American journal of veterinary research最新文献

Objective: To determine the presence of Tritrichomonas foetus in the accessory sex glands, epididymis, and testicular tissue of T foetus-positive bulls and to assess the impact of post mortem tissue acidity on quantitative reverse-transcription PCR results.

Methods: 8 bulls were euthanized from June 12 through June 15, 2023, and samples from their accessory sex glands, testicles, and epididymis were collected for T foetus testing. Preputial smegma was obtained before and after euthanasia and tested for T foetus by quantitative reverse-transcription PCR. The pH of the penile and preputial epithelial surfaces was measured.

Results: Tritrichomonas foetus was not detected in samples from the testicle, epididymis, or epididymal semen. A post mortem decrease in the pH of the penis and prepuce correlated with a rise in cycle threshold values.

Conclusions: Tritrichomonas foetus was not present in samples taken, suggesting its absence in these specific reproductive tissues. A decrease in the pH of the penis and prepuce over time post mortem correlated with an increase in cycle threshold values in the samples. This relationship indicates that changes in pH may impact the detectability or stability of genetic material in these tissues, possibly affecting diagnostic outcomes as time from death progresses.

Clinical relevance: This research enhances the understanding of T foetus pathology in bulls and suggests that epididymal semen recovery could be a viable method for preserving genetic material from valuable bulls that test positive for T foetus. It also emphasizes the need for timely post mortem sampling to ensure accurate detection and management of T foetus in the cattle industry.

Objective: Pergolide, labeled for the treatment of pituitary pars intermedia dysfunction, is 90% protein bound and might cause a decrease in blood thyroid hormone concentrations by displacing them from binding proteins. This study investigated the effect of pergolide on the equine thyroid function.

Methods: This was an analytic, observational, cohort study. Six horses (17 to 24 years old and 530 to 599 kg) received 1 mg of pergolide mesylate orally once a day from days 1 to 6. Total T4 (tT4) was measured daily from day 0 to 11 (before, during, and after pergolide treatment). Thyrotropin-releasing hormone (TRH) stimulation tests were conducted on days 0 and 6. Total T3 (tT3), tT4, and free T4 by equilibrium dialysis (fT4) were measured at baseline and 2 hours (tT3) and 4 hours (tT3, T4, and fT4) after TRH administration. The effect of pergolide on thyroid hormone concentration was determined by ANOVA, with P < .05 considered significant.

Results: No effect of pergolide was detected on tT4 during and after treatment. Administration of TRH resulted in significant increases in tT3 (effect size: +165.8 ng/dL [95% CI, 109.4 to 222.2 ng/dL]), tT4 (+1.162 µg/dL [95% CI, 0.7135 to 1.610 µg/dL]), and fT4 (+1.195 µg/dL [95% CI, 0.7195 to 1.670 µg/dL]). There was, however, no significant effect of pergolide on any thyroid hormone concentration.

Conclusions: Pergolide has no detected effect on blood thyroid hormone concentrations and equine thyroid function.

Clinical relevance: Protein-bound agents do not necessarily affect thyroid hormone concentrations. In horses with pituitary pars intermedia dysfunction, low thyroid hormone concentrations are likely due to the condition itself, not pergolide treatment.

Objective: This study investigates the molecular epidemiology of orf virus (ORFV) in the Fujian province in 2024, with the goal of gaining insights that can enhance disease prevention and control strategies.

Methods: This experimental study was conducted from January 2024 through March 2024. The samples, showing suspected orf lesions, tested positive for ORFV via PCR. The ORFV059 (F1L) and ORFV011 (B2L) genes from these samples were cloned and sequenced.

Results: Analysis identified 3 ORFV strains: FJ-2401, FJ-2402, and FJ-2403. For the F1L gene, nucleotide sequence identity ranged from 95.7% to 99.6%, and amino acid identity ranged from 95.0% to 99.7% compared to the reference strain. These strains were closely related to others from Fujian, Guangzhou, and India but differed from the NZ2 reference strain, the German D1701 weak strain, and Chinese vaccine strains, which were in separate branches. For the B2L gene, nucleotide identity ranged from 97.4% to 99.6%, and amino acid identity ranged from 97.1% to 100%. Evolutionary analysis indicated potential recombination events with strains from Fujian, Jilin, and India. The B2L gene showed distinct branching from the German D1701 weak strain, Fujian GO strain, and Chinese vaccine strains, suggesting that current vaccines might be inadequate.

