Morphologic changes in the mammary gland of megestrol acetate-treated and untreated cats: a retrospective study

Abnormal mammary gland growth is a side effect of progestin therapy in some cats. In this retrospective study, the nature and significance of morphologic changes in the mammary gland of 17 megestrol acetate (MA)-treated cats were compared to mammary lesions in 97 untreated cats. Fourteen out of 17 MA-treated cats had non-neoplastic mammary lesions including fibroepithelial hyperplasia (nine cats), lobular hyperplasia (three cats), and duct ectasia (two cats); whereas three MA-treated cats had mammary neoplasms including one adenoma and two carcinomas. Although MA has been causally linked to mammary cancer in cats, only mammary fibroepithelial hyperplasia was clearly associated with MA therapy in this study. Fibroepithelial hyperplasia occurred in older (average age 8.1 years) neutered male and female cats in the MA-treated group and in younger (average age 2.1 years) female cats in the untreated group. Morphologically, both intraductal and solid fibroepithelial growth patterns were seen. Intraductal fibroepithelial hyperplasia was further subdivided into papillary and circumferential types. An apparent greater association between MA therapy and the intraductal types of fibroepithelial hyperplasia was noted. Furthermore, it appears likely that mammary lobular hyperplasia also is linked to MA therapy. Possible mammatrophic effects of MA and other growth-promoting agents in the cat are discussed.     

Prevalence of and carcass condemnation from maedi-visna,paratuberculosis and caseous lymphadenitis in culled sheep from Quebec,Canada

We determined the prevalence of lung and mammary gland lesions associated with maedi-visna (MV) infection, the prevalence of paratuberculosis (PTB), and the prevalence and lesions distribution of caseous lymphadenitis (CL) in culled sheep. Total of 451 ewes and 34 rams were selected randomly from two slaughterhouses in Quebec, Canada. MV serostatus was determined by recombinant ELISA test. PTB diagnosis was based on characteristic histological lesions in the terminal ileum, ileocecal lymph node and/or ileocecal valve and CL by gross detection of abscesses and isolation of Corynebacterium pseudotuberculosis. Seroprevalence of MV was 44% (95% CI: 40, 48). Seropositivity increased with age and was higher in ewes than in rams. The percentages of lung and mammary gland lesions in seropositive sheep were 14 and 40%, respectively, but mammary gland lesions lack specificity. The prevalence of PTB was 3% (95% CI: 2, 5). PTB increased with age and was lower among sheep with abscesses. The prevalence of CL was >/=21% (95% CI: 17, 24). The most-prevalent site of caseous lymphadenitis lesions was the thoracic cavity. The risk of carcass condemnation was significantly associated with region, body score and abscesses. Only the presence of abscesses was associated with an increase in trimming of carcasses.     

Mammary tumors in a colony of beagle dogs

In a lifetime study, female beagle dogs in a closed colony were administered 226radium and 90strontium. An unirradiated control group was included in the study. A total of 223 of 356 dogs at risk developed 1,112 mammary proliferative growths (hyperplastic nodules and neoplasms). There was no correlation between occurrence and types of lesions in radiation and control groups. The age range for first occurrence of lesions was 10.4 to 13.9 years; hyperplastic nodule and benign mixed tumor occurred 1 to 2 years earlier than other lesions. A multiplicity of growths of similar or different morphological type were common throughout the lifetime of the dog. The female beagles, collectively, developed 244 hyperplastic nodules, 78 adenomas, 694 benign mixed tumors, 78 carcinomas, 14 malignant mixed tumors, and four myoepitheliomas. Proliferations occurred with increasing frequency from the cranial to caudal mammary glands. Metastasis was found in 77% of the dogs with carcinoma. The median time from diagnosis to metastasis was 10 months, but was shorter in dogs with infiltrative carcinoma.     

Expression and significance of PTEN and VEGF in canine mammary gland tumours

To investigate the relationship between the expression of the PTEN (phosphatase and tensin homolog deleted on chromosometen) and VEGF (vascular endothelial growth factor) and the clinicopathological features in canine mammary gland tumours, the expression levels of PTEN and VEGF protein were assessed in 50 cases of canine mammary gland tumours tissues and 4 cases of normal mammary gland tissues with using immunohistochemical method. The over-expression rate of PTEN protein was 100% in normal and well-differentiated mammary gland tissues and 67% in breast cancer cases respectively with a significant difference between the two groups (P<0.01). Expression of PTEN was not related to age and tumour size, but closely correlated to lymph node metastasis (P<0.01). The over-expression rate of VEGF protein was 33.3% in normal mammary gland tissues, and 78% in canine mammary gland tumours with a significant difference between the two groups (P<0.01).Expression of VEGF was not related to age or tumour size, but closely correlated with lymph node metastasis and clinical stage (P<0.05).Therefore the combination detection of PTEN and VEGF could serve as an important index to estimate the biological behavior and prognosis of canine mammary gland tumours. Reduced expression of PTEN might be involved in carcinogenesis and progression of canine breast cancer by up-regulating the VEGF expression to enhance angiogenesis.     

