Prevalence and seasonal distribution of Ctenocephalides canis (Curtis) and Ctenocephalides felis (Bouché) infestations in urban dogs of the city of Aguascalientes, Mexico, were studied. Between January and December 2007, 863 dogs in the Municipal Canine and Feline Control Center were examined. Overall prevalence of infestation was 12% (95% CI 10-14). Seasonal distribution revealed that prevalences in spring and summer were highest, while autumn and winter had lower prevalences. Two infestation peaks were observed, i.e., in April (17.7%) and July (18.9%). A positive correlation was detected between prevalence and temperature during the winter season (P < 0.05). Prevalence in relation to gender showed that males were more frequently infested, 14% (95% CI 11-17), than females, 9.4% (95% CI 7-13); hair length did not affect differences in prevalence. Six hundred twenty-nine fleas were examined; 62% were C. canis and 38% C. felis . Dogs infested with only C. canis were 48% (95% CI 38-58), while 18% were infested only with C. felis (95% CI 11-27); the remainder, 34% (95% CI 24-44), had mixed infestations.

In Mexico, intensive production of bullfrogs is one of the most important aquaculture activities, due to growing demand for their meat. Frogs can be hosts for several parasites that negatively affect their development and health. The objective of this study was to identify the presence of intestinal parasites in bullfrogs in aquaculture production units. Eighteen bullfrogs aquaculture production units were selected, and 20 animals (n=360) from each farm. Fecal samples were obtained by mucosal scraping and processed using the concentration method. The overall prevalence of intestinal parasites was 70.5%, and all farms had frogs infected by some species of parasite. Two species of parasites were identified: Eimeria sp. and Strongyloides sp. Significant differences were found regarding parasite prevalence between males and females (73.8% vs 58.8%) and regarding tibia length (5.5 vs 6.1 cm) and weight (168 vs 187 g) between parasitized and non-parasitized frogs. In conclusion, the present study showed a high prevalence of intestinal parasites, and morphometric alterations (weight, snout-cloaca length, radio-ulna length, tibia length and distance between parotid glands) were identified in the parasitized animals. These results provided useful information that will enable establishment of adequate control measures to help minimize the adverse effects of these parasites.

Aflatoxins (AFs) are secondary metabolites of Aspergillus spp. They are highly toxic, carcinogenic, and immunosuppressive; AFs cause nonspecific disorders in humans and animals, which makes their diagnosis complex. The objective was to describe the time course of toxic effects of a single exposure to AFs-contaminated feed. Fifteen male calves (2 weeks old) were examined over 30 days for clinical, biochemical, and pathological changes resulting from the ingestion of AF-contaminated feed (1.0 mg/kg BW). Compared with 15 unexposed calves, exposed calves showed transient depression and rough coat; BW gain, dry matter intake, albumin, total plasma protein, and hepatic and renal glutathione-S-transferase concentrations progressively decreased. However, conversion ratio (feed/BW), total bilirubin, direct bilirubin, alkaline phosphatase, reduced glutathione, gamma-glutamyltransferase, and alanine and aspartate aminotransferases progressively increased. Necropsy and histology at 7 days postexposure (dpe) showed liver with multifocal hemorrhages, yellowish coloration, friable consistency, periportal fibrosis, and steatosis. Kidneys were hemorrhagic, with brush border losses, glomerular atrophy, sclerotic glomerulonephritis, and lymphocytic infiltration. However, at 30 dpe, the liver showed pale discoloration, diffuse macrovesicular steatosis, and periportal fibrosis. The kidneys had mottled appearance and firm consistency, fibrosis, loss of normal architecture, and thickening of Bowman’s capsule. These results suggest that the identification of alterations in animal performance and biochemical and histological characteristics could be useful for integrating a proper diagnosis of bovine aflatoxicosis.

