Ticks (Acari: Ixodidae) associated with domestic dogs in Franca region, São Paulo, Brazil

Ticks on 140 domestic dogs from both urban and rural areas of Franca region in São Paulo state were identified with 102 dogs from urban areas and 38 from rural areas. Of urban dogs, 27.5% were infested exclusively by Rhipicephalus sanguineus ticks. Of the rural dogs, 36.8% were infested with the following tick species: R. sanguineus, Boophilus microplus, Amblyomma ovale and A. cajennense. Mixed infestations included a dog hosting A. cajennense and A. ovale and another with B. microplus and R. sanguineus. The most intense infestations were detected on urban dogs. Hemolymph tests of these ticks performed to detect rickettsial or Borrelia bacteria yielded negative results.

The comparative efficacy of yohimbine and atipamezole to treat amitraz intoxication in dogs

This study compared the efficacy of yohimbine with atipamezole, a new α2-adrenergic antagonist, to treat canine amitraz intoxication. Thirty dogs were divided equally into 3 groups (A, AY, and AA). Group A received 2.5% amitraz iv at 1 mg/kg; Group AY received the same dose of amitraz followed 30 min later by 0.1 mg/kg (2 mg/mL) yohimbine iv; and Group AA received the same dose of amitraz followed 30 min later by 0.2 mg/kg (5 mg/mL) atipamezole iv. Temperature, heart rate, respiratory frequency, mean arterial pressure, degree of sedation, mean time of tranquilization and diameter of pupils were monitored for 360 min. Sedation, logs of reflexes, hypothermia bradycardia, hypotension, bradypnea and mydriasis were observed in Group A, with 3rd eyelid prolapse, increased diuresis and vomiting in some animals. Yohimbine reversed all alterations induced by amitraz, but induced significant cardiorespiratory effects such as tachycardia and tachypnea. Atipamezole was a useful antagonist for amitraz, with less cardiorespiratory effects, suggesting its potential role as an alternative treatment of amitraz intoxication in dogs.

Antigens from Rhipicephalus sanguineus ticks elicit potent cell-mediated immune responses in resistant but not in susceptible animals

In the present study we compared the immunological reactions between Rhipicephalus sanguineus tick-infested susceptible (dogs and mice) and tick-resistant hosts (guinea pigs), elucidating some of the components of efficient protective responses against ticks. We found that T-cells from guinea pigs infested with adult ticks proliferate vigorously in the presence of concanavalin A (ConA), whereas ConA-induced cell proliferation of tick-infested mice and dogs was significantly decreased at 43.1 and 94.0%, respectively, compared to non-infested controls. Moreover, cells from mice and dogs submitted to one or three successive infestations did not exhibit a T-cell proliferative response to tick antigens, whilst cells from thrice tick-infested guinea pigs, when cultured with either a tick extract or tick saliva, displayed a significant increase in cell proliferation. Also, we evaluated the response of tick-infested mice to a cutaneous hypersensitivity test induced by a tick extract. Tick-infested mice developed a significant immediate reaction, whereby a 29.9% increase in the footpad thickness was observed. No delayed-type hypersensitivity (DTH) reaction was detected. Finally, the differential cell count at the tick attachment site in repeatedly infested mice exhibited a 6.6- and 4.1-fold increase in the percentage of eosinophils and neutrophils, respectively, compared to non-infested animals, while a decrease of 77.0-40.9 in the percentage of mononuclear cells was observed. The results of the cutaneous hypersensitivity test and the cellular counts at the tick feeding site for mice support the view that tick-infested mice develop an immune response to R. sanguineus ticks very similar to dogs, the natural host of this species of tick, but very different from guinea pigs (resistant host), which develop a DTH reaction in addition to a basophil and mononuclear cell infiltration at the tick-attachment site. In conclusion, saliva introduced during tick infestations reduces the ability of a susceptible animal host to respond to tick antigens that could stimulate a protective immune response. As a consequence, the animals present a lack of DTH response and disturbed cellular migration to tick feeding site, which can represent a deficient response against ticks. © 2003 Elsevier B.V. All rights reserved.

