2. Universidad Cardenal Herrera-CEU

La sarna es una enfermedad de la piel altamente contagiosa causada por una o varias especies de ácaros, que puede producir inmunosupresión y reacciones inflamatorias. En el conejo, Sarcoptes scabiei y Psoroptes equi cuniculi son los ácaros que producen esta patología en mayor medida. El diagnóstico y tratamiento de esta enfermedad son relativamente sencillos una vez se evidencia la sintomatología en los animales; pero si no se instauran tratamientos y medidas de control en las granjas afectadas, la infestación por sarna puede provocar graves pérdidas económicas.

Las conejas reproductoras son el eslabón más importante en la cadena productiva, ya que su enfermedad puede resultar en una mayor mortalidad entre los gazapos. Existen diferencias en las enfermedades que afectan a los conejos según la edad, así las patologías digestivas y respiratorias son más comunes en conejos jóvenes, mientras que las enfermedades respiratorias y reproductivas son la principal causa de muerte en hembras adultas. Debemos tener en cuenta, tanto los problemas reproductivos (esterilidad, subfecundidad, etc.) como las patologías reproductivas (mastitis, metritis, etc.), ya que la reproducción ocupa el 90% de la vida productiva de una coneja.

Las patologías digestivas son una de las principales enfermedades que afectan al sector cunícola, debido a su elevada mortalidad y morbilidad, sobre todo en el periodo de destete, lo cual supone una gran pérdida económica y el empeoramiento de los índices productivos. La etiología puede ser muy variada y los signos clínicos muy similares, lo cual dificulta su diagnóstico. Se pueden clasificar según su etiología en: bacterianas, entre las que se encuentran la colibacilosis, clostridiosis, enfermedad de Tyzzer, salmonelosis y enteropatía proliferativa; parasitarias, como la coccidiosis y criptosporidiosis; víricas, como rotavirus o parvovirus; y la enteropatía mucoide o enterocolitis epizoótica del conejo, todavía de etiología desconocida. En este artículo se realiza una breve descripción de todas ellas, sin olvidar que además de controlar el agente causal, se debe tener muy en cuenta la alimentación y manejo de los animales, así como la higiene en la explotación.

Pasteurella multocida es uno de los patógenos más importantes que infectan a los conejos, provocando importantes pérdidas económicas en la cría comercial. La presentación de esta enfermedad es muy variada, siendo la forma más común que podemos observar a nivel respiratorio la presencia de rinitis, otitis y neumonía, así como metritis, abscesos y mastitis. Abordaremos distintos aspectos relacionados con la patogenia, así como el diagnóstico diferencial con la mixomatosis y la enfermedad vírica hemorrágica. Además, nos centraremos en la prevención, siendo las medidas higiénicas las más eficientes a la hora de disminuir el porcentaje de los enfermos.

Las infecciones del aparato respiratorio ocupan el segundo lugar en importancia, tanto por el porcentaje de granjas afectadas, como por el número de animales que enferman. Afectan tanto a explotaciones comerciales en naves cerradas, como explotaciones al aire libre, sobre todo si las condiciones climáticas son inapropiadas. Los procesos del aparato respiratorio generan graves pérdidas económicas, por su influencia en el rendimiento de todos los eslabones de la cadena productiva, desde los gazapos hasta los adultos, y también por el elevado coste que su control exige. Entre las patologías respiratorias más comunes, destaca la pasteurelosis, la cual presenta signos clínicos y formas de presentación diversas: rinitis-coriza, neumonía, otitis, abscesos, mastitis, metritis y la forma septicémica. Debemos hacer un diagnóstico diferencial con la mixomatosis atípica, que cursa con rinitis, blefaritis y conjuntivitis, la cual se tratará a continuación. En este artículo también hablaremos de la enfermedad hemorrágica vírica, que puede confundirse con la pasteurelosis septicémica.

Staphylococcal mastitis is a major health problem in humans and livestock that leads to economic loss running in millions. This process is currently one of the main reasons for culling adult rabbit does. Surprisingly, the two most prevalent S. aureus lineages isolated from non-differentiable natural clinical mastitis in rabbits (ST121 and ST96) generate different immune responses. This study aimed to genetically compare both types of strains to search for possible dissimilarities to explain differences in immune response, and to check whether they showed similar virulence in in vitro tests as in experimental intramammary in vivo infection. The main differences were observed in the enterotoxin gene cluster (egc) and the immune-evasion-cluster (IEC) genes. While isolate ST121 harboured all six egc cluster members (seg, sei, selm, seln, selo, selu), isolate ST96 lacked the egc cluster. Strain ST96 carried a phage integrase Sa3 (Sa3int), compatible with a phage integrated into the hlb gene (β-haemolysin-converting bacteriophages) with IEC type F, while isolate ST121 lacked IEC genes and the hlb gene was intact. Moreover, the in vitro tests confirmed a different virulence capacity between strains as ST121 showed greater cytotoxicity for erythrocytes, polymorphonuclear leukocytes and macrophages than strain ST96. Differences were also found 7 days after experimental intramammary infection with 100 colony-forming units. The animals inoculated with strain ST121 developed more severe gross and histological mastitis, higher counts of macrophages in tissue and of all the cell populations in peripheral blood, and a significantly larger total number of bacteria than those infected by strain ST96.

