Epidural administration of combinations of ropivacaine, morphine and xylazine in bitches undergoing total unilateral mastectomy: a randomized clinical trial.

OBJECTIVE: To investigate the epidural administration of combinations of ropivacaine, morphine and xylazine in bitches undergoing unilateral mastectomy. STUDY DESIGN: Prospective, randomized, blinded, clinical study. ANIMALS: A total of 22 bitches scheduled to undergo unilateral mastectomy for mammary tumor excision. METHODS: Dogs were anesthetized with acepromazine (0.02 mg kg-1) and morphine (0.3 mg kg-1) intramuscularly, propofol intravenously (IV) and isoflurane. Prior to the beginning of surgery, dogs were randomly administered one of three epidural treatments: ropivacaine (0.75 mg kg-1) with morphine (0.1 mg kg-1) (group RM, n = 7); ropivacaine with xylazine (0.1 mg kg-1) (group RX, n = 8); or ropivacaine with morphine and xylazine (group RMX, n = 7). Cardiopulmonary variables and the expired concentration of isoflurane (Fe'Iso) were recorded intraoperatively. Meloxicam (0.1 mg kg-1) was administered IV during skin closure. Postoperative pain scores were evaluated with the Glasgow composite measure pain scale short form for 24 hours, and rescue analgesia with morphine (0.5 mg kg-1) was administered intramuscularly when pain scores were ≥ 6/24. RESULTS: Fe'Iso was significantly higher in group RM than in groups RX and RMX. Heart rate decreased significantly in groups RX and RMX, but blood pressure remained within acceptable values. The number of dogs administered rescue analgesia within 24 hours was significantly higher in group RX (seven dogs, 87.5%) than in groups RM (one dog, 14.3%; p = 0.01) and RMX (two dogs, 28.6%; p = 0.04). Time to standing was significantly longer in group RX than in group RM. CONCLUSIONS AND CLINICAL RELEVANCE: All epidural treatments provided adequate antinociception with minimal cardiovascular adverse effects during mastectomy. The inclusion of morphine (groups RM and RMX) provided the best postoperative analgesia. Owing to the undesirable effect of xylazine on ambulation, the combination ropivacaine-morphine appeared to provide greater benefits in bitches undergoing unilateral mastectomy.

Hemorrhagic diathesis and bone marrow aplasia secondary to lomustine overdose in a dog.

A 9-year-old mixed breed 13 kg spayed female dog was presented for evaluation of two masses in the right abdominal mammary gland region. Surgery was conducted to excise the masses. A grade I complex mammary gland carcinoma and high grade (grade III) mast cell tumor with an inguinal lymph node metastasis were diagnosed. Forty-seven days after the surgical procedure, the mast cell tumor relapsed, and neoadjuvant treatment with lomustine (81 mg/m2 ) was prescribed. Thirteen days from initiation of lomustine therapy, the dog was re-presented to the hospital with bloody diarrhea, hematemesis, epistaxis, an elevated rectal temperature, depression, severe dehydration, and marked dyspnea. The CBC showed severe thrombocytopenia and leukopenia. According to the owner, lomustine (45mg per os [PO]) was mistakenly administered daily for 10 consecutive days (total dose, 810 mg/m2 ). The dog died and a necropsy was performed. The main gross lesions consisted of severe multifocal hemorrhages in multiple organs, especially in the digestive system. Histopathologic evaluation revealed disseminated hemorrhages, as well as marked bone marrow aplasia. This report describes the clinical, hematologic, gross, and histologic findings in a fatal case of lomustine overdose in a dog.

