Fernando Nájera

Dr. Fernando Nájera

Department of Animal Physiology Faculty of Veterinary Medicine Complutense University of Madrid
orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 February 2021 in Animals
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Journal Article
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FNFernando Nájera
Fernando Nájera
RGRebeca Grande-Gómez
Rebeca Grande-Gómez
JMJorge Peña Martínez
Jorge Peña Martínez
AVAnastasio Vázquez
Anastasio Vázquez
MPMaría Jesús Palacios
María Jesús Palacios
JJJosé Jiménez
José Jiménez
The restoration of Iberian lynx (Lynx pardinus) populations in Extremadura (Southwestern Spain) have been carried out since 2014. One of the measures to ensure the success of this program is to examine the effects that diseases may have on reintroduction. Since diseases may be greatly located at certain sites because of the specific ecological requirements of the pathogens and/or vectors, reintroduced individuals may present a risk of infection once released. To determine which pathogens the reintroduced individuals may encounter, we performed a molecular and sero-epidemiological survey in reintroduced and wild-born lynxes. From 2015 to 2019, 69 Iberian lynxes (40 reintroduced and 29 wild-born) were sampled and screened against 10 viral, bacterial and piroplasmid agents. In parallel, 195 sympatric carnivores from the families Canidae, Felidae, Viverridae, Herpestidae and Mustelidae were tested against current or past infections to six common canine/feline viruses. In the Iberian lynx, low contact rates of active infection were obtained for the feline leukemia provirus (FeLV: 1.5%; 1/67), feline parvovirus (FPV: 1.5%; 1/67) and Cytauxzoon sp. (6.7%; 1/15). We also confirmed the emergence of Aujeszky’s disease (suid herpesvirus-1) in this population (SuHV-1: 11.8%; 2/17). Evidence of previous exposure was detected for canine distemper virus (CDV: 5.8%; 3/52), feline coronavirus (1.9%; 1/52), FPV (7.7%; 1/13) and feline calicivirus (FCV: 5.3%; 1/19). From 25 recovered lynx carcasses, we could confirm infectious etiology involvement in the death of four individuals (SuHV-1 in two individuals, coinfection of Cytauxzoon spp. and Aeromonas veronii in one lynx and a Streptococcus canis myositis in another lynx). We confirmed the circulation of CDV, FPV, FeLV, FCV and the feline immunodeficiency virus within the sympatric carnivore community. Due to the low contact rate of infectious agents in such a small, endangered population, we recommend continuing a disease surveillance program to determine the prognostic factors of survival, understand the role that disease may play during the reintroduction and anticipate disease outbreaks that may pose a risk for the entire reintroduced population.

1 January 2017 in Journal of Veterinary Medical Science
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FNFernando Nájera
Fernando Nájera
AHAndrew J. Hearn
Andrew J. Hearn
JRJoanna Ross
Joanna Ross
DSDiana A. Ramírez Saldivar
Diana A. Ramírez Saldivar
MEMeaghan N. Evans
Meaghan N. Evans
LRLuis Revuelta
Luis Revuelta
There is currently no available information regarding the veterinary management of Sunda clouded leopards (Neofelis diardi), either in captivity or in the wild. In this study, 12 Sunda clouded leopards were anesthetized between January 2008 and February 2014 for medical exams, and/or GPS-collaring. Seven wild-caught individuals were kept in captivity and 5 free-ranging animals were captured by cage traps. Two anesthesia combinations were used: medetomidine-ketamine (M-K) or tiletamine-zolazepam (T-Z). Atipamezole (0.2 mg/kg im) was used as an antagonist for medetomidine. Medetomidine (range: 0.039-0.054 mg/kg) and ketamine (range: 3-4.39 mg/kg) were administered during 5 immobilizations, resulting in median induction times of 7 min. After a median anesthesia time of 56 min, atipamezole was injected, observing effects of antagonism at a median time of 12 min. T-Z (range: 6.8-10.8 mg/kg) was administered on 7 occasions. Median induction times observed with this combination were shorter than with M-K (4 min vs 7 min; P=0.04), and anesthesia and recovery times were significantly longer (244 and 35 min vs 56 and 16 min, respectively; P=0.02). Lower heart rates were measured in the M-K group, while lower rectal temperatures were found in the T-Z group. Both combinations resulted in safe and reliable immobilizations, although given the favorable anesthesia and recovery times of M-K, we recommend this approach over T-Z for the veterinary handling of Sunda clouded leopards.

