Factors influencing recovery from and duration of lameness in Michigan (USA) horses.

The objective of this study was to identify factors that may affect recovery from and duration of a case of lameness in a stratified random sample of Michigan horses. This was done using data from Phase-II of the Michigan equine monitoring system (MEMS Phase-II), the equine health-monitoring study [Kaneene et al., Prev. Vet. Med. 29 (1997b) 277-292; Ross and Kaneene, Prev. Vet. Med. 28 (1996a) 209-224; Ross and Kaneene, Prev. Vet. Med. 29 (1996b) 59-75; Ross et al., Am. J. Vet. Res. 59 (1997) 23-29]. In this study, statistical modelling was conducted to evaluate risk factors affecting recovery from and duration of lameness using multivariable logistic regression and Cox's proportional hazards regression, respectively. Of 357 incident lameness cases reported during MEMS Phase-II, 280 (78.6%) were reported to have recovered. The median duration of a lameness case was 18 days (1st quartile (Q): 1, maximum (Max): 360). A total of 296 of 357 (82.9%) incident lameness cases received some type of treatment. Of 619 total treatments used, 329 (53.2%) were administered, conducted or applied by a veterinarian. Horses experiencing other types of lameness were less likely to recover than those experiencing hoof lameness (odds ratio (OR) = 0.48; 95% CI: 0.25, 0.93). Horses that had participated in exercise-related activities during the study period and prior to the lameness were more likely to recover (OR = 1.91; 95% CI: 1.05, 3.50). Treatment of the lameness was associated with an increased likelihood of recovery (OR = 1.82; 95% CI: 0.97, 3.45). Cases with a veterinarian involved in the diagnosis were associated with a decreased risk of recovery (OR = 0.48; 95% CI: 0.27, 0.84) and a longer duration lameness (HR = 0.58; 95% CI: 0.45, 0.73)--which might indicate that these cases were more complex or severe. Although cases treated for lameness were more likely to recover (OR = 1.82; 95% CI: 1.05, 3.50), treatment was not associated with lameness duration (HR = 0.58; 95% CI: 0.45, 0.73).     

The Michigan equine monitoring system. I. Design, implementation and population estimates

The Michigan equine monitoring system (MEMS) was designed and implemented in the State of Michigan, starting in 1991. The program was designed systematically to track the State's equine population, its health, and its economic implications to the equine industry. The MEMS was designed as a two-phase program. Phase I (the population and economic survey; the subject of this paper) was designed to provide new and statistically valid information describing the size, composition, location and economic characteristics of the Michigan equine industry. A standardized questionnaire was used to collect data via mail, telephone and personal interviews.

Of the 3000 randomly selected list-frame samples, 2800 (93%) participated. However, 650 of these had no equids. There were 129932 equids reported compared with 160000 in 1984. The American Quarter Horse, Standardbred and Arabian breeds were the most numerous. Detailed results, including the size of equine operations/herds, uses, geographical distribution and the financial structure of the industry, are presented. A detailed account of the strategies used in designing and implementing the system is provided.     

The Michigan equine monitoring system. II. Frequencies and impact of selected health problems

A prospective study was designed to document the frequencies of equine health problems in the state of Michigan, USA. A total of 2469 horses from a random sample of 138 equine operations were monitored in the study in two 12-month periods: 1992–1993 and 1993–1994. All the major breeds of horses in the state were proportionately represented in the sample. Using weighted annual incidence densities as measures of disease frequencies, the 10 most frequently observed groups of health problems were (from most to least frequent) leg lameness, dermatological problems, respiratory problems, hoof and foot problems, reproductive problems, systemic problems, colic, whole body lameness, neurological problems and gastrointestinal problems (other than colic). This ranking of the top 10 health problems was different from the ranking provided by equine owners/operators at the beginning of the study.

Overall, very low specific mortality rates were observed in the study. However, the conditions that were associated with mortality resulted in fairly high case fatalities. The five specific illnesses that most commonly resulted in fatalities were (from greatest to least case fatality risk) systemic problems, colic, gastrointestinal problems (other than colic), neurological problems, and foot and hoof problems.