犬乳腺肿瘤的病理组织学观察及p63蛋白的表达

通过对35例犬乳腺肿瘤的临床病史调查、光学显微镜观察和免疫组化染色,探讨了犬乳腺肿瘤的临床病理形态学特点、诊断和鉴别诊断.结果显示34例发生在5岁以上,6岁～10岁为发病高峰期;51.4％的病例为恶性肿瘤,其中44.4％的乳腺癌发生转移.免疫组化染色结果显示,在正常乳腺和良性肿瘤组织中,p63蛋白100％表达,并且仅仅...     

Emergency-culling and mortality in growing/fattening pigs in a large Hungarian "farrow-to-finish" production unit

The trial was carried out in a large Hungarian 2000 sow "farrow-to-finish" production unit. Out of a total number of 15,841 evaluated growing/finishing pigs, 1319 pigs died or were emergency-culled and were post-mortem routinely examined. For the purpose of this study the emergency-culling and mortality were recorded into the same category. The average annual emergency-culling/mortality rate was unusual high (8.62%). Five body condition related categories were registered. The majority of the mortality comprised animals of body condition "below average", representing 891 pigs (67.56%) and "average" (407 pigs = 30.85%). The rest of the examined animals comprised 17 pigs (1.29%) "emitted", 2 pigs "kachexia" (stunted pig) or "fat" (0.15% each). The overall study showed that gastrointestinal tract disorders (395 animals = 29.95%) were the most frequently recorded cause of emergency-culling or mortality. Both inflammatory disorders (7.66%) and rectal stricture (7.51%) were in this category the most frequent diagnosis followed by rectal prolapse (5.92%). Gastric ulcers comprised 4.55% of the necropsied animals. Torsion of abdominal organs and miscellaneous cases represented slightly more than 2% of the post-mortem examined pigs. Lesions which involved the respiratory system, comprised 14.85% of the necropsied pigs. Bronchopneumonia due to Mycoplasma hyopneumoniae occurred in 5.61%, embolic suppurative or necrotic pneumonia in 4.78% and pleuropneumonia due to Actinobacillus pleuropneumoniae in 3.1% of the cases. Diseases involving the urinary system were diagnosed in 21 cases (1.59%). Five cases of skin disorders were registered (0.38%). Cardiovascular disorders were represented by congestive heart failure (31 pigs = 2.35%), pericarditis (22 animals = 1.66%) or endocarditis (21 pigs = 1.60%). Cardiomyopathy was found in 15 (1.2%) animals. Lesions involved the locomotor system ranked second of all cases (15.92%). Claw lesions accounted 13.72%, arthritis 2.13% of the animals and luxation or fracture was diagnosed only in one case (0.07%). Systemic infections were reported in 96 cases (7.28%) including polyserositis (4.09%), erysipelas, edema disease or miscellaneous causes (each category slightly more than 1%). Genetic problems were involved in 8.19% of the fatal cases and social stress or cannibalism related culling or mortality comprised 37 animals (2.81%). In 161 cases (12.20%) of the mortality the causes of death were not established. Two or more lesions related to culling or mortality were found in 320 pigs (24.26%, p < 0.001). The most common diagnosed pathologic changes in association with other lesions were Mycoplasma hyopneumoniae caused bronchopneumonia (4.09%), embolic suppurative or necrotic pneumonia (4.55%), followed by inflammatory gastrointestinal problems (3.10%), gastric ulcer (2.35%), claw lesions (2.19%) and arthritis (1.14%). It appears from the presented study that a routine post-mortem examination of all emergency-culled or dead pigs over a long period of time gives a clear picture of causes of mortality enabling the management to plan management strategies as vaccination programs, genetic improvements and optimising environmental conditions.     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Teat lesions and their relationship to intramammary infections on small-scale dairy farms in Kiambu district in Kenya

