Clinical prevalence and associated intraoperative surgical complications of reproductive tract lesions in pot-bellied pigs undergoing ovariohysterectomy: 298 cases (2006-2016)

Validation of a human paper-based blood typing method for use in pet pigs

BACKGROUND

Evidence-based medical practices for pet pigs are needed. EldonCard is a human blood-typing card shown to be rapid and reliable in identifying blood phenotypes of pet pigs. The objective of this study was to validate EldonCard by determining its reliability, reproducibility, and robustness for its routine use in the clinical setting.

KEY FINDINGS

Twenty-four venous blood samples from pet pigs were collected for a prospective in vitro study. Blood genotypes ("EAAA0 " and "EAA00 ") were identified in 15 samples via polymerase chain reaction (PCR). All samples were phenotyped ("A," "Aweak ," and "0" or "-") via EldonCard. Kappa (κ) statistics measured the level of agreement between 2 raters, and between EldonCard and PCR. McNemar's test determined if an association between the blood types and EldonCard or PCR exists, with significance at P < 0.05. Agreement between raters and methods was perfect (60/60 [100%], κ:1, P < 0.001; 15/15 [100%], κ:1, P < 0.001). There was no difference in the proportions of blood groups based on method.

SIGNIFICANCE

In conjunction with previous data, EldonCard is a rapid, accurate, reliable, precise, and robust in-clinic blood-typing method for the A0 system of pet pigs. EldonCard is now a validated blood-typing tool for the A0 system of pet pigs and maybe used for pretransfusion screenings and identification of donors and recipients.

Prevalence of AO blood group and level of agreement for AO blood-typing methods in pet pigs from Louisiana

OBJECTIVES

Pet pigs are a species of growing medical interest, and evidence-based practices for blood transfusions are needed. The objectives of this study were to quantify the prevalence of 3 blood group (Bg) phenotypes ("A" and "Aweak " resulting from EAAAA and EAAAO , "0" from EAA00 , or "-" from EAA00 or SSS alleles) in pet pigs and compare results using a human blood-typing card (EldonCard), standard saline agglutination (SSA), and polymerase chain reaction (PCR) sequencing.

DESIGN

Cross-sectional study.

SETTING

University veterinary teaching hospital.

ANIMALS

Ninety-seven pet pigs from Louisiana.

INTERVENTIONS

Blood was sampled from randomly selected pet pigs of various breeds, anticoagulated with EDTA, and typed using each investigated test according to the manufacturers' directions or standard laboratory technique. Samples for PCR analysis were stored at -80°C until analysis. Phenotypes were screened via EldonCard. Association between Bg and sex was investigated using chi-square test, with significance at P < 0.05. Kappa (κ) statistic was used to measure the level of agreement between the 3 tests.

MEASUREMENTS AND MAIN RESULTS

Pot-bellied pigs represented the majority (84.5%) of this population, with 52 (53.6%) males and 45 (46.4%) females. Genotypic frequencies were 30%, 30%, and 40% for "EAAAA ," "EAAAO ," and "EAA00 ," respectively. Based on EldonCard, 38 phenotypes were classified as "A," 5 as "Aweak ," and 54 as "0" or "-." Results were identical for Bg, with the 3 tested techniques in 90% (45/50) of samples. Agreement between EldonCard and PCR was almost perfect (49/50 [98%], κ = 0.959; P < 0.001). Agreement between SSA and PCR, and EldonCard and SSA was substantial (46/50 [92%], κ = 0.803, P < 0.001 and 93/97 [95.9%], κ = 0.764, P < 0.001, respectively).

CONCLUSIONS

The most common blood type was "0" or "-" (55.7%), followed by "A" (39.2%) and "Aweak " (5.1%). There was strong agreement between EldonCard and PCR testing. EldonCard allowed for rapid and reliable phenotype identification ("A," "Aweak ," and "0" or "-") and represents a clinically applicable laboratory method for blood typing in pet pigs.