Impact of disease was evaluated in terms of average duration of a case and days lost for performance. Neurological problems, lameness and dermatological problems had the longest duration per case. Neurological problems, lameness, respiratory problems and gastrointestinal problems (other than colic) had the longest average days lost per case.     

Vegetative Endocarditis in Equids (1994–2006)

Background: Endocarditis is a rare heart condition with variable clinical expressions in equids. Risk factors for this disease are incompletely understood. Objective: Describe risk factors for endocarditis in equids. Animals: One hundred and fifty‐three equids admitted to Liège University, 9 diagnosed with endocarditis and 144 free from endocarditis but admitted to the hospital with a differential diagnosis including this disease. Methods: Retrospective case‐control study. Results: Equids with endocarditis were significantly younger (mean age = 4.84 ± 5.74 years) than control equids (mean age = 10.8 ± 7.73 years) (P= .01). No sex or breed predisposition was observed. Animals with hyperthermia (odds ratio [OR] = 24.4; confidence interval [CI] = 1.40–428), synovial distension (OR = 13.4; CI = 3.00–59.8), lameness (OR = 6.52; CI = 1.63–26.1), hyperglobulinemia (OR = 26.4; CI = 3.03–229), hypoalbuminemia (OR = 11.4; CI = 1.34–96.8), hyperfibrinogenemia (OR = 9.81; CI = 1.16–82.7), or leukocytosis (OR = 7.12; CI = 1.40–36.4) presented a significantly higher risk of having endocarditis than control horses. The presence of two of the clinical signs mentioned above significantly increased the probability of a diagnosis of endocarditis (P≤ .05). Conclusions and Clinical Importance: Age is associated with equine endocarditis. The diagnostic value of certain clinical signs and abnormalities in blood parameters in this disease are described.     

Operation-management factors associated with early-postnatal mortality of US foals

Of 7320 equine foals reported born alive during 1997 on 1043 operations that had equids on 1 January 1997, and that participated in the United States National Animal Health Monitoring System (NAHMS) Equine 1998 Study, 120 foals were reported to have died (by either euthanasia or natural causes) within the first 2 days of a live birth. The weighted estimate was 1.7% mortality (standard error=0.5) within the first 2 days of live birth for all foals born on operations in the 28 states included in the study.A multivariable logistic-regression model revealed that foals born in the southern region were more likely to have been reported to have died within the first 2 days of live birth than in the western region. In addition, the following operation-level factors were associated with increased odds of a foal dying within the first 2 days of live birth: not routinely testing newborn foals for adequate absorption of colostral immunoglobulins during the first 2 days of life; adding new resident equids to the operation during 1997; having non-resident equids stay on the operation for 1-30 days during 1997; never requiring an official health certificate (for operations that had non-resident equids stay on the operation for 1-30 days); using something other than straw or hay as the predominant bedding type; and feeding equids a vitamin-mineral supplement/premix with forage and/or grain.     

The use of a geographic information system in an epidemiological study of pseudorabies (Aujeszky''s disease) in Minnesota swine herds

A geographic information system (GIS) is being developed to study the spread of pseudorabies virus (PRV) among swine herds in the state of Minnesota. This GIS features an interface with a database management system that stores and manages pertinent data. These data include herd size, type of production system, degree of confinement, topographical features surrounding the farm, density of swine herds and distance to the closest quarantined herd. A pilot study was conducted in one Minnesota county with 280 swine herds, of which the PRV status was known in 115. Cox regression analysis was used to determine factors associated with herd PRV status. Relative risks (RR) and 95% confidence intervals (CI) were calculated. No association was detected between the PRV status of the herd and distance to the nearest county road, highway or quarantined herd. However, the following factors were significant: located within 1 km of a river or lake (RR, 0.524; CI, 0.328–0.828); farrow to finish (RR, 2.120; CI, 1.194–3.791); complete confinement (RR, 3.423; CI, 1.639–7.139); density of swine herds within a 5 km radius (RR, 1.036 per herd; CI, 0.996–1.064).     

