Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Hematological parameters are widely used in avian health assessment and ecological monitoring; however, information on wild birds inhabiting the central Argentine Monte Desert is scarce. In this study, we present the hematological profiles of 172 wild birds, mainly passerines, representing 14 species from the protected nature reserves of Ñacuñán and Telteca. Birds were captured with mist nets during spring, and blood samples were taken to analyze hematocrit (HCT), total red blood cell (RBC) and white blood cell (WBC) counts, differential leukocyte count, and heterophil/lymphocyte ratio (H/L). HCT values ranged from 47 to 60 %, RBC values ranged from 2.48 to 5.88 cell × 10⁶/µL and WBC values ranged from 1.84 to 7.07 cell × 103/µL. According to the predominant leukocyte lineage, most species in this study (12 of 14) showed a lymphocytic profile, with H/L ratios generally below 1.0. In particular, the Tropical kingbird (Tyrannus melancholicus) and Common diuca-finch (Diuca diuca) showed heterophilic profiles with H/L ratios ≥ 1.0, unlike other passerines. Although low H/L values suggest minimal chronic stress, these heterophilic species may require increased caution when interpreting stress-related indicators. This study provides the first reported values for these bird species inhabiting a desert environment characterized by natural stressors but limited anthropogenic disturbance, offering valuable references for ecological, veterinary, and conservation applications.

Flavonoids such as diosmin and hesperidin produce antinociceptive and anti-inflammatory effects, potentially involving the inhibition of carbonic anhydrase (CA) as a mechanism of action. It is believed that CA inhibition helps reduce inflammation by improving symptoms such as pain, redness, swelling, warmth, and loss of mobility in the affected area. We showed that diosmin and hesperidin produced an anti-inflammatory effect involving inhibition of CA. The study was conducted on male Wistar rats by measuring the time spent licking and the number of shakings after the 1 % formalin was administered to the plantar area of the hind limb. Treatments were as follows: vehicle, diosmin, hesperidin, meloxicam, acetazolamide, sulfonamide, and combinations of inhibitors with the flavonoids. Subsequently, measurements in both hind limbs were carried out to evaluate the degree of inflammation. The results indicated that diosmin and hesperidin at 100 and 316.2 mg/kg decreased the time-spent licking and number of shakings in phase 2 of the 1 % formalin test, whereas when administered in combination with acetazolamide and sulfonamide at 100 mg/kg, the anti-inflammatory effect of the flavonoids was reversed. These findings suggest that CA’s activity plays an important role in the antinociceptive and anti-inflammatory effects of the flavonoids diosmin and hesperidin.

The aim of present study was to determine whether intramuscular administration of injectable fasciolicide prodrug, fosfatriclaben, in a single dose at 6 mg/kg in mixed breed sheep, produces adverse reactions reflected in blood biochemical and histopathological profiles, particularly in tissues involved in drug metabolism. For this purpose, two sheep groups were formed. Group 1 (G1) of 15 sheep was treated, Group 2 (G2) of 5 sheep served as control. On days 0, 7, 14, 28, and 35 post-treatment, liver, kidney, and injection site samples were taken for histopathology, as well as blood samples for biochemical analysis. The results did not provide important histopathological changes or significant differences in blood biochemical (P < 0.05); analytes values remained within the reference range. It is estimated that the trial prodrug could have similar safety characteristics to its precursor, triclabendazole.

Encephalitozoon cuniculi is an obligate intracellular microorganism primarily found in rabbits, although it has also been reported in various species such as horses, rodents, dogs, monkeys, foxes, cats, goats, and pigs. Immunodeficient humans are also vulnerable to this infection. This study aimed to determine the seroprevalence of E. cuniculi in 89 companion rabbits in Mexico City using an enzyme-linked immunosorbent assay (ELISA). The results indicated a seroprevalence of 70 %. Clinically healthy rabbits constituted 92 % of the sample, of which 68 % were positive for antibodies against E. cuniculi. The findings align with global reports of high seroprevalence. Despite most infections being subclinical, a substantial portion of asymptomatic rabbits were seropositive, highlighting the need for early disease recognition to prevent its spread. This study is the first to describe the seroprevalence of E. cuniculi in Mexico and the common associated signs.

Las especies de Circovirus porcinos (Porcine circovirus, PCV por sus siglas en inglés) son ubicuos en la población porcina doméstica y silvestre. Hasta el momento, se han descrito cuatro especies (PCV1 al PCV4), siendo el PCV2 la especie más documentada por su participación en la Enfermedad Asociada a Circovirus Porcino cuya patología compleja conduce al desarrollo de diferentes presentaciones clínicas que causan pérdidas económicas importantes en la industria porcina. En el presente trabajo, se revisan los conceptos recabados con relación en los PCVs, incluyendo genotipos, interacción y replicación en las células del huésped, patogenia e inmunidad, así como la posible asociación del PCV3 y PCV4 con la enfermedad, enfatizando sobre la problemática de establecer dicho potencial debido a la alta tasa de coinfección entre los PCVs y otros virus patógenos y emergentes.

