dogs may be a reservoir host for Angiostrongylus costaricensis

Angiostrongylus costaricensis is a parasitic nematode of wild rodents. Several other vertebrate species including man may become infected by ingestion of the third stage larvae produced by the intermediate hosts, usually slugs from the family Veronicellidae. There is a report of the diagnosis of abdominal angiostrongyliasis in Canis familiaris with lesions resembling those found in human disease. As a preliminar evaluation of the adequacy of a canine model for pathogenetic studies, a dog was inoculated with 75 L3 of A. costaricensis. Infection was established and fist stage larvae were found in feces up to 88 days post infection, sometimes in very large numbers (9.5 x 10(4) L1/g). No clinical manifestations or significant lesions were detected. These are indications that dog may play a role as a reservoir host for A. costaricensis.

Visceral leishmaniasis in Brazil: rationale and concerns related to reservoir control

The control of zoonotic visceral leishmaniasis is a challenge, particularly in Brazil, where the disease has been gradually spreading across the country over the past 30 years. Strategies employed for decreasing the transmission risk are based on the control of vector populations and reservoirs; since humans are considered unnecessary for the maintenance of transmission. Among the adopted strategies in Brazil, the sacrifice of infected dogs is commonly performed and has been the most controversial measure. In the present study, we provide the rationale for the implementation of different control strategies targeted at reservoir populations and highlight the limitations and concerns associated with each of these strategies.

EVIDENCE OF Leishmania (Leishmania) infantum INFECTION IN DOGS FROM JUIZ DE FORA, MINAS GERAIS STATE, BRAZIL, BASED ON IMMUNOCHROMATOGRAPHIC DUAL-PATH PLATFORM (DPP®) AND PCR ASSAYS

In Brazil, domestic dogs are branded as the primary reservoir for zoonotic visceral leishmaniasis, due to the clear positive correlation observed between human and canine infection rates. This study aimed to carry out a serological survey of canine visceral leishmaniasis (CVL) in dogs housed at a public kennel in the municipality of Juiz de Fora, Minas Gerais State, Brazil, using the immunochromatographic TR DPP® CVL rapid test. Additionally, conventional and/or real time PCR assay was used to detect and confirm L. infantum infection in the DPP positive dogs only. Of the 400 dogs studied, most did not present clinical signs for CVL (p < 0.05), and fifteen (3.8%) were seropositive in the DPP test. There was no statistically significant difference between the DPP seropositive dogs and the clinical signs of the disease (p > 0.05). Both conventional and real time PCR tests confirmed L. infantum infection in nine (75.0%) of the twelve DPP seropositive dogs that remained alive during the follow-up period. This study is the first seroepidemiologic survey of CVL held in the city of Juiz de Fora, and the results reinforce the idea that this disease is currently in a process of expansion and urbanization in Brazil. Furthermore, this study highlights the use of the DPP test as an alternative for diagnosing CVL in large and mid-sized cities, due to its ease of implementation.

Evaluation of Leishmania (Leishmania) chagasi strains isolated from dogs originating from two visceral leishmaniasis-endemic areas in Brazil using multilocus enzyme electrophoresis

INTRODUCTION: Domestic dogs are the most important reservoir in the peridomestic transmission cycle of Leishmania (Leishmania) chagasi. The genetic variability of subpopulations of this parasite circulating in dogs has not been thoroughly analyzed in Brazil, even though this knowledge has important implications in the clinical-epidemiological context. METHODS: The objective of this study was to evaluate and compare the phenotypic variability of 153 L. chagasi strains isolated from dogs originating from the municipalities of Rio de Janeiro (n = 57) and Belo Horizonte (n = 96), where the disease is endemic. Strains isolated only from intact skin were selected and analyzed by multilocus enzyme electrophoresis using nine enzyme systems (6PG, GPI, NH1 and NH2, G6P, PGM, MDH, ME, and IDHNADP). RESULTS: The electrophoretic profile was identical for all isolates analyzed and was the same as that of the L. chagasi reference strain (MHOM/BR/74/PP75). Phenetic analysis showed a similarity index of one for all strains, with the isolates sharing 100% of the characteristics analyzed. CONCLUSIONS: The results demonstrate that the L. chagasi populations circulating in dogs from Rio de Janeiro and Belo Horizonte belong to a single zymodeme.

