Large or Food Animal and Equine Medicine Commons^™

The Buck Effect In Goats: A Review Of Neuroendocrine Mechanisms, Modulating Factors, And Applications In Reproductive Management, Nitira Anakkul, Sopita Suttikrai, Ratree Jintana, Theerawat Swangchan-Uthai

The Thai Journal of Veterinary Medicine

The male effect (buck effect) is a sustainable, hormone-free biostimulation strategy in caprine reproduction, in which introducing sexually active bucks to seasonally anestrous does increases luteinizing hormone (LH) pulse frequency, thereby stimulating folliculogenesis and ovulation. This review provides a comprehensive synthesis of the sensory, neuroendocrine, breed-related, and management factors governing male biostimulation in goats (Capra hircus). Olfactory signals, including the identified primer pheromone 4-ethyloctanal, are perceived through the main and accessory olfactory systems and act together with visual, auditory, and tactile cues. These sensory inputs activate the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator probably through the medial amygdala …

Genetic Diversity And Morphotypes Of Haemonchus Contortus In Sheep In Thailand: A Combined Morphological And Molecular Approach, Gunjan Das, Mohamed H. Hamad, Witchuta Junsiri, Piyanan Taweethavonsawat

The Thai Journal of Veterinary Medicine

Haemonchus contortus is a highly pathogenic gastrointestinal nematode of small ruminants, yet molecular information on sheep-derived isolates in Thailand remains limited. This study aimed to characterize H. contortus recovered from sheep in Nakhon Pathom Province using integrated morphological and molecular approaches. Adult nematodes collected post-mortem from the abomasum were examined morphologically, and the internal transcribed spacer 2 (ITS2) region of ribosomal DNA was amplified and sequenced. Morphological examination identified males with characteristic copulatory bursae and females exhibiting linguiform, knobbed, and simple vulvar morphotypes. ITS2 sequences showed 95.26–98.11% identity with reference H. contortus sequences deposited in GenBank. Molecular and phylogenetic analyses …

How To Improve Neonatal Beef Calf Health: A Hands-On Workshop Approach, Gabriele Maier, Essam Abdelfattah, Erik Fausak

Journal of Extension

Even though failure or inadequate transfer of passive immunity in beef calves is common, few interventions on the ranch address the issue. A workshop series that used calf simulators and live calves improved rancher knowledge on passive transfer and other topics relevant to neonatal calf health across operation sizes and experience levels. At the conclusion of the workshop, participants expressed a positive attitude towards using pain control for painful procedures in calves, with cost being the most important reason for not using it. Based on participant feedback, roundtable discussions would improve the workshop format.

New Frontiers In Diagnosing Equine Lameness, Hyrum Hoopes, Karl Hoopes

All Current Publications

Lameness is one of the most common and expensive health problems seen in horses. Modern technology allows veterinarians to look beneath the surface. Tools such as artificial intelligence (AI), computed tomography (CT), magnetic resonance imaging (MRI), digital radiography (X-rays), nuclear scintigraphy, ultrasound, and positron emission tomography (PET) give clearer, more detailed pictures of what’s happening inside the horse’s leg. Each technology offers different advantages, from identifying uneven movement to revealing hidden damage within bones, joints, or soft tissues. When combined with veterinary visual evaluation, they help pinpoint the cause of lameness faster and more accurately than ever before.

Investigation Of The Functional Dimensions Of Teats Up To Mid-Lactation In Bulgarian Murrah Buffaloes Established By Ultrasonography, Ivan Fasulkov, Pencho Penchev, Yordanka Ilieva, Manol Karadaev

The Thai Journal of Veterinary Medicine

The aim of this study was to monitor the changes in teat measurements from early to mid-lactation in the Bulgarian Murrah buffaloes. The experiment was carried out with twenty (10 primiparous and 10 pluriparous) lactating buffaloes. Five series of ultrasound measurements were performed, each consisting of two sessions for each animal corresponding to the phases of lactation: first lactation month (day 1 to day 30 postpartum) and mid- lactation (day 122 to day 152). The studied parameters were teat canal length (TCL), teat diameter (TD), teat wall thickness (TWT), and teat cistern diameter (TCD). The data were processed using the …

Using Fecal Diagnostic Tests To Assess The Prevalence Of Fasciola Hepatica In The United States Sheep Population, Brooke A. Delcambre

LSU Master's Theses

Fasciola hepatica, the common liver fluke, is endemic in the Pacific Northwest and Gulf Coast of the United States. To provide updated information on F. hepatica prevalence, as part of the USDA National Animal Health Monitoring System Sheep 2024 study, sheep operations in the top 30 sheep-producing states were identified, and producers were invited to participate. For each operation, feces were collected from at least eight sheep and pooled to form a single composite sample. Two methods were used to identify sheep infected with F. hepatica: fecal sedimentation and indirect sandwich ELISA. At the national level, across 318 operations, 7.1 …