Pharmacokinetics of intramuscular maropitant in pigs (Sus scrofa domesticus)

Pigs are at risk of vomiting from medical conditions as well as the emetic side effects of drugs administered for peri-operative manipulations, but there is a lack of pharmacokinetic data for potential anti-emetic therapies, such as maropitant, in this species. The main objective of this study was to estimate plasma pharmacokinetic parameters for maropitant in pigs after a single intramuscular (IM) administration dosed at 1.0 mg/kg. A secondary objective was to estimate pilot pharmacokinetic parameters in pigs after oral (PO) administration at 2.0 mg/kg. Maropitant was administered to six commercial pigs at a dose of 1.0 mg/kg IM. Plasma samples were collected over 72 h. After a 7-day washout period, two pigs were administered maropitant at a dose of 2.0 mg/kg PO. Maropitant concentrations were measured via liquid chromatography/mass spectrometry (LC-MS/MS). A non-compartmental analysis was used to derive pharmacokinetics parameters. No adverse events were noted in any of the study pigs after administration. Following single IM administration, maximum plasma concentration was estimated at 412.7 ± 132.0 ng/mL and time to maximum concentration ranged from 0.083 to 1.0 h. Elimination half-life was estimated at 6.7 ± 1.28 h, and mean residence time was 6.1 ± 1.2 h. Volume of distribution after IM administration was 15.9 L/kg. Area under the curve was 1336 ± 132.0 h*ng/mL. The relative bioavailability of PO administration was noted to be 15.5% and 27.2% in the two pilot pigs. The maximum systemic concentration observed in the study pigs after IM administration was higher than what was observed after subcutaneous administration in dogs, cats, or rabbits. The achieved maximum concentration exceeded the concentrations for anti-emetic purposes in dogs and cats; however, a specific anti-emetic concentration is currently not known for pigs. Further research is needed into the pharmacodynamics of maropitant in pigs to determine specific therapeutic strategies for this drug.

Miniature Companion Pig Sedation and Anesthesia

With their increase in popularity in North America as pets, miniature companion pigs are in need of veterinary professionals familiar with sedation and anesthesia for the species. This article provides a review of the agents used for sedation, premedication, induction, and maintenance of anesthesia for miniature companion pigs. This review also covers species-specific anatomic and physiologic factors of miniature companion pigs with respect to administration of anesthetics, endotracheal intubation, anesthetic maintenance, and common complications so that the reader can make an informed anesthetic plan for the species.

Surgical treatment of uterine neoplasia in 13 production size pigs with a comparison to pot-bellied pigs

OBJECTIVES

The primary objective of this study was to describe the clinical management and surgical treatment of production size pigs (PrdP) with uterine neoplasia. A secondary objective was to compare tumor diagnoses as well as short- and long-term survival between PrdP and a published report of pot-bellied pigs (PBP) following surgical intervention.

STUDY DESIGN

Retrospective clinical study.

ANIMALS OR SAMPLE POPULATION

Client-owned PrdP (n = 13) treated with exploratory celiotomy ±ovariohysterectomy for uterine neoplasia.

METHODS

Medical records from a university hospital were reviewed for historical treatment, presenting complaint, clinical signs, diagnostics, surgical intervention, pathology, and outcome. An online owner survey was performed for follow-up. The novel PrdP cohort was compared to a previously published PBP cohort for differences in tumor diagnoses, surgical complications, and survival. Descriptive statistics, Fischer's exact tests and odds ratios were reported.

RESULTS

PrdP were affected by uterine leiomyoma (4/11), leiomyosarcoma (2/11), adenoma (1/11), adenocarcinoma (3/11), and carcinosarcoma (1/11) with no difference in tumor types between PrdP and PBP. PrdP surviving to hospital discharge (6/13) survived at least 1 year postoperatively, with median follow-up of 16 months (14-60 months). PrdP were less likely than PBP to survive in the short-term despite similar frequencies of marked intraoperative hemorrhage. PrdP and PBP had comparable rates of long-term survival following hospital discharge.

CONCLUSION

PrdP are afflicted by similar uterine neoplasia diagnoses as PBP, but they have lower rates of short-term survival to hospital discharge with surgical treatment.

CLINICAL SIGNIFICANCE/IMPACT

PrdP have a guarded prognosis for survival to hospital discharge when operated for uterine neoplasia.

