{"id":2206729,"date":"2026-08-21T18:00:22","date_gmt":"2026-08-21T17:00:22","guid":{"rendered":"https:\/\/focusingonwildlife.com\/news\/?p=2206729"},"modified":"2026-08-22T11:32:59","modified_gmt":"2026-08-22T10:32:59","slug":"brazils-wildcats-face-multiple-diseases-due-to-habitat-fragmentation","status":"publish","type":"post","link":"https:\/\/focusingonwildlife.com\/news\/brazils-wildcats-face-multiple-diseases-due-to-habitat-fragmentation\/","title":{"rendered":"Brazil\u2019s wildcats face multiple diseases due to habitat fragmentation"},"content":{"rendered":"

Every day, millions of Brazilians recall how rich the country\u2019s feline biodiversity is when they reach into their wallets: Since entering circulation in 2010, the\u00a0\u201850 real\u2019 notes\u00a0have carried a printed drawing of a jaguar (Panthera onca<\/em>), the largest feline in the Americas. In Brazil, one can even trace the animal that inspired the design of the popular banknotes: It is the jaguar called \u201cGabi,\u201d a 2002-born female that lived in the old Rio de Janeiro Zoo (today Rio\u2019s BioParque). The \u201cmodel\u201d Gabi\u00a0died in 2022, but she remains alive in the imagination of Brazilian consumers in every day-to-day cash transaction.<\/p>\n

Despite the tribute, alongside species such as the puma (Puma concolor<\/em>), the ocelot (Leopardus pardalis<\/em>), and the jaguarund\u00ed (Herpailurus yagouaroundi<\/em>) or gato-mourisco, as it is known in Brazil, the jaguar faces a common crisis among Brazilian species:\u00a0I<\/a>ts existence is threatened\u00a0by problems ranging from illegal wildlife trafficking to the accelerated degradation of its habitats across different biomes. Also, there is a silent emergency that places these wild felines in a threatening environmental context: Diseases that affect domestic animals.<\/p>\n

\u201cThere is a risk for all feline species. Especially for our native species and for those that are endangered,\u201d said Flavia Tirelli, a doctor in zoology and coordinator of the Geoffroy\u2019s Cat Working Group, an international network fighting for the conservation of\u00a0Leopardus geoffroyi<\/em>\u00a0and other wild felines. According to the specialist, who also acts as a researcher at the Laboratory of Evolution, Systematics, and Ecology of Birds and Mammals of the Federal University of Rio Grande do Sul (UFRGS), in southern Brazil, the spread of common diseases among domestic cats (Felis catus<\/em>) \u2014 such as feline immunodeficiency virus (FIV), feline leukemia virus (FeLV), and panleukopenia, caused by the feline parvovirus (FPV), among others \u2014 can significantly affect the feline fauna throughout Brazil.<\/p>\n

\u201cSpecies threatened with extinction have smaller and more isolated populations within our anthropic matrix [as natural environments modified by human action are called] and can also be near domestic animals that carry these viruses,\u201d Tirelli said. It is\u00a0estimated that Brazil ranks third globally\u00a0in the number of pets, with about 30 million domestic cats. At the same time, the number of felines living on the street or without a defined owner also exceeds millions: Data from the World Health Organization (WHO)\u00a0suggest\u00a0there are 10 million cats in these uncertain and vulnerable conditions.<\/p>\n

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A Geoffroy\u2019s cat (Leopardus geoffroyi) resting on a tree. Image by Fernando da Rosa via\u00a0Wikimedia Commons\u00a0(CC BY-SA 4.0).<\/figcaption><\/figure>\n

This scenario, experts say, favors the appearance of feral animals, hinders birth control, and accelerates the spread of diseases. Also, as Mongabay has previously reported, there are\u00a0risks of hybridization between wild species and domestic animals, which, besides threatening wild populations by compromising their genetic profile, opens the way for animals more prone to sickness.<\/p>\n

Tirelli explained that the potential impact of \u201cdomestic\u201d diseases is not limited to a single species: It can expose different, biologically sensitive felines to dangerous pathogens. These pathogens, in turn, can manifest as viral infections \u2014 but also bacterial, fungal, or parasitic ones; many of these diseases can be fatal. The environmental hazard posed by common diseases carried by domestic animals adds many challenges to the conservation of extremely threatened species, such as\u00a0Leopardus munoai<\/em>, one of the species of the pampa cat. This mysterious feline ranks among wildcats at the highest risk of extinction in Brazil, according to the expert.<\/p>\n

