Search Results (62)

Studies evaluating the effects of cryopreservation on epididymal spermatozoa of Cavia porcellus remain limited. This study compared the effects of rapid and slow freezing protocols on microscopic characteristics, morphometry, and morphometric correlations. Epididymal spermatozoa from twelve guinea pigs were diluted in OptiXcell^® extender with 25% egg yolk and equilibrated at 4 °C for 6 h. One aliquot was evaluated, while the other was cryopreserved using rapid (n = 5) or slow (n = 7) protocols. After thawing, motility, viability, plasma membrane functionality, acrosomal and chromatin integrity, and morphometry were assessed; cooling profiles were characterized using linear and cubic regression models. Cryopreservation reduced microscopic parameters compared with refrigerated samples (p < 0.05). Comparison showed no significant differences in motility, viability, acrosomal integrity, or plasma membrane function (p > 0.05), whereas chromatin integrity was higher after slow freezing (p = 0.03). Rapid freezing reduced acrosomal area, acrosomal perimeter, and head length, whereas slow freezing preserved morphometric variables and correlations, although correlation patterns should be interpreted as associations among morphometric traits rather than structural preservation. Both cooling curves were well described by linear and cubic models. Slow freezing was associated with better preservation of chromatin integrity and selected morphometric characteristics. Full article

This study characterized the non-traditional or “exotic” pets most frequently admitted to a referral center (Center for Medicine and Research in Wild Animals–CEMPAS) located in Botucatu, São Paulo state, Brazil, and identified the main reasons for admission according to affected body systems or sense organs. A retrospective review of medical records was performed over 11 years, and data were grouped into four vertebrate classes: reptiles, mammals, amphibians, and birds. From 2014 to 2019, bird admissions exceeded mammals (p = 0.0001), whereas no significant difference was observed from 2020 to 2024 (p = 0.625). Reptiles were the least represented, and no amphibians were recorded in any year. In the bird class (n = 961), cockatiels (Nymphicus hollandicus) were the most common species (47.76%), followed by domestic chickens (Gallus gallus domesticus) (15.19%), and blue-fronted Amazons (Amazona aestiva) (8.01%). The digestive, integumentary, and musculoskeletal systems were the most affected. The mammal class accounted for 882 admissions, with rabbits (Oryctolagus cuniculus) predominating (52.38%), followed by guinea pigs (Cavia porcellus) (17.57%), brown rats (Rattus norvegicus) (10.77%), and Syrian hamsters (Mesocricetus auratus) (6.00%). In these animals, digestive disorders were most common, followed by integumentary, musculoskeletal, and reproductive conditions. The reptile class accounted for 164 admissions, mainly tortoises (70.12%) and turtles (18.90%), with the integumentary, musculoskeletal, and digestive systems most frequently affected. Overall, birds and mammals were the most commonly admitted non-traditional or “exotic” pets, while the digestive and integumentary systems were the most frequently affected across species, emphasizing the value of regional epidemiological data for improving exotic animal veterinary care. Full article

This retrospective study describes the relative frequency of common diseases in pet Guinea pigs (Cavia porcellus, GP) presented to a specialist exotic-animal clinic (Exo-Pet Veterinary Center, Budapest, Hungary). Data from 600 GPs across 1768 visits were reviewed; 51.3% were male and 48.7% female. Malocclusion of the molars was the most common problem (27.5%), followed by urinary tract diseases (18.67%), reproductive tract diseases (16.2%), ectoparasites (16.5%), neoplasms (tumors), and tumor-like lesions (15.8%). We fitted multivariable logistic-regression models with coat type, age, and sex as predictors. Almost one-third of the intact females (32.40%) had ovarian cysts. Age was associated with the recorded incidence of several diseases, although diagnostic opportunity was generally greater in older animals. The incidence of infectious diseases (e.g., fungal disease) declined with age. Owners should be made aware of ectoparasites and fungal infections to prevent potential zoonotic disease. The odds of ovarian cysts, neoplasms (tumors) and tumor-like lesions, gastrointestinal, hepatobiliary and urinary disease increased with age; these associations remained after adjustment for the number of veterinary visits. Males are more likely to develop malocclusion of the molars and incisors. Regular, detailed dental examinations of GPs are important for both prevention and early diagnosis. Full article