Conclusions: Viruses are constantly evolving, and currently available commercial vaccines may not provide sufficient protection against emerging ORFV strains. This underscores the urgent need for updated vaccines and improved management strategies.

Clinical relevance: The study reveals significant genetic diversity and potential recombination in ORFV strains in Fujian, highlighting their divergence from known references.

Objective: To document objective metrics of attenuation of the pulmonary parenchyma on inspiratory and expiratory breath-hold CT in dogs with bronchomalacia (BM) and dogs without BM (NoBM) using automated software analysis. Metrics included mean lung attenuation, percent low-attenuation area at -856 HU, percent high-attenuation area at -700 HU, and percent attenuation area between -600 and -250 HU.

Animals: Client-owned dogs with BM (n = 123) and NoBM (20).

Methods: This retrospective study utilized 3D Slicer software (Brigham and Women's Hospital) to assess pulmonary CT attenuation. Analysis used Spearman correlation and 2-way ANOVA with beta regression.

Results: Comparing the difference between inspiratory and expiratory phases, there was a significantly greater increase in mean lung attenuation (P = .001), a significant reduction in percent low-attenuation area at -856 HU (P = .016), and a significant increase in percent high-attenuation area at -700 HU and percent attenuation area between -600 and -250 HU (P < .001 and P < .0001, respectively) in BM versus NoBM dogs.

Conclusions: The higher inspiratory and expiratory difference in lung attenuation in BM compared to NoBM dogs supports the presence of impaired parenchymal aeration downstream of segmental and subsegmental airway collapse.

Clinical relevance: Quantitative image analysis holds promise for objectively evaluating changes with BM.

Objective: The expression of luteinizing hormone (LH) receptors has been reported in canine nonneoplastic and neoplastic lymphocytes. This study aimed to determine the effect of LH receptor activation in neoplastic canine T lymphocytes.

Methods: Cell lines (CLC, CLK, EMA) derived from 3 dogs with primary T-cell lymphoma were used. Cell lines were previously phenotyped and evaluated for LH receptor expression with flow cytometry. Cell lines were stimulated with increasing concentrations (0, 4, 400, and 4,000 U/mL) of human chorionic gonadotropin (hCG; an LH receptor agonist), RNA was extracted, cDNA was synthesized, and gene expression was determined using quantitative PCR and the 2-ΔΔCt method. Cell lines were stimulated with the same increasing concentrations of hCG, and cell proliferation, adhesion, and transmigration were determined using commercial assays. The effects of LH receptor activation were compared between hCG concentrations using a one-way ANOVA. Significance was defined as P < .05.

Results: LH receptor stimulation increased LH receptor gene expression in the CLC cell line, and there was a trend for increased expression in the EMA cell line but no effect in the CLK cell line. Activation of LH receptors increased proliferation in all 3 cell lines, endothelium adhesion in 2 cell lines (CLC, CLK), and transmigration in 2 cell lines (CLK, EMA).

Conclusions: LH receptor stimulation using hCG increased LH receptor gene expression in neoplastic canine T lymphocytes and increased cell proliferation, adhesion, and transmigration.

Clinical relevance: These findings may provide a physiologic mechanism for the increased incidence of lymphoma reported in dogs with sustained supraphysiologic LH concentrations.

Objective: To determine the association between ionized calcium (iCa) and/or total magnesium (tMg) and the development of sepsis and to investigate whether iCa or tMg is associated with mortality in puppies with canine parvoviral enteritis (CPE).

Methods: 64 client-owned puppies with CPE were enrolled in this prospective cohort study. Serum iCa and tMg were measured daily from admission until death or discharge. Fifteen healthy client-owned puppies were used as controls.