Linfonodo axilar como sentinela de neoplasia mamária em cadelas / Axillary lymph node as sentinel for mammary neoplasia in bitches

Linfonodo axilar como sentinela de neoplasia mamária em cadelas. O estudo dos tumores de mama em cadelas é de grande importância devido à alta frequência com que surgem na clínica de pequenos animais. O presente estudo teve como objetivo avaliar a importância do linfonodo axilar como sentinela em neoplasias mamárias de cadelas. Foram avaliadas 49 fêmeas com neoplasia mamária, submetidas à mastectomia unilateral total, utilizando o corante azul patente para a identificação do linfonodo axilar, o qual foi submetido à análise histopatológica com a coloração de hematoxilina-eosina e imuno-histoquímica (IHQ) com anticorpo citoqueratina (AE1/AE3) para procura de metástase. Oito cadelas apresentaram metástases em linfonodo axilar, sendo sete detectadas por histopatologia e por IHQ e uma somente pela IHQ (micrometástase). Uma paciente que apresentava tumor em mamas abdominal caudal e inguinal tinha metástase no linfonodo axilar e inguinal. Assim, observa-se que o tumor pode causar alteração na drenagem linfática provocando metástase em linfonodos que normalmente não drenam determinadas mamas, por isso a retirada do linfonodo axilar deve ser incluída como técnica de rotina para permitir melhor estadiamento das neoplasias mamárias de cadelas.(AU)

Mammary tumors research in bitches is important due to their high incidence. The aim of this study was to evaluate the importance of the axillary lymph node as a sentinel lymph node for mammary neoplasms in female dogs. Forty-nine bitches with mammary neoplasia were submitted to total unilateral mastectomy, and the axillary lymph node was identified using the patent blue dye. This lymph node was processed routinely for histopathological analysis and stained with hematoxylin-eosin and by immunohistochemistry (IHC) with cytokeratin antibody (AE1/AE3) to search for metastasis. Eight dogs had axillary lymph node metastases, seven of which were detected by histopathology and by IHC and only one by IHC (micrometastasis). One dog who presented tumor in caudal and inguinal abdominal mammary glands had metastases in the axillary and inguinal lymph nodes. It is concluded that the mammary tumor can cause alteration in lymphatic drainage leading to metastases in lymph nodes which normally do not drain certain glands; so the removal of the axillary lymph node should be included as a routine technique to allow better staging of mammary neoplasms of bitches.(AU)

Genetic variability and phospholipase production of Malassezia pachydermatis isolated from dogs with diverse grades of skin lesions.

Little detailed information is available on the association of Malassezia pachydermatis genotypes and the extent of skin damage that they cause. In the present study, isolates of M. pachydermatis, recovered from the skin of healthy dogs and dogs with dermatitis in Brazil, were characterized on the basis of partial sequencing of the large subunit (LSU), first internal transcribed spacer (ITS-1) and chitin synthase 2 gene (chs-2). The determination of phospholipase production was also included in the investigations. The severity of lesions and hyperpigmentation of dogs with skin disease were evaluated. For each locus, two main sequence types were designated as genotypes A and C. Two other minor sequence types (A2(I)-C2(I)) were also recorded and defined for the ITS-1. Genotype A isolates were the most prevalent, being recovered from healthy and diseased animals. No significant difference was detected among genotypes or ITS-1 sequence types and grades of skin damage or hyperpigmentation in the dogs with skin lesions. The number of M. pachydermatis isolates that produced phospholipase was statistically higher for diseased dogs than for strains found in healthy animals. The present study reveals that multiple genetic variants of M. pachydermatis occur in dogs and that the distribution patterns of particular genotypes on the skin of dogs in Brazil might be related to environmental and ecological factors which maintain distinctive genotype assemblages in specific geographical areas.