Evaluation of prevalence and risk factors for methicillin-resistant Staphylococcus aureus colonization in veterinary personnel attending an international equine veterinary conference

Infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) are now increasingly being reported in animals and people who work with animals, including horses and horse personnel. The objectives of this study were to evaluate the prevalence of MRSA colonization in veterinary personnel attending an international equine veterinary conference, and to identify risk factors for MRSA colonization in this group. Volunteers were recruited at the conference to provide a single nasal swab and complete a questionnaire regarding contact with the human health care system, contact with horses, and personal hand hygiene. Colonization with MRSA was found in 26/257 (10.1%) of study participants. Multivariable analysis showed an increased risk of MRSA colonization associated with having been diagnosed with or having treated a patient diagnosed with MRSA colonization or infection in the last year (odds ratio [OR] 8.41, 95% confidence interval [CI] 1.51–49.92, P = 0.015; OR 3.27, 95% CI 1.05–10.11, P = 0.039, respectively), whereas hand washing between infectious cases (OR 0.27, 95% CI 0.11–0.72, P = 0.009) and hand washing between farms (OR 0.35, 95% CI 0.14–0.98, P = 0.047) were protective. The prevalence of MRSA colonization among equine veterinary personnel found in this study was high compared to that of other studies of the general population. These data support previous suggestions that equine veterinary personnel are at increased risk of colonization with MRSA. This is the first study to demonstrate a statistically significant association between hand hygiene practices and a measurable clinical outcome in veterinary medicine.     

A herd-level analysis of risk factors for antibodies to Sarcocystis neurona in Michigan equids

Equine protozoal myeloencephalitis (EPM) is a neurological disease of horses and ponies caused by infection of the central nervous system with the protozoan parasite Sarcocystis neurona. A herd-level analysis of a cross-sectional study of serum antibodies to S. neurona in Michigan equids was conducted, using data collected in 1997 for study that included 1121 equids from 98 Michigan horse farms. Our objective was to identify specific herd-level risk factors associated with seropositivity. We tested associations between herd seroprevalence and various farm-management practices (including feed-storage methods and wildlife control). Multivariable models were developed for three strata based on relative opossum abundance (opossum districts). Herd seroprevalence ranged from 0 to 100% (median=57%). No risk factor was significantly associated with herd seroprevalence at P< or = 0.05 in all opossum districts. Our results suggest that equids living in areas with large opossum populations might be infected with S. neurona from multiple sources.     

A multicenter, matched case-control study of risk factors for equine laminitis

Risk factors for equine laminitis were examined in a prospective case-control study of the 258 cases seen at six collaborating veterinary teaching hospitals over a 32-month period. Case-control pairs were matched on institution, clinician, and season of diagnosis. The 90% of case-control pairs (78 acute, 155 chronic) that had complete data for age, gender, and breed were used in separate conditional logistic-regression models for acute and chronic laminitis. There was an increase in risk for horses with acute laminitis from 5 to 7 years of age (OR 4.7, 95% CI 1.3–16) and from 13 to 31 years of age (OR 3.9, 95% CI 1.3–12) (both compared to <5 years); risk was increased for chronic laminitis from 10 to 14 years (OR 3, 95% CI 1.4–6.8) and from 15 to 38 years (OR 2.9, 95% CI 1.4–6.1) (both compared to <6 years). Mares — but not stallions — were more likely than geldings to develop acute laminitis (OR 2.6, 95% CI 1.1–6.2) and chronic laminitis (OR 2.0, 95% CI 1.1–3.6). In the small acute-laminitis data set, the breed variable was collapsed into three categories: Thoroughbred (THB, reference), the Quarter Horse (QH), and other (non-QH-THB). The non-QH-THB group was at increased risk of acute laminitis (OR 3.8, 95% CI 1.2–11.8). For the seven breed-group categories used in the chronic-laminitis model, however, all non-THB breed groups appeared significantly at risk as compared to the THB, with odds ratios ranging from 3.3 (95% CI 1.3–8.30) for the QH to 9.1 (95% CI 2.1–39.3) for ponies.     

