Oxytocin is a hormone which plays a crucial role in many reproductive and behavioural functions. It affects many organs and the classical peripheral targets are the mammary glands during lactation and uterus during labour. Oxytocin receptors have recently been described in a variety of normal tissues and primary cell cultures, but also in neoplastic tissues and established neoplastic cell lines, as breast cancer cell lines. The signalling pathways and biological effects of the oxytocin/oxytocin receptor system seem to depend on species, type of tissue, physiological versus neoplastic state and receptor location within the cell membrane.The aim of this project was to find out if the cell proliferation in the canine mammary carcinoma cell line CMT-U27 was affected upon stimulation of oxytocin, and to investigate the presence of oxytocin receptors in these cells. The cell proliferation was examined by using an ELISA-kit, where the absorbance measured is relative to the amount of living cells.

An inflammatory reaction is induced after release of proinflammatory mediators such asinterleukin 1 and 6 and tumour necrosis factor ?. These mediators stimulate the liver tosuppress the syntheses of albumin and endure the syntheses of acute phase protein forinstance C-reactive protein. The aim of this paper was to perform a method validation on animmune turbidimetric assay to quantify C-reactive protein in canine serum at the laboratory atSkara Animals Hospital, Skara, Sweden. The validation involved evaluation of the assaylinearity, precision, stability and recovery.The method was proved to be linear for both TruLab control and Medinor control.

Complete tumour regression is the optimal outcome of cancer therapies. There are however types of tumours that naturally regress. Most of these are benign, dermatological and have an early onset in life. This literature study aims to elucidate the mechanisms behind spontaneous tumour regression. In Libechov Melanoblastoma-Bearing minipigs, an animal-model specifically bred to develop malignant melanoma, the tumours usually involute within three months.

Malignant melanoma represents 4-7% of all canine neoplasms and they are the most common malignant tumors of the oral cavity and digits. These tumors are often aggressive and metastasize quickly. To date there is no effective treatment and survival times are short. Most dogs are euthanized due to complications caused by metastases. Melanin pigment is a hallmark of melanomas and is usually present in large amounts in these tumors.

The purpose of this study is to describe melanotic tumours and the pathogenesis of these tumours. The focus of this study is on differences between benign and malignant tumours as well as the prognosis one may expect when diagnosing this disease. The mechanisms responsible for the occurrences of the tumours are not yet fully understood. It is believed that factors such as chronic trauma, infections, medications and hormones affect the cell mechanisms in some way. Determinants of the malignancy of the tumour are not completely known.

Pseudopregnancy is a condition that is estimated to affect 40 % of all female dogs. Common symptoms are decreased activity level, weight gain, mammary enlargement, milk production, nesting behavior, anorexia and maternal behavior. The symptoms are displayed during metoestrus. Prolactin is one of the causes behind pseudopregnancy, but the full process is not yet known. Due to the fact that the condition affects that many bitches and often is recurrent, it is relevant to examine how the condition affects the bitch?s behavior and performance.

This article presents a retrospective case study combined with a review of the current literature concerning canine gestational diabetes. A total of 14 cases have been collected from six different clinics in Sweden. There are few previously published reports on canine gestational diabetes. Gestational diabetes is a disease that rarely occurs in pregnant bitches. The condition is due to the rise of progesterone that occurs during the estrus cycle.

This literature study aims to examine the existence of cancer stem cells in breast cancer. The cancer stem cell theory states that there is a hierarchical organization within a tumour, in which a small subpopulation of the cells can initiate new tumours and maintain tumour growth whilst the bulk of the tumour cannot. These tumour initiating cells have shown to possess many characteristics similar to those of adult stem cells, which is why they are often referred to as cancer stem cells. Both cell types have the capacity of asymmetric division and have shown to possess mechanisms of resistance to both apoptosis and cancer drugs. The cancer stem cell theory elucidates many biological aspects such as the heterogeneity of tumours and the relapse of many cancers after what appeared to be successful treatments.

