Outcome of adjuvant chemotherapy with lomustine, vinblastine and chlorambucil on management of canine mast cell tumour of high to intermediate risk

ABSTRACT In spite of the many available protocols, the use of chemotherapy for the management of canine mast cell tumours (MCT) remains empirical, and there is lack of criteria for the choice of protocol and definition of patients who may benefit from treatment. The objective of this study was to evaluate the outcome of dogs with MCT after adjuvant chemotherapy according to the risk of recurrence or metastasis proposed on the literature. This prospective study included 89 followed up dogs with prognosis assesment including clinical, histological, immunohistochemical and genetic features of canine MCT. Patients were grouped according to risk of recurrence and metastasis and recommended treatment with lomustine followed by chlorambucil if considered at high-risk, or vinblastine followed by chlorambucil if a patient was at intermediate risk. Outcome was defined by disease-free interval (DFI) and overall survival (OS) estimated by Kaplan-Meier curve. Adjuvant lomustine was useful for control of canine MCT of high-risk of recurrence or metastasis, but only when sequentially associated to chlorambucil with a DFI of 686 days and not reached OS. There was no difference in outcome in the intermediate-risk group despite choosen treatment. Patients at intermediate-to-low risk may not require adjuvant treatments, even in the absence of free surgical margins.

RESUMO Apesar dos inúmeros protocolos disponíveis, o uso da quimioterapia permanece empírico para o mastocitoma canino e faltam critérios para escolha do protocolo e da definição dos pacientes que poderiam se beneficiar do tratamento. O objetivo deste estudo foi avaliar o resultado de cães com mastocitoma após a quimioterapia adjuvante, de acordo com o risco de recorrência ou metástase proposto na literatura. Este estudo prospectivo incluiu 89 cães com acompanhamento clínico e avaliação prognóstica, incluindo características clínicas, histológicas, imuno-histoquímicas e genéticas dos mastocitomas. Os pacientes foram agrupados segundo o risco de recorrência ou metástase, sendo recomendado tratamento com lomustina seguida de clorambucila, se considerados sob alto risco, ou vimblastina seguida de clorambucila, se estivessem sob risco intermediário. O resultado final foi definido pelo intervalo livre de doença (ILD) e pela sobrevida global (SG), estimados pela curva de Kaplan-Meier. Na adjuvância, a lomustina foi útil no controle do mastocitoma canino de alto risco, mas apenas quando associada ao clorambucila, com um ILD de 686 dias, sem atingir a mediana para SG. Não houve diferença no grupo de risco intermediário, independentemente do tratamento escolhido. Pacientes de risco intermediário podem não necessitar de tratamentos adjuvantes, mesmo na ausência de margens cirúrgicas livres.

Detection of Mycoplasma gallisepticum in dead captive psittacines in Belo Horizonte, Brazil

Mycoplasma gallisepticum (Mg) infection of wild native Brazilian psittacines (Psittaciformes) which died of any cause during sorting, rehabilitation, or conservation, was investigated by PCR. Two previously described PCR methodologies using Mg specific primers were employed for the analyses of 140 swab samples (cloaca, trachea, or palatine cleft). Average positive Mg detection in cloacal swabs was 51.9%, with 80.0% (n=5) of Blue-and-yellow Macaws (Ara ararauna), 60.0% (n=3) Dusky Parrots (Pionus fuscus), 52.5% (n=59) Amazon Parrots (Amazona aestiva), 50.0% (n=2) Orange-winged Parrots (Amazona amazonica), 50.0% (n=2) Jandaya Parakeetsor Jandaya Conures (Aratinga jandaya), 0% (n=2) Golden Conures or Golden Parakeets (Guarouba guarouba), and 0% (n=2) Hyacinth Macaws (Anodorhynchus hyacinthinus). Palatine cleft swab sampling was more sensitive to detect Mg, with 85.4% (n=17) detection rate, as compared to 67.4% (n=46) obtained with tracheal samples, and 53.5% (n=77) with cloacal swabs. The surprisingly high Mg incidence in psittacines kept in conservation or triage environments is possibly due to the proximity or cohabitation with several bird species during confinement and housing psittacines of different origins together. The implementation of biosecurity measures and species-specific facilities is recommended.

Detection of Mycoplasma gallisepticum in dead captive psittacines in Belo Horizonte, Brazil

Mycoplasma gallisepticum (Mg) infection of wild native Brazilian psittacines (Psittaciformes) which died of any cause during sorting, rehabilitation, or conservation, was investigated by PCR. Two previously described PCR methodologies using Mg specific primers were employed for the analyses of 140 swab samples (cloaca, trachea, or palatine cleft). Average positive Mg detection in cloacal swabs was 51.9%, with 80.0% (n=5) of Blue-and-yellow Macaws (Ara ararauna), 60.0% (n=3) Dusky Parrots (Pionus fuscus), 52.5% (n=59) Amazon Parrots (Amazona aestiva), 50.0% (n=2) Orange-winged Parrots (Amazona amazonica), 50.0% (n=2) Jandaya Parakeetsor Jandaya Conures (Aratinga jandaya), 0% (n=2) Golden Conures or Golden Parakeets (Guarouba guarouba), and 0% (n=2) Hyacinth Macaws (Anodorhynchus hyacinthinus). Palatine cleft swab sampling was more sensitive to detect Mg, with 85.4% (n=17) detection rate, as compared to 67.4% (n=46) obtained with tracheal samples, and 53.5% (n=77) with cloacal swabs. The surprisingly high Mg incidence in psittacines kept in conservation or triage environments is possibly due to the proximity or cohabitation with several bird species during confinement and housing psittacines of different origins together. The implementation of biosecurity measures and species-specific facilities is recommended.

Occurrence of chicken anemia virus in backyard chickens of the metropolitan region of Belo Horizonte, Minas Gerais

The occurrence of CAV in backyard chickens in the metropolitan area of Belo Horizonte, Brazil, was evaluated. The spleen and thymus of chickens from different origins were collected for DNA extraction and nested-PCR. CAV genome was detected in 30% of the flocks (n=20) examined. CAV origin for backyard chickens is speculated, taking into consideration its widespread incidence in the chicken industry, the contamination of live vaccines with CAV prior to its eradication from SPF flocks, and the use of attenuated CAV vaccines.

Occurrence of chicken anemia virus in backyard chickens of the metropolitan region of Belo Horizonte, Minas Gerais

The occurrence of CAV in backyard chickens in the metropolitan area of Belo Horizonte, Brazil, was evaluated. The spleen and thymus of chickens from different origins were collected for DNA extraction and nested-PCR. CAV genome was detected in 30% of the flocks (n=20) examined. CAV origin for backyard chickens is speculated, taking into consideration its widespread incidence in the chicken industry, the contamination of live vaccines with CAV prior to its eradication from SPF flocks, and the use of attenuated CAV vaccines.