Behavioural and endocrinological changes in Syrian hamsters (Mesocricetus auratus) under domestication

This study aimed to quantify differences in response to stress between two strains of Syrian hamsters to evaluate the consequences of domestication in this species by measuring behavioural traits in the open-field, adrenal gland masses (ADR), and faecal and blood corticosterone concentrations (CC). We studied a laboratory (lab)- and a wild-derived population (wild). The lab hamsters were significant heavier than the wild hamsters. The lab males had the highest ADR, and it was independent of their high body mass (BM). The ADR of lab females and wild hamsters was linearly dependent of BM. The lab males had the highest faecal and blood CC, whereas the lab females had the lowest CC. In the open field, the lab hamsters began later to groom, groomed shorter, groomed less frequently, began later to rear, reared longer and reared less frequently. In the lab population, females reared more often and groomed longer than males. The sex differences in the behaviours of the lab population and the differences between the populations mirror the differences neither in the ADR nor in the CC. The founder effect and the breeding history of lab Syrian hamsters are discussed as causes of the differences between the studied populations.     

A novel phenomenon predicting the entry into a state of hibernation in Syrian hamsters (Mesocricetus auratus)

When Syrian hamsters (Mesocricetus auratus) are bred in a cold and short-day environment, most animals go into hibernation after a certain period of time. However, to date it has not been possible to predict which hamster will enter hibernation. In this study, we subcutaneously implanted thermo-loggers in hamsters bred in the cold environment, and recorded the subcutaneous temperature at short intervals until they went into hibernation. A time series analysis of temperature disclosed that a fall of 0.4 to 0.8 degrees C in subcutaneous temperature was seen 5 to 16 days before entering hibernation, and this phenomenon continued for three days or more. No hamster went into the hibernation without displaying this signal. Although the mechanism by which this phenomenon takes place is not clear, it is a sign from the body, which is useful for indicating if a hamster will enter hibernation shortly.     

A rapid multiple immunofluorescence method for the simultaneous detection of CD20 and CD3 in canine and feline cytological samples

CD20 and CD3 are considered reliable markers for B and T cells, respectively. This study aimed to develop a rapid multiple immunofluorescence (RMIF) method for the detection of CD20 and CD3 on a single cytology slide. Air-dried smears were prepared using samples collected from dogs (n=26) and cats (n=6). Immunosignal detection using the newly developed method required 60 min. Clear immunosignals for CD20 and CD3 were detected in 24 of 26 samples in dogs and in all 6 cats. As the RMIF (CD20/CD3) method can detect markers of both B and T cells simultaneously on a single cytology smear, it would be an efficient tool for the immunophenotyping of canine and feline lymphoma samples.     

Dynamics of CD3+ T-cell Distribution Throughout the Estrous Cycle and Gestation in the Bovine Endometrium

T cells are the dominant lymphocytes in the endometrium and are considered to play a crucial role in implantation and in the maintenance of gestation through cytokine production and immune regulation. The mechanisms underlying immunoregulation at the feto-maternal interface are still obscure for this complex system. Understanding the role of T cells is a key factor in understanding the endometrial immune system. In this study, the distribution of endometrial CD3⁺ T cells in bovines was examined by immunohistochemical analysis. The estrous cycle and gestation was divided into 4 stages, and the number of CD3⁺-positive T cells was counted in each stage. CD3⁺ cells were found in the endometrium in significant numbers throughout the estrous cycle and were mostly located in the subepithelial area. The number of CD3⁺ cells significantly increased in the early and mid-luteal phases but decreased after implantation with the progression of gestation. No T cells were found in the placentome or specifically in the tissues near the fetus, including the trophoblastic area. In addition, very few T cells were found in stromal regions close to the myometrium of the endometrium. These findings suggest that downregulation of bovine endometrial CD3⁺ T-cell functions is closely related to the successful maintenance of gestation in a spatiotemporal manner.     