Objetivo . Identificar la prevalencia de la infección por parásitos digestivos (PD) y su distribución estacional en perros de Aguascalientes, México. Materiales y métodos . Se examinó una muestra estadísticamente representativa (n=927), seleccionada sistemáticamente (primero de cada 10), de perros vagabundos o entregados voluntariamente por sus propietarios al centro local de control y bienestar animal. Inmediatamente después de la eutanasia legal (preanestesia más sobredosis de anestesia) se extrajo el intestino, se tamizó el contenido y se recogieron los helmintos macroscópicos; una muestra de heces por duplicado se examinó mediante flotación, McMaster y frotis teñido con Lugol. Resultados . La prevalencia global de los PI fue 42.8%; pero fue más alta entre cachorros (60.6%), perros con mala condición corporal (72.7%) y perros vagabundos (57.5%), en comparación con los entregados (37.5%; p < 0.01); además, se encontraron más casos durante las estaciones húmedas (51.0 vs 33.1%; p<0.01). Se estimaron los valores de prevalencia de: Dipylidium caninum (26.2%), Taenia spp. (4.1%), Giardia spp . (13.6%), Cystoisospora spp. (7.8%), Sarcocystis spp . (5.3%); Toxocara canis (14.0%), Ancylostoma caninum (12.9%), Uncinaria stenocephala (4.2%), Toxascaris leonina (0.5%) y Oncicola canis (0.1%). La prevalencia de PD alcanzó cientos de formas adultas en el intestino y miles de huevos u ooquistes por gramo de heces. Conclusiones . Estos resultados indicaron una alta prevalencia y abundancia de PD en perros del centro de México, especialmente en el segmento poblacional constituido por animales vagabundos, jóvenes y de bajo peso, lo cual es relevante por su reconocida capacidad zoonótica.

Crops contamination with aflatoxins (AFs) and zearalenone (ZEA) threaten human and animal health; these mycotoxins are produced by several species of Aspergillus and Fusarium. The objective was to evaluate under field conditions the influence of the wet season on the dissemination of AF- and ZEA-producing fungi via houseflies collected from dairy farms. Ten dairy farms distributed in the semi-arid Central Mexican Plateau were selected. Flies were collected in wet and dry seasons at seven points on each farm using entomological traps. Fungi were isolated from fly carcasses via direct seeding with serial dilutions and wet chamber methods. The production of AFs and ZEA from pure isolates was quantified using indirect competitive ELISA. A total of 693 Aspergillus spp. and 1274 Fusarium spp. isolates were obtained, of which 58.6% produced AFs and 50.0% produced ZEA (491 ± 122; 2521 ± 1295 µg/kg). Houseflies and both fungal genera were invariably present, but compared to the dry season, there was a higher abundance of flies as well as AF- and ZEA-producing fungi in the wet season (p < 0.001; 45.3/231 flies/trap; 8.6/29.6% contaminated flies). These results suggest that rainy-weather conditions on dairy farms increase the spread of AF- and ZEA-producing Aspergillus spp. and Fusarium spp. through houseflies and the incorporation of their mycotoxins into the food chain.

Aflatoxins (AFs) represent a major threat to poultry health and food safety due to their hepatotoxic, immunosuppressive, and carcinogenic effects. This study evaluated the chemoprotective potential of ethoxyquin (EQ) and N-acetylcysteine (NAC) in laying hens (80.8 and 33.3 mg/kg BW/d) exposed to chronic dietary AFs contamination (0.0–1.5 mg/kg). A total of 360 Hy-Line W36 Leghorn hens were monitored over 72 weeks using biochemical and histopathological analyses of liver and kidney tissues. NAC significantly (p < 0.01) increased hepatic and renal levels of reduced glutathione (GSH) and stimulated glutathione S-transferases (GST) and gamma-glutamyl transferase (GGT) activity, enhancing detoxification. Both agents significantly (p < 0.05) reduced plasma ALT and AST levels, preserved total protein concentrations, and attenuated liver and kidney hypertrophy. EQ demonstrated antioxidant effects, stabilizing enzymatic responses and limiting tissue damage. Histopathological analysis revealed fewer structural alterations and cellular degeneration, especially in the NAC-treated group (p < 0.01). These results suggest that NAC and EQ activate endogenous detoxification mechanisms, both enzymatic and non-enzymatic, effectively mitigating chronic aflatoxin toxicity. Their dietary supplementation offers a safe and sustainable chemoprotection strategy to support poultry health and productivity, particularly in regions facing high mycotoxin exposure.