The dog has often served as a model animal for humans in scientific studies. This is due to the fact that dogs are susceptible to a wide range of diseases which also affect humans. One example is cancer, a condition that affects dogs as well as owners. Neoplastic diseases account for 18-23 % of all deaths in dogs (Bonnet et al., 2005 and Jagielski et al., 2002). Mammary tumor, or tumor of the breast, is the most common tumor form in intact dogs and women (Im et al., 2013). Mammary tumors originate in the udder, and are classified according to their histological characteristics.

The WT1 gene is a complex gene originally known to suppress cancer in kidneys. Studies of WT1 knockout mice have confirmed the important role of WT1 in the pathogenesis of Wilms? tumour, a tumour which counts for 95% of all childhood renal tumours. In that case the WT1 gene acts as a tumour suppressor gene. Subsequent research has shown that the WT1 gene in many other cases acts as an oncogene, e g in leukemia or lung cancer (even though these cancer forms can emerge as a result of many other aetiological factors).

Thymidine kinase 1 (TK1) is an intracellular enzyme involved in ?the salvage pathway? where the uncomplete parts of DNA are transformed into DNA precursors. The expression of TK1 is cell cykle specific, with the highest level during S-phase when DNA-synthesis is most active. One kind of TK1 is present in serum and an increase in TK1 activity in serum is due to either the level of DNA synthesis in the body or the number of cells dying in a state of replication. This can be used and is used as a marker for prognosis and evaluation of treatment in human patients with leukemia and lymphoma.

Canine parvovirus is associated with two disorders: enteritis, which is common, and myocarditis, which is rare. Prominent clinical signs of parvovirus enteritis are vomiting, diarrhea and rapid dehydration. Canine parvovirus type 2 (CPV-2) is very contagious. When CPV-2 first emerged it had high rates of mortality, but later studies have shown that most infections are self-limiting and do not require veterinary care. Mortality rates vary greatly, and therefore it is important to determine risk factors for developing severe canine parvovirus enteritis.

Malt lymphoma is a malignant disease that can arise in a variety of extra nodal sites. Previous studies indicate that tumour arise from more mature B-cells.Our purpose was to examine the presence of clonality and somatic hypermutation of immunoglobulin (IgV?) of MALT lymphomas.Paraffin-embedded tumour samples from13 MALT lymphoma were subjected to rearrangement analysis, by using PCR, heteroduplex gels and sequence analysis.Successful amplification was seen in 10/13 cases and sequences of IgV? genes were obtained in 6/13, all of them were mutated. The percentage of mutation compared to germline sequences was 1,1% to 8,6% monoclonal rearrangemang. It was demonstrated that 5 of 7 clones were derived from the V?3 family, 2 from V?1 and 1 from the V? 4 family..

Mammary tumors are the most frequent type of tumors in bitches in Sweden. Many studies have been published concerning mammary tumors, but there is still much to be learned about this disease. One has, since some time ago, had the knowledge that addition to or removal of methyl groups to genes can inhibit or activate gene-expression. Methylation and demethylation is a normal phenomenon in the body and it is essential for the development and survival of the individual. The risk of developing a tumor disease is increased if the global methylationstatus is changed; if oncogenes demethylates (activates) or if tumor suppressor genes methylates (inactivates). In the human medicine one has seen that there are differences in methylationstatus between different tumors. In this study tumor and normal tissue from ten dogs were examined with regard to methylationstatus.

I denna studie har förekomst av progesteronreceptorer i olika typer av primära juvertumörer undersökts med hjälp av immunohistokemi. Dessutom har tumörceller från carcinomcellinjen CMT-U27 odlats i olika cellodlingsmedium och exponerats för olika testsubstanser som binder till progesteronreceptorn (progesteron och RU486/mifepristone). Cellernas receptoruttryck och progesteroninnehåll utvärderades med hjälp av ELISA och tumörcellernas viabilitet analyserades med Colorimetric Cell Viability Test. Av resultaten framgår att samtliga undersökta primära juvertumörer uttryckte progesteronreceptorer. De odlade cellerna hade högre cellviabilitet när de odlades utan fetalt bovint serum (FBS). Efter exponering med progesteron minskade tumörcellernas uttryck av progesteronreceptorer, vilket hämmades av mifepristone.