Reproductive tract neoplasia in adult female Asian elephants (Elephas maximus)

Recent reports have highlighted a lower-than-expected prevalence of neoplasia in elephants and suggested mechanisms for cancer resistance. But despite infrequent reports in the literature, uterine neoplasia is common in managed Asian elephants (Elephas maximus). This study is an archival review of reproductive tract neoplasia in 80 adult female Asian elephant mortalities in managed care facilities in the United States from 1988 to 2019. Neoplasms occurred in 64/80 (80%) of cases. Most were in the uterus (63/64; 98%) with only a single case of ovarian neoplasia. Myometrial leiomyomas were present in 57/63 (90%) cases with uterine neoplasia. Uterine adenocarcinoma was present in 8/63 (13%) cases. Remaining cases included endometrial adenoma (2), focal carcinoma in situ in endometrial polyps (1), anaplastic carcinoma (1), endometrial hemangioma (1), primitive neuroectodermal tumor (PNET; 1), and angiosarcoma (1). One case with uterine adenocarcinoma had a separate pelvic mass histologically characterized as an anaplastic sarcoma. Distant metastases were documented in 5/8 (63%) cases of uterine adenocarcinoma, and in the uterine anaplastic carcinoma, PNET, and angiosarcoma. Four uterine adenocarcinomas and one carcinoma in situ were examined immunohistochemically for pan-cytokeratin, vimentin, and estrogen receptor. In all, neoplastic cells were pan-cytokeratin positive and vimentin negative, and in 2 cases were immunoreactive for estrogen receptor. Results show that female reproductive tract neoplasia, particularly of the uterus, is common in Asian elephants and is not limited to leiomyomas. Importantly, uterine neoplasms have the potential to impact fecundity and may represent obstacles to conservation in managed care.

Significantly delayed polyglactin 910 suture-related pseudoinfection in a Yucatan pig

BACKGROUND

Polyglactin 910 is a synthetic braided, absorbable suture commonly used in surgery. Though polyglactin 910 suture-related pseudoinfection is well documented in the human literature, it has not been previously reported in the veterinary literature.

CASE DESCRIPTION

A 3-year-old female, ovariectomized but otherwise experimentally naïve Yucatan pig was evaluated for a several week history of bilateral multifocal abscesses in the area of the paralumbar fossa, which continued to worsen despite oral antibiotics and non-steroidal anti-inflammatory medications. The multi-focal abscesses continued to worsen and additional diagnostics were pursued including cytology, culture (aerobic, anaerobic and fungal), and bloodwork. All supported a non-infectious etiology. Biopsy results indicated a suture-related pseudoinfection. Despite treatment including parenteral antibiotics, pain medications and superficial surgical debridement, the dermatologic lesions worsened. Euthanasia was elected. Post-mortem necropsy demonstrated a suture-related pseudoinfection with extrusion of suture material from the ovarian pedicle ligatures through the body wall and skin leading to numerous sterile abscesses in the bilateral paralumbar fossa.

CONCLUSIONS

This is the first published report of a significantly delayed polyglactin 910 suture-related pseudoinfection in a Yucatan pig. While likely an isolated incident, it supports further research into this area. Additionally for critical research studies using Yucatan pigs, pre-surgical assessment with hypersensitivity patch testing may be appropriate.

Fatal Ovarian Hemorrhage Associated With Anticoagulation Therapy in a Yucatan Mini-Pig Following Venous Stent Implantation

Swine models are commonly utilized in endovascular research for development of intravascular interventions and medical device development. As part of a pilot study for a venous vascular stent device, a 5-year-old female Yucatan mini-pig underwent bilateral external iliac vein stent placement under general anesthesia. To reduce thrombotic complications by reduction of thrombus formation on wires, sheaths, and catheters, the pig was heparinized with a total of 300 IU/kg of heparin, establishing an activated clotting time (ACT) of 436 s. The ACT had returned to below 200 s by the end of the procedure. To prevent postoperative thrombosis, the pig received an anticoagulation therapy protocol consisting of enoxaparin, clopidogrel, and aspirin. There were no complications during the immediate postoperative period. However, the pig died 4 days after surgery. Necropsy established the cause of death as abdominal exsanguination due to severe, acute, intra-ovarian hemorrhage, most likely related to ovulation. Life-threatening ovarian hemorrhage is occasionally seen in women with congenital or acquired bleeding disorders; to our knowledge this is the first report of fatal ovarian hemorrhage in an animal enrolled in a pre-clinical research trial.