Herd-level factors associated with isolation of Salmonella in a multi-state study of conventional and organic dairy farms II. Salmonella shedding in calves

The objective of this study was to evaluate associations between herd-level factors and the isolation of Salmonella in calves from dairy farms in Minnesota, Wisconsin, Michigan and New York. Study farms were 129 conventional and organic farms enrolled without regard to previous history of Salmonella infection. Herds were sampled at 2-month intervals over a 1-year period. Salmonella was isolated in fecal samples from 176 (3.8%) of 4673 preweaned calves with 40 (31.0%) of 129 farms having at least one positive calf sample over the course of the study. Multivariable logistic regression using the generalized estimating equations approach was used to evaluate risk factors for Salmonella shedding after adjustment for effects of herd size, season, state of origin and the multiple sampling occasions per herd. Factors retained in the final model that were associated with an increased odds for Salmonella shedding were lack of routine feeding of milk replacer containing antimicrobials to preweaned calves (OR = 2.8, 95% CI: 1.4, 5.8), use of maternity housing as a hospital area for sick cows more than once a month (OR = 2.1, 95% CI: 1.1, 4.0), and cow prevalence level by visit, categorized into the following four-levels: ≥20% (OR = 11.6, 95% CI: 5.7, 23.7), 10–19.9% (OR = 4.7, 95% CI: 2.0, 11.5), 0.1–9.9% (OR = 3.6, 95% CI: 1.5, 8.7) and 0% (reference level). Herd size was not associated with Salmonella shedding in the final multivariable model.     

Investigation of the aetiology of udder-thigh dermatitis in French dairy cattle

Udder-thigh dermatitis (UTD) is a common disease in dairy cattle. The aim of this study was to define UTD incidence, its risk factors and the involved pathogens. Of 74 respondents, 72 (97%) reported having had the disease. On those farms the incidence was 5.3 cases per 100 cow years. The odds ratio (OR) of UTD in primiparous compared to multiparous cows was 23.4 (95% CI 17.3-33.8). Compared to tied stalls, the ORs of UTD were 0.65 (95% CI 0.45-0.92) and 0.43 (95% CI 0.24-0.71) for free stalls and straw yards, respectively. Udder oedema was reported in 98.3% of cows with UTD. The most common bacteria isolated from affected skin were Fusobacterium spp. (12/14 cases). This study suggests that UTD management should focus on local treatment, reducing udder oedema and increasing exercise.     

Risk factors for owner-reported occurrence of equine protozoal myeloencephalitis in the US equine population

BACKGROUND: Equine protozoal myeloencephalitis (EPM) is a serious and often fatal neurologic disease of horses, but few studies have investigated risk factors. OBJECTIVES: To evaluate operation- and individual-level factors associated with likelihood of the occurrence of EPM. ANIMALS: Data were collected as part of a study of the US equine industry from 1,178 operations representing 83.9% of horses and 51.6% of operations with > or =3 horses in 28 states. METHODS: Probability-based sampling was used to enroll representative operations in a cross-sectional study. Interviews were conducted to collect information regarding health and management of horses. A nested case-control study was used to investigate risk factors among individual horses. Interview data were combined with climate data, human population density, and opossum regional ecology categories. Data were analyzed using logistic regression to identify risk factors for the occurrence of EPM. RESULTS: Owners reported that 95% of EPM cases included in this study were diagnosed by veterinarians. Variables associated with EPM occurrence on premises included opossum regional ecology, reported exposure to small wildlife, climate, terrain, housing, choice of bedding material, method of storing feeds, equine stocking density, and primary use of horses. Among individual horses, age was most strongly associated with disease risk. Associations also were identified with sex, breed, primary use, and participation in competitions. CONCLUSIONS AND CLINICAL IMPORTANCE: Because the risk of EPM occurrence on operations is closely tied to factors that impact exposure to opossums, their feces, and their environment, controlling these exposures may be important in preventing the occurrence of EPM.     

