Zatloukal J., J. Lorenzová, F. Tich˘, A. Neãas, H. Kecová, P. Kohout: Breed and Age as Risk Factors for Canine Mammary Tumours. Acta Vet. Brno 2005, 74: 103-109.Mammary tumours in 214 dogs were evaluated at the Department of Surgery and Orthopaedics, Veterinary and Pharmaceutical University Brno, between 1997 and2001. Lesions of the mammary gland were classified as dysplasia/hyperplasia, benign and malignant tumours in 19, 61 and 134 patients, respectively. When there were different lesions of the mammary gland in one individual, the patient was classified according to the most malignant one. The above-mentioned patients were compared to the population of 17 053 dogs treated during the same period to determine age and breed predisposition.Considering the lesions of the mammary gland, the highest relative risk of dysplasia/hyperplasia, benign tumours and malignant tumours was at the age of 8, 10 and 13 years, respectively. Our results thus confirm the previous studies stating the highest incidence after 10 years of age.Poodles, English Cocker Spaniels and Dachshunds had a statistically significant relative risk developing benign and malignant tumours of the mammary gland (χ 2 -test, p < 0.01), confirming conclusions of previous studies concerning these breeds. We did not, however, prove higher relative risk in Irish Setters, Labrador Retrievers and Boxers. Breast neoplasms, histopathology, incidence, predisposition, retrospective studyThe mammary gland belongs to body areas with the highest incidence of neoplasia. Tumours of the mammary gland in female dogs represent up to 42% of all tumours (Johnson 1993;Dorn et al. 1968). They occur with much higher incidence than in other females of domestic animals and women (Brodey et al. 1983;Schneider 1970).Risk factors associated with the increased occurrence of mammary tumours in female dogs have already been studied. Higher incidence was found after the 6th year of age with the maximum being 9 to 11 years. Female dogs younger than 2 years were rarely affected (Schneider 1970;Brodey et al. 1983). Increased incidence of mammary tumours was found in many large as well as smaller breeds of dogs. The lowest occurrence was found in mongrels, Boxers and Chihuahuas (Dorn et al. 1968;Brodey et al. 1983;Cohen et al. 1974). Spayed dogs had a 3 to 7 times lower incidence of mammary tumours than the intact ones (Mulligan 1975;Priester 1979;Hahn et al. 1992;Alenza et al. 2000). The effect of spaying on the decreased incidence of mammary tumour, however, depended on the age of the dog at the time of surgery. The most significant decrease of incidence was found in females spayed prior to their first oestrus (0.5% incidence as compared to intact female dogs) and between the first and second oestrus (8%). Advanced age at the time of spaying increases the incidence of tumors (26% between the second and fourth estrus) and no positive effect of spaying was found after the fourth estrus (Misdorp 1988;Schneider et al. 1969). Characteristics such as abnormal oestrous cycle, false pregn...

Risk factors for damage of the medial meniscus in 160 cranial cruciate deficient stifles in 138 dogs have been evaluated. The medial meniscal damage was found in a total of 72 patients (45%) with CCL rupture. The risk of damage to the meniscus was significantly higher in dogs of 25-45 kg compared to those weighing less than 24 kg. Cases of more severe grades of arthritis and joint effusion were significantly more often accompanied by the medial meniscal damage. Severe osteoarthritis of grade 3, as compared to the grade 1, was considerably frequently (p < 0.01) associated with the medial meniscal lesion. The meniscal damage was most commonly accompanied by moderately severe stifle joint effusion. The medial joint cavity collapse was a very important radiographic sign expressing the medial meniscal damage (p < 0.01). Its sensitivity and specifity in the diagnostics of the medial meniscal damage is 52% and 71%, respectively. Duration of lameness, extent of the CCL rupture (partial versus total) and radiographically measured index of the stifle joint laxity do not belong to statistically significant risk factors of the medial meniscal damage.

