Pituitary ACTH and adrenocortical secretion in critically ill dogs

OBJECTIVE: To evaluate pituitary-adrenal function in a population of critically ill dogs by measuring serial plasma concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH. DESIGN: Prospective study. ANIMALS: 20 critically ill dogs admitted to an intensive care unit (ICU). PROCEDURE: Basal plasma cortisol, ACTH-stimulated cortisol, and endogenous ACTH concentrations were measured for each dog within 24 hours of admission and daily until death, euthanasia, or discharge from the ICU. Established reference ranges for healthy dogs were used for comparison. Survival prediction index (SPI) scores were calculated for each dog within 24 hours of admission. RESULTS: No significant difference was found between initial concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH in 13 dogs that survived and those in 7 dogs that died. High initial basal endogenous ACTH concentrations were correlated with subsequent high values. Low basal ACTH-stimulated cortisol concentrations were predictive of higher subsequent values. All basal and ACTH-stimulated cortisol concentrations were within or above the reference range in the 52 plasma samples collected from the 20 dogs during hospitalization. The SPI scores correlated with outcome (ie, alive or dead), but none of the plasma hormone concentrations correlated with SPI score or outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that none of the critically ill dogs in our study population developed adrenal insufficiency during hospitalization in the ICU.     

Incidence and clinical relevance of hyperglycemia in critically ill dogs

BACKGROUND: Hyperglycemia associated with critical illness in nondiabetic human patients is a common occurrence in the intensive care unit (ICU), with a reported incidence as high as 71%. HYPOTHESIS: Hyperglycemia in critically ill dogs increases the risk of morbidity and mortality. ANIMALS: Two hundred forty-five dogs hospitalized in the ICU over a 2-month period were evaluated. METHODS: Prospective observational study was conducted over a 2-month period. All dogs in the ICU had their highest daily blood glucose concentration recorded. All dogs with diabetes were excluded from the study. Hyperglycemia was defined as a blood glucose concentration >120 mg/dL. Dogs with hyperglycemia were monitored for persistence and resolution of hyperglycemia. RESULTS: During the study period, 245 dogs were evaluated, of which 38 (16%) were hyperglycemic. Twenty-six percent (10/ 38) developed hyperglycemia during hospitalization, whereas 74% (28/38) were hyperglycemic at presentation. Length of hospitalization (LOH) was shorter in dogs that presented with hyperglycemia compared with those that developed hyperglycemia during hospitalization (P = .001). Seventy-one percent (27/38) of dogs were discharged from the hospital, whereas the remaining 29% (11/38) died or were euthanatized. Nonsurvivors had significantly higher median glucose concentration (median, 176 mg/dL; range 122-310 mg/dL) than did survivors (median, 139 mg/dL; 121-191 mg/dL; P = .021). CONCLUSIONS AND CLINICAL IMPORTANCE: The incidence of hyperglycemia in this population of dogs was 16%. Dogs that developed hyperglycemia had longer LOH and nonsurvivors had more pronounced hyperglycemia than did survivors.     

Prior joint disease is associated with increased risk of periarticular histiocytic sarcoma in dogs

Periarticular histiocytic sarcoma (PAHS) is the most common synovial tumour in dogs and is characterized by aggressive local disease with a high rate of distant metastasis. Previously, an association between PAHS and prior joint disease has been demonstrated in the Bernese Mountain Dog breed and suggested in the Rottweiler. We hypothesized that this association would be present in other breeds and investigated this via a retrospective, case‐controlled analysis. Cases were dogs diagnosed with PAHS of the stifle or elbow. Controls were age, breed and sex‐matched dogs without a diagnosis of histiocytic sarcoma. Diagnosis of prior joint disease was determined based on review of medical records and direct veterinarian and owner communications. Data were evaluated using logistic regression, 2‐sampled t tests, and chi‐squared analysis. Our study population consisted of 28 cases and 46 controls, including Flat‐Coated, Golden and Labrador Retrievers, Rottweilers, English Bulldogs, Shih Tzus, Australian Shepherds, Staffordshire Terriers and mixed breed dogs. Dogs with PAHS were more likely to have prior joint disease in the tumour‐affected joint compared with the control population (odds ratio [OR] = 13.42, P < .0001, 95% confidence interval [CI] = 4.33‐48.63). A total of 88.2% of dogs with stifle PAHS had prior joint disease in their tumour‐affected joint, most commonly cranial cruciate ligament rupture. This study confirms that the previously noted association between prior joint disease and PAHS in Bernese Mountain Dogs also applies to other breeds. Additional studies are needed to further investigate for a causal relationship.     

Serum antibodies against human albumin in critically ill and healthy dogs

OBJECTIVE: To characterize the magnitude and duration of the antibody response against human albumin (HA) in critically ill and healthy dogs. DESIGN: Cohort and cross-sectional study. ANIMALS: Fourteen critically ill dogs that received 25% HA as part of their treatment protocol, 2 healthy dogs with no known previous exposure to HA that received 2 infusions of 25% HA (positive control dogs), and 47 healthy dogs and 21 critically ill dogs with no known exposure to HA (negative control dogs). PROCEDURES: An ELISA to detect IgG against HA was developed. Serum samples were obtained from the critically ill dogs prior to infusion of HA, at the time of hospital discharge, and 4 to 6 weeks and 6 months after HA administration. Serum samples were obtained at 2- to 4-week intervals from both positive control dogs for 101 weeks. A single serum sample was obtained from each of the negative control dogs. RESULTS: All 14 critically ill dogs developed serum IgG against HA. Peak antibody response was detected 4 to 6 weeks after HA administration. In both positive control dogs, IgG against HA was detected 10 days after HA administration and continued past 97 weeks. The peak antibody response was detected at 3 weeks in 1 dog and at 9 weeks in the other. Five of the 68 (7%) negative control dogs had a positive antibody response. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that dogs developed a pronounced IgG response following exposure to HA and that some dogs with no history of HA administration were positive for anti-HA IgG.     

Descending thoracic aortic blood flow parameters during emergent surgery in anesthetized critically ill dogs

Objective: To explore the potential value of transesophageally‐determined descending thoracic aortic blood flow parameters in critically ill dogs undergoing surgery. Design: Observational case series. Setting: Private small animal referral hospital. Animals: Ten anesthetized critically ill dogs that underwent emergent surgery. Interventions: Placement of the ultrasonic transesophageal probe. Measurements and main results: Transesophageally‐determined descending thoracic aortic blood flow, stroke volume, blood velocity, blood acceleration, left ventricular ejection time interval, and heart rate parameters were recorded every minute. Systolic and mean arterial blood pressures were non‐invasively determined and recorded at 1–5 minute intervals. The anesthetist and surgeon were blinded to the descending thoracic aortic blood flow parameters. All dogs received fluid challenges as part of their management, and 2 dogs received dopamine. The variability of the descending thoracic aortic blood flow parameters within each dog was greater than has been reported in non‐critically ill anesthetized dogs. Consistent trends in descending thoracic aortic blood flow parameters after fluid challenges were not found. An escalating dopamine infusion was, however, accompanied by increasing aortic blood flow, stroke volume, acceleration, and peak velocity. Conclusions: Descending thoracic aortic blood flow parameters may eventually be useful for evaluating the responses to and suggesting the need for cardiovascular interventions during emergent surgeries in anesthetized critically ill canine patients. For this to occur, more experience with this technology will be required.