Long-term incidence and risk of noncardiovascular and all-cause mortality in apparently healthy cats and cats with preclinical hypertrophic cardiomyopathy.

BACKGROUND: Epidemiologic knowledge regarding noncardiovascular and all-cause mortality in apparently healthy cats (AH) and cats with preclinical hypertrophic cardiomyopathy (pHCM) is limited, hindering development of evidence-based healthcare guidelines. OBJECTIVES: To characterize/compare incidence rates, risk, and survival associated with noncardiovascular and all-cause mortality in AH and pHCM cats. ANIMALS: A total of 1730 client-owned cats (722 AH, 1008 pHCM) from 21 countries. METHODS: Retrospective, multicenter, longitudinal, cohort study. Long-term health data were extracted by medical record review and owner/referring veterinarian interviews. RESULTS: Noncardiovascular death occurred in 534 (30.9%) of 1730 cats observed up to 15.2 years. Proportion of noncardiovascular death did not differ significantly between cats that at study enrollment were AH or had pHCM (P = .48). Cancer, chronic kidney disease, and conditions characterized by chronic weight-loss-vomiting-diarrhea-anorexia were the most frequently recorded noncardiovascular causes of death. Incidence rates/risk of noncardiac death increased with age in AH and pHCM. All-cause death proportions were greater in pHCM than AH (65% versus 40%, respectively; P < .001) because of higher cardiovascular mortality in pHCM cats. Comparing AH with pHCM, median survival (study entry to noncardiovascular death) did not differ (AH, 9.8 years; pHCM, 8.6 years; P = .10), but all-cause survival was significantly shorter in pHCM (P = .0001). CONCLUSIONS AND CLINICAL IMPORTANCE: All-cause mortality was significantly greater in pHCM cats due to disease burden contributed by increased cardiovascular death superimposed upon noncardiovascular death.

Comparison of metabolomics and platelet aggregometry between Plavix and generic clopidogrel in cats: a pilot study.

OBJECTIVES: This pilot study sought to assess the metabolism of Plavix (Bristol-Myers Squibb/Sanofi) and generic clopidogrel in cats, using a novel assay for the measurement of clopidogrel, clopidogrel carboxylic acid (CCA) and clopidogrel active metabolite (CAM-D). METHODS: This was a prospective, randomized, double-blind study. Four healthy, skeletally mature cats were enrolled into the study. There were two treatment phases during which cats received either Plavix or generic clopidogrel at a dosage of 18.75 mg PO q24h for 7 days with a 2 week washout between phases. During each phase, plasma concentrations of parent drug and active and inactive metabolites were measured along with impedance platelet aggregometry in response to adenosine diphosphate (ADP). RESULTS: The ratio of CAM-D between generic clopidogrel and Plavix was 0.83 (equivalence reference 1.00, 90% confidence interval 0.80-1.25). Inhibition of ADP-induced platelet aggregation was variable, with two cats classified as non-responders in both treatment phases. The concentrations of CAM-D were not predictive of aggregometry-based responsiveness to either formulation of clopidogrel. CONCLUSIONS AND RELEVANCE: This is the first study comparing Plavix and generic clopidogrel in cats. Administration of the generic formulation resulted in comparable plasma concentrations of clopidogrel active metabolite when compared with Plavix.

In vitro effects of the glycoprotein IIb/IIIa receptor antagonists abciximab and eptifibatide on platelet aggregation in healthy cats.

OBJECTIVE: To determine effects of the glycoprotein IIb/IIIa receptor antagonists abciximab and eptifibatide on in vitro inhibition of cat platelets. SAMPLE: Venous blood samples from 10 healthy cats. PROCEDURES: Blood samples were anticoagulated with hirudin. Aliquots of whole blood from each cat were allocated to 5 treatments (baseline, 50 µg of abciximab/mL, abciximab volumetric control treatment, 4 µM eptifibatide, and eptifibatide volumetric control treatment). Impedance platelet aggregometry was performed with 6.5 µM ADP or 32 µM thrombin receptor activator peptide (TRAP). Magnitude of platelet aggregation was determined by measuring the area under the curve 15 minutes after addition of ADP or TRAP. RESULTS: Eptifibatide caused a significant reduction in platelet aggregation, compared with baseline values, for aggregometry with both ADP (median, 50.0; range, 8 to 122 [baseline median, 306.0; baseline range, 130 to 664]) and TRAP (median, 75.5; range, 3 to 148 [baseline median, 219.0; baseline range, 97 to 578]). There was no significant difference in platelet aggregation with abciximab, the abciximab volumetric control treatment, or the eptifibatide volumetric control treatment for aggregometry with ADP or TRAP. CONCLUSIONS AND CLINICAL RELEVANCE: Eptifibatide caused a significant reduction in platelet aggregation in vitro, but there was no identifiable antiplatelet effect for abciximab. Eptifibatide and abciximab have different binding and inhibitory actions; therefore, it can be hypothesized that abciximab would be ineffective in cats because of a lack of receptor binding, reduced binding kinetics, or lack of downstream signaling. Eptifibatide may be useful in identifying hyperreactive platelets in cats in an in vitro platelet inhibitory assay.

Identification of low and high frequency ranges for heart rate variability and blood pressure variability analyses using pharmacological autonomic blockade with atropine and propranolol in swine.