The appearance of methicillin-resistant strains of Staphylococcus aureus (MRSA) in several animal species (including rabbits) has set o alarms for their capacity to act as reservoirs for this bacterium. This is especially important in wild animals given its epidemiological implications. The objectives of this study were to identify and characterize S. aureus, specifically MRSA, strains in wild lagomorph high-density areas. Ten hares and 353 wild rabbits from 14 towns with a high rabbit density in the Valencian region (eastern Spanish coast) were sampled. Swabs from the nasal cavity, ears, perineum and lesions (when present) were taken for microbiological studies. The detection of di erent genes and antibiotic susceptibility studies were also carried out. Of all the animals, 41.3% were positive for S. aureus, of which 63.3% were MRSA. Ears were the anatomical location with more S. aureus and MRSA strains. The more frequently identified MLST type was ST1945 (97.1%, 136/140). The mecA gene was found only in one sample. The rest (n = 139) carried the mecC gene and were included in CC130, except one. Penicillin resistance was detected in 28 mec-negative isolates and, in one case, bacitracin resistance. mecA isolate presented resistance to enrofloxacin and tetracycline, and 10 mecC isolates also showed bacitracin resistance. No MRSA isolate was positive for genes chp, sea, tst and PVL. Two ST1945 isolates contained IEC type E (comprising genes scn and sak). mecA-isolate was positive for blaZ. Of the 28 MSSA strains showing resistance to penicillin, 22 carried the blaZ gene. These surprising results highlight the marked presence of MRSA strains in wild rabbits in high-density areas.

In recent decades, concern about rabbit welfare and sustainability has increased. The housing system is a very important factor for animal welfare. However, information about how different available housing types for female rabbits affect their health status is scarce, but this is an important factor for their welfare. Hence, the objective of this study was to evaluate the health status of female rabbits in five common housing systems: three different single-housing systems with distinct available surfaces and heights; a single-housing system with a platform; a collective system. Female rabbits in the collective and platform cages had greater cortisol concentrations in hair than those in the single-housing system with no platform. Haptoglobin concentrations and kit mortality rates during lactation were greater for the collective-cage female rabbits. The collective group had more culled females and more lesions than in the other groups. The main reasons for culling in all the groups were reproduction problems and presence of abscesses, and the collective group of females was the most affected. In conclusion, it appears that keeping females together in collective systems negatively affects their health status and welfare, while single-housing systems imply lower kit mortality rates during lactation and cortisol concentrations, and fewer lesions in female rabbits.

The main purpose of this study was to find several early factors affecting stayability in rabbit females. To reach this goal, 203 females were used from their first artificial insemination to their sixth parturition. Throughout that period, 48 traits were recorded, considered to be performance, metabolic and immunological indicators. These traits were initially recorded in females’ first reproductive cycle. Later, removed females due to death or culling and those that were non-removed were identified. A first analysis was used to explore whether it was possible to classify females between those reaching and those not reaching up to the mean lifespan of a rabbit female (the fifth reproductive) cycle using information from the first reproductive cycle. The analysis results showed that 97% of the non-removed females were classified correctly, whereas only 60% of the removed females were classified as animals to be removed. The reason for this difference lies in the model’s characteristics, which was designed using early traits and was able to classify only the cases in which females would be removed due to performance, metabolic or immunologic imbalances in their early lives. Our results suggest that the model defines the necessary conditions, but not the sufficient ones, for females to remain alive in the herd. The aim of a second analysis was to find out the main early differences between the non-removed and removed females. The live weights records taken in the first cycle indicated that the females removed in their first cycle were lighter, while those removed in their second cycle were heavier with longer stayability (−203 and þ202 g on average, respectively; P < 0.05). Non-removed females showed higher glucose and lower beta-hydroxybutyrate concentrations in the first cycle than the removed females (þ4.8 and −10.7%, respectively; P < 0.05). The average lymphocytes B counts in the first cycle were 22.7% higher in the non-removed females group (P < 0.05). The females removed in the first reproductive cycle presented a higher granulocytes/lymphocytes ratio in this cycle than those that at least reached the second cycle (4.81 v. 1.66; P < 0.001). Consequently, non-removed females at sixth parturition offered adequate body development and energy levels, less immunological stress and a more mature immune function in the first reproductive cycle. The females that deviated from this pattern were at higher risk of being removed from the herd.