Flavya Mendes-de-Almeida

Reduction of feral cat (Felis catus Linnaeus 1758) colony size following hysterectomy of adult female cats.

The size of urban cat colonies is limited only by the availability of food and shelter; therefore, their population growth challenges all known population control programs. To test a new population control method, a free-roaming feral cat colony at the Zoological Park in the city of Rio de Janeiro was studied, beginning in 2001. The novel method consisted of performing a hysterectomy on all captured female cats over 6 months of age. To estimate the size of the colony and compare population from year to year, a method of capture-mark-release-recapture was used. The aim was to capture as many individuals as possible, including cats of all ages and gender to estimate numbers of cats in all population categories. Results indicated that the feral cat population remained constant from 2001 to 2004. From 2004 to 2008, the hysterectomy program and population estimates were performed every other year (2006 and 2008). The population was estimated to be 40 cats in 2004, 26 in 2006, and 17 cats in 2008. Although pathogens tend to infect more individuals as the population grows older and maintains natural behavior, these results show that free-roaming feral cat colonies could have their population controlled by a biannual program that focuses on hysterectomy of sexually active female cats.

Prevalence of Bartonella species DNA and antibodies in cats (Felis catus) submitted to a spay/neuter program in Rio de Janeiro, Brazil.

The prevalence of Bartonella species DNA and antibodies for Bartonella henselae were studied in 40 clinically healthy cats (Felis catus, Linnaeus 1758) submitted to a spay/neuter program in Rio de Janeiro, Brazil. Additionally, the prevalence of Bartonella species DNA was investigated in the fleas found parasitizing the subject cats. For this purpose, blood samples were obtained from all cats, and DNA extraction was performed on the blood, and blood clotted samples, as well as on pools of fleas obtained from them. Antibodies for B henselae were detected on serum samples. Bartonella species DNA was detected in 17 cats, whereas serum reactivity for B henselae was found in 19. A total of 20 cats were flea-infested and nine of these 20 had Bartonella species DNA in their blood. In four of the 20 flea-infested cats, Bartonella species DNA was detected in the fleas obtained from those cats, but only one of these four cats had Bartonella species DNA in its blood.

Updated canine infection rates for Dirofilaria immitis in areas of Brazil previously identified as having a high incidence of heartworm-infected dogs

BackgroundCanine heartworm infections were frequently diagnosed in Brazil before the new millennium. After the year 2000, the frequency of diagnosis showed a sharp decline; however, a few years later, new evidence indicated that the parasite was still present and that canine infection rates seemed to be increasing. Therefore, an updated survey of canine heartworm prevalence was conducted in several locations in south, southeast, and northeast Brazil.MethodsDogs from 15 locations having previously reported a high prevalence of heartworm infection were included in the survey according to defined criteria, including the absence of treatment with a macrocyclic lactone for at least 1 year. Blood samples from 1531 dogs were evaluated by an in-clinic immunochromatography test kit (Witness® Heartworm, Zoetis, USA) for detection of Dirofilaria immitis antigen. At each location, epidemiologic data, including physical characteristics and clinical signs reported by owners or observed by veterinarians, were recorded on prepared forms for tabulation of results by location, clinical signs, and physical characteristics.ResultsThe overall prevalence of canine heartworm infection was 23.1%, with evidence of heartworm-infected dogs detected in all 15 locations studied. There was a tendency for higher prevalence rates in environmentally protected areas, despite some locations having less-than-ideal environmental temperatures for survival of vector mosquitoes. Among physical characteristics, it was noted that dogs with predominantly white hair coats and residing in areas with a high (≥20%) prevalence of heartworm were less likely to have heartworm infection detected by a commercial heartworm antigen test kit than were dogs with other coat colors. In general, dogs older than 2 years were more frequently positive for D. immitis antigen than were younger dogs. Clinical signs of heartworm infections were rare or owners were unable to detect them, and could not be used for reliable prediction of the presence of heartworm.ConclusionsThese results indicate that the prevalence of D. immitis has increased in these areas of Brazil over the past few years. Small animal practitioners in these areas should include routine screening tests for heartworm infections in every dog’s annual evaluation protocol and make sure to have uninfected dogs on prevention.

