Ana Maria Reis Ferreira

Leptospirosis as the most frequent infectious disease impairing productivity in small ruminants in Rio de Janeiro, Brazil.

Despite the importance of small ruminants breeding in developing countries, milk/meat productivity remains unsatisfactory. Infectious diseases, such as leptospirosis, brucellosis, and small ruminant lentiviruses (SRLVs), contribute to this scenario. The objective of the present study was to determine the role of each of these diseases in the productivity of small ruminants breeding in Rio de Janeiro, Brazil. In goats, 343 samples were tested for leptospirosis, 560 for Brucella abortus, and 506 for caprine arthritis-encephalitis (CAE), whereas in sheep, 308 samples were tested for leptospirosis, 319 for B. abortus, 374 for Brucella ovis, and 278 for Maedi-Visna (MV). Regarding leptospirosis, 25.9% of goats and 47.4% sheep were seroreactive, with serovar Hardjo the most prevalent in both species. Anti-B. abortus agglutinins were found in 0.7% of all samples, exclusively in goats. In relation to SRLVs, 8.6% of goats and 3.2% of sheep samples were positive for CAE and MV, respectively. Leptospirosis was the major infectious problem in the small ruminants sampled and may contribute to impaired productivity of these animals.

Kidney ultrastructural lesions in dogs experimentally infected with Dirofilaria immitis (Leidy, 1856)

Kidneys of 16 beagles with experimentally induced heartworm (Dirofilaria immitis) infections and 4 heartworm-nai;ve dogs were studied by light and electron microscopy. The infections were induced either by subcutaneous injection of infective larvae or by the transplantation of adult parasites, and infection periods varied from 111 to 818 days and 365 to 923 days, respectively. One control group of heartworm-naïve dogs and four groups of heartworm-infected dogs, which were divided according to the type and the length of infection, were used. In the infected dogs, thickening of the glomerular basement membrane (GBM), the presence of dense deposits in the GBM, and foot process effacement were the most frequent lesions observed. In some dogs, electron dense deposits were seen in the GBM and the mesangium and/or enlargement of the mesangial matrix could be characterized. The longer the infection period, the thicker the GBM and the more common the occurrence of foot process effacement. In general, these alterations were more evident in animals that had been infected for more than 1 year, had high microfilaremia, and had 14 or more parasites in the main pulmonary artery and its branches. The presence of dense deposits suggests that the pathogenesis of kidney disease in dirofilariasis is associated with deposits of immune complexes in the membrane. The finding of ultrastructural changes in dogs with early prepatent infections suggests that immature heartworms, as well as microfilariae and possibly adult worms, contribute to the glomerulonephropathy.

SURVEY OF DIROFILARIA IMMITIS (LEIDY, 1856) IN RANDOM SOURCE CATS IN METROPOLITAN RIO DE JANEIRO, BRAZIL, WITH DESCRIPTIONS OF LESIONS

To evaluate the prevalence of heartworm disease in metropolitan Rio de Janeiro, RJ, Brazil, cats submitted for euthanasia were evaluated by laboratory tests and by necropsy for signs of heartworm infection. Of the 135 cats examined, one (0.8%)--a stray male from an urbanizing district--had one male worm (14.5 cm) in the left lung and showed severe muscular hypertrophy of small pulmonary arteries and arterioles with no right ventricle enlargement or passive congestion. Microfilariae were not detected in the blood of any cats. The prevalence of canine heartworm in the area from which this cat originated is estimated to be approximately 12%. The prevalence of canine heartworm in the urban area of Rio de Janeiro has been determined to be approximately 5%. It has been shown that the prevalence of feline heartworm disease parallels that in dogs, but at a lower rate. Results of this survey strongly suggest that heartworm prevention measures should be taken under consideration, especially among cats living in a high canine heartworm prevalence area.