National estimates of the bioenergy potential of livestock manure still rest on static inventories that apply conversion yields to the gross mass of manure, ignoring the fraction that is actually recoverable under each production system and the substrate-specific nature of anaerobic co-digestion. This study develops a category-level predictive model of the technical biogas potential of livestock manure in Peru, projected to 2030, resolving seven livestock categories: dairy and non-dairy cattle, broilers and layers, swine, guinea pigs (Cavia porcellus) and goats. Recoverability is formulated as a time-dependent factor tracking the progressive confinement of production systems; the technical potential is bounded between a mono-digestion floor and a co-digestion ceiling constrained by a co-location criterion that admits synergy only when the co-substrate originates within the same production system; and a greenhouse-gas layer quantifies avoided emissions from methane conversion factors. All coefficients are reported as intervals and propagated jointly by Monte Carlo simulation. Two yield hypotheses are carried throughout: experimental biochemical methane potential and the IPCC-consistent digester ceiling. The national net technical potential is 1975 ${\mathrm{GWh}}_{\mathrm{p}}$${\mathrm{yr}}^{-1}$ under mono-digestion (731 ${\mathrm{GWh}}_{\mathrm{e}}$; 95% credible interval 1628–2404 ${\mathrm{GWh}}_{\mathrm{p}}$, Monte Carlo $N=\mathrm{100,000}$) and 2093 ${\mathrm{GWh}}_{\mathrm{p}}$${\mathrm{yr}}^{-1}$ under co-digestion. The gross approach exceeds the recoverable resource by a factor of 3.94, equivalently a contraction of 74.6% (95% CI 68.9–79.1%), and a symmetric Shapley decomposition attributes 76.1% of that contraction to recoverability rather than to conversion yield—a share that is stable across both yield hypotheses. The greenhouse-gas layer yields a result that reverses the expected policy ordering: broilers rank first by recoverable energy but last by avoided methane, whereas swine rank first by mitigation because liquid slurry storage is the only baseline system emitting enough methane for anaerobic digestion to displace. Below a digester leakage of 4.6%, methane abatement is negative at the national scale. Full article

Iron deficiency and associated anemia remain major public health concerns, requiring innovative food fortification systems with adequate technological and sensory performance. This study aimed to develop a multicomponent fortified gummy candy using heme iron from Cavia porcellus erythrocytes, non-heme iron from Feranin^®, and elderberry juice, integrated through microencapsulation and stabilized by vacuum foam drying. Erythrocytes were isolated, dehydrated, and microencapsulated in a tara gum–maltodextrin matrix, yielding a powder with 1.49 mg Fe/g dry matter. The microencapsulates exhibited compact morphology, lower polydispersity, and negative ζ potential, indicating suitable surface stability. Three gummy formulations (F1–F3) were prepared with different proportions of encapsulated erythrocytes, non-heme iron, and elderberry juice. Iron content increased significantly from 0.21 to 0.89 mg Fe/g of gummy candy. The formulations showed variations in water activity (0.84–0.88), moisture (33.79–40.22%), pH (4.64–6.15), soluble solids (41.00–46.67 °Brix), phenolic compounds (0.80–1.14 mg GAE/g), flavonoids (0.13–0.27 mg QE/g), and antioxidant capacity (1.53–3.75 µmol TE/g). FTIR and SEM confirmed structural preservation and matrix integration. Sensory evaluation showed comparable overall acceptability among formulations, with F3 showing higher mean ranks for flavor and texture. Overall, vacuum foam drying was a feasible strategy for valorizing animal-derived by-products in fortified gelled confectionery. Full article

Cryptosporidium spp. are common protist pathogens, and the growing popularity of pet rodents raises concerns about their potential role in zoonotic parasites transmission. However, epidemiological data on Cryptosporidium spp. in pet rodents in Yunnan Province is scarce. To examine the occurrence of Cryptosporidium spp. in pet rodents in Yunnan, we collected 762 fecal samples from four rodent species across four cities. Nested PCR and DNA sequencing were used to characterize the species and subtypes of Cryptosporidium. The occurrence of Cryptosporidium spp. in guinea pigs (Cavia porcellus), Siberian dwarf hamsters (Phodopus sungorus), Syrian hamsters (Mesocricetus auratus) and fancy rats (Rattus norvegicus domestica) was 18.7% (80/426), 17.3% (36/207), 12.5% (15/120), 0% (0/9), respectively, with an overall rate of 17.2% (131/762). According to regions, the positivity rate of Cryptosporidium spp. in Zhaotong city, Kunming city, Yuxi city and Qujing city was 21.0%, 17.9%, 16.8% and 10.5%, respectively. In terms of sampling location, the occurrence of Cryptosporidium spp. in pet markets, farms and shops was 19.5%, 18.6% and 0%, respectively. Sequence analysis of the small subunit ribosomal RNA (SSU rRNA) gene identified six Cryptosporidium species/genotypes: Cryptosporidium homai (n = 52), Cryptosporidium wrairi (n = 30), Cryptosporidium sp. hamster genotype (n = 25), Cryptosporidium andersoni (n = 20), Cryptosporidium parvum (n = 5), and Cryptosporidium muris (n = 1). Further subtyping of C. andersoni isolates using multilocus sequence typing (MLST) revealed a single subtype, with all isolates identified as A3A4A2A2. All five C. parvum isolates were identified as subtype IIdA15G1 based on the gp60 gene. Our findings demonstrated the presence of the zoonotic C. parvum IIdA15G1 subtype in pet rodents, suggesting that these animals, particularly hamsters, may serve as reservoirs for human-pathogenic Cryptosporidium species. These results underscore the need for improved biosecurity and husbandry practices in the pet rodent trade to mitigate public health risks. Full article