This\u00a0small and rare animal, endemic to the Pampa biome (in the southern part of South America, including southern\u00a0Brazil, Argentina, and Uruguay), is already under harassment from humans \u2014 for being a predator of domestic birds \u2014 the reduction of its habitat, and the\u00a0risk of being run over on roads. As it lives under the threat of different forms of contagion, this feline is exposed to additional health factors that can drastically reduce its already sparse population.<\/p>\n

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A rare record of Leopardus munoai, the pampa cat. Image courtesy of F\u00e1bio Mazim, Paulo Wagner, Maur\u00edcio Santos, Mois\u00e9s Barp, Yan Rodrigues\/Bichos Raros dos Pampas.<\/figcaption><\/figure>\n

Habitat fragmentation facilitates the spread of diseases<\/strong><\/h2>\n

According to\u00a0data\u00a0from Brazil\u2019s Institute for the Conservation of Neotropical Carnivores (\u2018Pr\u00f3-Carn\u00edvoros\u2019), a Brazilian civil initiative created in 1996 and officially recognized, Brazil has 10 species of the\u00a0Felidae<\/em>\u00a0family in its territory. Although they inhabit different areas and have diverse forms and behaviors, something unites their stories: The struggle for survival. From the Amazon rainforest\u2019s humid woods to the\u00a0plains of the Cerrado savannah, their habitats are being pressured by biome fragmentation. Whether large or small, when continuous natural areas are reduced to \u201cislands\u201d of vegetation, disconnected spaces are created.<\/p>\n

The crisis combines urban expansion, the conversion of natural areas into agricultural zones, and the construction of infrastructure,\u00a0such as roads and highways that cross extensive areas of forest. Among its multiple\u00a0consequences for biodiversity\u00a0is the spread of diseases.<\/p>\n

\u201cHabitat fragmentation and urban expansion have greatly facilitated the transmission of pathogens between domestic and wild species,\u201d Tirelli said. \u201cThe more this fragmentation increases, with more \u2018little pieces\u2019 of natural areas within a modified anthropogenic matrix \u2014 whether urban, rural, or countryside \u2014 humans bring with them domestic animals that can transmit diseases to the wild [animals] ones.\u201d<\/p>\n

In addition to the best-known viruses, such as those causing feline leukemia (FeLV) and panleukopenia (FPV),\u00a0a 2024 Brazilian study\u00a0dedicated to a bibliographic review of diseases in wild felines of Brazil also highlighted the risk of exposure to the canine distemper virus (CDV), adenoviruses, and the rabies virus.<\/p>\n

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A domestic cat (Felis catus) in an open area. The introduction of urban species into forested areas can expose wildcats to different diseases. Image by Kell Kell via\u00a0Wikimedia Commons\u00a0(CC BY-SA 4.0).<\/figcaption><\/figure>\n

In the case of CDV, better known as distemper, additional risks arise: It represents \u201ca global risk for dogs, and although it does not significantly affect cats, it has been shown that other felines are susceptible to this disease.\u201d The research also highlights that the transmission of this disease to wild species \u201ccan occur through contact with dogs\u201d and that its symptoms \u201ccan be aggressive and lead to the animal\u2019s death.\u201d<\/p>\n

Regarding rabies, which is extremely lethal, the dangers can be broader. The study states that \u201cwild feline species are not considered reservoirs for rabies, but they can act as vectors and transmit the virus to humans and other species.\u201d The matter becomes critical as the scientific study mentions other studies that report the presence of antibodies against the rabies virus in jaguars, indicating exposure to the disease in the Pantanal and in the\u00a0Emas National Park, an important conservation unit for the great American feline in the state of Goi\u00e1s, in central-western Brazil. Considered a UNESCO World Heritage site, the park protects 132,000 hectares (326,000 acres) of the Cerrado and houses a rich biodiversity.<\/p>\n

In all cases, the study concludes that there is \u201ca clear relationship between human actions and the exposure of wild animals to viral agents, as the destruction of their natural habitats forces them to approach areas inhabited by humans and domestic animals.\u201d Among the prevention measures, the study mentions \u201cthe vaccination of dogs and cats and the protection of natural areas to preserve the health of wild feline populations.\u201d<\/p>\n

In addition, as highlighted by Tirelli and other experts, avoiding the fragmentation of wild habitats is a \u201cpriority measure\u201d to prevent exposure of different species to urban risks. This is extremely important, they explain, since strategies for monitoring pathogens within fragmented forest environments can be \u201cvery complex,\u201d Tirelli observes, given that \u201ceach virus and each variant can modify the effectiveness of transmission,\u201d which imposes additional challenges on scientific efforts in the field.<\/p>\n

\"A<\/a>
A characteristic landscape of the Pampa biome, where florestal areas may be close to urban zones, featuring the presence \u2014 and potential interaction \u2014 of domestic animals, semi-domesticated animals, and wild felines. Image by Arlei Antunes via\u00a0Wikimedia Commons\u00a0(CC BY-SA 4.0).<\/figcaption><\/figure>\n