Results: Mean iCa concentrations of the CPE group on admission were significantly lower compared to the control group (1.35 mmol/L vs 1.52 mmol/L). Ionized calcium concentrations of nonsurvivors were significantly higher compared to survivors on day 2 but not on any other days. Puppies that were hypercalcemic on day 2 were also significantly more likely to die than normocalcemic puppies (OR, 10.7; 95% CI, 1.7 to 71). Ionized calcium was not associated with the development of sepsis on any day. In contrast, mean admission tMg concentrations of the CPE group were significantly higher compared to the control group (0.72 mmol/L vs 0.63 mmol/L). However, tMg concentrations were not significantly different between survivors and nonsurvivors nor were they associated with the development of sepsis on any day.

Conclusions: On admission, puppies with CPE had lower iCa and higher tMg compared to healthy puppies, and higher iCa a day after initiation of treatment was associated with increased odds of mortality.

Clinical relevance: The results of this study provide insight into calcium homeostasis in critically ill young dogs with CPE.

Objective: Histologically evaluate damage to rabbit femur after the creation of bicortical 1.5-mm-diameter holes using a standard surgical drill bit, an acrylic drill bit, and a Kirschner wire (K-wire).

Methods: 10 femora (5 pairs) from skeletally mature female intact New Zealand white rabbits were used. The bone diaphyses were divided into 4 locations, systematically undergoing each test (surgical drill bit, acrylic drill bit, K-wire, and intact control). Four pairs were drilled using a mechanical testing machine, and 1 pair was drilled by hand. Cross-sections of the bone were stained en bloc with basic fuchsin for undecalcified histological evaluation. Damaged bone was reported as a percentage of a standardized area and categorized by location (cis- or transcortex), drill contact (entrance or exit of the cortex), and total damage (both cortices).

Results: The drilling method (hand vs mechanical testing machine) had no effect on histologic damage, so results were analyzed by combining all data. The K-wire demonstrated the greatest area of cracks/damage compared to both standard surgical and acrylic drill bits, whereas no difference in damage was noted between the 2 drill bits for all variables.

Conclusions: The K-wire and drill bits caused microdamage; K-wire drilling created more microdamage than drill bits.

Clinical relevance: The rabbit bone cortex is thin and brittle relative to dogs and cats, leading to failure during and after fracture fixation. The clinical failure of rabbit bone is at least partially caused by drill bits or K-wires causing microcracks.

Objective: To study the feasibility of ultrasound-guided intervertebral disc (IVD) injection of contrast medium and methylene blue to aid in intraoperative identification of cervical IVD spaces in dogs.

Methods: This was a single-center experimental cadaver study using randomly chosen skeletally mature dog cadavers from January 2, 2023, to March 23, 2023. For each cadaver, 1 cervical IVD was randomly selected. The ventral cervical region was ultrasonographically examined, pushing the trachea leftwards. A 50/50 contrast medium (iohexol, 300 mgI/mL) and methylene blue mixture was injected under ultrasound guidance in the IVD and ventral soft tissues. The x-rays and CT scans were performed before and after injection. Each cadaver was dissected using a ventral slot procedure. The cadavers and IVD characteristics, the success rate in ultrasonographically identifying the correct IVD space, time to injection, most caudal IVD space feasibly injectable, and semiquantitative imaging and surgical scores were recorded.

Results: 20 canine cadavers were used. The IVD injections were successfully performed in the correct IVD space in all cadavers. The median time to injection was 3.95 minutes (Q1 to Q3, 3.22 to 5.88 minutes). The contrast medium was clearly visible on at least 1 radiographic projection in all but 1 case and on the CT in all cases. During surgical dissection, the dye was clearly visible in all but 1 case. The dogs' weight was significantly different between most caudal IVD spaces feasibly injectable.

Conclusions: Ultrasonographical cervical IVD space identification and mixture injection are feasible and might help intraoperative cervical IVD space identification in dogs.

Clinical relevance: This technique could be used presurgically in patients with cervical IVD diseases.