Effects of doxycycline on the endosymbiont Wolbachia in Dirofilaria immitis (Leidy, 1856)—Naturally infected dogs

Dirofilaria immitis carries intracellular endosymbiotic bacteria of the genus Wolbachia, known to be vital for the worms and sensitive to tetracycline antibiotics. With the purpose of studying the interaction between D. immitis and the endosymbiont Wolbachia sp., heartworm naturally infected microfilaremic or antigenemic dogs were treated with doxycycline (10mg/kg/day of the drug in three cycles of 21 days each, with 6-month intervals). Blood samples were collected on days 0, 7 and 21 of each treatment as well as on day 111 after the beginning of each cycle. A final sample was collected on day 723 from the beginning of the first treatment. The samples were examined for the presence and number of microfilariae and the presence of antigen as well as the presences of D. immitis and Wolbachia sp. DNA using PCR (polymerase chain reaction). With this approach, an evaluation of the effect of doxycycline on antigenemia and on the presence of Wolbachia sp. DNA in dogs with heartworm infection was possible. Doxycycline treatment did not alter the detection of adult parasite antigens with the exception of two animals, though the number of animals carrying Wolbachia sp. DNA decreased, despite the presence of the microfilariae. The effect of the antibiotic therapy on the worms may have interfered with the transmission of heartworm disease because the population of microfilariae and the number of microfilaremic dogs were reduced and the microfilariae positive samples that were found did not test positive for Wolbachia sp. in many cases. These findings suggest that in areas were doxycycline is extensively used D. immitis transmission may be impaired by the reduction on the number of microfilariae and on the endosymbiotic bacteria in the larvae turning them incapable of completing development once they infected a new host.

Seroprevalence of Toxoplasma gondii in cats (Felis catus, Linnaeus 1758) living in Lima, Peru.

The aim of this study was to determine the frequency of infection by T. gondii in cats, by examining serum and fecal samples from animals attended at veterinary clinics in the Metropolitan Region of Lima, Peru. We collected and analyzed 154 cat serum samples and 50 fecal samples, regardless of the age, gender or breed. In parallel with the sample collections, the owners answered an epidemiological questionnaire that investigated the following variables: age group, gender, lifestyle (confined, semi-confined or free-living animals), feeding and hunting habits. The serum and fecal samples were analyzed using indirect hemagglutination (IHA) and coproparasitological tests, respectively. IHA showed that the frequency of cat exposure to T. gondii was 11%. Age and gender showed no association with exposure to the parasite. Exposure among the cats was associated with hunting (x2 = 4.98, p = 0.016) and feeding habits (x2 = 13.34, p = 0.001): those fed with raw meat were more exposed than those fed with commercial cat food (x2 = 9.50, p = 0.004) or with homemade food (x2 = 4.1, p = 0.027). The frequency of cats diagnosed in the chronic phase of T. gondii infection was 88% (15/17). No T. gondii oocysts were found in any of the 50 fecal samples examined.

SEROPREVALENCE OF Toxoplasma gondii (Nicole & Manceaux, 1909) AND RETROVIRAL STATUS OF CLIENT-OWNED PET CATS (Felis catus, Linnaeus, 1758) IN RIO DE JANEIRO, BRAZIL

Cats, as definitive host, play an important role in the transmission of Toxoplasma gondii. This study aimed to establish the seroprevalence of anti-T. gondii immunoglobulins G and M, and determine the frequency of oocysts in the feces of the domestic cat population in Rio de Janeiro, Brazil. We also aimed to study the association between T. gondii infection and age, sex, breed, lifestyle, diet and retroviral infection. A total of 108 cats were included in the study and fecal samples of 54 of those cats were obtained. Only 5.6% of the cats were seropositive for anti-T. gondii immunoglobulins using the indirect hemagglutination test. None of the 54 cats presented oocysts in their fecal samples. Although not statistically significant, males, mixed-breed, free-roaming and cats aged two years and older were found to be more exposed. Age, lifestyle and the use of litter boxes were found to play an important role as risk factors. Anemia and retroviral infections were independent of T. gondii infection. No antibodies were detected in the majority of cats (94.4%), indicating that those cats had never been exposed to the parasite and, therefore, once infected, they could present the risk of shedding large numbers of oocysts into the environment.

