Isoniazid toxicosis in dogs: 137 cases (2004-2014).

OBJECTIVE To establish the minimum toxic dose of isoniazid in dogs, characterize the clinical signs and outcomes for dogs following isoniazid ingestion, and determine whether IV administration of pyridoxine to dogs with isoniazid toxicosis is protective against death. DESIGN Retrospective case series. ANIMALS 137 dogs with isoniazid toxicosis. PROCEDURES The electronic database of the American Society for the Prevention of Cruelty to Animals Animal Poison Control Center was reviewed from January 2004 through December 2014 to identify dogs with isoniazid toxicosis. For each dog identified, information extracted from the medical record included signalment, estimated dose of isoniazid ingested, clinical signs, treatment, and outcome. Follow-up communication with pet owners or primary care veterinarians was performed when necessary to obtain missing information. RESULTS Clinical signs of isoniazid toxicosis were observed in 134 of 137 (98%) dogs and included seizures (n = 104), CNS signs without seizures (94), and gastrointestinal (41), cardiovascular (19), urogenital (4), and respiratory (1) abnormalities. Of the 87 dogs for which the outcome was available, 61 survived, 18 died, and 8 were euthanized. Probability of survival was positively associated with body weight and IV administration of pyridoxine and negatively associated with dose of isoniazid ingested and presence of seizures. Dogs that received pyridoxine IV were 29 times as likely to survive as dogs that did not receive pyridoxine IV. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated rapid diagnosis of isoniazid toxicosis and prompt treatment of affected dogs with pyridoxine and other supportive care were imperative for achieving a successful outcome.

Retrospective evaluation of coyote attacks in dogs: 154 cases (1997-2012).

OBJECTIVE: To describe the clinical presentation and outcome of known attacks in client-owned dogs caused by the common coyote, Canis latrans. DESIGN: Retrospective observational study. SETTING: Private referral hospital. ANIMALS: One hundred fifty-four client-owned dogs known to be attacked by coyotes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Records from a private referral hospital from May 1997 through December 2012 were reviewed. Time of day and month/season of year, signalment, body temperature, heart rate, respiratory rate, body weight, location and severity of wounds inflicted, common injuries, length of hospitalization, necessity of surgical wound repair under anesthesia, antimicrobial use and mortality were recorded. Eighty-six percent of dogs presenting following coyote attack weighed <10 kg. Overall mortality rate was 15.6%. Dogs with bite wounds to the thorax had the highest mortality at 21.3%. Criteria for systemic inflammatory response syndrome (SIRS) based on admission vital signs were met in 58.8% of dogs and the presence of SIRS was significantly associated with mortality (P < 0.001). Common coyote-induced injuries included rib fracture (38/154; 24.6%), pulmonary contusion (30/154; 19.4%), tracheal tear (18/154; 11.6%), pneumothorax (16/154; 10.3%), abdominal wall hernia (9/154; 5.8%), and abdominal penetrating wounds (8/146; 5.5%). Dogs <10 kg were significantly more likely to incur wounds to multiple body parts or sustain abdominal penetrating wounds. The presence of rib fracture was significantly associated with mortality. Frequency of coyote attacks over the time of this study increased by 330%. CONCLUSIONS: Coyote attacks on dogs are a problem in Southern California and are associated with substantial morbidity and mortality, especially in dogs with wounds to the thorax. Aggressive management involving surgical wound repair was associated with survival to discharge.

Type III hypersensitivity reaction with immune complex deposition in 2 critically ill dogs administered human serum albumin.

OBJECTIVE: To describe 2 cases of vasculitis that were attributed to a type III hypersensitivity reaction in critically ill dogs occurring 8-16 days postadministration of human serum albumin (HSA). CASE OR SERIES SUMMARY: Skin biopsies were obtained from 3 different sites in 2 critically ill dogs that developed vasculitis 8-16 days following treatment with HSA. Histopathological findings from both dogs indicated epidermal pallor, widespread edema and hemorrhage, degenerative neutrophilic perivascular infiltrates, and multifocal areas of neutrophilic or leukocytoclastic vasculitis. Immunohistochemical staining using an anti-human serum albumin rabbit antibody suggested that the antigen-antibody complexes seen in the dermis were associated with the administration of HSA. NEW OR UNIQUE INFORMATION PROVIDED: In this case series, we documented a leukocytoclastic vasculitis and probable antigen-antibody complexes to human albumin in the dermis of 2 critically ill dogs after administration of HSA. Previously, type III hypersensitivity reactions had only been reported in healthy dogs that had received HSA. This report also describes the potential use of immunohistochemical staining to detect the HSA antigen in tissue sections through the use of specifically labeled antibodies.

Therapeutic percutaneous ultrasound-guided cholecystocentesis in three dogs with extrahepatic biliary obstruction and pancreatitis.

Three dogs were examined because of acute pancreatitis. In all 3, distension of the gallbladder was seen ultrasonographically, and extrahepatic biliary tract obstruction (EHBO) was diagnosed on the basis of ultrasonographic findings and serum biochemical abnormalities (i.e., high serum bilirubin and cholesterol concentrations and increased hepatic enzyme activities). In all 3 dogs, percutaneous ultrasound-guided cholecystocentesis (PUCC) was used to decompress the gallbladder, with cholecystocentesis performed multiple times in 1 dog. Serum bilirubin concentration was substantially decreased following the procedure in all 3 dogs. Two of the 3 dogs did not require surgery to resolve the obstruction. In the third dog, an exploratory laparotomy was performed because of concerns about development of abdominal effusion following the procedure. Bile staining of the mesenteric fat was seen during the laparotomy, but no defect in the gallbladder wall could be identified. In most dogs with EHBO secondary to pancreatitis, the obstruction resolves spontaneously as the acute pancreatitis improves so that surgery is not required. In those few dogs in which EHBO does not resolve or in which EHBO results in complications, therapeutic PUCC may be useful in relieving gallbladder distension.