Seroincidence of porcine T. solium infection in the Peruvian highlands

We performed repeated serological sampling of pigs in an endemic area of the Peruvian highlands (eight villages) to assess the feasibility of detecting incident cases of Taenia solium infection as indicators of ongoing transmission of the parasite. A total of 2245 samples corresponding to 1548 pigs were collected in three sampling rounds (n=716, 926, and 603, respectively). Village-period specific seroprevalences of antibodies by enzyme-linked immunoelectrotransfer blot (EITB) assay varied from 39% (95% CI: 34, 44) to 76% (95% CI: 72, 79). The prevalence of cysticercosis increased with the age of the pigs (similarly for both sexes). Around 40% of pigs were re-sampled at the end of each 4-month period. Crude incidence risks were 48% (57/120, 95% CI: 43–52) and 58% (111/192, 95% CI: 54–61) for each period. A proportion of seropositive animals became seronegative at the end of each period (23 and 15%). Incidence varied by the village, and the exposure period, and was higher in males than females (but did not differ by age).     

Herd-level factors associated with isolation of Salmonella in a multi-state study of conventional and organic dairy farms I. Salmonella shedding in cows

The objective of this study was to evaluate associations between herd characteristics and the isolation of Salmonella from dairy cows in Minnesota, Wisconsin, Michigan, and New York. Study farms were 129 conventional and organic farms enrolled without regard to previous history of Salmonella infection. Herds were sampled at 2-month intervals over a 1-year period. This is the largest study to date on Salmonella shedding in dairy cows and the only study evaluating herd-level risk factors using longitudinal sampling to characterize Salmonella shedding on dairy farms. Salmonella was isolated in fecal samples from 1026 (4.9%) of 20,089 cows. Over the course of the study, 113 (87.6%) of 129 farms had at least one positive cow sample. Multi-variable logistic regression using the generalized estimating equations approach was used to test the association between herd-level risk factors and the dependent variable of within-herd prevalence by visit (number of Salmonella-positive cows/number of cows sampled) after adjustment for effects of herd size, season, state of origin, and the multiple sampling occasions per herd. Factors retained in the final model included lack of use of tiestall or stanchion facilities to house lactating cows (OR = 1.9; 95% CI: 1.1–3.3), not storing all purchased concentrate or protein feeds in an enclosed building (OR = 2.5; 95% CI: 1.3–4.9), not using monensin in weaned calf or bred heifer diets (OR = 3.2; 95% CI: 2.0–5.4), access of lactating or dry cows to surface water (e.g., lake, pond, river, or stream) (OR = 2.3; 95% CI: 1.3–3.9), disposal of manure in liquid form (slurry or irrigation, as opposed to disposal of manure by broadcast/solid spreader only) on owned or rented land (OR = 1.8; 95% CI: 1.3–3.9), and cows eating or grazing of roughage from fields where manure was applied in solid or liquid form and not plowed under during the same growing season (OR = 1.8; 95% CI: 1.0–3.0). A seasonal association was also present as cows were more likely to be Salmonella-positive in summer, spring, and fall compared to winter. Herd size was not associated with Salmonella shedding in the final multi-variable model. The herd-level risk factors identified in this study could potentially be implemented in Salmonella control programs on dairy farms.     

