Mast cell tumours and other skin neoplasia in Danish dogs - data from the Danish Veterinary Cancer Registry

Background

The Danish Veterinary Cancer Registry (DVCR) was established in May 2005 to gather information about neoplasms in the Danish dog and cat populations. Practitioners from more than 60 clinics throughout Denmark have submitted data on these species. The objectives of the current study were, with a special focus on mast cell tumours (MCT) to investigate the occurrence, gender distribution, biological behaviour, locations, types, the diagnostic method used and treatment of skin neoplasms in dogs based on information reported to the DVCR.

Methods

From May 15^th 2005 through February 29^th 2008, reports on a total of 1,768 canine cases of neoplasia in the skin, subcutis or adnexa were submitted.) Of these, 765 cases (43%) were confirmed by cytology or histopathology.

Results

The majority of dogs had a benign neoplasm (66%) while 21% were cases of malignant neoplasia. The most commonly encountered malignant neoplasms were MCT and soft tissue sarcomas and for benign neoplasms, lipomas and histiocytomas were the most common. The location of the neoplasms were primarily in the cutis, subcutis or in the perianal region. The occurrence, gender distribution, biological behaviour and location of canine skin neoplasias in Denmark were similar to earlier reports, although some national variations occurred. A correlation between grade of MCT and the proportion of cases treated surgically was observed.

Conclusions

Population based cancer registries like the DVCR are of importance in the collection of non-selected primary information about occurrence and distribution of neoplasms. The DVCR provides detailed information on cases of skin neoplasms in dogs and may serve as a platform for the study of sub-sets of neoplastic diseases (e.g. MCT) or subgroups of the canine population (e.g. a specific breed).     

Effect of nutritional status and sampling intensity on recovery after dorsal aorta cannulation in free-swimming Atlantic salmon (Salmo salar L.)

Recovery from implantation of a cannula in the dorsal aorta (DA) of Atlantic salmon (Salmo salar) was studied in relation to nutritional status and sampling intensity. The incentive for the study was the inconsistency between published reports and our own experience of recovery and longevity of fish exposed to this protocol. In two studies using starved fish, blood (0.3 ml) was sampled 0, 1 and 24 h after DA-cannulation, and thereafter at 48 and 72 h and thereafter once weekly for four weeks. In a third study using fed fish, four consecutive samples (0, 3, 6 and 12 h after a meal) were obtained twice a week over a four-week period. All fish displayed a sharp increase in pCO₂ and haematocrit (Hct) during surgery, followed by a marked raise in cortisol, glucose, sodium and potassium (1 h). pCO₂, pH and Hct approached baseline levels as early as the 1 h post-surgery sample, while this was not the case for cortisol and electrolytes before the 24 h post-surgery sample. Glucose did not display any significant changes post surgery. From then on, all variables displayed minor but non-significant (P > 0.05) changes indicating a steady state close to baseline values for unstressed fish. This pattern was independent of sampling procedure, i.e. repeated single or multiple samples and thus volume of blood removed. Nutritional status (fed vs. starved) did not affect post-surgical recovery pattern. Only K⁺ and Hct displayed consistent and significant post-prandial patterns. We found marked differences between baseline level of cannulated fish and uncannulated control fish, in pH, K⁺ and Hct indicating that cannulation may be the preferred method to obtain representative resting values in fish.     

Genetic mapping of the barley lodging resistance locus Erectoides‐k

The barley (Hordeum vulgare L.) mutant erectoides‐k.32 (ert‐k.32) was isolated in 1947 from an X‐ray‐mutant population of cultivar ‘Bonus’. The mutant was released as a cultivar in 1958 with the name ‘Pallas’ – one of the first cereal crop cultivars developed from induced mutants. ‘Pallas’ is a semi‐dwarf barley cultivar known for its culm stability and resistance to lodging. In total, eight allelic ert‐k mutants are known that show different phenotypic strength concerning culm length and spike architecture. They represent alternatives to the widely used, but pleiotropic ‘Green Revolution’ alleles of the Sdw1 (semidwarf1/denso) and Uzu1 (semi‐brachytic1) genes in breeding of robust elite barley cultivars. In the present study, we locate Ert‐k to a 15.7‐cM region in the centromeric region of chromosome 6H. Although the interval is estimated to contain approximately 700 genes, the work provides a solid foundation for the identification of the underlying mutations causing the ert‐k lodging‐resistant phenotype. In addition, the linked markers could be used to follow the ert‐k mutant genotype in marker‐assisted selection of new lodging‐resistant barley cultivars.     