Human-driven climate change generates extreme weather events, a well-known consequence of global warming. This leads to increased exposure of most living beings to higher temperatures, resulting in longer, more frequent, and more intense heat stress (HS) periods. This jeopardizes the welfare and survival of animals, negatively affecting the process that connects generations and ensures subsistence and natural selection: reproduction. This letter aims to draw attention to the impact of increasing HS on animal reproductive capacity and the potential alternatives to address this phenomenon. With rising temperatures in most regions worldwide, heat stress will increase in many animals, including humans. This will occur even if we achieve the goal of limiting global temperature rise to no more than 1.5 °C by the year 2100, relative to pre-industrial levels, as set in the 2015 Paris Agreement(1). Roth(2) indicates that HS, upon inducing cellular stress, triggers both indirect (e.g., systemic physiological alterations) and direct (e.g., perturbation of gametes, embryos, and reproductive tissues) negative effects on animal reproduction. In this context, the fertility of insects,(3) aquatic organisms;(1, 3, 4) amphibians,(5) reptiles,(6) birds,(7) mammalian pets,(8) cattle,(2, 9, 10) wild mammals,(11) laboratory mammals,(12) non-human primates,(13) and humans(4) is threatened by elevated temperatures. Consequently, given the unavoidable increase in HS, if this trend continues, potentially all animal groups are at risk of experiencing at least partial declines in reproductive capacity worldwide. This scenario will endanger the production of food and goods from animal sources, affect animal welfare, and potentially threaten the survival of animal populations, including humans. To mitigate widespread animal reproductive failures due to excessive heating, or to prevent them, alongside the coordinated environment-oriented efforts by governments, private industry, scientists, and the general public to reduce global warming, modifications in the management of animals, or their gametes and embryos, are necessary. For instance, Hansen(9) suggests the following alternatives to mitigate the negative effects of HS on reproduction in farm animals: diet pattern changes; active or passive cooling systems; genetic selection or transgenesis to achieve greater thermotolerance; in vivo supplementation of compounds that reduce cellular stress (e.g., orally, or by intramuscular/intravenous administration); and in vitro supplementation of gametes/embryos (for use in reproductive biotechnologies) to decrease cellular stress. These strategies aim to reduce heat-induced fertility alterations, both systemically and directly in reproductive structures. Given the serious risk that global warming poses due to the impact of heat on physiology, we urgently need more studies on the overall context of animal reproduction under HS. In addition, we require a specific focus on the impact of HS on reproductive processes, considering factors such as regions, production systems, species, breeds/strains, and specific genetic backgrounds. Therefore, whether the heating that planet Earth experiences will lead to disastrous effects on animal reproductive capacity or a more controlled, perhaps partially reversible, decrease in such capacity, could be influenced by the measures we plan now. These include efforts from society, governments, and veterinary professionals. Time is running out: the situation calls for immediate action.

Antimicrobial resistance is frequently blamed for clinical failures of treatment or control of bovine respiratory disease (BRD). Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis are generally recognized as the four main bacterial pathogens associated with BRD. This study used data from randomized, controlled, clinical trials that recorded qualitative classification of clinical outcomes (success, or failure) and of results of antimicrobial susceptibility testing (AST; classified as resistant, or not resistant to florfenicol, gamithromycin, tildipirosin, or tulathromycin). Association of results in vitro to clinical outcome for treatment or control of naturally occurring BRD (1 319 calves) was quantitatively evaluated. Clinical outcome was not significantly (P = 0.4643) associated (Fisher’s exact test) with qualitative results of AST in vitro for pathogens that were not exposed to antimicrobial medication in vivo (971 head of cattle). Clinical outcome was significantly (P < 0.0001) associated with qualitative results of AST in vitro for pathogens that were exposed to antimicrobial medication in vivo (348 head of cattle). For pathogens not exposed to antimicrobial medication in vivo, 1.85 % (95 % confidence interval [CI] = 0.38 to 5.32) of clinical failures were attributable to antimicrobial resistance. For pathogens exposed to antimicrobial medication in vivo, 51.72 % (95 % CI = 32.53 to 70.55) of clinical failures were attributable to antimicrobial resistance. In conclusion, antimicrobial resistance of bacterial pathogens associated with BRD and not exposed to antimicrobial medication in vivo is a quantitatively minor cause of clinical failure for treatment or control of naturally occurring BRD.