Retrospective evaluation of surgical versus conservative treatment of keratomas in 41 lame horses (1995-2001)

A keratoma is a rather uncommon disorder of the equine hoof that can lead to lameness. Few quantitative data exist about the prognosis of different treatment regimens. The outcome of 41 cases that were presented to the Department of Equine Sciences in the period 1995-2001 and that were treated according to different regimens was retrospectively evaluated. All horses showed lameness that could be attributed to the keratoma: 23 (56%) were treated surgically using a standardized procedure, while the other 18 (44%) were treated conservatively. Results were based upon 35 horses; 6 were lost to follow-up. Range of recovery time for the surgically treated patients, was 2-12 months and for the conservatively treated group 2 weeks to 6 months. Of the surgically treated patients 83% (n =23) returned to the same or higher performance level as before the onset of the lameness, as opposed to 42% (n = 12) of the conservatively treated horses (p<0.05). The average hospitalization period was significanty longer for the surgically treated patients (35 vs. 5 days, p<0.05). It is concluded that surgical excision of the keratoma is the preferred treatment for horses suffering from lameness caused by a keratoma, because the better outcome outweighs the longer hospitalization and the longer overall recovery time.     

Prevalence of multidrug resistant (MDR) Salmonella in bovine dairy herds in western France

As a part of our effort in quantitative risk analysis of food-borne diseases, we carried out an epidemiologic study to estimate the prevalence of multidrug resistant (MDR) Salmonella in dairy herds situated in western France. The study population consisted of 489 farms in the region and manure or slurry was sampled from these operations and tested for the Salmonella spp. All strains isolated during the study were serotyped and tested for their antimicrobial susceptibility. Salmonella spp. was isolated from 8.1% (95% confidence interval (CI 95%): 4.5–13.3%) of the sampled herds. The herd prevalence of MDR Salmonella among the sampled herds was 1.9% (CI 95%: 0.5–5.4%). Spatial statistics were used to check for sampling representativeness and to determine if infected herds were clustered spatially.     

Impact of probiotic administration on the health and fecal microbiota of young calves: a meta-analysis of randomized controlled trials of lactic acid bacteria

Before weaning, dairy calves are susceptible to many pathogens which can affect their subsequent performance. The use of lactic acid bacteria (LAB) has been identified as a tool to maintain the intestinal microbial balance and to prevent the establishment of opportunistic pathogenic bacterial populations. However, a consensus has not been reached as to whether probiotics may be effective in reducing the prevalence of gastrointestinal diseases in young calves. The aim of this meta-analysis was to assess the effect of probiotics on diarrhea incidence and the intestinal microbial balance. LAB supplementation has been shown to exert a protective effect and to reduce the incidence of diarrhea (relative risk, RR=0.437, 95% confidence interval (CI) 0.251-0.761). In the subanalysis, this protective effect of the probiotics against diarrhea was observed only in trials that used whole milk (RR=0.154, 95% CI 0.079-0.301) and trials that used multistrain inocula (RR=0.415, 95% CI 0.227-0.759). Probiotics did not improve the fecal characteristics (standardized mean difference, SMD=-0.4904, 95% CI -1.011-0.035) and were unable to change the LAB:coliforms ratio (SMD=0.016, 95% CI -0.701-0.733). Probiotics showed a beneficial impact on the LAB:coliforms ratio in the subanalysis that included trials that used whole milk (SMD=0.780, 95% CI 0.141-1.418) and monostrain inocula (SMD=0.990, 95% CI 0.340-1.641). The probability of significant effects (probiotic positive effect) in a new study was >0.70 for diarrhea and fecal consistency. Whole milk feeding improved the action of the probiotic effect on the incidence of diarrhea and LAB:coliforms ratio. The probability to find significant effects in the diarrhea frequency and LAB:coliforms ratio was higher (P>0.85) if the new studies were conducted using whole milk to feed calves. This paper defines the guidelines to standardize the experimental designs of future trials. LAB can be used as growth promoters in calves instead of antibiotics to counteract the negative effects of their widespread use.     