Hemostatic response to surgical neutering via ovariectomy and ovariohysterectomy in dogs

Objective-To investigate the hemostatic response to surgery and compare the response for ovariohysterectomy with that for ovariectomy and to evaluate the usefulness of thromboelastography on plasma samples. Animals-42 female dogs. Procedures-Dogs were assigned to undergo ovariohysterectomy or ovariectomy. Blood samples were collected immediately before and 1, 6, and 24 hours after surgery and stored at -80°C for subsequent analysis. Plasma samples were subjected to thromboelastography after thawing. In addition, coagulation variables were measured, including concentrations of von Willebrand factor antigen, fibrinogen, antithrombin, and protein C; activity of factor VIII; activated partial thromboplastin time; prothrombin time; and thrombin time. The fibrinolytic response was assessed via concentrations of D-dimer, plasminogen, and α-2-antiplasmin (plasmin inhibitor). Results-Substantial hemostatic and fibrinolytic activation was evident after surgery in both groups, as characterized by significantly increased global clot strength and an overall hypercoagulable state at 4 hours after surgery in addition to decreases in von Willebrand factor antigen and factor VIII concentrations and shortened prothrombin and thrombin times. The dogs also typically had activation of the fibrinolytic system, as evidenced by increased postoperative concentrations of D-dimer, plasminogen, and plasmin inhibitor. Differences between the 2 groups could not be detected for any variables. Conclusions and Clinical Relevance-Elective surgery with limited tissue trauma induced hemostatic activation in dogs, which led to hypercoagulability after surgery. A difference between the ovariohysterectomy and ovariectomy groups was not detected. Thromboelastography can be used on plasma samples and may be useful for evaluating patterns over time.     

Reduced Acid Deposition Leads to a New Start for Brown Trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>) in an Acidified Lake in Southern Norway

Acid deposition has led to acidification and loss of fish populations in thousands of lakes and streams in Norway. Since the peak in the late 1970s, acid deposition has been greatly reduced and acidified surface waters have shown chemical recovery. Biological recovery, in particular fish populations, however, has lagged behind. Long-term monitoring of water chemistry and fish populations in Lake Langtjern, south-eastern Norway, shows that around 2008, chemical recovery had progressed to the point at which natural reproduction of brown trout (Salmo trutta) reoccurred. The stocked brown trout reproduced in the period 2008–2014, probably for the first time since the 1960s, but reproduction and/or early life stage survival was very low. The results indicate that chemical thresholds for reproduction in this lake are approximately pH?=?5.1, Al_i?=?26 μg l^?1, ANC?=?47 μeq l^?1, and ANC_oaa?=?10 μeq l^?1 as annual mean values. These thresholds agree largely with the few other cases of documented recovery of brown trout in sites in Norway, Sweden, and the UK. Occurrence and duration of acidic episodes have decreased considerably since the 1980s but still occur and probably limit reproduction success.     

Detection of Antiplatelet Antibody With a Platelet Immunofluorescence Assay

An indirect platelet immunofluorescence assay (PIFA) was developed for detection of circulating antiplatelet antibody in dogs with suspected immune-mediated thrombocytopenia (ITP). The PIFA was performed on 10 healthy dogs with normal platelet counts; 76 thrombocytopenic dogs, 20 of which were suspected of having ITP; and 18 dogs with other diseases and normal platelet counts. All normal dogs had negative test results. Fourteen (70%) of 20 dogs suspected of having ITP had positive test results. Fifteen of the remaining 56 thrombocytopenic dogs had positive test results, 9 had cancer and 6 had other immune-mediated diseases including systemic lupus erythematosus (SLE). In this study, the PIFA assay seemed to be more sensitive (70%) than the megakaryocyte immunofluorescence assay (41 %) in the diagnosis of ITP. Of the 9 PIFA-positive dogs with neoplasia, 6 had lymphoproliferative disorders. The PI FA was positive in 5 of 18 diseased dogs with normal platelet counts. There was an inverse relationship between the platelet count and the intensity of fluorescence in the PIFA-positive dogs. We conclude that the PIFA is a sensitive screening method for detecting circulating antiplatelet antibody.     