Background/Objectives: Multidrug-resistant (MDR) Escherichia coli has increasingly been recognized as a pathogen capable of causing severe systemic infections in various animal species. However, reports describing respiratory and septicemic infections caused by MDR E. coli in guinea pigs remain scarce. The objective of this report was to describe the clinical, pathological, and microbiological findings associated with a fatal infection in a domestic guinea pig. Case Study: A 10-month-old female guinea pig (Cavia porcellus), kept as a companion animal in a household environment, presented with acute respiratory distress, lethargy, and anorexia, progressing rapidly to death within approximately 36 h of onset. Post-mortem examination revealed severe pulmonary congestion, diffuse inflammatory lesions in the trachea, and generalized vascular congestion in multiple organs. Bacteriological cultures obtained from lung and bone marrow samples yielded pure growth of Escherichia coli. Identification was confirmed using MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing demonstrated resistance to several antibiotic classes, including β-lactams, fluoroquinolones, tetracyclines, sulfonamides, and phenicols, while susceptibility was retained only to aminoglycosides. Molecular analysis revealed the presence of virulence genes involved in adhesion and iron acquisition, supporting the pathogenic potential of the isolate. Conclusions: This report highlights the ability of MDR E. coli to cause severe respiratory and systemic infections in guinea pigs. The findings underline the importance of early diagnosis, appropriate antimicrobial stewardship, and improved husbandry conditions in preventing such infections. From a One Health perspective, the circulation of resistant strains in companion animals may represent a potential risk for both environmental and human health. Full article

The radiographic appearance of the urinary bladder in guinea pigs (Cavia porcellus) affected by cystitis is poorly characterized. This retrospective case–control study assessed the radiographic characteristics of the urinary bladder (digital abdominal and whole-body radiographs) in 24 healthy guinea pigs and 24 guinea pigs diagnosed with cystitis. Inclusion criteria for the cystitis cohort included presence of clinical signs (hematuria, incontinence, stranguria, abdominal discomfort, apathy, and inappetence), leukocyturia and/or bacteriuria, complemented by right lateral radiographs and either ultrasound or a positive urine culture. Radiographic criteria indicative of cystitis were systematically evaluated using a vertebral bladder score (VBS) expressed in lumbar vertebral units (LVU) and reference marker lines on lateral radiographs to assess urinary bladder distension. Compared to the control group, radiographs of guinea pigs with cystitis demonstrated increased bladder opacity (46% of cases) and solitary uroliths (25%). Bladder height in patients with cystitis exceeded that of healthy counterparts (median: 16.6 vs. 13.0 mm). The VBS in the cystitis group was significantly elevated (median: 1.50 vs. 1.20 LVU). This investigation revealed that enhanced bladder distension and increased bladder opacity, with a VBS surpassing 1.3 LVU, correlated with the presence of cystitis. Full article

