loon JP, Sloet van Oldruitenborgh-Oosterbaan MM

Abstract
A single dose of 40μg/kg bodyweight (BW) of oromucosal detomidine gel was administered sublingually to 10 healthy Dutch Warmblood mares aged 7±4years (mean±SD) and BW 580±69kg. Blood and urine samples were collected before and for 8days following administration and evaluated qualitatively in an FEI Reference Laboratory and quantitatively in a research laboratory. Clinical effects were evaluated at baseline and for 24h after administration. Sedation was determined using head height and scores of reaction to auditory and mixed auditory/sensory stimuli. Mechanical nociceptive thresholds (MNTs) were assessed using pressure algometry to evaluate analgesia. Heart rate (HR) was measured and ataxia scored. All horses were considered negative for detomidine in blood samples by 48h post-administration and in urine by 60h. These results indicated that a safe withdrawal time for detomidine oromucosal gel may be 72h following a single sublingual administration of 40μg/kgBW. Decreases in HR and head height were maximal at 40 and 60min post-administration, respectively. The maximal decrease in response to stimuli was observed at 100min. Ataxia was maximal at 60min. At 40 and 80min MNTs were significantly increased compared to baseline. All parameters, except the MNTs of two locations, which were decreased, returned to baseline values within 24h post-administration.

PMID: 23062724 [PubMed – as supplied by publisher]

Field efficacy of praziquantel oral paste against naturally acquired equine cestodes in Ethiopia.

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Field efficacy of praziquantel oral paste against naturally acquired equine cestodes in Ethiopia.

Parasitol Res. 2012 Sep 22;

Authors: Getachew AM, Innocent G, Proudman CJ, Trawford A, Feseha G, Reid SW, Faith B, Love S

Abstract
The efficacy of an oral formulation of praziquantel (Equitape, Horse paste, Fort Dodge) in the reduction of cestode egg counts and serum antibody level against Anoplocephala perfoliata was assessed in 44 donkeys under field conditions. The donkeys were confirmed both by faecal examination and serum antibody assessed by an enzyme-linked immunosorbent assay to have natural infection with tapeworms. The donkeys were randomly allocated into treatment (n = 22) and control (n = 22) groups. The treatment group was treated with both praziquantel and ivermectin (Ivomec, Merial) at a dose rate of 1 mg/kg and 200 μg/kg, respectively while the control group was treated only with ivermectin. Faecal samples were collected before treatment (day-0) and 2, 6, 8, 12, and 16 weeks post-treatment while blood samples were collected before treatment and 8 and 16 weeks after treatment and analysed. The results of the study demonstrated that praziquantel paste was highly effective in reducing cestode eggs in donkeys and had an efficacy of more than 99 % until week 16 (day 112). No cestode egg reappearance by 16 weeks post-treatment in any animal in the treatment group was observed while donkeys in the control group continued shedding cestode eggs. The immunological assay also showed a significant reduction in serum antibody level against A. perfoliata in treated donkeys compared to the control group (p = 0.0001). This marked decrease in serum antibody level indicates reduced risk of cestode-associated colic and other gastrointestinal disorders and clinical diseases. No adverse reactions or clinical effects were encountered in any animal within either group throughout the trial period.

PMID: 23001508 [PubMed – as supplied by publisher]

Psychological factors affecting equine performance.

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Psychological factors affecting equine performance.

BMC Vet Res. 2012 Sep 27;8(1):180

Authors: McBride SD, Mills DS

Abstract
ABSTRACT: For optimal individual performance within any equestrian discipline horses must be in peak physical condition and have the correct psychological state. This review discusses the psychological factors that affect the performance of the horse and, in turn, identifies areas within the competition horse industry where current behavioral research and established behavioral modification techniques could be applied to further enhance the performance of animals. In particular, the role of affective processes underpinning temperament, mood and emotional reaction in determining discipline-specific performance is discussed. A comparison is then made between the training and the competition environment and the review completes with a discussion on how behavioral modification techniques and general husbandry can be used advantageously from a performance perspective.

PMID: 23016987 [PubMed – as supplied by publisher]

Estimating variance components and predicting breeding values for eventing disciplines and grades in sport horses.

Estimating variance components and predicting breeding values for eventing disciplines and grades in sport horses.

Animal. 2012 Sep;6(9):1377-88

Authors: Stewart ID, White IM, Gilmour AR, Thompson R, Woolliams JA, Brotherstone S

Abstract
Eventing competitions in Great Britain (GB) comprise three disciplines, each split into four grades, yielding 12 discipline-grade traits. As there is a demand for tools to estimate (co)variance matrices with a large number of traits, the aim of this work was to investigate different methods to produce large (co)variance matrices using GB eventing data. Data from 1999 to 2008 were used and penalty points were converted to normal scores. A sire model was utilised to estimate fixed effects of gender, age and class, and random effects of sire, horse and rider. Three methods were used to estimate (co)variance matrices. Method 1 used a method based on Gibbs sampling and data augmentation and imputation. Methods 2a and 2b combined sub-matrices from bivariate analyses; one took samples from a multivariate Normal distribution defined by the covariance matrix from each bivariate analysis, then analysed these data in a 12-trait multivariate analysis; the other replaced negative eigenvalues in the matrix with positive values to obtain a positive definite (co)variance matrix. A formal comparison of models could not be conducted; however, estimates from all methods, particularly Methods 2a/2b, were in reasonable agreement. The computational requirements of Method 1 were much less compared with Methods 2a or 2b. Method 2a heritability estimates were as follows: for dressage 7.2% to 9.0%, for show jumping 8.9% to 16.2% and for cross-country 1.3% to 1.4%. Method 1 heritability estimates were higher for the advanced grades, particularly for dressage (17.1%) and show jumping (22.6%). Irrespective of the model, genetic correlations between grades, for dressage and show jumping, were positive, high and significant, ranging from 0.59 to 0.99 for Method 2a and 0.78 to 0.95 for Method 1. For cross-country, using Method 2a, genetic correlations were only significant between novice and pre-novice (0.75); however, using Method 1 estimates were all significant and low to moderate (0.36 to 0.70). Between-discipline correlations were all low and of mixed sign. All methods produced positive definite 12 × 12 (co)variance matrices, suitable for the prediction of breeding values. Method 1 benefits from much reduced computational requirements, and by performing a true multivariate analysis.

PMID: 23031512 [PubMed – in process]