Expression pattern of markers in the canine ovarian cycle.

Although hormonal changes during different phases of the oestrous cycle of bitches are well-described, knowledge about the luteal phase and anoestrus is incomplete. Furthermore, which paracrine and autocrine critical factors that differentiate between follicles destined for atresia and those that continue to develop are unknown. In this study, ovarian tissue was collected from 39 healthy bitches that were subject to ovariectomy or ovariohysterectomy for surgical neutering or medical purposes such as unwanted pregnancy. Bitches were allocated to different groups depending on the stage of the oestrous cycle. Serum progesterone, LH, FSH and 17beta-estradiol (E(2)) -levels were determined and immunhistochemistry was performed for a variety of receptor antigens; Ki-67, vimentin, pan cytokeratin antibody, p53 and oestrogen receptor (ER) alpha antigens. Marked differences were found in progesterone concentration between pregnant and non-pregnant animals. Oestrogen concentration was significantly lower in pro-oestrus and ovulation than during the luteal phase. Although progesterone could be detected in cytoplasm of ovarian cells at each stage, its presence was restricted to follicular cells during anoestrus. A strong presence of AE1/AE3, vimentin and p53 was found in each oestrous stage, in contrast with Ki67. The localization of ERalpha appeared to vary during the oestrous cycle, a phenomenon that suggests a switch between target cells of oestrogen; while as a proliferation marker, the mild reaction of p53 during parturition suggests an apoptotic process at this stage of the cycle.

Immunohistochemical detection of progesterone and cellular proliferation in canine mammary tumours.

Immunohistochemical expression of progesterone and the cellular proliferation marker Ki-67 was assessed in formalin-fixed, paraffin wax-embedded samples from 43 canine mammary tumours. Benign tumours showed high surface membrane progesterone expression (mean 196.42+/-25.91 positively labelled cells per 500 tumour cells) and low cellular proliferation (52.14+/-16.73 positively labelled cells per 500 tumour cells), whilst malignant tumours had low progesterone expression (68.19+/-17.53 positively labelled cells per 500 tumour cells) and higher cellular proliferation (141.72+/-23.65 positively labelled cells per 500 tumour cells), the difference being statistically significant (P<0.005) in both cases. These findings suggest that the majority of progesterone receptors in canine mammary tumour tissue are not associated with bound progesterone. The progression towards malignancy in spontaneously arising canine mammary tumours therefore appears to be associated with a decrease in steroid hormone dependency. Progesterone expression was also noted in the cytoplasm of tumour cells where it may be associated with a cellular repair mechanism. This hypothesis is supported by the finding of significantly higher progesterone content in the cytoplasm of benign tumour cells.

Chronic hepatitis in the dog--a review.

Chronic hepatitis is a heterogeneous group of inflammatory-necrotizing diseases of the liver. There is controversy in both human and veterinary medicine about the classification of chronic hepatitis and this is likely to remain until a classification based on aetiology rather than on morphology is introduced. Controversy exists as to whether chronic hepatitis in dogs is comparable to the human disorder. The aetiology of chronic hepatitis in dogs is poorly understood, whereas in humans an increasing number of viral causes have been found. Liver biopsy is essential for the diagnosis of chronic hepatitis both in dogs and in humans. Histopathological evaluation of the liver is required to make the diagnosis, which is based on the presence of liver cell necrosis and inflammatory reaction. The proposed criteria for the classification of hepatitis in dogs are then as follows: aetiology is the primary denominator (infectious, drug induced, autoimmune, or, if unknown, idiopathic). The other criteria are histopathological, with severity reflecting the severity of the necro-inflammatory activity (minimal, mild, moderate or severe) and chronicity reflecting the extent of fibrosis (none, mild, moderate, severe or cirrhosis).

Oncological scintigraphy in dogs with 99mTechnetium MIBI and DMSA(V)--two case reports.