Ehrlichiosis in anemic, thrombocytopenic, or tick-infested dogs from a hospital population in South Brazil

Ehrlichia canis has a worldwide distribution, but clinical manifestations may vary geographically. We selected 129 dogs to determine prevalence of ehrlichiosis in dogs with anemia, thrombocytopenia, or ticks presented to a Veterinary Teaching Hospital in South Brazil. Of the 129 dogs, 68 carried the brown dog tick (Rhipicephalus sanguineus), 61 had thrombocytopenia (platelet count <150,000/μl), and 19 had anemia (PCV < 22%). Twenty dogs fulfilled more than one inclusion criteria. Ehrlichiosis was diagnosed by positive amplification of ehrlichial DNA by PCR using primers ECC and ECB that amplify a sequence of the 16S rRNA gene. Presence of E. canis was confirmed by cleavage of the amplified DNA using endonucleases HaeIII and AvaI. Fourteen of 68 (21%) dogs with ticks had ehrlichiosis, whereas 12 of 61 (20%) dogs presented with thrombocytopenia and 4 of 19 (21%) anemic dogs had ehrlichiosis. Similar results were obtained in dogs with thrombocytopenia and anemia (one of eight positive) and in dogs with thrombocytopenia and ticks (two of seven positive). All four dogs with anemia and ticks, and the dog that fulfilled all inclusion criteria yield no amplification of ehrlichial DNA by PCR. Based on our results, one in each five dogs infested by the brown dog tick, with anemia or thrombocytopenia had ehrlichosis. Contrary to widespread believe, ehrlichiosis was not the main cause for thrombocytopenia in our region. © 2003 Elsevier B.V. All rights reserved.

Immunocytochemical study of Ki-67 as a prognostic marker in canine mammary neoplasia

Background: Canine mammary tumors are challenging for clinicians and pathologists because of complex histologic classification, low specificity of cytologic diagnosis, and unpredictable biological behavior. In histologic specimens, expression of tumor proliferation marker Ki-67, a nuclear nonhistone protein, has been shown to have prognostic value for canine mammary tumors and to correlate with malignancy and low survival rates. Objective: The objective of this study was to measure the proliferation index of canine mammary tumors by immunochemical detection of Ki-67 in cytologic specimens and to determine its relationship to clinical and pathologic variables and patient outcome. Methods: Spontaneous mammary tumors from 31 female dogs were surgically excised. Imprint specimens for cytologic evaluation were wet-fixed in ethanol; histologic specimens were prepared routinely. Immunostaining was performed with the PH 177 monoclonal antibody against Ki-67; proliferation index was graded from negative to +++. Dogs were followed for 18 months. Multivariate logistic regression analysis was used to determine correlations between immunocytochemical results, tumor and clinical variables, and patient outcome. Results: Ki-67 proliferation indices in cytologic specimens were significantly lower for nonmalignant tumors than for malignant tumors. High index values of Ki-67 were positively correlated with metastasis, death from neoplasia, low disease-free survival rates, and low overall survival rate. With the exception of 4 specimens for which cellularity was insufficient, positive expression of Ki-67 in cytologic specimens correlated with that of histologic specimens. Conclusions: The prognostic value of the Ki-67 index in canine mammary tumors by using wet-fixed cytology imprint specimens was similar to that observed previously for histologic specimens. Immunocytochemical detection of Ki-67 could improve the accuracy and value of cytology by providing safe and rapid information about malignancy and patient outcome. © 2004 American Society for Veterinary Clinical Pathology.