This study examined the effects of zinc–iron (Zn–Fe) biofortified alfalfa on mineral deposition, growth performance, feed efficiency, and selected meat-quality traits in guinea pigs (Cavia porcellus). Four alfalfa cultivars (Cuf101, Moapa69, California55, and Yaragua) were cultivated under two fertilization levels (0–0 and 2–2 kg ha⁻¹ Zn–Fe). Biofortification increased forage Zn concentrations from 26.8 to 36.4 mg kg⁻¹ to as high as 325.8 mg kg⁻¹, and Fe concentrations from 139.7 to 425.0 mg kg⁻¹ to 450.1 mg kg⁻¹. A total of 48 weaned guinea pigs (initial body weight 0.30 ± 0.01 kg) were allocated to a randomized multi-factorial feeding trial. Growth performance, feed intake, feed conversion ratio (FCR), and tissue mineral concentrations were evaluated over a 35–50 day period and analyzed using a multi-factorial ANOVA within a General Linear Model framework. Dietary biofortification resulted in a significant improvement in feed efficiency, with FCR decreasing from 6.3 in the control diet to 5.8 in the enriched diet, and the lowest FCR was observed in animals fed the California55 cultivar (5.1). No statistically significant sex effect was detected for live weight gain, although males showed higher total weight gain (248.7 g) than females (187.8 g). Tissue Zn (≈20.7 mg kg⁻¹) and Fe (≈10.2 mg kg⁻¹) concentrations in meat were only marginally affected by diet, suggesting strong physiological regulation of mineral deposition. Multivariate analyses indicated that the enriched diet produced more homogeneous meat-quality profiles and reduced inter-animal variability. Overall, Zn–Fe biofortified alfalfa improved feed efficiency without compromising growth performance or meat quality, indicating potential relevance for smallholder guinea pig production systems. However, given the limited sample size per factorial cell, the findings should be interpreted with caution and considered exploratory, warranting confirmation in larger, adequately powered studies. Full article

Diet plays a pivotal role in shaping the gut microbiota, influencing host physiology, immune function, and nutrient metabolism. In this study, we evaluated the impact of three distinct feeding systems—Forage only, Balanced feed only, and Mixed system—on the cecal microbiota of guinea pigs (Cavia porcellus) using 16S rRNA gene amplicon sequencing in a randomized allocation of 18 males across the three diets (n = 6 per group) over 7 weeks. A total of 2,135,852 high-quality reads were obtained, with rarefaction curves and Good’s coverage confirming sufficient sequencing depth. Alpha diversity indices revealed significantly higher microbial richness and evenness in the mixed group, while beta diversity analyses demonstrated distinct microbial community structures across diets. Taxonomic profiling showed that forage-based diets enriched fiber-degrading genera such as Fibrobacter and Treponema, whereas the Balanced feed group favored mucin- and protein-degrading bacteria like Akkermansia and Bacteroides. LEfSe and t-test analyses identified several biomarkers and diet-specific genera, suggesting functional divergence in microbial metabolism. Forage-fed animals showed microbiota associated with short-chain fatty acid production and enhanced fiber utilization, while the Balanced feed group showed microbial traits linked to mucin degradation and potential gut barrier disruption. These findings highlight the strong influence of dietary composition on gut microbial ecology and suggest that fiber-rich diets promote a more diverse and functionally beneficial cecal microbiome in guinea pigs. Full article

A common cause of teeth malocclusion and feeding disorders in guinea pigs is macrodontia and odontogenic abscesses. If the maxillary second or third molar teeth are affected, surgical access to them has so far been achieved through enucleation or orbital evisceration due to their location at the base of the orbit. The study aims to demonstrate a transorbital surgical approach to the apices of the maxillary molar teeth (M2 and M3) in guinea pigs, allowing preservation of the eye. Twenty six apicoectomies of maxillary M2 and M3 were performed. The surgical approach involved a skin incision above the zygomatic arch, followed by soft tissue dissection, incision of the orbital ligament, and gentle dorsolateral displacement of the eyeball. Blunt dissection between the lacrimal and zygomatic glands provided direct access to the affected tooth apices, which were removed using a dental bur. After the procedure, the soft tissues and the eye were repositioned and the skin was sutured. All animals recovered uneventfully. The described method may be applied in cases where it is necessary to perform maxillary second and/or last molar tooth apicoectomy while avoiding damage to the eyeball. Care must be taken to protect the corneal surface of the affected eye. Full article

Reproductive system diseases are common in guinea pigs, but cases presenting with the coexistence of ovarian cysts and cystic endometrial hyperplasia (CEH) are poorly documented. This case describes a two-year-old female with abdominal tenderness and an ultrasonographic diagnosis of bilateral ovarian cysts and CEH, structured accordingly to the CARE guidelines. An ovariohysterectomy was performed via a ventral midline approach under multimodal anaesthesia and analgesia. Histopathological examination confirmed rete ovarii cysts and cystic endometrial hyperplasia. The postoperative course was uneventful, with complete recovery achieved within 21 days. To the authors’ knowledge, this is the first case report, structured accordingly to the CARE guidelines, to provide complete clinical aspects, diagnostic testing (including imaging), treatment, and final confirmation of the diagnosis of both lesions in the same patient. Abdominal ultrasonography proved to be an essential tool for the simultaneous diagnosis of ovarian and uterine abnormalities in guinea pigs. Surgical management combined with multimodal anaesthesia ensured safe outcomes and satisfactory recovery. This case report also highlights the importance and value of structuring veterinary case reports according to the CARE guidelines, thereby improving the quality, transparency, and reproducibility of clinical reporting in exotic animal medicine. Full article