Clinical, cytological and histopathological evaluation of mammary masses in cats from Rio de Janeiro, Brazil

The vast majority of mammary tumors in cats are malignant with high metastatic and mortality rates. This study evaluated clinical, cytological and histopathological aspects of 20 cases of cat mammary masses deriving from the city of Rio de Janeiro. Data on history, macroscopic description, evidence of regional lymph node and distant metastases, clinical examination and treatment were collected. The cats were treated with unilateral mastectomy, unilateral mastectomy plus chemotherapy or chemotherapy alone. Tissues were submitted for cytological and histological evaluation. Histopathological analysis described one case of mammary hyperplasia and 19 cases of adenocarcinoma. Inadequate surgical margins were obtained in two cats while six showed evidence of microscopic invasion in other mammary glands. Multiple mammary involvement and greater tumor size (diameter over 7.05 cm) were correlated with increased chance of local metastases. Ulceration of tumors and metastases were common. These facts support the highly malignant nature of this neoplasia and emphasize the risks associated with delay in diagnosis and treatment of feline patients. In conclusion, mammary palpation should be performed routinely in the clinical practice.

Immunohistochemical identification of Toxoplasma gondii in tissues from Modified Agglutination Test positive sheep

Toxoplasma gondii is a zoonotic agent of great importance in veterinary and public health. The aim of this study was to identify T. gondii by IHC (immunohistochemistry) in different sheep tissues and to determine if an association exists between the results obtained by this method and those obtained by the Modified Agglutination Test (MAT). Tissue specimens of twenty-six sheep seroreactive for T. gondii were selected for histopathological evaluation. The presence of T. gondii was investigated in brain, liver and heart samples by IHC and a possible anti-T. gondii antibody cross reactions with other parasites. McNemars, Chi-square and Fishers Exact Tests were applied for the statistical analysis of the results. The analysed tissues showed at least one of the following histopathological changes: mild-to-moderate congestion, focal polymorphonuclear inflammatory infiltrate and multifocal or focal mononuclear inflammatory infiltrate. Sarcocystis spp. were identified in the histological sections from both the heart and diaphragm tissues of 88.5% (23/26) of the animals. A total of 46.2% (12/26) of the T. gondii seroreactive sheep was also positive for T. gondii by IHC in at least one organ (brain, liver or heart). The liver IHC-positivity for T. gondii was statistically equivalent to the global individual IHC-positivity, according to McNemars test. In addition, IHC allowed the detection of T. gondii in infected animals regardless of the titration observed in the MAT. The statistical difference observed between the three organs when comparing the low titration group, suggested that the heart might be the most suitable organ to detect T. gondii infection by IHC. The IHC results in this study revealed that almost half of MAT positive animals could serve as potential sources of infection for humans because bradyzoites were identified in different tissues, regardless of the MAT titration.

Radiation therapy for feline cutaneous squamous cell carcinoma using a hypofractionated protocol

The objective of this paper was to evaluate the efficacy of a hypofractionated radiation protocol for feline facial squamous cell carcinoma (SCC). Twenty-five histologically confirmed SCCs in 15 cats were treated with four fractions of 7.6–10 Gy each, with 1 week intervals. The equipment used was a linear accelerator Clinac 2100 delivering electron beam of 4 or 6 MeV, and a bolus of 5 or 10 mm was used in all lesions. Of the lesions, 44% were staged as T4, 16% as T3, 8% as T2 and 32% as T1. Of the irradiated lesions, 40% had complete response, 12% had partial response and 48% had no response (NR) to the treatment. For T1 tumors, 62.5% had complete remission. Mean overall survival time was 224 days. Owners requested euthanasia of cats having NR to the treatment. Mean disease free time was 271 days. Side effects observed were skin erythema, epilation, ulceration and conjunctivitis, which were graded according to Veterinary Radiation Therapy Oncology Group (VRTOG) toxicity criteria. Response rates found in this study (52%) were lower when compared to other protocols, probably due to technique differences, such as fractionation schedule, bolus thickness and energy penetration depth. However, the hypofractionated radiation protocol was considered safe for feline facial SCC. Modifications of this protocol are being planned with the objective of improving the cure rates in the future.

AFLATOXIN EFFETC ON THE OOCYSTS MORPHOMETRY AND CONTRIBUTION ON THE MORPHOLOGY OF Eimeria bateri BHATIA, PANDEY AND PANDE, 1965 FROM THE JAPANESE QUAIL Coturnix japonica IN BRAZIL