Plication of the free wall of the left ventricle in dogs with doxorubicin-induced cardiomyopathy

Objective - To evaluate plication of the free wall of the left ventricle, which reduces the left ventricular area and volume, as a method to improve the left ventricular systolic function without cardiopulmonary bypass. Animals - 8 mixed-breed adult dogs. Procedure - Dilated cardiomyopathy (DCM) was induced in each dog by administration of doxorubicin (30 mg/m2, IV, q 21 d for 168 days). Two dogs died during induction of cardiomyopathy. Plication surgery was performed in 4 dogs. Two dogs did not ondergo to surgery (control group). Values for cardiac output (CO), 2-dimensional and M-mode echocardiography, arterial blood pressure, electrocardiography, blood cell counts, and serum biochemical analyses were recorded after induction of DCM (baseline) and 1, 2, 7, 15, 21, 30, 60, 90, 120, 150, and 180 days after plication surgery. Ambulatory ECG (Holter) recordings were conducted for 24 hours on the day of surgery. Results - 1 dog died after plication surgery. The remaining dogs undergoing ventricular plication had a significant improvement in CO, ejection fraction, and fractional shortening and reductions of left ventricular area and volume after surgery. Electrocardiographic and Holter recordings revealed premature ventricular complexes, which resolved without treatment during the first week after surgery. Clinical condition of the control dogs declined, and these 2 dogs died approximately 40 days after induction of cardiomyopathy. Conclusions and Clinical Relevance - Plication of the free wall of the left ventricle improved left ventricular systolic function in dogs with doxorubicin-induced cardiomyopathy. Additional studies are needed to evaluate its application in dogs with naturally developing DCM.

Evaluation of adverse effects of long-term oral administration of carprofen, etodolac, flunixin meglumine, ketoprofen, and meloxicam in dogs

Objective - To evaluate adverse effects of long-term oral administration of carprofen, etodolac, flunixin meglumine, ketoprofen, and meloxicam in dogs. Animals - 36 adult dogs. Procedures - Values for CBC, urinalysis, serum biochemical urinalyses, and occult blood in feces were investigated before and 7, 30, 60, and 90 days after daily oral administration (n = 6 dogs/group) of lactose (1 mg/kg, control treatment), etodolac (15 mg/kg), meloxicam (0.1 mg/kg), carprofen (4 mg/kg), and ketoprofen (2 mg/kg for 4 days, followed by 1 mg/kg daily thereafter) or flunixin (1 mg/kg for 3 days, with 4-day intervals). Gastroscopy was performed before and after the end of treatment. Results - For serum γ-glutamyltransferase activity, values were significantly increased at day 30 in dogs treated with lactose, etodolac, and meloxicam within groups. Bleeding time was significantly increased in dogs treated with carprofen at 30 and 90 days, compared with baseline. At 7 days, bleeding time was significantly longer in dogs treated with meloxicam, ketoprofen, and flunixin, compared with control dogs. Clotting time increased significantly in all groups except those treated with etodolac. At day 90, clotting time was significantly shorter in flunixin-treated dogs, compared with lactose-treated dogs. Gastric lesions were detected in all dogs treated with etodolac, ketoprofen, and flunixin, and 1 of 6 treated with carprofen. Conclusions and Clinical Relevance - Carprofen induced the lowest frequency of gastrointestinal adverse effects, followed by meloxicam. Monitoring for adverse effects should be considered when nonsteroidal anti-inflammatory drugs are used to treat dogs with chronic pain.

Rectovaginal fistula with anal atresia in 5 dogs

Five dogs with rectovaginal fistula and atresia ani that had been treated by surgical correction of the malformations were studied retrospectively. Ages at presentation varied from 1 to 3 months and weight from 350 g to 7.5 kg. The histories included voiding of feces through the vulva, with or without tenesmus, usually observed after weaning. Artesia ani, presence of feces in the vaginal canal, abdominal distention, and discomfort on abdominal palpation were observed during clinical examination. Also, 3 dogs had partial tail agenesis. In all dogs, the rectovaginal fistula was isolated and transected, the vulvar and rectal defects were closed separately, and the atresia ani was repaired. Normal defecation was restored, but 1 dog had fecal incontinence that subsequently resolved. One dog died 2.5 months postoperatively, and follow-up was done on the others for periods ranging from 1.6 year to 7.7 years. Surgical correction in dogs with rectovaginal fistula and atresia ani may result in a favorable outcome, if it is done early.