Climate Factors as Important Determinants of Dengue Incidence in Curaçao

Macro‐ and microclimates may have variable impact on dengue incidence in different settings. We estimated the short‐term impact and delayed effects of climate variables on dengue morbidity in Curaçao. Monthly dengue incidence data from 1999 to 2009 were included to estimate the short‐term influences of climate variables by employing wavelet analysis, generalized additive models (GAM) and distributed lag nonlinear models (DLNM) on rainfall, temperature and relative humidity in relation to dengue incidence. Dengue incidence showed a significant irregular 4‐year multi‐annual cycle associated with climate variables. Based on GAM, temperature showed a U‐shape, while humidity and rainfall exhibited a dome‐shaped association, suggesting that deviation from mean temperature increases and deviation from mean humidity and rainfall decreases dengue incidence, respectively. Rainfall was associated with an immediate increase in dengue incidence of 4.1% (95% CI: 2.2–8.1%) after a 10‐mm increase, with a maximum increase of 6.5% (95% CI: 3.2–10.0%) after 1.5 month lag. A 1°C decrease of mean temperature was associated with a RR of 17.4% (95% CI: 11.2–27.0%); the effect was inversed for a 1°C increase of mean temperature (RR= 0.457, 95% CI: 0.278–0.752). Climate variables are important determinants of dengue incidence and provide insight into its short‐term effects. An increase in mean temperature was associated with lower dengue incidence, whereas lower temperatures were associated with higher dengue incidence.     

Prevalence of herds with young sows seropositive to pseudorabies (Aujeszky's disease) in northern Belgium

In Belgium, pseudorabies in swine has been the subject of a mandatory eradication programme since 1993. From December 1995 to February 1996, a survey was conducted in the five provinces of northern Belgium to estimate the provincial pseudorabies virus (PRV) herd seroprevalence. Seven hundred and twenty randomly selected herds were included in this survey. To detect recently infected animals, only young sows were sampled. The results show that 44% of these herds had an important number of PRV-seropositive young sows. The highest herd seroprevalence was observed in West Flanders (68%), followed by Antwerp (60%), East Flanders (43%), Limburg (18%), and Flemish Brabant (8%). Assuming a diagnostic test sensitivity and specificity of 95% and 99%, respectively, and a true PRV within-herd prevalence of 43%, the overall true PRV herd prevalence was estimated to be 35%. A logistic multiple-regression revealed that the presence of finishing pigs was associated with a two-fold increase in odds of a herd being seropositive (odds ratio (OR)=2.07, 95% confidence interval (CI)=1.31–3.26); a breeding herd size ≥70 sows was associated with a four-fold increase in odds of a herd being seropositive (OR=4.09, 95% CI=2.18–7.67); a pig density in the municipality of ≥455 pigs/km² was associated with a 10-fold increase in odds of a herd being seropositive (OR=9.68, 95% CI=5.17–18.12). No association was detected between the PRV herd seroprevalence and purchase policy of breeding pigs (purchased gilts, or use of homebred gilts only).     

The range and prevalence of pathological abnormalities associated with lameness in working horses from developing countries

Reasons for performing study: Lameness is highly prevalent in working horses, but published reports on the associated pathological abnormalities are lacking. With over 42 million horses in developing countries and the majority used for work, lameness has major welfare implications. Objectives: To describe the range and prevalence of pathological abnormalities associated with lameness in working horses. Methods: A standard lameness assessment was adapted for field use in working equids. Data on pathological abnormalities and pain responses in the feet, limbs and spine were collected through observation, palpation, manipulations and gait assessment in working horses from India (n = 110) and Pakistan (n = 117). Lameness at the walk was scored on a scale of 0–4 (sound‐nonweightbearing). Results: All horses examined were lame. Overall, 98% showed a gait abnormality in all 4 limbs and 87% had at least one limb scoring 3 or 4 on the lameness scale. Multiple pathological abnormalities within each limb were associated with lameness, with similar results in both countries. Chronic foot pathology was seen in every horse; 94% horses showed signs of chronic joint disease; 83% had digital flexor tendonitis in at least one limb. Lameness and pathological abnormalities were associated with specific pain responses in the feet, limbs and spine. Conclusions: The extremely high prevalence of multilimb lameness and its association with pain is of great concern. The multiple pathological abnormalities present in working horses makes lameness complex to address. Potential relevance: The results of this detailed study of lameness should facilitate the identification of risk factors and the implementation of interventions to reduce the prevalence of lameness in working equids.