Differences in natural antibody titres comparing free-ranging guanacos (Lama guanicoe) and capybaras (Hydrochoerus hydrochaeris)

Parasites can be detrimental to the health of wildlife populations and may negatively affect several aspects of the life history of their hosts. Investigating host health, therefore, is key to understanding important mechanisms of the host–parasite interaction at the individual and population levels. Recently, we reported a prevalence of 10% of Trypanosoma evansi Steel, 1884 in a population of capybaras (Hydrochoerus hydrochaeris (L., 1766)) from Esteros del Iberá, Argentina; however, the impact of T. evansi infection on capybaras is unknown. The aim of this study was to explore associations between T. evansi infection and biochemical and physiological parameters in wild capybaras using blood samples (n = 60) from a managed population of free-ranging capybaras from Esteros del Iberá. Infection by T. evansi was negatively associated with body condition, albumin, alpha-2 globulin concentrations, albumin/globulin ratio, and eosinophil counts, and it was positively associated with spleen index and gamma-globulin concentrations. These results suggest that T. evansi infection may pose a significant impact on the health of wild capybaras.

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Morphometric Patterns and Blood Biochemistry of Capybaras (Hydrochoerus hydrochaeris) from Human-Modified Landscapes and Natural Landscapes in Brazil

Veterinary Sciences ◽

10.3390/vetsci8080165 ◽

2021 ◽

Vol 8 (8) ◽

pp. 165

Author(s):

Hector R. Benatti ◽

Hermes R. Luz ◽

Daniel M. Lima ◽

Vinicius D. Gonçalves ◽

Francisco B. Costa ◽

...

Keyword(s):

Body Mass ◽

Biochemical Parameters ◽

Serum Levels ◽

Condition Index ◽

Human Beings ◽

Body Condition Index ◽

Hydrochoerus Hydrochaeris ◽

Natural Landscapes ◽

The World ◽

Free Ranging

The capybara, Hydrochoerus hydrochaeris, is the largest extant rodent of the world. To better understand the correlation between size and body mass, and biochemical parameters of capybaras from areas with different degrees of anthropization (i.e., different food supplies), we sampled free-ranging capybaras from areas of natural landscapes (NLs) and human-modified landscapes (HMLs) in Brazil. Analyses of biometrical and biochemical parameters of capybaras showed that animals from HMLs were heavier (higher body mass) than those from NL, a condition possibly related to fat deposit rather than body length, as indicated by Body Condition Index (BCI) analyses. Biochemical parameters indicated higher serum levels of albumin, creatine kinase, cholesterol, fructosamine and total protein among capybaras from HMLs than from NLs; however, when all adult capybaras were analyzed together only cholesterol and triglycerides were positively correlated with body mass. We propose that the biochemical profile differences between HMLs and NLs are related to the obesity condition of capybaras among HMLs. Considering that heavier animals might live longer and reproduce more often, our results could have important implications in the population dynamics of capybaras among HMLs, where this rodent species is frequently represented by overgrowth populations that generate several levels of conflicts with human beings.

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A predictive model to diagnose pregnancy in guanacos (Lama guanicoe) using non-invasive methods

Canadian Journal of Zoology ◽

10.1139/cjz-2019-0070 ◽

2020 ◽

Vol 98 (1) ◽

pp. 13-20

Author(s):

A. Marozzi ◽

V.I. Cantarelli ◽

F.M. Gomez ◽

A. Panebianco ◽

L.R. Leggieri ◽

...