The health of swine populations is increasingly threatened by diseases such as classical swine fever (CSF), African swine fever (ASF), and Japanese encephalitis (JE), which causeeconomic losses. This study investigated the seroprevalence and distribution of these pathogens across 13 districts in Chhattisgarh, Madhya Pradesh, and Telangana, India. A total of 345 serum samples and 275 whole blood samples were collected for various diagnostic testing. Samples were analyzed using reverse transcriptase polymerase chain reaction (RT-PCR), virus neutralization test (VNT), and indirect enzyme-linked immunosorbent assay (iELISA), with CSF showing the highest seroprevalence in Chhattisgarh (76.63%), while ASF waslowest (7.21%). In Madhya Pradesh, the CSF seroprevalence was 33.33%, with no ASF detected. JE positivity was 12.37% in Chhattisgarh and 44.44% in Madhya Pradesh. RT-PCR of 275 whole blood samples from Telangana revealed 11.27% positivity for CSF and 9.45% for JE, with no ASF cases. In Chhattisgarh, 7.20% of the samples showed concurrent antibody positivity for both CSF and ASF. Additionally, 2.06% were positive for CSF, ASF, and JE, indicating concurrent exposure to multiple pathogens. Age-wise analysis showed the highest CSF positivity among older pigs in Chhattisgarh and Madhya Pradesh, with higher rates observed in pigs >2 years. These findings emphasize the necessity of antigen and antibody testing for effective swine disease surveillance, revealing concurrent exposure to multiple pathogens. A combined approach using serological and molecular diagnostics strengthens surveillance, supports multi-disease control strategies, and is vital for limiting disease spread and maintaining swine health.

This study evaluated the impacts of Bacillus and Lactobacillus probiotics on broiler chicken growth performance, carcass traits, stress responses, and intestinal health at high stocking density. A total of 200 one-day-old broiler chicks (Cobb 500) were randomly assigned to five equal groups (4 replicates with 10 chicks per replicate) as follows: 1) LSD: low stocking density; 2) HSD: high stocking density; 3) HSDBacil: high stocking density with Bacillus probiotic; 4) HSDLAB: high stocking density with Lactobacillus probiotic; and 5) HSDMix: high stocking density with combined Bacillus and Lactobacillus probiotic. The LSD- and HSD-broilers were subjected to 12.5 and 16 birds/m2 stocking density, respectively. Growth performance, carcass traits, serum cortisol levels, oxidative stress markers, and ileal histomorphology were measured. The results indicated that body weight, body weight gain, and the weights of Fabricius bursa and breast meat were also adversely affected by high stocking density. Probiotic administration, particularly Bacillus-based probiotic, increased body weight, body weight gain, and breast meat weight. Elevated serum cortisol and malondialdehyde levels, as well as decreased serum levels of total antioxidant capacity in the HSD group, confirmed the presence of heightened stress and oxidative damage, which were significantly reduced by probiotic administration. In addition, improvements in ileal histomorphology, including increased villus height and crypt depth, were observed in the probiotic-treated groups. Results indicated that the Bacillus-based probiotic had a stronger impact on attenuating the undesirable effects of high stocking density in broilers and can be used as a beneficial nutritional additive against stressful conditions.

Ten turtle species have been reported for Paraguay, and eight of them are in threatened categories. Wildlife commerce is strictly regulated, and according to the most recent data, there is no legal way of acquiring a turtle in the country. The objective of this study is to report the species of turtles that were assisted at the Wild and Exotic Animals Clinic of the Facultad de Ciencias Veterinarias, Universidad Nacional de Asunción, and the main clinical findings. Patient files from 2004 to 2023 were reviewed, and the following data were registered in a spreadsheet: file number and date, species, weight, sex, approximate age, origin, time with the person, feeding, diagnosis, and sub-classification. A total of 496 turtles were registered in individual patient files. Of these, 256 were Chelonoidis chilensis, 125 C. carbonaria, 4 unknown Chelonoidis spp., 8 Acanthochelys macrocephala, 1 A. pallidipectoris, 7 Mesoclemmys vanderhaegei, 6 Phynops spp. (3 P. hilarii, 2 P. geoffroanus, 1 unknown), 2 Hydromedusa tectifera, 14 Kinosternon scorpioides, and 12 unknown Pleurodira. Regarding casuistry, of the 256 C. chilensi brought to the practice, the main cause of consultation was trauma, representing 130 (50.78 %) of the registered files for the species. Regarding C. carbonaria, of the 125 cases, 26 were related to trauma, although routine control was the main cause of consultation. This constitutes the first report on turtle casuistry in Paraguay and may aid in identifying critical species to work with, while concluding that the main problem is still illegal traffic.