Understanding autonomic nervous system functioning, which mediates behavioral and physiological responses to stress, offers great potential for assessing farm animal stress and welfare. Evaluation of heart rate variability (HRV) and blood pressure variability (BPV), using time and frequency domain analyses may provide a sensitive and reliable measure of affective states and stress-mediated changes in sympathetic and parasympathetic tones. The aim of this research was to define low (LF) and high frequency (HF) power spectral ranges using pharmacological autonomic blockade, and to examine HRV and BPV parameter changes in response to atropine and propranolol in swine. Ten, 13-week old, barrows (n=6) and gilts (n=4) underwent surgery to place an intra-cardiac electrode and a blood pressure catheter attached to a biotelemetric transmitter; pigs had a 3-week recovery period prior to data collection. Each pig was subjected to administration of 4 intravenous (i.v.) drug treatments: a control treatment, 3 mL of saline, and 3 blockade treatments; 0.1 mg/kg of atropine, 1.0 mg/kg of propranolol, and .1 mg/kg of atropine together with 1.0 mg/kg of propranolol. All treatments were delivered by injection in the jugular vein with a minimum of 48 h between individual treatments. Behavior, ECG and blood pressure data were recorded continuously for a total of 1h, from 30 min pre-injection to 30 min post-injection. For data analyses, two 512-beat intervals were selected for each treatment while the pig was lying and inactive. The first interval was selected from the pre-injection period (baseline), and the second was selected between 10 and 30 min post-injection. Time and frequency domain (power spectral density) analyses were performed on each data interval. Subsequent, LF and HF bands from the power spectral densities were defined based on general linear and regression analyses. The HRV and BPV were computed with a covariate (baseline) factorial analysis of treatment by sex interaction, and day of injection, with mixed models and Tukey's post-hoc tests. The best-fit range for LF was 0.0-0.09 Hz, and HF was 0.09-2.0 Hz (r²: 0.41 and 0.43, respectively). Propranolol and saline injections led to a greater overall total power and overall higher inter-beat interval, HF and LF power. Atropine led to a dominant sympathovagal balance of the cardiac activity in pigs. In addition, atropine led to an increase in LF power of both systolic and diastolic blood pressures in gilts suggesting vagal tone mediation of BPV. The understanding of autonomic regulation of HRV and BPV in domestic swine facilitates our ability to detect and quantify stress responses, and broadens its application in assessing farm animal welfare.

Treatment of acute epistaxis secondary to guttural pouch mycosis with transarterial nitinol vascular occlusion plugs in three equids.

CASE DESCRIPTION: 2 horses and 1 pony were evaluated for right-sided (1 horse and the pony) and left-sided (1 horse) acute epistaxis of 1 day's to 1 month's duration. CLINICAL FINDINGS: Endoscopic examination of the 3 equids revealed that the hemorrhage originated from the right maxillary artery in 2 equids and from the left internal carotid artery in the third. Mycosis of the auditory tube diverticulum (guttural pouch) was detected in all 3 equids. TREATMENT AND OUTCOME: All 3 equids underwent surgery, and transarterial nitinol intravascular plugs were placed to occlude affected blood vessels. All equids survived for a long period (ie, a minimum of 1 to 2 years) and returned to their previous use. All had complete regression of clinical signs of guttural pouch mycosis without additional medical treatment. CLINICAL RELEVANCE: The use of transarterial nitinol intravascular plugs appeared to be an effective alternative to other techniques for the treatment of epistaxis secondary to guttural pouch mycosis, including transarterial occlusion devices such as embolization coils.

Transcatheter closure of patent ductus arteriosus in a dog with a peripheral vascular occlusion device.

A 4-month-old, intact female mixed-breed dog presented to the Purdue University Veterinary Teaching Hospital for evaluation of a cardiac murmur. A large left-to-right patent ductus arteriosus (PDA) was diagnosed and interventional correction was achieved with a commercially available peripheral vascular occlusion device (VOD). The VOD is composed of a nitinol wire mesh and is similar in composition and shape to a commercially available human PDA occluder, however, it can be deployed through smaller delivery catheters and is much less expensive. The product and procedural details of the device are described.

Evaluation of antiplatelet effects of ticlopidine in cats.

OBJECTIVE: To determine whether ticlopidine exerts an antiplatelet effect, estimate the pharmacodynamics of ticlopidine, and evaluate any acute adverse effects associated with administration of ticlopidine in cats. ANIMALS: 8 domestic purpose-bred sexually intact male cats. PROCEDURE: Ticlopidine was administered orally (50 mg, q 24 h; 100 mg, q 24 h; 200 mg, q 24 h; and 250 mg, q 12 h). Each treatment period consisted of 10 days of drug administration. Platelet aggregation studies with adenosine diphosphate (ADP) and collagen and evaluation of oral mucosal bleeding times (OMBTs) were performed on days 3, 7, and 10 during each drug administration. Serotonin was measured to evaluate secretion at baseline and on day 10 for cats that received the 250-mg dosage. RESULTS: A significant reduction in platelet aggregation was detected in response to ADP on days 7 and 10 at 100 mg, on day 3 at 200 mg, and on days 3, 7, and 10 at 250 mg. A significant increase in the OMBT and decrease in serotonin release on day 10 at 250 mg was also detected; however, the cats had anorexia and vomiting at the 250-mg dosage. CONCLUSIONS AND CLINICAL RELEVANCE: Although there was a consistent antiplatelet effect at the 250-mg dosage, there was dose-dependent anorexia and vomiting that we conclude precludes the clinical usefulness of this drug in cats.