Keyword(s):

Predictive Model ◽

Large Scale ◽

Population Studies ◽

Lama Guanicoe ◽

Non Invasive ◽

Pregnant Females ◽

Metabolite Concentrations ◽

Scale Population ◽

Pregnancy Status ◽

Free Ranging

Pregnancy status is usually not included in ecological studies because it is difficult to evaluate. The use of non-invasive methods to determine pregnancy, without physically restraining individuals, would enable pregnancy to be included in population studies. In this study, we evaluated sex steroid hormones in plasma and fecal samples from pregnant and non-pregnant females to develop a pregnancy predictive model for guanacos (Lama guanicoe (Müller, 1776)). Samples were obtained during live-shearing management (i.e., capture, shear, and release) of guanacos. Enzyme immunoassays were used to evaluate progesterone (P4) and estradiol (E2) concentrations in plasma and pregnanediol glucuronides (PdG) and conjugated estrogens (EC) in feces. Mean hormonal and fecal metabolite concentrations were significantly higher in pregnant females than in non-pregnant females. A linear relationship was found between each hormone and its fecal metabolite. Finally, hormonal data were combined with an independent source of pregnancy diagnosis such as abdominal ballottement to develop a logistic regression model to diagnose pregnancy in non-handled individuals. The use of predictive models and non-invasive methods might be suitable to incorporate pregnancy information in large-scale population studies on guanaco and other free-ranging ungulates.

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Exposure of free‐ranging capybaras ( Hydrochoerus hydrochaeris ) to the vaccinia virus

Transboundary and Emerging Diseases ◽

10.1111/tbed.13376 ◽

2019 ◽

Vol 67 (2) ◽

pp. 481-485

Author(s):

João Marcelo Azevedo de Paula Antunes ◽

Iara Apolinário Borges ◽

Giliane de Souza Trindade ◽

Erna Geessien Kroon ◽

Tatiana Morosini de Andrade Cruvinel ◽

...

Keyword(s):

Vaccinia Virus ◽

Hydrochoerus Hydrochaeris ◽

Free Ranging

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Rickettsial infection in free-ranging capybaras (Hydrochoerus hydrochaeris) and their ticks (Acari, Ixodidae) in the Caatinga and Atlantic forest biomes, Northeastern Brazil

Veterinary Parasitology Regional Studies and Reports ◽

10.1016/j.vprsr.2021.100649 ◽

2021 ◽

pp. 100649

Author(s):

Silvia Gabriela Nunes da Silva Yang ◽

Dênisson da Silva e Souza ◽

Ana Cláudia da Silva Santiago ◽

Raizza Barros Sousa Silva ◽

Márcia Almeida de Melo ◽

...

Keyword(s):

Atlantic Forest ◽

Northeastern Brazil ◽

Rickettsial Infection ◽

Hydrochoerus Hydrochaeris ◽

Free Ranging

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Parasite prevalence in free-ranging farm cats,Felis silvestris catus

Epidemiology and Infection ◽

10.1017/s0950268800052468 ◽

1996 ◽

Vol 116 (2) ◽

pp. 217-223 ◽

Cited By ~ 48

Author(s):

N. Yamaguchi ◽

D. W. Macdonald ◽

W. C. Passanisi ◽

D. A. Harbour ◽

C. D. Hopper

Keyword(s):

Parasite Prevalence ◽

Virus Antigen ◽

Chlamydia Psittaci ◽

Feline Calicivirus ◽

Cowpox Virus ◽

Toxocara Cati ◽

Leukaemia Virus ◽

Antibody Titres ◽

Feline Leukaemia Virus ◽

Free Ranging

SUMMARYNo animals tested were positive for feline leukaemia virus antigen andChlamydia psittaciantibodies, but all were positive for antibodies to feline calicivirus (FCV), feline herpesvirus 1 (FHV1) and rotavirus. They had antibodies to feline parvovirus (96%), feline coronavirus (84%) and cowpox virus (2%). Antibody to feline immunodeficiency virus (FIV) was found in 53% of animals, which were less likely to be infected withHaemobartonella felis, and had higher FHV antibody titres than cats without FIV. FCV was isolated from 51% cats and FHV1 and feline reovirus each from 4%.H. feliswas present in 42% of animals, and antibody toToxoplasma gondiiin 62%. Clinical abnormality had a significant association with FIV and feline calicivirus infections, but sex, age, social status and feeding group had no significant association with prevalence of any parasites.Toxocara catiandToxascaris leoninaeggs were found, respectively, in 91% and 82% of animals tested.

