Surgical management and outcome of acquired inguinal hernias in mature bulls: 13 cases (2005-2017).

OBJECTIVE: To describe rates of surgical complications, survival, and return to breeding soundness following herniorrhaphy for bulls with inguinal hernias. ANIMALS: 13 sexually mature bulls with acquired inguinal hernias. PROCEDURES: Medical record databases of 3 veterinary teaching hospitals were searched to identify records of bulls that underwent herniorrhaphy for correction of an inguinal hernia from 2005 to 2017. Information extracted from the medical records included breed, age, duration and side of the hernia, surgical procedure details, postoperative complications, and information regarding subsequent fertility. RESULTS: All 13 bulls had a left inguinal hernia and were anesthetized and underwent herniorrhaphy via an inguinal approach. The left testicle was removed during the surgical procedure in 2 bulls. Nylon or polypropylene mesh secured with size-5 polyester suture was used to facilitate inguinal ring closure in 2 bulls. The inguinal ring was closed with size-5 or size-2 polyester suture in the remaining bulls. Postoperative complications included hernia recurrence (n = 4), excessive scrotal swelling (3), and transient radial nerve paralysis (1). Follow-up information was available for 7 bulls. All 7 bulls had impregnated cows or heifers following surgery, including 1 bull that had hernia recurrence and underwent unilateral castration during the second herniorrhaphy. CONCLUSIONS AND CLINICAL RELEVANCE: Inguinal herniorrhaphy with or without mesh was a safe and effective procedure for inguinal hernia repair in bulls and was associated with a good prognosis for subsequent fertility. However, sparing the ipsilateral testicle during the herniorrhaphy procedure might increase the risk for hernia recurrence.

Hormone-responsive organoids from domestic mare and endangered Przewalski's horse endometrium.

The endometrium, the inner uterine lining, is composed of cell layers that come in direct contact with an embryo during early pregnancy and later with the fetal placenta. The endometrium is responsible for signals associated with normal reproductive cyclicity as well as maintenance of pregnancy. In the mare, functionally competent in vitro models of the endometrium have not been successful. Furthermore, the ability to study various reproductive processes in vitro may allow critical evaluation of signaling pathways involved in the reproductive diseases of animals that cannot be handled frequently, such as various wildlife species. Here we report the establishment of organoids, 3D structures, derived from fresh and frozen-thawed equine endometrium (Equus ferus caballus and E. f. przewalskii). Although organoids from domestic mares responded to exogenous hormonal stimuli, organoids from Przewalski's horse failed to respond to exogenous hormones. The present study represents a 'first' for any large animal model or endangered species. These physiologically functional organoids may facilitate improved understanding of normal reproductive mechanisms, uterine pathologies, and signaling mechanisms between the conceptus and endometrium and may lead to the development of novel bioassays for drug discovery.

Dimethyl sulfoxide maintains structure and function of cryopreserved equine endometrial explants.

Availability of viable frozen-thawed endometrial tissues could facilitate detailed studies into physiologic and disease processes influencing the endometrium. This study was designed to investigate the cryosurvival of equine endometrial tissue. Previous studies in the human and horse have focused on cryopreservation of dissociated endometrial cells. To our knowledge, there are no studies on cryopreservation of endometrial explants. Our objectives were to 1) determine the influence of differing concentrations of the permeating cryoprotectant dimethyl sulfoxide (Me2SO) on viability, structural integrity, and gene expression of cryopreserved equine endometrial tissues prior to and following a 5-day explant culture in vitro and 2) examine the influence of low (1000 mg/L dextrose) vs high (4500 mg/L dextrose) glucose medium during in vitro culture. Both 10% and 20% (v/v) concentrations of Me2SO maintained viability following cryopreservation and in vitro culture. In addition, gene expression remained unaltered following cryopreservation with either 10% or 20% Me2SO. However, tissue structural integrity was slightly reduced compared to the fresh control. Furthermore, there was no difference in structural integrity, cell viability, or gene expression between low and high glucose medium during in vitro culture. Although E-cadherin and Ki67 gene expression was not different among fresh, 10% Me2SO, and 20% Me2SO treatments prior to or following tissue culture, estrogen receptor-α and progesterone receptor gene expression were reduced in all groups after explant culture. This is the first report of successful cryopreservation of equine endometrial explants.