Obtaining more data on breed predisposition of dogs to the cranial cruciate ligament (CCL) rupture and data on accompanying abnormalities of joints of pelvic limbs affected by the CCL rupture may help in answering some questions concerning the etiology and pathogenesis of the disorder.In 183 patients affected by the CCL rupture out of the total of 11579 dogs, evaluated and/or treated in the Clinic of Surgery and Orthopedics at the Veterinary and Pharmaceutical University Brno from January 1997 till April 2000, the breed, weight, sex and concurrent joint abnormalities of pelvic limbs (hip dysplasia, patellar luxation and osteochondrosis of the stifle joint) were recorded.A total of 213 stifle joints (16.39% of cases were bilateral CCL ruptures) were affected. Increased breed predisposition (χ 2 -test; p < 0.01) was found in American Staffordshire Terrier, Rottweiler, Brazilian Fila, Labrador Retriever, American Cocker Spaniel, Chow Chow, German Shorthaired Pointer, Saint Bernard and Bullmastiff and also on the 5% level of significance in Boxer.Contrary to published data, the high incidence of CCL rupture was found in Brazilian Fila (13.43% of prevalence). The risk of the CCL rupture in German Shepherd Dog was significantly lower (χ 2 -test; p < 0.01) than in other breeds studied. At the same time in 27 patients with the CCL rupture we diagnosed canine hip dysplasia, in 9 dogs medial patellar luxation and in 5 cases osteochondrosis of the stifle joint. The data found are briefly discussed in relation to the possible CCL rupture etiology. Stifle joint, cranial cruciate ligament injury, prevalence, etiopathogenesisCranial cruciate ligament (CCL) rupture belongs to the most frequent acquired diseases of the stifle joint not only in dogs and cats (Ryer 1981) but also in man (Griffin et al. 2000). Many questions concerning the etiopathogenesis of the CCL rupture remains unanswered. The integrity of the cranial cruciate ligament may be lost due to direct trauma of the stifle which may also result in damage of other structures of the stifle such as the caudal cruciate ligament, medial and lateral collateral ligaments, meniscus, joint capsule and eventually bone structures of the joint (femur, tibia and patella) (Bruce 1998). The number of cases of in such a way originated CCL ruptures is relatively small. With regard to the absence of direct trauma of the stifle joint in most cases of CCL rupture, various predisposing factors taking part in decreasing the firmness of the ligament, resulting in its inability to stand up to normal loading and subsequent rupture have been considered. Decreased CCL resistance to forces of pull has been proved in animals with aging. Results of concurrent histological examination have proved degenerative changes of the ligament that were more severe with advancing age of dogs and occurred earlier in dogs of large breeds (body weight > 15 kg) (Vasseur et al. 1985). There may also be other predisposing factors such as

Synovial fluid samples from 64 stifles of 54 dogs with spontaneous rupture of the cranial cruciate ligament were investigated for total and differential leukocyte counts and lymphocyte subsets using the methods of flow cytometry and anti-canine monoclonal antibodies. Synovial fluid samples from 19 healthy (without lameness, pain, macroscopic and roentgenological changes) joints of 12 dogs were used as a control. Total and differential leukocyte counts from joints after cranial cruciate ligament rupture did not differ from healthy joints. Less than 5 × 10 6 leukocytes per millilitre were detected and neutrophils constituted less than 5% of all leukocytes. Percentages of lymphocytes expressing CD4 and CD8 were higher in synovial fluid from joints after cranial cruciate ligament rupture. On the other hand, percentages of lymphocytes expressing the CD45RA isoform were significantly lower in synovial fluid from joints after cranial cruciate ligament rupture. Results show some role of cell-mediated immunity in pathogenesis of spontaneous rupture of the cranial cruciate ligament.

The epidemiology of bite wounds in dogs that resulted from intraspecies conflicts and were treated at the Small Animal Clinic, Department of Surgery and Orthopedics, University of Veterinary and Pharmaceutical Sciences, Brno was evaluated from 246 records in 1989-90 and 337 records in 1998-99. The number of bite incidents fluctuated during the year. The majority of incidents occurred in summer months, i.e. in the second (n = 149) and third (n = 193) trimester of the year. In comparison, only 119 and 122 bite victims were treated in winter months, i.e. in the first and fourth trimester, respectively. The total number of bite victims increased (p < 0.01) between the first and the second period under study. Most treated dogs belonged to small (37.9%), and large (24.8%) breeds, followed by medium-sized (19.0%), giant (11%) and toy breeds (7.3%). A high proportion of the victims were 1 year (11.4%) and 2 years (15.6%) of age, and the proportion decreased with age down to 1% at 11 years. Also, there were indicators for a sex effect. Of the 571 cases where the dog´s sex was recorded 176 concerned a female (30.3%) and 405 (69.7%) a male. For 503 dogs the positions of the wounds were recorded. A large portion of the wounds was administered to the thorax (26.6%) and head (24.30%), i.e. the frontal body parts. More than one fourth of all head wounds were in the relatively small areas around the eyes (28.7%). Fewer bites were on the limbs (17.7%), neck (17.3%) and in the abdominal regions (14.3%). These data suggest that for dogs the risk of being wounded by a conspecific differs between seasons and depends on a dog´s age, sex and body size.