23 April 2019 in European Journal of Wildlife Research
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Journal Article
Closed access
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FNFernando Nájera
Fernando Nájera
SSS. Sánchez-Cuerda
S. Sánchez-Cuerda
GLG. López
G. López
TRT. Del Rey-Wamba
T. Del Rey-Wamba
CRC. Rueda
C. Rueda
JJJ. Jiménez
J. Jiménez

1 March 2021 in Pathogens
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Ana M. FigueiredoAna M. Figueiredo
Ana M. Figueiredo
Luis Madeira de CarvalhoLuis Madeira de Carvalho
Luis Madeira de Carvalho
MGMaría J. P. González
María J. P. González
RTRita Tinoco Torres
Rita Tinoco Torres
SPSamuel Pla
Samuel Pla
FNFernando Nájera
Fernando Nájera
The Iberian lynx (Lynx pardinus) is one of the most endangered felid species in the world. Conservation efforts have increased its population size and distribution and reinforced their genetic diversity through captive breeding and reintroduction programmes. Among several threats that the Iberian lynx faces, infectious and parasitic diseases have underlined effects on the health of their newly reintroduced populations, being essential to identify the primary sources of these agents and assess populations health status. To achieve this, 79 fresh faecal samples from Iberian lynx and sympatric mesocarnivores were collected in the reintroduction area of Extremadura, Spain. Samples were submitted to copromicroscopic analyses to assess parasite diversity, prevalence, and mean intensity of parasite burden. Overall, 19 (24.1%, ±15.1–35.0) samples were positive for at least one enteric parasite species. Parasite diversity and prevalence were higher in the Iberian lynx (43.8%) compared with the others mesocarnivores under study (e.g., the red fox Vulpes vulpes and the Egyptian mongoose Herpestes ichneumon). Ancylostomatidae and Toxocara cati were the most prevalent (15.6%) parasites. Obtained results revealed that Iberian lynx role as predator control might have reduced parasite cross-transmission between this felid and mesocarnivores due to their decreasing abundances. Surveillance programs must include regular monitoring of this endangered felid, comprising mesocarnivores, but also domestic/feral and wild cat communities.

25 August 2021 in Animals
Verified
Journal Article
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FNFernando Nájera
Fernando Nájera
ECElena Crespo
Elena Crespo
AGAmalia García-Talens
Amalia García-Talens
RGRebeca Grande-Gómez
Rebeca Grande-Gómez
FHF. Javier Herrera-Sánchez
F. Javier Herrera-Sánchez
LRLuis Revuelta
Luis Revuelta
Sarcoptic mange caused by the mite Sarcoptes scabiei is a worldwide-distributed skin infestation with a wide range of hosts, among them several species within the Felidae family. Sarcoptes scabiei was diagnosed in a dead adult female European wildcat (Felis silvestris silvestris) from Spain, based on histological evaluation of skin biopsies and identification of the arthropod from skin scrapings and molecular methods. This is the first description of Sarcoptes scabiei in a European wildcat. Due to its critical demography in the southernmost population of the Iberian Peninsula, the impacts of infectious diseases, including sarcoptic mange, as a new potential threat should be considered during disease surveillance programs of the species’ populations.

5 March 2024 in Scientific Reports
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Journal Article
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FNFernando Nájera
Fernando Nájera
GLGuillermo Lopez
Guillermo Lopez
TRTere del Rey-Wamba
Tere del Rey-Wamba
RMRimsha A. Malik
Rimsha A. Malik
GGGermán Garrote
Germán Garrote
MMMarina L. Meli
Marina L. Meli
Feline leukemia virus (FeLV) infection is considered one of the most serious disease threats for the endangered Iberian lynx (Lynx pardinus) Over 14 years (2008–2021), we investigated FeLV infection using point-of-care antigen test and quantitative real-time TaqMan qPCR for provirus detection in blood and tissues in lynxes from Andalusia (Southern Spain). A total of 776 samples from 586 individuals were included in this study. The overall prevalence for FeLV antigen in blood/serum samples was 1.4% (5/360) (95% CI: 0.2–2.6), FeLV proviral DNA prevalence in blood samples was 6.2% (31/503) (95% CI: 4.1–8.6), and FeLV proviral DNA in tissues samples was 10.2% (34/333) (95% CI: 7–13.5). From a subset of 129 longitudinally sampled individuals, 9.3% (12/129) PCR-converted during the study period. Our results suggest that FeLV infection in the Andalusian population is enzootic, with circulation of the virus at low levels in almost all the sampling years. Moreover, since only one viremic individual succumbed to the infection, this study suggests that lynxes may therefore control the infection decreasing the possibility of developing a more aggressive outcome. Although our results indicate that the FeLV infection in the Iberian lynx from Andalusia tends to stay within the regressive stage, continuous FeLV surveillance is paramount to predict potential outbreaks and ensure the survival of this population.