Oncological scintigraphy is described in two dogs with malignant lymphoma and malignant schwannoma, respectively. The distribution of the radiopharmaceuticals could be visualized for the purpose of detection of neoplasia and eventual metastases, and to evaluate the effectivity of therapy. It is concluded that 99mTechnetium MIBI and 99mTc DMSA (V) scintigraphy is useful for the detection of soft tissue malignancy in dogs.

Radiography and ultrasonography in the diagnosis and treatment of abdominal enlargements in five guinea pigs.

Five guinea pigs with palpable abdominal masses were examined by radiography and ultrasonography, and laparotomy was performed. Splenic haematoma, splenic and uterine haemangioma, uterine fibroma and ovarian teratoma were found on histological examination after excision of the relevant organs. Both of the imaging methods allowed localisation of the affected organs, but the inner structure of the masses could only be imaged by ultrasonography. Ultrasonography served as an aid in decision-making with respect to the laparotomy. Surgery was successful in four out of the five cases. Both imaging methods were found to be useful in diagnosis and in determining the choice of treatment in cases of abdominal masses in guinea pigs.

Ultrasonography and surgery of canine biliary diseases.

Findings of hepatic and gallbladder ultrasonography were analyzed in 12 dogs with gallbladder and/or extrahepatic biliary tract obstruction and compared with the results of exploratory laparotomy. Hepatic ultrasonography demonstrated normal liver in 2 dogs and hepatic abnormalities in 10 animals. The following ultrasonographic diagnoses were established compared to surgical findings: gallbladder obstruction caused by bile sludge (correct/incorrect: 1/2, surgical diagnosis: choleliths in one case), gallbladder obstruction caused by neoplasm (0/1, surgical diagnosis: mucocele), gallbladder and extrahepatic biliary tract obstruction due to choleliths (3/3), extrahepatic biliary tract obstruction caused by pancreatic mass (1/1) and small intestinal volvulus (1/1). Bile peritonitis caused by gallbladder rupture (4/4) was correctly diagnosed by ultrasound, aided with ultrasonographically-guided abdominocentesis and peritoneal fluid analysis. Rupture of the gallbladder should be suspected in the presence of a small, echogenic gallbladder or in the absence of the organ together with free abdominal fluid during ultrasonography. Laparotomy was correctly indicated by ultrasonography in all cases. However, the direct cause of obstruction could not be determined in 2 of the 12 dogs by ultrasonography alone.

Use of the argyrophilic nucleolar region method for cytologic and histologic examination of the lymph nodes in dogs.

Argyrophilic nucleolar organizer region (AgNOR) counts in cytologic and histologic lymph node samples from healthy dogs and dogs with lymphoma were compared. Control samples were taken from 10 Beagle dogs (six female and four male dogs, 1.5-2 years), and lymphoma samples were taken from 16 dogs. Cytologic samples were obtained by fine-needle aspiration and impression and histologic samples by excision or incisional biopsy. Altogether, 26 cytologic, 19 excisional, and 7 incisional biopsy samples were examined. Lymph nodes of controls showed a moderate inflammatory pattern; of the lymphoma cases, nine were low-grade forms and seven were high-grade forms. Mean AgNOR counts per nucleus were determined. AgNOR counts were statistically different (P < 0.001) between controls and lymphoma cases in cytologic (1.35 and 3.59, respectively) and histologic (1.4 and 2.89, respectively) samples. In lymphoma cases, AgNOR counts in cytologic samples were higher than those in histologic samples by 0.81 (P < 0.001) and showed a linear relationship (r = 0.6; P < 0.05) with the histologic counterparts in excisional biopsy samples. AgNOR counts in low- and high-grade lymphomas were significantly different (P < 0.05) in cytologic (3.21 and 4.08, respectively) and histologic (2.68 and 3.18, respectively) samples. In conclusion, AgNOR counts were higher in lymph nodes with lymphoma than in reactive nodes. In the case of dogs with lymphoma, AgNOR counts in cytologic samples were linearly related to excisional but not to incisional biopsy samples. Although AgNOR counts were different between cytologic and histologic samples, either sample type provided enough sensitivity to differentiate between high- and low-grade forms of lymphoma.