Factors in cattle affecting embryo transfer pregnancies in recipient animals.

The use of embryo transfer (ET) in cattle is important for profitability and improved genetic gains. The advent of the commercial embryo collection and transfer industry has led to advancements in multiple techniques and practices. Specific variables, however, have historically affected pregnancy rates but an understanding of the magnitude of these effects in the current industry is limited. Transfer location (cranial, middle, or caudal third of the uterine horn ipsilateral to the ovary with a CL), transfer score (range of 1-3 with 1 being excellent and 3 poor, based on difficulty of accessing the site of embryo deposition), and amount of time to complete a transfer, therefore, were recorded. These variables were collected in a setting designed to mimic commercial production practices as well as exaggerated time (due to data collection) to assess effects on pregnancy rates. Fresh and frozen in vivo-derived embryos (n = 256) from Bos taurus cows were transferred to Bos taurus recipients. There tended to be more pregnancies when embryos were deposited in the cranial part of the uterus (P = 0.08) compared to the middle and caudal third of the uterus. With a lesser degree of difficulty in transfers (score 1), there tended to be more pregnancies established (P = 0.07). When lesser time was needed for transferring embryos and collecting data, there were greater pregnancy rates (P = 0.03). Thus, these traditionally accepted variables of influence (site of embryo placement in uterus, difficulty, and time) continue to influence ET pregnancy success.

Surgical Procedures of the Genital Organs of Bulls.

Reproductive surgical techniques are considered by practitioners of theriogenology to be the best method to manage infertility-causing conditions or diseases of the bull. Injury or diseases of the reproductive tract may cause abnormalities that may result in substantial losses to the producers of beef and dairy cattle. The most cost-effective method of dealing with reproductive conditions or diseases of the bull is culling and replacement. Some injuries, diseases, or conditions are amenable to surgical management. Surgical management may preserve the genetic potential of the bull and economic productivity. The surgical procedures described are commonly used methods to restore fertility in bulls.

Surgical Procedures of the Genital Organs of Cows.

Reproductive surgical techniques are considered by practitioners/clinicians of theriogenology to be the most beneficial reproductive management that can be performed to treat conditions of cows that may affect fertility. Conditions affecting the reproductive tract can cause pathologic changes that may result in substantial economic and genetic losses to beef and dairy producers. Some injuries and diseases are amenable to surgical treatment. Surgical restoration of fertility preserves genetic potential and economic productivity. The surgical procedures described in this article are some of the most commonly used to restore fertility in cows with injury or diseases affecting their reproductive tracts.

Successful treatment of a Vietnamese potbellied pig with an ovarian leiomyoma.

CASE DESCRIPTION: An adult sexually intact female Vietnamese potbellied pig was examined because of abdominal distention of 5 months' duration. CLINICAL FINDINGS: The pig was moderately anemic, and its abdomen was greatly distended. A freely movable abdominal mass was detected during palpation and ultrasonographic examination of the abdomen. Examination of abdominal and thoracic radiographs revealed faint, ill-defined, linear and curvilinear mineralized opacities in the region of the mass and that the gastrointestinal tract was displaced craniodorsally. Results of radiographic examination suggested that the cause of distention was a single abdominal mass (possibly a neoplasm). TREATMENT AND OUTCOME: Surgery was performed, and the mass, which was identified as the right ovary, was removed. The left ovary had a normal appearance, but it was also removed during surgery. The pig was administered a transfusion (314 mL of plasma and 296 mL of packed RBCs) before and during surgery. The mass, which accounted for approximately one-third of the pig's body weight, was identified histologically as an ovarian leiomyoma. CLINICAL RELEVANCE: Pigs can safely be administered a transfusion of RBCs and plasma. Ovarian tumors can be removed from Vietnamese potbellied pigs, which allows them to be used as pets or for reproduction when only 1 ovary is affected. Uterine masses in older sexually intact Vietnamese potbellied pigs are more common than are ovarian tumors; thus, complete ovariohysterectomy should be considered when the primary purpose of the pig is to serve as a pet.