Detection of Pneumocystis in lungs of bats from Brazil by PCR amplification / Detecção de Pneumocystis em pulmões de morcegos no Brasil por Nested-PCR

Pneumocystis has been isolated from a wide range of unrelated mammalian hosts, including humans, domestic and wild animals. It has been demonstrated that the genome of Pneumocystis of one host differs markedly from that of other hosts. Also, variation in the chromosome and DNA sequence of Pneumocystis within a single host species has been observed. Since information about the occurrence and nature of infections in wild animals is still limited, the objective of this work was to detect the presence of Pneumocystis sp. in lungs of bats from two states from Brazil by Nested-PCR amplification. The bats, captured in caves and in urban areas, were obtained from the Program of Rabies Control of two States in Brazil, Mato Grosso and Rio Grande do Sul, located in the Mid-Western and Southern regions of the country, respectively. DNAs were extracted from 102 lung tissues and screened for Pneumocystis by nested PCR at the mtLSU rRNA gene and small subunit of mitochondrial ribosomal RNA (mtSSU rRNA). Gene amplification was performed using the mtLSU rRNA, the primer set pAZ102H - pAZ102E and pAZ102X - pAZY, and the mtSSU rRNA primer set pAZ102 10FRI - pAZ102 10R-RI and pAZ102 13RI - pAZ102 14RI. The most frequent bats were Tadarida brasiliensis (25), Desmodus rotundus (20), and Nyctinomops laticaudatus (19). Pneumocystis was more prevalent in the species Nyctinomops laticaudatus (26.3 percent = 5/19), Tadarida brasiliensis (24 percent = 6/25), and Desmodus rotundus (20 percent = 4/20). Besides these species, Pneumocystis also was detected in lungs from Molossus molossus (1/11, 9.1 percent), Artibeus fimbriatus (1/1, 100 percent), Sturnira lilium (1/3, 33.3 percent), Myotis levis (2/3, 66.7 percent)and Diphylla ecaudata (1/2, 50 percent). PCR products which could indicate the presence of Pneumocystis (21.56 percent) were identified in DNA samples obtained from 8 out of 16 classified species from both states (5 bats were not identified). This is the ...

Pneumocystis tem sido isolado de uma grande variedade de hospedeiros mamíferos, incluindo humanos, animais domésticos e selvagens. Tem se demonstrado que o genoma do Pneumocystis de um hospedeiro difere marcadamente do de outros, assim como há variação no cromossomo e na seqüência de DNA dentro de uma única espécie de hospedeiro. Sabendo que a informação da ocorrência e natureza da infecção em animais silvestres ainda é limitada, o objetivo do trabalho foi detectar, por Nested-PCR, a presença de Pneumocystis sp. em pulmões de diferentes espécies de morcegos de dois estados do Brasil. Estes mamíferos voadores foram capturados em cavernas, áreas florestadas, de campo e urbanas pelo Programa de Controle da Raiva do Mato Grosso (região Centro-Oeste) e do Instituto de Pesquisas Veterinárias Desidério Finamor (RS) e Instituto Sauver no Rio Grande do Sul (região Sul). Os DNAs foram extraídos de 102 pulmões e realizado Nested-PCR utilizando os primers pAZ102H-pAZ102E e pAZ102X/R1-pAZY/R1 para amplificação do gene mtLSU-rRNA, e pAZ102 10F-RI - pAZ102 10R-RI e pAZ102 13-RI - pAZ14-RI para amplificação do gene mtSSU-rRNA. As espécies mais freqüentes foram Tadarida brasiliensis (25), Desmodus rotundus (20) e Nyctinomops laticaudatus (19). Pneumocystis foi detectado com maior prevalência nas Nyctinomops laticaudatus (26,3 por cento = 5/19), Tadarida brasiliensis (24 por cento = 6/25) e Desmodus rotundus (20 por cento = 4/20). Além destas espécies, Pneumocystis foi também detectado nos pulmões de Molossus molossus (1/11, 9,1 por cento), Artibeus fimbriatus (1/1, 100 por cento), Sturnira lilium (1/3, 33 por cento), Myotis levis (2/3, 66,7 por cento)e Diphylla ecaudata (1/2, 50 por cento). Os produtos de PCR indicaram a presença de Pneumocystis (21.56 por cento) em amostras obtidas de 8 das 16 espécies classificadas para ambos os estados (cinco morcegos não foram classificados). Este é o primeiro registro de detecção de Pneumocystis em morcegos no Brasil.