Hexavalent chromium [Cr(VI)] is the toxic form of chromium often used in industry for its hardness, bright colors, and anticorrosive properties. Cr(VI) is a known human lung carcinogen, making its inhalation an occupational hazard. Growing evidence emphasizes the neurotoxic potential of Cr(VI), though it is not linked to brain cancers. Few studies consider neurotoxicity in chromate workers, reporting impaired olfactory discrimination and an increased risk of death from mental health disorders. A major factor limiting translation of most rodent Cr(VI) studies to human populations has to do with vitamin C, which can reduce the toxic Cr(VI) to non-toxic Cr(III). Rats and mice synthesize vitamin C and are likely more resistant to Cr(VI) than humans. Here, we considered Cr(VI) neurotoxicity in guinea pigs (Cavia porcellus), which do not endogenously synthesize vitamin C. We exposed Hartley guinea pigs (both sexes) to occupationally relevant concentrations of Cr(VI) via oropharyngeal aspiration weekly for 90 days. We observed behavioral effects in the open field assay, elevated plus maze, Y-maze, and novel object recognition test during weeks 9–12 of exposure. After euthanasia, we assessed Cr accumulation and essential metal dyshomeostasis in the hippocampus. We observed significantly increased hippocampal Cr accumulation in females, while males exhibited essential metal dyshomeostasis. Full article

The aim of this study was to identify the presence and magnitude of right–left asymmetry in the fore- and hindlimb long bones of adult guinea pigs (Cavia porcellus), and, in parallel, to evaluate sex-related differences in shape and size in the same bones. For this purpose, the stylopodium and zeugopodium bones were analyzed together. Computed tomography data were obtained from all animals under a standard protocol, three-dimensional bone models were generated from these datasets, and these models formed the basis for the geometric morphometric analyses. The analyses showed that sex accounted for a small but consistent proportion of shape variation (approximately 5–7%) in the antebrachium, femur and crus, whereas this effect was more limited in the humerus. Asymmetry analysis based on paired right–left data revealed that directional asymmetry was generally low, whereas fluctuating asymmetry varied across bones. The highest asymmetry was detected in the antebrachium, the crus showed an intermediate level, and the stylopodial elements, humerus and femur, were comparatively more symmetrical. This pattern is consistent with the biomechanical expectation that small right–left deviations tend to accumulate in distal and functionally more active forelimb segments that are positioned farther from the trunk. In conclusion, the findings indicate that asymmetry arises gradually as a function of bone position and functional use rather than from a single growth error, and that distal forelimb elements should therefore be given particular attention in asymmetry studies. Full article

The skull provides essential diagnostic features for species identification and sex determination. Cranial sexual dimorphism in guinea pigs (Cavia porcellus) is particularly important to understand, as these animals are frequently used in experimental research and veterinary practice, yet detailed morphometric evaluations remain limited. This study aimed to assess cranial size and shape variation between sexes using three-dimensional geometric morphometric (GM) methods. Computed tomography scans of 30 clinically healthy guinea pigs were used to reconstruct three-dimensional skull models. Twenty-one anatomical landmarks were digitized, and the dataset was subjected to generalized Procrustes analysis, followed by principal component analysis, Procrustes ANOVA, and regression-based allometric assessments. The results revealed pronounced sexual dimorphism. Males exhibited significantly larger centroid sizes and more robust cranial morphologies, whereas females presented smaller and more gracile skull forms. Procrustes ANOVA confirmed significant shape differences between sexes (p < 0.01), with size being the primary driver of morphological divergence. Body weight had a weaker but detectable influence on cranial variation, although its effect diminished after accounting for centroid size (R²: 0.085). These findings demonstrate that three-dimensional geometric morphometrics can effectively detect subtle patterns of cranial dimorphism in guinea pigs. Beyond their anatomical relevance, the results provide a valuable reference for veterinary sciences, taxonomy, and future biomedical research requiring precise morphological characterization. These findings show that three-dimensional geometric morphometrics can effectively detect subtle patterns of sexual dimorphism in cranial shape, which is particularly relevant for sex identification in skeletal collections and for the development of comparative anatomical databases in veterinary and experimental research. Full article