Seroprevalence for brucellosis and leptospirosis in dogs from Belém and Castanhal, State of Pará, Brazil

Brucellosis and leptospirosis are widely spread bacterial infections and dogs are the most important source of infection and reservoir for diseases. Dogs can disseminate the agents in the environment and transmit them to humans and/or other animals. The objective of this study was assess the occurrence of reactive to antibodies anti-Leptospira spp., Brucella canis and B. abortus in Belém and Castanhal, State of Pará, Amazon, Brazil. A total of 156 samples were randomly collected in the city of Belém and 158 samples in Castanhal. The anti-B. canis antibodies research was performed by Agar Gel Immunodiffusion (AGID) with and without 2-mercaptoethanol serum treatment (AGID-2ME). To assess the anti-B. abortus antibodies, the technique of Fast Seroagglutination with buffered acidified plate antigen (BAPAT) was used. For anti-Leptospira spp. antibodies research, the Microscopic Agglutination Technique (MAT) was used. No animal reacted to Brucella abortus and one animal was reactive to B. canis at the AGID, but it was negative to the AGID-2ME test. Seventeen percent of dogs (47/274) presented anti-Leptospira spp. antibodies, with prevalence of serovar Canicola. The dogs from Belém and Castanhal are not source of infection for B. abortus and B. canis, however, they are reservoirs for different serovars of Leptospira spp.

An enzyme-linked immunosorbent assay (ELISA) for the detection of IgM antibodies against Leishmania chagasi in dogs

Visceral leishmaniasis is an emergent zoonosis with an increasing number of new cases in Brazil where the domestic dog is an important parasite reservoir in the infectious cycle of Leishmania chagasi. An enzyme-linked immunosorbent assay (ELISA), based upon the use of a total soluble antigenic preparation of L. chagasi, was adapted for the detection of IgM antibodies in the serum of infected dogs. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkboard titrations. The specificity and sensitivity of the ELISA were 100 %. A total of 110 serum samples were taken from dogs in Belo Horizonte, Minas Gerais, Brazil, and examined for anti-L. chagasi IgM antibody by ELISA and indirect fluorescent antibody test (IFAT). About 25% (n=27) of all the dogs tested were found serologically positive for L. chagasi by IFAT, while 89.09% (n=98) were seropositive by ELISA. The results obtained by ELISA and IFAT were significantly different (P<0.01). The combined use of ELISA and IFAT is recommended in order to enable veterinary services to more efficiently detect canine visceral leishmaniasis.

Distribution of liposome-encapsulated antimony in dogs

The achievement of complete cure in dogs with visceral leishmaniasis is currently a great challenge, since dogs are the main reservoir for the transmission of visceral leishmaniasis to humans and they respond poorly to conventional treatment with pentavalent antimonials. In order to improve the efficacy of treatment, we developed a novel formulation for meglumine antimoniate based on the encapsulation of this drug in freeze-dried liposomes (LMA). The aim of the present study was to evaluate the biodistribution of antimony (Sb) in dogs following a single intravenous bolus injection of LMA. Four healthy male mongrel dogs received LMA at 3.8 mg Sb/kg body weight and were sacrificed 3, 48 and 96 h and 7 days later. Antimony was determined in the blood, liver, spleen and bone marrow. In the bone marrow, the highest Sb concentration was observed at 3 h (2.8 µg/g wet weight) whereas in the liver and spleen it was demonstrated at 48 h (43.6 and 102.4 µg/g, respectively). In these organs, Sb concentrations decreased gradually and reached levels of 19.1 µg/g (liver), 28.1 µg/g (spleen) and 0.2 µg/g (bone marrow) after 7 days. Our data suggest that the critical organ for the treatment with LMA could be the bone marrow, since it has low Sb levels and, presumably, high rates of Sb elimination. A multiple dose treatment with LMA seems to be necessary for complete elimination of parasites from bone marrow in dogs with visceral leishmaniasis.

