1. Investigación

Las consultas relacionadas con cojera son frecuentes en la clínica veterinaria diaria. Los métodos de diagnóstico diferencial ordenado son necesarios y útiles en el quehacer diario de la consulta, evitando errores por omisión. En el presente trabajo se revisarán las causas de cojeras no traumáticas del miembro posterior de aparición más frecuente en el perro. Con ello, se pretende mostrar un método ordenado de diagnóstico y pautas básicas de tratamiento de las cojeras. Puesto que el objetivo de este trabajo es mostrar de forma amplia las posibles causas de cojera no traumáticas del miembro posterior, nos es imposible profundizar en los tratamientos y pronósticos. Por ello, recomendamos al lector recurrir a textos especializados para ampliar la información de este tema.

Prevalence and temporal evolution of the infection by the acanthocephalan Macracanthorhynchus hirudinaceus is studied in the Valencian Community (Eastern Spain), a region only recently fully colonized by the expanding native Eurasian wild boar (Sus scrofa). For 8 years, a total of 1486 wild boars were sampled in order to look for the parasite. The mean prevalence was 20.7% (95% CI, 18.6–22.8; 307/1486). We observed an increasing trend through time, both in the number of wild boars and affected districts. The prevalence of M. hirudinaceus rose in parallel to the annual capture of wild boars, and its presence has been expanding towards the East. A hotspot of M. hirudinaceus is located to the west of the study area, in Muela de Cortes Game Reserve, where 89.6% of the wild boars were positive for the infection, constituting one of the world’s highest known prevalence areas.

During a 12 month period, a group of 14 medusa-stage jellies of the genus Chrysaora, including Pacific sea nettle (Chrysaora fuscescens, n = 11) and Japanese sea nettle (Chrysaora pacifica, n = 3), that were maintained in a public aquarium developed progressive ulcerative umbrellar lesions. In 6 cases (42.9%), ulceration was deep, transmural, and perforated through the mesoglea and subumbrella. In 6 cases (42.9%), ciliated protozoa histomorphologically consistent with scuticociliates were observed in the mesoglea and gastrovascular cavity. In 2 cases (14.3%), commensal dinoflagellates (zooxanthellae) were in the mesoglea and in the cytoplasm of the scuticociliates. During this period, water quality parameters including temperature [°C], pH, oxidation-reduction potential (ORP) [mV], salinity [psu], dissolved oxygen [%], ammonia (NH3), and nitrite (NO2) levels were monitored daily or weekly. The main water quality abnormalities were increased NO2 and pH levels above recommended reference ranges for C. fuscescens and elevated temperature above recommended reference ranges for C. pacifica tank. After correction of water quality parameters, apparent improvement of jellies was observed. In this case, environmental factors were considered the most likely predisposing factors for the development of ulcerative lesions, and ciliated protozoa were considered secondary rather than primary pathogens.

Rho proteins are a large family of GTPases involved in the control of actin cytoskeleton dynamics, proliferation and survival. Rnd1, Rnd2 and RhoE/Rnd3 form a subfamily of Rho proteins characterized by being constitutively active. The role of these proteins has been studied during the last years in several systems; however, little is known about their expression and functions in the reproductive organs. In this work we analysed the localization and the effect of RhoE deficiency in the testes using mice lacking RhoE expression (RhoE gt/gt), and our research shows some unexpected and relevant results. First, we have observed that RhoE is only expressed in Leydig cells within the testicular parenchyma and it is absent of seminiferous tubules. In addition, RhoE is expressed in the excurrent ducts of the testis, including the ductuli efferentes, epididymis and ductus deferens. Moreover, the testes of postnatal 15-day-old RhoE null mice are smaller, both in absolute values and in relation to the body weight. Furthermore, the dimensions of their seminiferous tubules are also reduced compared with wild-types. In order to study the role of RhoE in the adult, we analysed heterozygous animals as RhoE null mice die early postnatally. Our results show that the testes of adult RhoE heterozygous mice are also smaller than those of the wild-types, with a 17% decrease in the ratio testis weight/body weight. In addition, their seminiferous tubules have reduced tubular diameter (12%) and a thinner epithelial wall (33%) that appears disorganized and with a swollen lumen. Finally, and probably as a consequence of those alterations, the sperm concentration of heterozygous animals was found to be lower than in the wild-types. These results indicate that accurate levels of RhoE in the testes are necessary for a correct development and function of male gonads, and suggest novel and unexpected roles of Rnd GTPases in the reproductive physiology.

As one of the most relevant foodborne diseases, it is essential to know the factors related to the transmission, persistence and prevalence of Toxoplasma gondii infection. Eurasian wild boar (Sus scrofa) might play a relevant role in T.gondii's life cycle. This species is the most consumed big game animal in Spain and may act as a source of infection if the meat is eaten raw or undercooked or due to cross-contaminations. Additionally, wild boar can act as an excellent bioindicator of T.gondii circulation in the ecosystem, because its natural behaviour leads to exposure to oocysts from the soil when rooting and tissular bradyzoites when scavenging. A total of 1003 wild boar were sampled from 2010 to 2017 in Mediterranean Spain. Blood samples were tested with an indirect ELISA test giving a total of 14.1% (95% confidence interval 12.0–16.4%) positive results. The prevalence was not homogeneous in neither the animals nor the sampled districts. Significant differences were found regarding age, climatic conditions and human space occupancy. Human population aggregation, assessed by Demangeon's index, was identified as an influential factor in T.gondii infection risk. This multiple approach allows us to evaluate local risks for human and environmental contamination.