Science seeks answers regarding felines and parasites<\/strong><\/h2>\n

Marcelo Alievi is a doctor in veterinary medicine and coordinator of the Center for Conservation and Rehabilitation of Wild Animals (Preservas), a project of the Federal University of Rio Grande do Sul (UFRGS) based in Porto Alegre, the state capital. Alievi shared a story of two margay specimens (Leopardus wiedii<\/em>). One arrived in 2025 under the care of Preservas in serious condition. The other had already been transferred lifeless. \u201cWe received [in 2025] a weakened margay, which eventually died,\u201d he told Mongabay Latam.<\/p>\n

According to Alievi, this small feline \u2014 classified as vulnerable to extinction by Brazil\u2019s Chico Mendes Institute for Biodiversity Conservation (ICMBio) \u2014 is just one of many wild species suffering from the reduction of its natural habitat and at risk of coming into contact with domestic animals and their diseases.<\/p>\n

\u201cIt is common for these animals to live in a small space, where the food supply is not so abundant. For this reason, they seek resources and other ways to survive \u2014 and it is not rare to see them in peri-urban regions [transition zones between rural and urban areas]. And contact [with domestic cats] can occur that way,\u201d Alievi told Mongabay.<\/p>\n

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A margay (Leopardus wiedii) recorded in the Parque Estadual do Turvo, located in the city of Derrubadas, state of Rio Grande do Sul, Brazil. Image by Anderson Cristiano Hendgen via Wikimedia Commons (CC BY-SA 4.0).<\/figcaption><\/figure>\n

However, something caught the specialist\u2019s attention after the necropsy of the felines: The presence of parasites. Speaking to Mongabay, professor Jo\u00e3o F\u00e1bio Soares, doctor in parasitic diseases and coordinator of the Protozoology Laboratory of UFRGS, stated that the conclusions \u2014 although still preliminary \u2014 pointed to a parasite specific to wild felines.<\/p>\n

\u201cThe parasite, however, presented an atypical condition in the wild feline: It was found in an organ in an unusual way, where it is not usually located. And that caused a more serious lesion,\u201d Soares said. Interestingly, in one of the margays, the presence of the domestic cat virus or feline AIDS [feline immunodeficiency virus] was also confirmed. According to the expert, that could have reduced its immunity and facilitated the emergence of the [parasitic] disease in that form.<\/p>\n

Although further research remains to reach conclusions on the specific case of the margays analyzed by UFRGS, the protozoology specialist highlighted another case of scientific relevance.<\/p>\n

\u201cWe had a case of\u00a0Lagochilascaris<\/em>, another parasite \u2014 this one associated with domestic cats \u2014 that infected\u00a0a southern tiger cat (Leopardus guttulus<\/em><\/a>)<\/a>, in the mountainous region of Rio Grande do Sul. In this case, it also presented in a very atypical way, infecting the animal\u2019s ear canal and, through it, reached the base of the brain. The animal suffered a serious neurological disease,\u201d Soares said.<\/p>\n

The expert explained that the case is related to the atypical living conditions the animal was subjected to, as it was near urban areas, which increases the possibility of contact with domestic cats. \u201cA veterinarian from the region, specialized in domestic felines, mentioned that cases of this parasite in cats are common. This reflects that proximity [between domestic and wild species]. Following these findings, we organized a vaccination and deworming campaign for domestic carnivores to mitigate these transmissions,\u201d Soares added.<\/p>\n

Bacteria and fungi live nearby<\/strong><\/h2>\n

In a\u00a02021 study\u00a0\u2014 involving different institutes and conducted by researchers from Brazil, including Tirelli \u2014 there are warnings about the advancement of other types of infections, equally harmful to the lives of felines and others. Particularly, it mentions feline sporotrichosis, a serious fungal infection, often caused by the fungus\u00a0Sporothrix brasiliensis<\/em>,\u00a0discovered in Brazil. The disease, already a cause for concern among specialists, is highly contagious and causes deep lesions that are difficult to heal in animals. Without proper treatment, it can spread through the lymphatic system and internal organs, leading to the death of the animal.<\/p>\n

\u201cUnlike other species, cats develop lesions with a very high fungal load and can also harbor the agent in their claws and oral cavity, making transmission extremely efficient,\u201d said Gabriela Kharsa Bastos, a veterinarian specializing in feline medicine from the S\u00e3o Paulo State University (Unesp) Botucatu. According to Bastos, semi-domestic cats or those with access to the street \u201cplay a fundamental role in maintaining the epidemiological chain.\u201d<\/p>\n

