Anticoagulant effects of low-molecular-weight heparins in healthy cats.

BACKGROUND: Low-molecular-weight heparin (LMWH) has potential benefit in cats at risk for thromboembolic disease. However, LMWH pharmacokinetics has not been characterized in the cat. Drug effect with LMWH may be evaluated with analysis of factor Xa inhibition (anti-Xa) or thromboelastography (TEG). HYPOTHESIS: Administration of LMWH at previously recommended dosages and schedules to healthy cats will result in inhibition of factor Xa and hypocoagulable TEG. ANIMALS: In vivo research with heparin was performed in 5 purpose-bred cats. METHODS: In a prospective study with randomized crossover design, heparin or placebo was administered. Treatments were unfractionated heparin (UFH), 250 IU/kg q6h; dalteparin, 100 IU/kg q12h; enoxaparin, 1 mg/kg q12h; or 0.9% saline, 0.25 mL/kg q6h. Each drug was administered for 5 consecutive days followed by a minimum washout of 14 days. Baseline and post-treatment analyses included anti-Xa, TEG, and prothrombin time/activated partial thromboplastin time. RESULTS: Mean anti-Xa activity 4 hours after enoxaparin (0.48 U/mL) approached the human therapeutic target (0.5-1.0 U/mL); however, mean trough anti-Xa activity was below detection limits. Mean anti-Xa activity 4 hours after dalteparin was lower, and only 1 cat attained therapeutic target at a single time point. Cats receiving UFH attained target anti-Xa activity and changes in TEG at trough and 4 hours. CONCLUSIONS: Cats have rapid absorption and elimination kinetics with LMWH therapy. On the basis of pharmacokinetic modeling, cats will require higher dosages and more frequent administration of LMWH to achieve human therapeutic anti-factor Xa activity of 0.5-1 U/mL. Peak anti-Xa activity is predicted at 2 hours after administration of LMWH.

Deployment morbidity among search-and-rescue dogs used after the September 11, 2001, terrorist attacks.

OBJECTIVES: To determine characteristics, variables associated with deployment morbidity, and injuries and illnesses of search-and-rescue dogs associated with the Sept 11, 2001, terrorist attacks. DESIGN: Historical cohort study. ANIMALS: 96 dogs. PROCEDURE: Data collected included previous medical or surgical history, physical attributes of dogs, type and number of years of training, site of deployment, shift and hours worked, and number of days deployed. Combined morbidity was defined as 1 or more abnormalities of body systems, including traumatic injuries. RESULTS: Handlers of 96 of the 212 dogs responded to the surveys. Fifty-nine dogs were deployed by the Federal Emergency Management Agency, 10 by police forces, and 27 as members of other search-and-rescue teams. Sixty-five dogs (incidence rate, 17 events/1,000 dog search hours) had combined morbidity during deployment. System-specific morbidity rates included gastrointestinal tract signs (5 events/1,000 dog search hours), cuts and abrasions mostly on the feet (5 events/1,000 dog search hours), fatigue (6 events/1,000 dog search hours), change in appetite (6 events/1,000 dogs search hours), dehydration (5 events/1,000 dog search hours), respiratory tract problems (2 events/1,000 dog search hours), heat exhaustion (2 events/1,000 dog search hours), and orthopedic or back problems (2 events/1,000 dog search hours). Dogs deployed to the World Trade Center were 6.6 times more likely to have combined morbidity, compared with dogs at the Pentagon. CONCLUSIONS AND CLINICAL RELEVANCE: Injury and illnesses occurred in most dogs and affected several organ systems, but all were minor.

Acute severe hemorrhage secondary to arterial invasion in a dog with thyroid carcinoma.

A 7-year-old spayed female Labrador Retriever was referred because of progressive swelling and bruising of the neck, hemothorax, a possible mediastinal mass, and stridor. At the time of admission, the dog was recumbent, mentally dull, tachycardic, and hypothermic. Fluid therapy with hydroxyethyl starch and a balanced electrolyte solution was administered because of presumed hypovolemic shock secondary to hemorrhage; multiple units of packed RBCs and fresh frozen plasma were also administered. On the basis of the computed tomographic images, extensive subcutaneous, subfascial, and cranial mediastinal hemorrhage; hemothorax; prescapular lymphadenopathy; and a contrast-enhancing mass in the left cranioventral aspect of the neck were diagnosed. Exploratory surgery of the neck was performed. All subcutaneous structures were encased in a large blood clot. During dissection of the clot, pulsatile bleeding was observed just caudal to and to the left of the larynx; ligation of the left common carotid artery resulted in immediate cessation of the pulsatile bleeding. Further surgical exploration revealed a 2.5 x 2.5-cm mass adhered to the left common carotid artery at the level of the branching to the left cranial thyroid artery. The mass was removed; the histologic diagnosis was thyroid carcinoma. Three weeks after surgery, treatment with a combination of radiation and chemotherapy (doxorubicin and carboplatin) was begun. Thirteen months after surgery, the dog continued to be free from clinical signs of disease.