Anovulvar cleft and vaginal prolapse-hyperplasia in a bitch

This report presents the case of a nine-month-old bitch with incomplete occlusion of the skin and mucosa between the anus and dorsal commissure of the vulva. This anomaly, known as anovulvar cleft, was associated with a vaginal prolapse-hyperplasia. Anovulvar cleft is a rare condition in bitches and is caused by incomplete closure of the dorsal urogenital folds. Anovulvar cleft can lead to clitoritis, abrasion, dryness and devitalisation of the smooth exposed mucosa. Surgery can correct the condition. In the present study, surgical resection of the hyperplasic vaginal tissue associated with perineoplasty using an inverted V-shaped incision showed excellent results. An ovariohysterectomy was also performed to prevent recurrence of the vaginal prolapse-hyperplasia. © 2007 British Small Animal Veterinary Association.

Ações de vigilância continuada, papel do cão como animal sentinela para toxoplasmose.

Toxoplasmosis is a worldwide zoonosis caused by Toxoplasma gondii and its definitive host is the domestic and wild felids infecting human beings and other warmblooded animals. Dogs are considered a potential risk on the transmission due they can mechanically transmit oocysts to man. In this study, a retrospective analysis of toxoplasmic infection in dog serum samples sent to Serviço de Diagnóstico de Zoonoses/FMVZ-UNESP/Botucatu, SP, in the period of 1998 to 2007 was performed. During this period 1097 serum samples were analyzed by the indirect fluorescent antibody test (IFAT), with 299 (27.25%) positive. The most frequent titer was 16 (42.80%), followed by 64 (37.79%). The results indicate that T.gondii is distributed in the environment showing the role of the dog as sentinel animal to toxoplasmosis to monitor public health actions to the control of this zoonosis.

Partial external mitral annuloplasty in dogs with myxomatous mitral valve degeneration and congestive heart failure: Outcome in 9 cases

Objective: To report the outcome of partial external mitral annuloplasty in dogs with congestive heart failure (CHF) due to mitral regurgitation caused by myxomatous mitral valve degeneration (MMVD). Animals, materials and methods: Nine client-owned dogs with CHF due to mitral regurgitation caused by MMVD. Surgery consisted of a double row of pledget-butressed continuous suture lines placed into the left ventricle parallel and just ventral to the atrioventricular groove between the subsinuosal branch of the left circumflex coronary artery and the paraconal branch of the left coronary artery. Results: Two dogs died during surgery because of severe hemorrhage. Two dogs died 12 and 36 h after surgery because of acute myocardial infarction. Three dogs were euthanized 2 and 4 weeks after surgery because of progression of CHF, 1 was euthanized 30 days after surgery for non-cardiac disease, and 1 survived for 48 months. In the 5 dogs that survived to discharge there was no significant change in the left atrium to aortic ratio with surgery (3.6 ± 0.56 before surgery; 3.1 ± 0.4 after surgery; p = 0.182), and no significant change in mitral regurgitant fraction in 4 dogs in which this measurement was made (78.7 ± 2.0% before surgery; 68.7 ± 7.5% after surgery; p = 0.09). Conclusions: Partial external mitral annuloplasty in dogs with CHF due to MMVD was associated with high perioperative mortality and most dogs that survived to discharge failed to show clinically relevant palliation from this procedure. Consequently, partial external mitral annuloplasty is not a viable option for dogs with mitral regurgitation due to MMVD that has progressed to the stage of CHF. © 2011 Elsevier B.V. All rights reserved.

A survey of owner attitudes and experiences in managing diabetic dogs

A survey of the experiences of owners of diabetic dogs was carried out by distributing questionnaires to veterinary clinics in São Paulo, Brazil. A total of 93 dog owners were surveyed over a 4. month period and descriptive statistical analysis, frequency distribution and correlations were performed. In most cases the clinical condition of the dogs had improved following treatment and owners were largely satisfied with veterinary intervention. Injection of neutral protamine hagedorm twice daily was the most commonly prescribed treatment and respondents found this procedure easy to perform, although it did pose some difficulties when the owners were away from their animals. Cost was considered an important factor at the initiation of treatment programs. The information gleaned from this survey, in providing useful insights into the attitudes and experiences of owners of diabetic animals, will contribute to improvements in the treatment and management of such patients. © 2011 Elsevier Ltd.