Mammary gland quarters of 139 lactating dairy cows from small-scale dairy herds were examined visually and by palpation for teat lesions and by California mastitis test (CMT) and bacterial culture for subclinical mastitis. Teat lesions were observed in 97 teats. These included teat chaps (39.2%), teat papillomas (23.7%), teat erosions (22.7%), teat fistulae (5.1%), inverted teats (5.1%) and blocked teats (4.2%). According to the CMT, the prevalence of subclinical mastitis was 33.4% in all the mammary gland quarters, 71.0% in quarters with teat lesions and 24.5% in quarters without teat lesions. There was a significant (P < 0.01) association between teat lesions and the prevalence of subclinical mastitis. The mammary gland quarters with teat lesions were 7.2 times more likely to have a positive CMT (P < 0.01) and 5.6 times more likely to have bacterial organisms (P < 0.01) isolated from them than those without any teat lesions. The bacterial organisms most frequently isolated from the CMT-positive milk samples from both the mammary gland quarters with teat lesions and those without teat lesions were Staphylococcus aureus (50.0%), Streptococcus spp. (34.8%) and Arcanobacterium pyogenes (6.2%).     

实时荧光定量PCR对犬乳腺肿瘤组织TNFR1基因的定量检测

乳腺肿瘤是母犬中最为常见的肿瘤,运用实时荧光定量PCR检测了37例犬乳腺肿瘤病例和37份正常乳腺组织.结果表明:犬乳腺肿瘤组织中肿瘤坏死因子受体(TNFR1)的表达量显著低于正常对照组织(P<0.05).该试验结果说明,犬乳腺肿瘤的发生很可能与TNFR1表达降低有关,为深人研究肿瘤形成的分子机理提供了重要参考.     

Postmortem findings in captive cane rats (Thryonomys swinderianus) in Gabon

The causes of morbidity and mortality in a population of cane rats (Thryonomys swinderianus) on an experimental farm in Gabon were monitored for 21 months; 94 of 546 animals (17.2 per cent) died and were examined postmortem, and complementary laboratory examinations were carried out on 23 of the cases together with samples from 13 other animals kept elsewhere in similar conditions. Twenty-six (28 per cent) of the deaths occurred in preweaned kits, 40 (42 per cent) in subadults and 28 (30 per cent) in adults. The average monthly mortality was 2.5 per cent. Trauma was responsible for 29 of the deaths, 12 were due to septicaemia, 10 to primary respiratory lesions, five to digestive disorders, four to urinary lesions, three to reproductive problems and three to other causes; no diagnosis could be reached in 28 cases.     

Effect of spaying and timing of spaying on survival of dogs with mammary carcinoma

The risk of developing mammary gland tumors in dogs is significantly decreased by ovariohysterectomy at an early age. However, previous studies have not found a benefit to ovariohysterectomy concurrent with tumor removal in dogs with established mammary gland tumors, suggesting that the progression of these tumors is independent of continued estrogen stimulation. The purpose of this study was to evaluate the effect of spaying and of the timing of spaying on survival in dogs with mammary gland carcinoma. Signalment, spay status and spay age, tumor characteristics, treatment. survival, and cause of death of 137 dogs with mammary gland carcinoma were analyzed. The dogs were classified into 3 groups according to spay status and spay time: intact dogs, dogs spayed less than 2 years before tumor surgery (SPAY 1), and dogs spayed more than 2 years before their tumor surgery (SPAY 2). Dogs in the SPAY 1 group lived significantly longer than dogs in SPAY 2 and intact dogs (median survival of 755 days, versus 301 and 286 days, respectively, P = .02 and .03). After adjusting for differences between the spay groups with regard to age, histologic differentiation, and vascular invasion, SPAY 1 dogs survived 45% longer compared to dogs that were either intact or in the SPAY 2 group (RR = .55; 95% CI .32-.93; P = .03). This study reveals ovariohysterectomy to be an effective adjunct to tumor removal in dogs with mammary gland carcinoma and that the timing of ovariohysterectomy is important in influencing survival.     

Mortality Patterns in Dairy Animals under Organized Herd Management Conditions at Karnal India

Mortality patterns of two Zebu cattle breeds, Sahiwal and Tharparkar, and two crossbred strains, Karan Swiss and Karan Fries, maintained at the National Dairy Research Institute, Karnal were studied. Nine-year (1989--90 to 1997--98) data on mortality were analysed for year, season, age and cause effects on mortality rate. The overall mortality was 14.17%. The mortality in Sahiwal, Tharparkar, Karan Swiss and Karan Fries averaged 14.35%, 7.21%, 17.12% and 13.46%, respectively. The breed mortality rate did not vary significantly between years, seasons, age categories and causes of disease. However, the trends indicated appreciable difference in mortality rates. The mortality was highest in the year 1994--95 (19.53%) and lowest in 1991--92 (8.56%). There was very little variation in seasonal mortality rate and mortality rate averaged 4.53%, 4.81% and 4.84% in hot-dry (March-June), hot-humid (July-October) and cold (November-February) seasons, respectively. The mortality up to 2 months of age accounted for a major share (50-60% or higher) in different breed groups. Digestive problems followed by respiratory disorders together accounted for 70-80% of total deaths.     