Anti-leishmania antibodies in cerebrospinal fluid from dogs with visceral leishmaniasis

Visceral leishmaniasis in Brazil is caused by Leishmania (Leishmania) chagasi and the dog is its most important reservoir. The clinical features in dogs include loss of weight, lymphadenopathy, renal failure, skin lesions, fever, hypergammaglobulinemia, hepatosplenomegaly, anemia, and, rarely, neurological symptoms. Most infected animals develop active disease, characterized by high anti-leishmania antibody titers and depressed lymphoproliferative ability. Antibody production is not primarily important for protection but might be involved in the pathogenesis of tissue lesions. An ELISA test was used to determine if there is an association between neurological symptoms and the presence of anti-L. chagasi antibodies in cerebrospinal fluid (CSF). Thirty serum and CSF samples from symptomatic mixed breed dogs (three with neurological symptoms) from a region of high incidence of visceral leishmaniasis in Brazil were examined for antibody using total parasite antigen and anti-dog IgG peroxidase conjugate. A high level of L. chagasi antibodies was observed in sera (mean absorbance ± SD, 1.939 ± 0.405; negative control, N = 20, 0.154 ± 0.074) and CSF (1.571 ± 0.532; negative control, N = 10, 0.0195 ± 0.040) from all animals studied. This observation suggests that L. chagasi can cause breakdown of filtration barriers and the transfer of antibodies and antigens from the blood to the CSF compartment. No correlation was observed between antibody titer in CSF and neurological symptoms.

A comparison of the effects of propofol and thiopental on tear production in dogs

The tear film plays an important role in maintaining the integrity of the ocular suface. During general anesthesia, tear production is considerably reduced, which requires care to prevent adverse effects that result in diseases of these structures. Studies comparing the effects of induction of anaesthesia with thiopental and propofol on tear production have not been carried out yet. Because these drugs are used in veterinary medicine, we decided to evaluate the tear production in 30 dogs undergoing experimental surgery as well as routine procedures at the veterinary hospital of Federal University of Viçosa. Patients were divided into two groups of equal number. All animals were sedated with clorpromazine and maintained with isoflurane in diluted oxygen. Group 1 was induced with thiopental whereas group 2 with propofol. Schirmer tear test 1 was performed before sedation (T0), 15 minutes after sedation (T1) and 10 minutes after induction of anesthesia (T2) with the drug chosen for one of the groups. There was a significant decrease in tear production for both drugs, but no significant statistical differences were found between them. Thus, considering the results and the way in which the study was conducted, we suggest protecting the cornea and conjunctiva of patients during anesthesia using any of the drugs here evaluated.

Particulate bioglass in the regeneration of alveolar bone in dogs: clinical, surgical and radiographic evaluations

Bone loss, either by trauma or other diseases, generates an increasing need for substitutes of this tissue. This study evaluated Bioglass as a bone substitute in the regeneration of the alveolar bone in mandibles of dogs by clinical, surgical and radiological analysis. Twenty-eight adult dogs were randomly separated into two equal groups. In each animal, a bone defect was created on the vestibular surface of the alveolar bone between the roots of the fourth right premolar tooth. In the treated group, the defect was immediately filled with bioglass, while in the control, it remained unfilled. Clinical evaluations were performed daily for a week, as well as x-rays immediately after surgery and at 8, 14, 21, 42, 60, 90 and 120 days post-operative. Most animals in both groups showed no signs of inflammation and wound healing was similar. Radiographic examination revealed a gradual increase of radiopacity in the region of the defect in the control group. In the treated group, initial radiopacity was higher than that of adjacent bone, decreasing until 21 days after surgery. Then it gradually increased until 120 days after surgery, when the defect became undetectable. The results showed that Bioglass integrates into bone tissue, is biocompatible and reduced the period for complete bone regeneration.