The purpose of this study was to characterize Eimeria bateri oocysts and to evaluate the aflatoxin effect in the morphometry of sporulated oocysts in Japanese quails infected naturally. Of a total of 50 quails naturally infected by E. bateri were randomly divided into two groups with 25 birds each. In one of them, quails were orally administered with aflatoxin in dose of 0.04 mg/kg body weight previously. Both experimental groups shed E. bateri oocysts. These oocysts were subspherical to ellipsoidal, 25.1 x 18.9 microm, with bi-layered wall. Micropyle and residuum were absent, but one or more polar granules were present. Sporocysts elongate ovoid, 12.5 x 7.4 microm. Stieda and substieda bodies were present. Sporocyst residuum was dispersed and sporozoites presented a nucleus and a refractile body. Histograms confirmed the presence of a single species, E. bateri. Linear regression proved that E. bateri oocysts are polymorphic, due, basically, to shape of these oocysts. The comparative morphometry between two experimental groups demonstrated that the aflatoxin influenced significantly in the E. bateri oocysts.

Assessing the histopathology to depict the different stages of bovine tuberculosis infection in a naturally infected herd

The standard method for detection of bovine tuberculosis (TB) is the single intradermal tuberculin test (SITT). Nevertheless, current studies suggest that a single test is not enough to detect all cattle infected by TB, particularly when animals present different stages of infection. A dairy herd comprised of 270 cows was studied and 15 were reactive to SITT plus nine inconclusive animals. Blood samples (for IFN and ELISA) were collected from these 24 cows. At 30 days after injection of PPD, all the cows that were reactive to any of the employed tests were slaughtered, and tissues were processed by Bacteriology, Histopathology (HP) and PCR. According to HP 33.4% of the animals were positive, 45.8% inconclusive and 20.8% were negative. The inconclusive samples came from IFN positive animals, signalizing recent infection. Regarding the animals that were negative to HP, all of them were identified by IFN while ELISA was negative. Immune responses are different in recent and advanced infections, what supports the identification between chronically or recently infected animals. This multidisciplinary approach is mandatory for the interpretation of the various tools that are frequently employed for the diagnosis of TB and mainly to identify all infected animals.

Helicobacter species detection and histopathological changes in stray cats from Niterói, Brazil

Tightly coiled bacteria are common inhabitants of the gastric mucosae of cats and there is considerable debate whether feline helicobacters are commensal or pathogenic organisms. To determine the prevalence of Helicobacter species and gastric histopathological findings, gastric mucosa samples of 56 stray cats were collected from cardia, fundus, body, antrum and pylorus at necropsy. The samples were examined by urease test, cytology, histopathology and culture. Helicobacter species were detected in 53 cats (94.6%) by at least one detection method. Urease test results were positive in gastric samples from 50 (89.3%) cats. Cytological and histological evaluations revealed Helicobacter species in 52 (92.8%) and 50 (89.2%) cats, respectively. Helicobacter species organisms were not cultured from any cat. Regardless of the presence of gastric bacteria, most of the cats had mild to moderate gastritis. These data reveal a high prevalence of Helicobacter species in stray cats from Niterói, Brazil.

Estudo comparativo de éguas repetidoras ou não de cio através da avaliação histológica do endométrio e das concentrações plasmáticas de progesterona

The study aimed to compare endometrial histology and plasmatic progesterone (P4) concentration of repeat breeds and healthy mares. The hypothesis was that there is a correlation between infertility and endometrial histology and P4 concentration in both groups. A total of 36 Campolina and Mangalarga Marchador mares in reproductive age (3-23 years) were used, 11 of them were healthy mares (Control group, 7 embryo recipient and 4 embryo donors), and 25 repeat breeders (10 embryo recipient and 15 embryo donors), classified as based on their reproductive history. Endometrial and blood samples were collected for respectively histological and plasma progesterone concentration evaluation. The endometrial samples obtained after biopsy were fixed in Bouins fluid, processed, included in paraffin, and stained with Hematoxylin-Eosin (HE) for histopathological examination. Plasmatic progesterone concentrations were evaluated by enzyme immunoessay (ELISA). There was no correlation between progesterone concentration and fertility. But there was a positive correlation between age and fertility, as older mares had major tendency of subfertility than younger ones. There was also a correlation between biopsy categories and fertility, as more histological alterations were found, higher were the chances for the mares to be subfertile. However not all mares classified as Category I and II maintained pregnancy until parturition. Other factors could influence pregnancy maintenance. In the same way, not all mares in Category III were infertile. The endometrial biopsy was shown to be an easy and cheap diagnostic technique with minimal discomfort to the animals and, together with other data, to be a very important component in the investigation of mare fertility.