Evaluation of thromboelastography in bitches with pyometra

Pyometra in Small Animals 3.0

Pyometra is a common disease in intact bitches and queens and occurs, although less frequently, in most other female pets. In bitches and queens, the illness is generally diagnosed within 4 months after estrus, in middle-aged to older individuals. Complications such as peritonitis, endotoxemia, and systemic inflammatory response syndrome are not uncommon and associated with more severe illness. Ovary-sparing surgical options such as hysterectomy could be considered in individuals with high-risk for detrimental side effects of spaying or without infection of the uterus but has not yet been evaluated for safety in pyometra.

Comparison of assessment of coagulation in healthy dogs by the TEG 6s and TEG 5000 viscoelastic analyzers

The TEG 6s (Haemonetics) point-of-care viscoelastic analyzer is portable, compact, simple to use, and has the potential for rapid viscoelastic analysis that can guide the treatment of veterinary patients at the site of care. Although approved for use in people, the TEG 6s has yet to be evaluated for hemostatic analysis in veterinary medicine. Citrated whole blood (CWB) was collected from 27 healthy dogs. An aliquot of CWB from each dog was diluted by 33% with an isotonic crystalloid, representing an in vitro model of hemodilution. Unaltered and diluted CWB samples were analyzed using 2 TEG 6s and 6 TEG 5000 (Haemonetics) analyzers. The 6 TEG 5000 analyzers ran duplicate analyses of either unaltered or diluted samples using 1 of 3 reagents (Haemonetics): Kaolin TEG, RapidTEG, or TEG Functional Fibrinogen. Duplicate TEG 5000 analyses were averaged and compared with a single TEG 6s analysis. Lin concordance correlation coefficient and Bland-Altman plots were used to evaluate agreement of reaction time, kinetic time, alpha angle, maximum amplitude (MA), and G value (G) for samples activated with Kaolin TEG, and agreement of MA for samples activated with RapidTEG between the 2 machines. Overall, agreement between the TEG 6s and TEG 5000 analyzers was poor. Viscoelastic measurements by the TEG 6s and TEG 5000 in healthy dogs were not all interchangeable. Agreement was satisfactory only for MA and G measurements of diluted blood samples activated with Kaolin TEG, and MA measurements for both unaltered and diluted blood samples activated with RapidTEG.

Surgery in a veterinary outpatient community medicine setting has a good outcome for dogs with pyometra

OBJECTIVE

To compare the outcome of canine pyometra surgeries performed at referral hospitals with those performed at community clinics (outpatient settings), and to evaluate factors that impact outcome.

ANIMALS

133 client-owned dogs with pyometra treated with ovariohysterectomy (OHE) at 2 community clinics or 2 referral hospitals between July 1, 2017, and June 30, 2019.

PROCEDURES

A retrospective electronic medical record search was used to identify eligible cases. Data about patient demographics and clinical characteristics were collected and analyzed for factors that could have impacted outcome.

RESULTS

Eighty-three dogs were treated at referral hospitals; 50 dogs were treated at community clinics. Survival to hospital discharge for all dogs was 97% (129/133) and did not differ between treatment facility type. Dogs treated at both types of facilities were similar in age, body weight, and clinical signs. Median duration between diagnosis and OHE was significantly shorter for dogs treated at referral hospitals (0 day; range, 0 to 0.7 days) versus community clinics (1.0 day; range, 0 to 14.0 days); however, delay was not related to survival to hospital discharge. Duration of hospitalization did not impact survival to hospital discharge nor survival for at least 1 week after surgery.

CLINICAL RELEVANCE

Results indicated that OHE for pyometra in dogs has a good outcome and that, although prompt surgical treatment remains a goal, in cases where limitations to performing surgery exist, a delay until surgery or discharging patients the same day is still associated with a high degree of success.

Presence of nucleosomes in plasma and increased thrombin generation in dogs with acute and chronic gastroenteropathies

Neutrophil extracellular traps (NETs) which contain nucleosomes protect the host by eliminating extracellular pathogens. However, any inflammatory stimuli can activate NETs and eventually lead to an immune overreaction leading to autoimmune diseases and thrombosis. Acute/chronic gastroenteropathies(aGE/cGE) are prevalent in dogs, and are associated with a strong inflammatory component. The aim of this study was to investigate if dogs with aGE and cGE have increased concentrations of nucleosomes indicative of NETs formation, and whether increased concentrations of nucleosomes are associated with hypercoagulability determined by increased thrombin generation. Twenty-six dogs were enrolled. The dogs were healthy (n = 11), or presented with aGE(n = 7) or cGE(n = 8). Minimum database including CRP, APTT, PT and fibrinogen, was obtained from all dogs. Citrated plasma was batched and used for subsequent analyses. Nucleosome concentration was analysed using a Cell-Death Detection ELISA-kit and thrombin generation by a calibrated automated thrombogram assay. No statistical differences in nucleosome concentrations were present between the groups. Although a numerically increased concentration of nucleosomes where seen in dogs with aGE(median;range) (0.019 AU;0.003-0.088) and cGE(0.023 AU;0.011-0.256) compared to controls(0.007 AU;0.003-0.042). One dog with GI-lymphoma demonstrated a markedly increased concentration of nucleosomes (0.256 AU). Dogs with aGE showed increased thrombin generation by increased peak (p = 0.03) and endogenous thrombin potential (p = 0.03); and increased CRP (p = 0.001), fibrinogen (p = 0.0002) and prolonged APTT (p = 0.03) compared to controls. This proof of concept study demonstrates that dogs with aGE and cGE have presence of nucleosomes with marked increase in one dog with GI-lymphoma. Nucleosomes might be linked to haemostatic alterations in dogs with inflammatory and neoplastic diseases.

Hemostatic function in Cavalier King Charles Spaniels assessed using thromboelastography

BACKGROUND

Macrothrombocytopenia is a well-known anomaly in Cavalier King Charles Spaniels (CKCSs), a breed also highly predisposed to develop myxomatous mitral valve disease (MMVD). Thromboelastography (TEG) has been shown to be a valuable instrument for whole blood hemostatic evaluation in dogs and correlates well with different physiologic and pathologic situations.

OBJECTIVES

We aimed to assess the influence of macrothrombocytopenia and the severity of MMVD on hemostatic function as measured by TEG.

METHODS

Associations between TEG variables (R, K, α, MA, and G) and dog characteristics, heart rates, systolic blood pressures, MMVD severities (healthy, mild or moderate, and severe), echocardiographic variables, platelet variables (platelet count, mean platelet volume [MPV], and plateletcrit), and hematocrits were evaluated in 47 prospectively recruited privately owned CKCSs. Blood samples were analyzed using a computerized thromboelastograph and an Advia 2120 hematology analyzer.

RESULTS

Univariable and multiple regression analyses showed an effect of left ventricular (LV) fractional shortening (FS%) on all TEG variables, an effect of LV FS% and age on TEG α, and an effect of LV FS% and MPV on TEG MA and TEG G. TEG MA and G increased with increasing MPV, but the associations were generally weak. No significant differences were detected in the TEG variables between the MMVD severity groups.

CONCLUSION

Macrothrombocytopenia and increased LV FS%, of which the latter commonly increases in various positive inotropic states, were both associated with a more hypercoagulable hemostatic system, according to the TEG results, in the present study.