Effects Of Acepromazine On Intraocular Pressure, Anterior Chamber Depth In Horses: A Prospective Randomized Controlled Study, Abdelhaleem Elkasapy, Magdy Elgioushy, Mohamed Marzok, Sayed Elhawari, Adel Almubarak, Mohamed Rizk, Sabry El-Khodery, Adel Al-Akraa

The Thai Journal of Veterinary Medicine

This study aimed to evaluate the effects of acepromazine on intraocular pressure (IOP), anterior chamber depth (ACD), cardiovascular and respiratory rates in horses. In a prospective, randomized, controlled trial, twelve horses were equally allocated randomly into two groups: treatment and control (n = 6 each). Horses of the treatment group received 0.1 mg/kg body weight (bwt) of acepromazine intravenously, while those in the control group received 0.4 mL/100 kg bwt of 0.9% sodium chloride intravenously. IOP, ACD, heart rate, and respiratory rate were recorded before (T0) and then at T10, T20, T30, T40, T50, T60, T70, T80, and T120 min …

Current Status Of Anthelmintic Resistance In Meat Goats: A Comparative Efficacy Study Of Albendazole And Fenbendazole In Maha Sarakham, Thailand, Minta Pipatsakulpak, Usanisa Boonum, Kotchakorn Roongruang, Benjawan Sae-Chue, Sukanya Leethongdee, Songsak Chumpawadee, Nattaya Watwiengkam, Pongphol Pongthaisong

The Thai Journal of Veterinary Medicine

Anthelmintic resistance in gastrointestinal nematodes threatens sustainable goat production globally. While resistance is well-documented in many regions, data from Thailand remain limited. This study determined the prevalence of gastrointestinal nematodes and assessed the efficacy of albendazole and fenbendazole in meat goats in Maha Sarakham province, northeastern Thailand. A two-stage cross-sectional study was conducted on 10 meat goat farms between August 2021 and March 2022. In Stage 1, fecal samples from 150 goats were examined using simple flotation and sedimentation techniques to identify parasite morphology. In Stage 2, the McMaster technique was employed to quantify fecal egg counts (FEC). Twenty-six goats …

Correlation Of Oxidative Stress Markers Between Serum And Colostrum And Their Association With Production Performance In Lactating Sows From A Prrs-Unstable Herd, Supasit Sopin, Yonlayong Woonwoong, Pichai Jirawattanapong, Prapassorn Boonsoongnern, Wirod Lakkanasombat, Alongkot Boonsoongnern

The Thai Journal of Veterinary Medicine

Oxidative stress occurs when the production of reactive oxygen species exceeds the antioxidant defense capacity of living organisms. Oxidative stress is commonly assessed using serum samples; however, blood sampling in pigs is often avoided on commercial farms because of disease transmission concerns and animal welfare considerations. This study aimed to evaluate the correlation between oxidative stress markers in serum and colostrum samples and to determine their association with production performance in lactating sows. A total of 34 Landrace × Large White sows from a commercial farrow-to-finish farm were included in the study. Blood and colostrum samples were collected immediately after …

Perceptions Of Rural Large Animal Owners On Cost And Distance As Barriers To Veterinary Medicine, Alyssa Dalleske

Honors College Theses

Access to veterinary care remains a significant issue in rural communities due to financial, geographic, and access barriers. Limited access to veterinary care can have an impact on animal welfare and an economic impact for producers. This study aimed to assess factors influencing access to veterinary services, including cost, distance to clinics, perceived value of care, and availability of mobile veterinary professionals. The survey was distributed to rural large animal owners using social media, and gained 20 participants. It collected data on perceived barriers within their communities. The survey results indicated that cost of care and distance to veterinary clinics …

Public Perception Of Equine Rabies And Its Implications For Future Education And Preventative Strategies, Kya Walton

Honors College Theses

This study examined the rabies knowledge, vaccination, and risks of exposures of horse owners/overseers across the state of Kentucky. Research was conducted to determine the need for public health educators and veterinarians to inform the public on rabies. Survey results concluded that respondents' general knowledge of rabies transmission and mortality rate was respectable, but knowledge relating to equine vaccination was comparatively lower. A weak inverse relationship was observed between general rabies knowledge and concern over an individual’s horses contracting rabies. A weak positive correlation was determined when looking into general rabies knowledge and the likelihood of vaccinating an individual’s horses. …