Pansteatitis (Steatitis, "Yellow Fat Disease") in the Cat: A Review Article and Report of Four Spontaneous Cases

Abstract— Pansteatitis was recognized in four cats fed a diet based mainly on oily fish. Except for fever, these cats had all the other typical findings of the disease, namely hyperesthesia, painful, nodular-to-irregular subcutaneous masses, neutrophilic leukocytosis, firm and discolored subcutaneous fat, and lobular and septal pyogranulomatous panniculitis with necrosis, mineralization, and ceroid pigment deposition. Three of the cats responded well to treatment and became clinically normal after 1 month, the fourth was lost to follow-up. Résumé— Une panstéatite a été reconnue chez 4 chats alimentés pricipalement avec du poisson gras. Exception falte de la fièvre, ces chats présentéalent les signes caractériqtiques de cette affection: hyperesthé-sie, douleur, masses sour-cutanées nodulaires á irrégullères, tissue adipeux sous-cutané dur et décoloré et pannicullte pyogranulomateuse septale avec nécrose, minéralisation et dépot de pigment céroïde. Trois des chats ont bien répondu au traitement et sont redevenus cliniquement normauz en un mois. Le quatrième n'a pas pu être suivi. Zusammenfassung— Bei 4 Katzen, die mit einer Diät ernährt wurden, die hauptsächlich aus fettreichem Fisch bestand, wurde eine Pansteatitis festgestellt. Mit Ausnahme von Fieber zeigten diese Katzen all die anderen typischen Symptome diesser Krankheit, nämlich Hypersästhesie, Schmerz, noduläre bis unregelmäßig geformte subkutane Gebilde, Leukozytose mit Neutrophilie, verhärtetes und farblich verändertes subkutanes Fett, lobuläre und septale pyogranulomatöse Pannikulitis mit Nekrose, Mineralisation und Einlagerung von zeroidem Pigment. Drei der Katzen sprachen gut auf die Therapie an und wurden nach einem Monat klinisch gesund. Bei der 4. Katze war der Krankheitsverlauf nicht weiter verfolgbar. Resumen En 4 gatos alimentados en una dieta basada fundamentalmente en pescado azul, se diagnosticó pansteataitis. Excepto por la aparición de la fiebre, éstos gatos presentaron los hallazgos clínicos típicos de la enfermedad, hiperestesia, dolor, nódulos o masas irregulares en el tejido subcutáneo, leucocitosis neutrofilica, grasa subcutánea descolorida y de consistencia firme, y paniculitis piogranulomatosa de tipo septal y lobular con la presencia de necrosis, mineralización y pigmento de deposición ceroide. Tres de los gatos respondieron favorablemente al tratamiento y llegaron a ser completamente normales despues de un mes, en el cuarto no se pudo hacer un seguimiento clinico.     

A retrospective study of the incidence and the classification of bone marrow disorders in the dog at a veterinary teaching hospital (1996-2004)

BACKGROUND: An 8-year retrospective study was conducted to evaluate the prevalence and the classification of canine bone marrow disorders in a clinical pathology service at a university referral hospital. ANIMALS: Dogs evaluated for bone marrow disorders at a veterinary teaching hospital. HYPOTHESIS: A better understanding of the spectrum and the prevalence of canine bone marrow disorders can be achieved with a multiyear retrospective study. METHODS: Bone marrow aspirate smears, core biopsy specimens, and case records from 717 dogs were reviewed. RESULTS: Bone marrow specimens were first categorized based on the presence or the absence of a primary bone marrow disorder. Nondysplastic and nonmalignant pathologic changes were placed into 14 subcategories. Frequently observed pathologic disorders included nonregenerative immune-mediated anemia, pure red cell aplasia, bone marrow necrosis, myelofibrosis, and hemophagocytic syndrome. Dysmyelopoiesis (n = 61) was subcategorized into myelodysplastic syndromes (n = 27), and congenital (n = 1) and secondary (n = 33) dysmyelopoiesis. One hundred twenty-six cases of neoplasia were divided into acute leukemia (n = 46), chronic leukemia (n = 7), stage 5 malignant lymphoma (n = 28), multiple myeloma (n = 25), malignant histiocytosis (n = 11), metastatic mast-cell tumor (n = 3), sarcoma (n = 5), and carcinoma (n = 1). CONCLUSIONS AND CLINICAL IMPORTANCE: This study provides a general indication of the spectrum and the prevalence of canine bone marrow disorders at a referral center in North America.