A comparison of two combinations of xylazine-ketamine administered intramuscularly to alpacas and of reversal with tolazoline.

OBJECTIVE: To evaluate the anesthetic and cardiorespiratory effects of two doses of intramuscular (IM) xylazine/ketamine in alpacas, and to determine if tolazoline would reduce the anesthetic recovery time. STUDY DESIGN: Prospective randomized crossover study. ANIMALS: Six castrated male alpacas. METHODS: Each alpaca received a low dose (LD) (0.8 mg kg(-1) xylazine and 8 mg kg(-1) ketamine IM) and high dose (HD) (1.2 mg kg(-1) xylazine and 12 mg kg(-1) ketamine IM) with a minimum of one week between trials. Time to sedation, duration of lateral recumbency and analgesia, pulse rate, respiratory rate, hemoglobin oxygen saturation, arterial blood pressure, blood-gases, and the electrocardiogram were monitored and recorded during anesthesia. With each treatment three alpacas were randomly selected to receive tolazoline (2 mg kg(-1) IM) after 30 minutes of lateral recumbency. RESULTS: Onset of sedation, lateral recumbency and analgesia was rapid with both treatments. The HD was able to provide > or =30 minutes of anesthesia in five of six alpacas. The LD provided > or =30 minutes of anesthesia in three of six alpacas. Respiratory depression and hypoxemia occurred with the HD treatment during the first 10 minutes of lateral recumbency: two animals were severely hypoxemic and received nasal oxygen for 5 minutes. Heart rate decreased, but there were no significant changes in arterial blood pressure. Tolazoline significantly shortened the duration of recumbency with the HD. CONCLUSIONS: The HD provided more consistent clinical effects in alpacas than the LD. Intramuscular tolazoline shortened the duration of lateral recumbency in alpacas anesthetized with the HD combination. CLINICAL RELEVANCE: Both doses of the combination were effective in providing restraint in alpacas and the duration of restraint was dose dependent. Supplemental oxygen should be available if using the HD and IM administration of tolazoline will shorten the recovery time.

Effects of acepromazine and butorphanol on tiletamine-zolazepam anesthesia in llamas.

OBJECTIVE: To evaluate sedative, antinociceptive, and physiologic effects of acepromazine and butorphanol during tiletamine-zolazepam (TZ) anesthesia in llamas. ANIMALS: 5 young adult llamas. PROCEDURES: Llamas received each of 5 treatments IM (1-week intervals): A (acepromazine, 0.05 mg/kg), B1 (butorphanol, 0.1 mg/kg), AB (acepromazine, 0.05 mg/kg, and butorphanol, 0.1 mg/kg), B2 (butorphanol, 0.2 mg/kg), or C (saline [0.9% NaCl] solution). Sedation was evaluated during a 30-minute period prior to anesthesia with TZ (2 mg/kg, IM). Anesthesia and recovery characteristics and selected cardiorespiratory variables were recorded at intervals. Antinociception was assessed via a toe-clamp technique. RESULTS: Sedation was not evident following any treatment. Times to sternal and lateral recumbency did not differ among treatments. Duration of lateral recumbency was significantly longer for treatment AB than for treatment C. Duration of antinociception was significantly longer for treatments A and AB, compared with treatment C, and longer for treatment AB, compared with treatment B2. Treatment B1 resulted in a significant decrease in respiratory rate, compared with treatment C. Compared with treatment C, diastolic and mean blood pressures were lower after treatment A. Heart rate was increased with treatment A, compared with treatment B1 or treatment C. Although severe hypoxemia developed in llamas anesthetized with TZ alone and with each treatment-TZ combination, hemoglobin saturation remained high and the hypoxemia was not considered clinically important. CONCLUSIONS AND CLINICAL RELEVANCE: Sedation or changes in heart and respiratory rates were not detected with any treatment before administration of TZ. Acepromazine alone and acepromazine with butorphanol (0.1 mg/kg) prolonged the duration of antinociception in TZ-treated llamas.

A comparison of two intramuscular doses of xylazine-ketamine combination and tolazoline reversal in llamas.