Pentatrichomonas hominis infection in two domestic cats with chronic diarrhea

Case series summary Chronic diarrhea is a common and recurring problem in feline medicine. Intestinal trichomonads have been reported as causative agents of diarrhea in cats. While Pentatrichomonas hominis is considered commensal, Tritrichomonas foetus has been found to cause feline large bowel diarrhea in cats. In our report, two young cats infected with the feline leukemia virus (FeLV) and presenting with chronic diarrhea were identified as having trichomonads in their feces, based on direct examination and fecal culture. Molecular assays (PCR and DNA sequencing) revealed that the parasite involved was P hominis, not T foetus, as was suspected. The animals had already been subjected to ineffective therapy with metronidazole, and after the use of ronidazole, their feces became dry and formed. Relevance and novel information This case report describes P hominis infection as a possible cause of chronic diarrhea in two young cats also infected by FeLV. The parasite was probably resistant to metronidazole, the drug of choice in the literature, and sensitive to ronidazole. Although considered commensal, P hominis infection should be evaluated as a differential diagnosis in cats with chronic diarrhea, especially those that are immunocompromised. Moreover, a combination of techniques such as direct examination and/or fecal culture and PCR is essential for an accurate diagnosis of P hominis infection.

Can P-glycoprotein and β-tubulin polymorphisms be used as genetic markers of resistance in Dirofilaria immitis from Rio de Janeiro, Brazil?

ObjectiveDirofilaria immitis, the causative agent of canine heartworm infection, is worldwide the most important filarid to affect domestic dogs. Prevention of this infection is done by macrocyclic lactones, but some reports on the lack of efficacy have been published. Although the actual cause of resistance is unknown, single nucleotide polymorphisms (SNPs) on a P-glycoprotein ABC transporter and β-tubulin genes have been pointed out as candidates for genetic markers of resistance. We conducted a survey to verify the presence of these suggested genetic markers in microfilariae from 30 naturally infected dogs under macrocyclic lactones treatment living in an endemic area in the state of Rio de Janeiro.ResultsThe analysis of these specific SNPs demonstrated no sign of polymorphism on the P-glycoprotein loci, while 72 and 48% of the samples were polymorphic to the first and second SNPs on β-tubulin loci, respectively. This work demonstrates that the P-glycoprotein position 11 and 618 were not polymorphic and, therefore, not suitable as a genetic marker of resistance in Rio de Janeiro whereas both β-tubulin loci were polimorphic. This work points out the difficulty of finding a universal genetic marker for resistance.

Efeito do análogo sintético do feromônio facial felino sobre o nível de cortisol salivar de gatos domésticos

Silva B.P.L., Knackfuss F.B., Labarthe N. & Mendes-de-Almeida F. 2017. Effect of a synthetic analogue of the feline facial pheromone on salivary cortisol levels in the domestic cat. Pesquisa Veterinária Brasileira 37(3):287-290. Programa de Pós-Graduação em Medicina Veterinária, Universidade Federal Fluminense, Rua Vital Brazil Filho 64, Niterói, RJ 24230-340, Brazil. E-mail: flavyama@id.uff.br This study aimed to evaluate the ability of a saliva collection device (Salivette®) to measure cortisol levels in saliva samples of domestic cats and to assess the effect of a synthetic analogue of the feline facial pheromone fraction F3 (Feliway®) on cortisol levels. A total of 28 domestic cats from a private high-quality sanctuary were sampled before exposure to the facial pheromone and after 35 days of exposure. Two pheromone devices were placed in the area where the animals ate to guarantee the exposure of all cats. The collecting device yielded a sufficient volume of saliva (>0.20mL) to allow cortisol measurement. Cortisol measurements ranged from 0.02g/dL to 0.16μg/dL, with a difference between before (42.1%) and after (62.6%) exposure to the pheromone (F=3.2351; p≤0.0002). No difference in cortisol levels was observed between before (x =0.078μg/dL) and after (x =0.066μg/dL) (t=1.79; p=0.08) exposure. However, salivary cortisol levels decreased in 75% (21/28) of the cats after exposure (x2=12.07; p=0.0005), suggesting that the animals have different susceptibilities to the pheromone or that they spent different lengths of time in the area where the pheromone devices were installed.