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Positive-reinforcement strategies to reduce capture-stress in Capybaras

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v41i1.45819 ◽

2019 ◽

Vol 41 ◽

pp. e45819

Author(s):

Derek Andrew Rosenfield ◽

Cristiane Schilbach Pizzutto

Keyword(s):

Positive Reinforcement ◽

Acute Stress ◽

Population Control ◽

Physical Restraint ◽

Chemical Restraint ◽

Hydrochoerus Hydrochaeris ◽

Conditioning Effect ◽

Capture Stress ◽

Related Stress ◽

Free Ranging

Prior to the administration of any anesthetics, capturing the semi-aquatic capybara (Hydrochoerus hydrochaeris) demands physical restraint, which presents immense challenges. Traditional methods, such as lassoing and traps, are prone to induce acute stress, may result in injury, and can even have fatal outcomes. As part of a larger population control project using contraceptive methods, frequent capture-induced stress and injury may directly affect normal reproductive physiology. Thus, choosing a less stress-inducing method was imperative. In this report, we describe methods of conditioning to enable frequent capture and manipulation, using bait as a positive reinforcement associated with a special click-sound, in a free-ranging population of 40 capybaras. The objectives were to attract, herd, and allow capybaras to voluntarily enter a coral. We evaluated the conditioning effect on individual and group behaviors, interpreting vocal and body language manifestations during the processes of conditioning, herding, capture, and recovery (post procedure/chemical restraint), with the aim of minimizing capture-related stress and injuries. Based on our observations, we report that conditioning, used as part of the capture strategies, noticeably facilitated physical restraint and manipulation throughout the procedures, while apparently maintaining the animals’ overall welfare as it relates to conditioning and capture.

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Parasites Circulating in Wild Synanthropic Capybaras (Hydrochoerus hydrochaeris): A One Health Approach

Pathogens ◽

10.3390/pathogens10091152 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1152

Author(s):

Manuel Uribe ◽

Carlos Hermosilla ◽

Arlex Rodríguez-Durán ◽

Juan Vélez ◽

Sara López-Osorio ◽

...

Keyword(s):

Opportunistic Infections ◽

Ecological Impact ◽

Domestic Animal ◽

Future Research ◽

New Host ◽

Hydrochoerus Hydrochaeris ◽

Wide Range ◽

Parasite Infections ◽

Zoonotic Parasites ◽

Free Ranging

Capybaras (Hydrochoerus hydrochaeris) are affected by a wide range of protozoan and metazoan-derived parasitic diseases. Among parasites of free-ranging capybaras are soil-, water-, food- and gastropod-borne parasitosis, today considered as opportunistic infections in semiaquatic ecosystems. The overlapping of the capybara’s natural ecological habitats with human and domestic animal activities has unfortunately increased in recent decades, thereby enhancing possible cross- or spillover events of zoonotic parasites. Due to this, three synanthropic wild capybara populations in the Orinoco Basin were studied for the occurrence of gastrointestinal parasite infections. A total of forty-six fecal samples were collected from free-ranging capybaras in close proximity to livestock farms. Macroscopical analyses, standard copromicroscopical techniques, coproELISA, PCR, and phylogenetic analysis revealed thirteen parasite taxa. In detail, the study indicates stages of five protozoans, four nematodes, one cestode, and three trematodes. Two zoonotic parasites were identified (i.e., Plagorchis muris, and Neobalantidium coli). The trematode P. muris represents the first report within South America. In addition, this report expands the geographical distribution range of echinocoelosis (Echinocoleus hydrochoeri). Overall, parasitological findings include two new host records (i.e., P. muris, and Entamoeba). The present findings collectively constitute baseline data for future monitoring of wildlife-derived anthropozoonotic parasites and call for future research on the health and the ecological impact of this largest semiaquatic rodent closely linked to humans, domestic and wild animals.

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