Prevalence of periodontal disease in dogs and owners' level of awareness - a prospective clinical trial

Periodontal disease (PD) is widely known among veterinarians for its high prevalence and serious consequences to the dogs. The objective of this study was to assess the occurrence of PD in dogs that live in the micro-region of Viçosa, treated at the Veterinary Hospital of the Federal University of Viçosa (HVT - Hospital Veterinário da Universidade Federal de Viçosa), as well as to assess how aware of this disease dog owners are. In order to do so, all dogs treated at the HVT from March 10th, 2009 to November 30th, 2009, on alternate days, had their oral cavities examined. Medical history data, such as age, type of food, main complaint and owner consent, halitosis, presence of dental calculus, inflammation and gingival recession and tooth loss, were collected. A prevalence of 88.67% was found for PD in dogs referred to the HVT, and 2.67% were referred due to this disease. Of all the owners who participated in the study, 43.83% knew about periodontal disease and of these 17.46% made use of some type of prevention or treatment. Therefore, periodontal disease is highly prevalent and the owners are not aware of the disease. Thus, a dog owner clarification program on periodontal disease is needed in the area where HVT-UFV operates.

Glucosamine and chondroitin sulfate in the repair of osteochondral defects in dogs - clinical-radiographic analysis

Among the proposed treatments to repair lesions of degenerative joint disease (DJD), chondroprotective nutraceuticals composed by glucosamine and chondroitin sulfate are a non-invasive theraphy with properties that favors the health of the cartilage. Although used in human, it is also available for veterinary use with administration in the form of nutritional supplement independent of prescription, since they have registry only in the Inspection Service, which does not require safety and efficacy testing. The lack of such tests to prove efficacy and safety of veterinary medicines required by the Ministry of Agriculture and the lack of scientific studies proving its benefits raises doubts about the efficiency of the concentrations of such active substances. In this context, the objective of this study was to evaluate the efficacy of a veterinary chondroprotective nutraceutical based on chondroitin sulfate and glucosamine in the repair of osteochondral defects in lateral femoral condyle of 48 dogs, through clinical and radiographic analysis. The animals were divided into treatment group (TG) and control group (CG), so that only the TG received the nutraceutical every 24 hours at the rate recommended by the manufacturer. The results of the four treatment times (15, 30, 60 and 90 days) showed that the chondroprotective nutraceutical, in the rate, formulation and administration at the times used, did not improve clinical signs and radiologically did not influence in the repair process of the defects, since the treated and control groups showed similar radiographic findings at the end of the treatments.

Comparison of pupil diameter and tear production in dogs treated with acepromazine, tramadol and their combination

Some ophthalmic surgeries require induction of mydriasis, however, drugs traditionally used for this purpose significantly reduces tear production. To evaluate the effect of acepromazine and tramadol, used alone or in combination, on pupil diameter, tear production, heart and respiratory rate, systolic blood pressure and rectal temperature, these drugs were administered to seven clinically normal dogs divided into three experimental groups (G1 - acepromazine; G2 - tramadol; G3 - tramadol + acepromazine) that differed only in the sedation protocol. Parameters were measured in four experimental moments. Miosis occurred in G1, in addition to reduced tear production and respiratory rate. No significant changes were found in the parameters assessed in G2, whereas in G3, there was decrease in tear production of the right eye, decrease in the respiratory rate and rectal temperature. Tramadol proved to be a drug suitable for pre-anesthetic procedures that require the maintenance of pupil diameter and keeps the tear production within normal parameters. However, the use of acepromazine alone or in combination with tramadol requires protection of the patient's eye surface to prevent the occurrence of undesirable ophthalmic changes.

Campylobacter intestinal carriage among stray and pet dogs

The natural distribution of thermotolerant Campylobacter sp. in dogs (150 stray animals and 64 pets) was studied. Campylobacters were more frequently isolated (p<0.01) from stray dogs (51.3%) rather than from pet dogs (21.9%). All the biotypes described by Lior for C. jejuni and C. coli were found among stray animals, whereas only C. jejuni biotypes I and II and C. coli biotype II were found among pet dogs. The need for more studies related to the role of environmental sanitary conditions in the spreading of Campylobacter species is noted.