OBJECTIVE: To evaluate the anesthetic and cardiorespiratory effects of two doses of intramuscular xylazine/ketamine in llamas, and to determine if an intramuscular injection of tolazoline would shorten the anesthesia recovery time. STUDY DESIGN: Prospective randomized study. ANIMALS: Six castrated male llamas. METHODS: Each llama received a low dose (LD) (0.4 mg kg(-1) xylazine and 4 mg kg(-1) ketamine) and high dose (HD) (0.8 mg kg(-1) xylazine and 8 mg kg(-1) ketamine). Time to sedation, duration of lateral recumbency and analgesia, pulse, respiratory rate, hemoglobin oxygen saturation, arterial blood pressure, blood gases, and the electrocardiogram were monitored and recorded during anesthesia. Three llamas in each treatment were randomized to receive intramuscular tolazoline (2 mg kg(-1)) after 30 minutes of lateral recumbency. RESULTS: Onset of sedation, lateral recumbency, and analgesia was rapid with both treatments. The HD was able to provide at least 30 minutes of anesthesia in all six llamas. The LD provided only 30 minutes of anesthesia in two out of six llamas. Respiratory depression and hypoxemia were seen in the HD treatment during the first 10 minutes of lateral recumbency. Two llamas were severely hypoxemic during this period and were given nasal oxygen for five minutes. Heart rate decreased, but there were no significant changes in blood pressure. Tolazoline significantly shortened the duration of recumbency in the HD treatment. CONCLUSIONS: The HD provided more consistent clinical effects in llamas than did the LD. Intramuscular tolazoline shortens the duration of lateral recumbency in llamas anesthetized with this combination. CLINICAL RELEVANCE: Both doses appear to be very effective in providing restraint in llamas. The LD may be used for procedures requiring a short period of anesthesia or restraint. The HD could be used when a longer duration of anesthesia is desired. Supplemental oxygen should be available if using the HD. Tolazoline (IM) shortened the recovery time with this combination in llamas.

Anaplasma marginale msp1alpha genotypes evolved under positive selection pressure but are not markers for geographic isolates.

Anaplasma marginale (order Rickettsiales, family Anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. Many geographic isolates of A. marginale occur in the United States and have been identified by major surface protein 1a (MSP1a), which varies in sequence and molecular weight due to different numbers of tandem 28- to 29-amino-acid repeats. The present study was undertaken to examine the genetic variations among isolates of A. marginale obtained during 2001 from infected cattle from east-central Oklahoma, where A. marginale is endemic. The gene and protein sequences of MSP1a and msp4 nucleotide sequences were used to infer the phylogenetic relationships among Oklahoma and New World isolates from Argentina, Brazil, Mexico, and the United States. All 11 A. marginale isolates collected from Oklahoma had different MSP1a sequences but identical MSP4 sequences. The phylogenies of the msp4 sequences of 13 isolates from Oklahoma in comparison with those of 7 Latin American isolates and 12 U.S. isolates by maximum-parsimony (MP) and maximum-likelihood (ML) analyses, with A. centrale and A. ovis sequences used as outgroups, provided strong bootstrap analysis support for a Latin American clade. Isolates of A. marginale from the southern United States (Florida, Mississippi, and Virginia) and the west-central United States (California, Idaho, Illinois, Oregon, Missouri, and Texas) also grouped into two clades. Both clades contained isolates from Oklahoma, suggesting extensive cattle movement. ML analysis of the msp4 sequences of isolates from Oklahoma provided bootstrap analysis support for east-central and north-central clades in Oklahoma, and both clades included isolates from Stillwater, Okla. Analysis of the codon and amino acid changes among the msp4 sequences of isolates with different phylogenies provided evidence that msp4 is not under positive selection pressure. In contrast, the phylogenies of the MSP1a DNA and protein sequences of 13 isolates from Oklahoma in comparison with those of 7 Latin American and 13 isolates from the United States by MP and ML analyses demonstrated no geographic clustering and provided evidence that this gene is under positive selection pressure. The results indicate that msp1alpha is not a marker for the characterization of A. marginale geographic isolates and suggest that the genetic heterogeneity observed among isolates of A. marginale within Oklahoma could be explained by cattle movement and the maintenance of different genotypes by independent transmission events.