Diagnostic importance of urothelial cells of the dog and cat

The cells lining the canine and feline urinary tract and their role in the diagnosis of urological diseases in small animals is assessed. The urothelium was found to consist of transitional epithelial cells ranging from the calyces to the urethra. Caudate cells were found lining the ureter, renal pelvis and the calyces. There was no feature that could be used to distinguish the transitional cells from different parts of the urothelium. Squamous cells were found lining the urinary tract from the trigone to the vagina in females and to the urethra in male animals. Hydropic degeneration in the form of vacuolation of the cytoplasm, granulation and total loss of cytoplasm was one of the urine-induced degenerative changes recorded in the transitional cells. The significance of the degenerative changes in the management of urological problems is discussed.     

Decreased plasma concentration of nitric oxide metabolites in dogs with untreated mitral regurgitation

Endothelium-dependent (nitric oxide [NO]-mediated) vasodilation is impaired in humans with heart failure. This dysfunction is an important therapeutic target. The plasma concentration of the NO metabolites nitrate and nitrite (collectively referred to as NOx) is a measure of whole-body NO production, provided that the dietary intake of the ions is low. Fifty clinically healthy dogs older than I year (median 5.0 years; interquartile interval 2.6-8.2 years) were studied, including 9 controls of various breeds, 23 Cavalier King Charles Spaniels (CKCSs) with no or minimal mitral regurgitation (MR), 9 CKCSs with mild MR (regurgitant jet occupying 15-50% of the left atrial area), and 9 CKCS with moderate to severe MR (jet >50%) due to myxomatous valve disease. None of the dogs received medication. The dogs were given NOx-free water and a diet with a low concentration of NOx for 96 hours before blood sampling. Multiple linear regression analysis revealed that dog group, but not gender, age, serum creatinine concentration, and platelet count, was associated with NOx concentrations. Control dogs had the same NOx concentration (median 20.0 microM; interquartile interval 15.1-25.5 microM) as CKCSs without MR (median 18.7 microM; interquartile interval 15.5-25.9 microM). Compared to CKCSs without MR, the NOx concentration was lower in CKCSs with mild (median 12.9 microM; interquartile interval 11.0-13.5 microM; P = .04) and moderate to severe (median 11.2 microM; interquartile interval 6.9-17.1 microM; P = .02) MR. In conclusion, CKCSs with mild to severe, clinically silent MR have decreased plasma NOx concentrations, suggesting that endothelial dysfunction develops early in the course of developing MR in dogs.     

Increased platelet aggregation response in Cavalier King Charles Spaniels with mitral valve prolapse

Mitral valve prolapse (MVP) is a fundamental feature of myxomatous mitral valve disease in the dog. In humans, primary MVP is associated with increased platelet reactivity. In Cavalier King Charles Spaniels (CKCS), a breed predisposed to myxomatous mitral valve disease, there is a high prevalence of hypomagnesemia and platelet anomalies, such as thrombocytopenia and macrothrombocytosis. The objective of this study was to evaluate platelet aggregation responses in CKCS and to determine the relationship between the platelet aggregation response and serum magnesium concentration, MVP, mitral regurgitation (MR), and platelet count. In 19 CKCS with MVP and 7 control dogs (not CKCS), the platelet aggregation response to 3 different agonists was compared. The CKCS with >100,000 platelets/microL (n = 10) had a significantly higher maximum aggregation response with regard to all tested agonists than the CKCS with <100,000 platelets/microL (n = 9) and control dogs (n = 7). The CKCS with <100,000 platelets/microL had a platelet aggregation response similar to the control dogs. There was no correlation between degree of MVP and platelet aggregation response. Platelet diameter increased (P = .006) and serum magnesium concentration decreased (P = .04) with lower platelet concentration. In conclusion, CKCS with MVP appeared to separate into 2 groups--1 group with <100,000 platelets/microL, normal platelet aggregation, low serum magnesium concentration, and enlarged platelets, and another group with >100,000 platelets/microL, increased platelet aggregation, and normal serum magnesium concentration and platelet size.