Immunohistochemical analysis of estrogen receptors in feline mammary gland benign and malignant lesions: comparison with biochemical assay

Estrogen receptors (ER) were determined by both the biochemical dextran-coated charcoal (DCC-ER) and the immunohistochemical Avidin biotin-peroxidase complex (IHC-ER) methods in proliferative mammary lesions collected from 37 cats: 20 malignant tumors without metastasis at first presentation, seven malignant tumors with lung and/or lymph node metastases and 10 benign tumors and dysplasias. Total number of samples analyzed by both methods was 44. The DCC-ER method was applied to frozen tissue samples and the IHC-ER method was applied to neutral buffered formalin-fixed, paraffin wax-embedded tissue samples by using the NCL-6F11 monoclonal antibody. Biochemically, 21 (47.7%) cases had equal or more than 5 fmol/mg of protein (standard positivity threshold). Immunohistochemically, 11 (25%) cases were scored positive, the percentage of positive nuclei being statistically linked to the intensity of immunostaining. Normal mammary gland tissue (13 cases) and/or dysplastic areas (5 cases) found in the surroundings of the main lesion were IHC-ER positive in 76.9% and 40% of the cases, respectively. Concordance between DCC-ER and IHC-DCC was 72.7% and the results of the DCC and the IHC-ER methods were significantly correlated (P < 0.05) by the chi2 test. Specificity (true negatives) and sensitivity (true positives) of the ICH-ER method were 95.6% and 47.6%, respectively. One out of eleven DCC-ER positive and IHC-ER negative discordant cases (9.09%) was a DCC-ER false positive, because the surrounding normal mammary gland tissue was IHC-ER positive. The remaining 10 cases had ER content values equal or lower than 23 fmol/mg of protein, a figure that could represent the sensitivity threshold of the immunohistochemical method employed.     

奶牛干奶期乳腺免疫力低下机理及影响因素分析

奶牛乳腺自身抵抗力下降是乳腺炎发生的直接原因,也是兽医产科学研究的重点,从提高奶牛自身抵抗力预防乳腺炎的发生已成近年来研究的新热点,作者着重就奶牛在泌乳周期中尤其是干奶期抵抗力下降的机理做了必要的分析和探讨,对影响干奶期免疫力低下的一些因素也作了详尽阐述,这些方面的论述对乳腺机能方面的进一步研究和预防乳腺炎的发生有一定的参考和应用价值。     

Systemic blastomycosis in a horse.

Progressive multisystemic disease caused by Blastomyces dermatitidis was diagnosed in a 17-year-old Quarter horse broodmare. The mare had been treated unsuccessfully with antibiotics for mastitis 3 months postpartum. The disease progressed to exudative cutaneous lesions affecting the ventrum, pectoral region, and limbs accompanied by weight loss across several months. Yeast bodies were observed in swabs of the cutaneous exudate, suggesting a clinical diagnosis of blastomycosis. Following referral, pleural effusion, cavitated lung lesions, and hyperproteinemia were identified, and the mare was euthanized because of poor prognosis. Necropsy revealed extensive pyogranulomas in the mammary gland, skin, subcutaneous tissues, and lungs, accompanied by thrombi in major blood vessels of the lungs and hind limbs. Histologically, pyogranulomatous inflammation was evident in many tissues, and fungal organisms were seen in sections of mammary gland, skin, subcutis, pericardium, and lung. Blastomyces dermatitidis was cultured from mammary tissue, lungs, lymph node, and an inguinal abscess. Although blastomycosis is endemic in the area of origin of the mare in northwestern Wisconsin, the disease is extremely rare in horses and hence easily misdiagnosed. Unique features of this case included the extent of mammary gland involvement and the presence of thrombi in multiple sites.     