Dextromethorphan And Trace Level Detections Of Dextrorphan In Post-Race Urine Samples – A Case Report And Analysis, Kimberly Brewer, Justin C. Holmes, Clara Fenger, Abelardo Morales-Briceño, Andreas F. Lehner, George A. Maylin, Robert Holland, Levent Dirikolu, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

Dextrorphan is a Phase I equine metabolite of dextromethorphan, a widely used anti-tussive / cough suppressant medication marketed and available in numerous over-the-counter formulations in the United States. Dextromethorphan is an Association of Racing Commissioners International (ARCI) drug class 4 penalty class B substance and a Horseracing Integrity and Welfare Authority (HIWU) CONTROLLED S7 B substance and is regulated as such in horse racing. In horses, dextromethorphan is metabolized to its Phase I metabolite, dextrorphan, which is next glucuronidated and the resultant dextrorphan-glucuronide conjugate then excreted at remarkably high concentrations in equine urine. Dextrorphan is therefore at times identified in …

Investigating The Potential Role Of Toxoplasma Gondii In The Development Of Equine Protozoal Myeloencephalitis, Brooklyn Nicole Shirah

Theses and Dissertations--Veterinary Science

Equine protozoal myeloencephalitis (EPM) is a neurologic disease of horses prevalent in the Americas, caused by the coccidian parasites Sarcocystis neurona and Neospora hughesi. Toxoplasma gondii is a related parasite that infects nearly all warm-blooded animals, including horses. Prior studies show conflicting results on whether T. gondii contributes to EPM, in part because no validated T. gondii serologic assay exists in horses. This study developed a recombinant TgSAG1 ELISA and confirmatory Western blot. These assays evaluated T. gondii seropositivity in 789 serum samples from healthy and neurologic horses across multiple geographic regions and examined 31 paired serum:CSF samples for …

Environmental Detection And Quantification Of Equid Alphaherpesviruses In Equine Facilities Using Air Sampling, Emma E. Hyde

Theses and Dissertations--Veterinary Science

Equid alphaherpesvirus 1 and 4 (EHV-1/-4) circulate at equestrian facilities, contributing to outbreaks. Due to the complexities of the pathogen, including the limited predictability of reactivation from latency and the effects associated with secondary sites of viral replication, abortion, and neurologic disease, EHV infections are of utmost concern to the equine industry. Recent studies have highlighted the prevalence of the viruses in stabling areas at competitions, though little is known about this phenomenon in other high-traffic equine environments. This thesis presents two studies using air sampling surveillance methods to further explore the viral detection in other equine environments (veterinary facility …

Comparison Of Spayed Heifer Performance To Intact Heifers Fed Melengestrol Acetate On Feedlot Performance And Carcass Characteristics, Tate S. Johnson, Rebecca L. Mcdermott, Halden J. Clark, Jim C. Macdonald, Jessica L. Sperber

Nebraska Beef Cattle Reports

Summary with Implications

Pregnancy and estrous cycle management are critical considerations when feeding intact heifers in the feedyard. Alternatively, producers can opt to spay heifers, which eliminates hormonal fluctuations associated with the estrous cycle. A proportion of U.S. feedlots have spayed heifers on feed, although there is limited data comparing the performance of spayed heifers to intact heifers. A commercial feedlot experiment was conducted to compare performance between spayed and intact heifers fed melengestrol acetate. Intact heifers had greater ADG and tended to have greater DMI compared to spayed heifers, although no difference in feed conversion was observed. Carcass weight …

Expression Pattern Of The Hifα-Family In Equine Chorioallantois During Pregnancy And Placental Pathology, Yatta Boakari, Hossam El-Sheikh Ali, Gustavo Henrique Doná Rodrigues Almeida, Kirsten E. Scoggin, Claudia Barbosa Fernandes, Sophia Panelli Marchio, Mats H. T. Troedsson, Ana Claudia Oliveira Carreira

Maxwell H. Gluck Equine Research Center Faculty Publications

Equine placental dysfunction impairs fetal growth and disrupts pregnancy outcomes. Despite many advances in diagnosis, the molecular pathophysiology of equine placentitis and premature placental separation remains poorly understood. However, the hypoxia-inducible factor (HIF-α) pathway is related to placental hypoxia, and its modulation in placental diseases has been shown in other species. Therefore, we hypothesized that in conditions marked by equine placental dysfunction, oxygen deprivation in the chorioallantois membrane triggers the activation of the HIF-α pathway, which is related to molecular alterations associated with placental insufficiency. Accordingly, we compared the expression of HIF1A, HIF2A, HIF3A, and HIF1AN genes in equine chorioallantois …