Bastos explained that the introduction of the fungus into native feline populations occurs in many ways: \u201cIn addition to direct transmission through bites and scratches, infected cats can contaminate the environment by sharpening their claws on tree trunks, fences, and other natural substrates, as well as depositing secretions and organic material containing the fungus.\u201d<\/p>\n

According to the Brazilian Ministry of Health, the country has recorded\u00a0an increase in sporotrichosis cases in recent years: In cats, the number of cases jumped from 1,412 in 2022 to 3,290 in 2023 \u2014 a 233% increase. Bastos warns, however, of substantial differences in how wild species populations are affected.<\/p>\n

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A pregnant jaguar (Panthera onca) in the Encontro das \u00c1guas State Park, Mato Grosso state, Brazil. Image by Zemanatureza via\u00a0Wikimedia Commons\u00a0(CC BY-SA 4.0).<\/figcaption><\/figure>\n

\u201cWhile domestic cats are present in large numbers, wild species have a lower population density and often already face threats such as habitat loss and roadkill. Therefore, even a few cases [of infection] can have significant importance in terms of conservation,\u201d she told Mongabay.<\/p>\n

According to Bastos, controlling sporotrichosis requires an integrated approach between animal health, human health and environmental conservation. Furthermore, she indicated that rapid diagnosis and immediate treatment of infected cats are necessary, as well as education on the zoonotic and environmental risks of the disease, expanding access to treatment and sterilization campaigns, and active epidemiological surveillance, especially in regions near natural areas.<\/p>\n

The 2021 research also focuses on a group of emerging bacteria of the genus\u00a0Bartonella<\/em>. According to the study, felines represent an important reservoir for various species of the bacteria, with domestic cats being the main reservoir for\u00a0Bartonella henselae<\/em>, the causative agent of cat-scratch disease (CSD).<\/p>\n

Publications\u00a0accessible on the website\u00a0of the State of S\u00e3o Paulo Regional Council of Veterinary Medicine (CRMV-SP) say that it rarely causes harm to the carrier cat, but even when it\u2019s benign, the disease can evolve into a serious condition \u201cmainly in immunodeficient individuals [infected humans], in whom it can cause a fatal infection.\u201d<\/p>\n

The study also underscores the importance of understanding the patterns of emergence and spread of pathogens in felines as \u201ca fundamental issue for wildlife conservation.\u201d The research also highlights that free-ranging carnivores are especially important in this context \u201cas they occupy the top of the food chain and act as bioaccumulators and biomagnifiers of pathogens.\u201d<\/p>\n

\"A<\/a>
A puma (Puma concolor), in Brazil, known as \u2018su\u00e7uarana\u2019 or \u2018on\u00e7a-parda,\u2019 recorded by camera trap at the Rio Doce State Park, Minas Gerais state, Brazil. Image by Richard Hatakeyama via\u00a0Wikimedia Commons\u00a0(CC BY-SA 4.0).<\/figcaption><\/figure>\n

So far, one thing is certain: All experts consulted agree on the need to pay attention to the problem, especially to prevent irreversible levels in wildcat population losses. This, they underscore, happens across Brazil \u2014 where different biomes remain harassed by human actions and urban advancement.<\/p>\n

\u201cThe more fragmented the animals\u2019 habitat is, and the closer we are to them, the more susceptible they will be to contamination by common and frequent diseases in domestic animals,\u201d Alievi concluded.<\/p>\n

\u00a0Citations:<\/strong><\/h2>\n

Gomes, A. K. V., Silva Filho, D. S. P., Silva, T. R., \u2026 Rodrigues, W. S. D.\u00a0 (2024)\u00a0 Doen\u00e7as virais em felinos selvagens nativos do Brasil.\u00a0Health Sciences, 28<\/em>(139). doi:10.69849\/revistaft\/ar10202410211208<\/a><\/p>\n

Souza, U. A., Webster, A., Dall\u2019Agnol, B., Morel, A. P., Peters, F. B., Favarini, M. O., \u2026 Reck, J. (2021). Molecular and Serological Survey of the Cat-Scratch Disease Agent (Bartonella henselae) in Free-Ranging Leopardus geoffroyi and Leopardus wiedii (Carnivora: Felidae) From Pampa Biome, Brazil: Souza UA et al.\u00a0Microbial ecology, 81<\/em>(2), 483\u2013492. doi:\u00a010.1007\/s00248-020-01601-x<\/a><\/p>\n

This article<\/a> by Lucas Berti was first published by Mongabay on 11 August 2026. Lead Image: An ocelot (Leopardus pardalis) photographed in the Encontro das \u00c1guas State Park, Mato Grosso, Brazil. Image by Giles Laurent on Wikimedia Commons (CC BY-SA 4.0).<\/em><\/p>\n

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