Mammary duct ectasia in dogs: 51 cases (1992-1999)

OBJECTIVE: To evaluate the clinical and pathologic characteristics of mammary duct ectasia in dogs. DESIGN: Retrospective study. ANIMALS: 51 dogs with mammary duct ectasia. PROCEDURE: Information regarding body condition, history, number and location of affected mammary glands, appearance of lesions, surgical treatment, nonsurgical treatment, and evidence of recurrence or development of mammary neoplasia was obtained from surveys sent to referring veterinarians. Results of information from examination of histologic sections and referring veterinarians were evaluated for all mammary duct ectasia biopsies performed between 1992 and 1999. RESULTS: Duct ectasia was the primary diagnosis in 51 of 1,825 (2.8%) mammary biopsy specimens and comprised 48% of nonneoplastic mammary diseases. Affected dogs were evenly distributed over a range of 1 to 13 years of age, with a mean age at the time of diagnosis of 6.1 +/- 3.1 years. All dogs were female (31 sexually intact, 20 spayed); 10 of 26 had whelped. Duct ectasia was described as nodular (26 dogs), cystic (13), and multiglandular (11) and located in caudal (31) more often than cranial (14) or middle glands (10). Ectasia recurred in 3 dogs. One dog had a history of previously excised mammary adenocarcinoma; another subsequently developed mammary carcinoma. CONCLUSIONS AND CLINICAL RELEVANCE: Duct ectasia affected mature, sexually intact and spayed female dogs over a wide age range. Certain breeds were affected more commonly than expected. Increased risk for mammary neoplasia was not evident. Duct ectasia should be considered as a cause for mammary enlargement, especially in young dogs or when its cystic nature is evident. Mastectomy is usually curative, and neoplasia should be ruled out in dogs with ectasia.     

Influence of host factors on survival in dogs with malignant mammary gland tumors

The purpose of our study was to determine if specific host factors, such as age at diagnosis, obesity, and hormone status, influence the prognosis of canine mammary gland carcinomas and to confirm if previously reported risk factors (ie, histologic subtype, tumor size, and World Health Organization [WHO] stage) were important in a large series of affected dogs. Ninety-nine female dogs with mammary gland carcinomas, no previous therapy, an excisional biopsy, and known cause of death were studied. No significant association with survival was noted for age at diagnosis (chronologic or physiologic), obesity, or hormone status (ie, spayed versus intact, regardless of time of being spayed). Of the tumor factors analyzed, the histologic subtype anaplastic carcinoma (P = .02), WHO stage I (P = .01), evidence of metastasis at the time of diagnosis (P = .004), and tumor size of 3 cm or smaller (P = .005) all significantly influenced survival. Dogs that were classified as having tumor-related mortality had a shorter postoperative survival compared to dogs that died of other causes (14 months versus 23 months; P = .03). In conclusion, histologic subtype, WHO stage, and tumor size remain important prognostic factors in canine mammary gland tumors. Further study of other prognostic factors is needed to determine which tumors are adequately addressed with local therapy only and which dogs may require adjuvant treatment with chemotherapy.     

IMAGING DIAGNOSIS—ENDOMETRIAL MINERALIZATION IN A DOG

A 9‐year‐old intact female mixed breed dog was presented for mammary gland tumor surgery, and preoperative radiographs showed a tubular soft tissue opacity mass with multifocal mineralization in the caudoventral abdominal cavity. Subsequent ultrasonography demonstrated uterine dilation with echogenic fluid and endometrial acoustic shadowing consistent with mineralization. Resection of mammary gland tumors and ovariohysterectomy were performed. Pyometra was diagnosed on cytologic examination of uterine fluid. Histopathology of the uterine tissue confirmed a diagnosis of cystic endometrial hyperplasia with uterine mineralization.     

Supplementation of distiller's grains during late gestation in beef cows consuming low‐quality forage decreases uterine,but not mammary,blood flow

Positive effects have been observed in offspring from beef cows supplemented with corn dried distillers grain with solubles (DDGS) during late gestation. The hypothesis of this study was that late gestational DDGS supplementation to beef cows would increase blood flow (BF) to the gravid uterus and mammary gland thus impacting birthweight and post‐natal growth of the offspring. Experiment 1 investigated mammary gland BF in multiparous cows during late pregnancy. Beef cows were fed a control (CON1) diet of low‐quality hay (n = 5) or a supplement diet (SUP1) of low‐quality hay with DDGS [1.7 g/kg of body weight (BW); n = 6]. In Experiment 2, multiparous late pregnant beef cows were fed either a control (CON2) diet of a low‐quality hay (n = 4) or a supplement diet (SUP2) of low‐quality hay with DDGS (1.7 g/kg of BW; n = 5). Uterine and mammary gland BF were recorded every 21 days during late gestation. In Experiment 1, there were no effects of diet or day on mammary gland hemodynamics. In Experiment 2, total and ipsilateral uterine BF was less (p ≤ 0.04) in SUP2 vs. CON2 cows and similar BF to contralateral horns. Mammary gland BF was unaltered by maternal supplementation. Even when measured in two different years in two different environments, mammary gland BF remained unaltered to DDGS supplementation. Investigations on the mechanism that may impact uterine BF during late gestation remain to be known.