Thomas Schermerhorn

Pulmonary Thromboembolism in Cats

Pulmonary thromboembolism (PTE) is rarely diagnosed in cats, and the clinical features of the disease are not well known. PTE was diagnosed at postmortem examination in 17 cats, a prevalence of 0.06% over a 24‐year period. The age of affected cats ranged from 10 months to 18 years, although young (<4 years) and old (10 years) cats were more commonly affected than were middleaged cats. Males and females were equally affected. The majority of cats with PTE (n = 16) had concurrent disease, which was often severe. The most common diseases identified in association with PTE were neoplasia, anemia of unidentified cause, and pancreatitis. Cats with glomerulonephritis, encephalitis, pneumonia, heart disease, and hepatic lipidosis were also represented in this study. Most cats with PTE demonstrated dyspnea and respiratory distress before death or euthanasia, but PTE was not recognized ante mortem in any cat studied. In conclusion, PTE can affect cats of any age and is associated with a variety of systemic and inflammatory disorders. It is recommended that the same clinical criteria used to increase the suspicion of PTE in dogs should also be applied to cats.

Normal glucose metabolism in carnivores overlaps with diabetes pathology in non-carnivores

Carnivores, such as the dolphin and the domestic cat, have numerous adaptations that befit consumption of diets with high protein and fat content, with little carbohydrate content. Consequently, nutrient metabolism in carnivorous species differs substantially from that of non-carnivores. Important metabolic pathways known to differ between carnivores and non-carnivores are implicated in the development of diabetes and insulin resistance in non-carnivores: (1) the hepatic glucokinase (GCK) pathway is absent in healthy carnivores yet GCK deficiency may result in diabetes in rodents and humans, (2) healthy dolphins and cats are prone to periods of fasting hyperglycemia and exhibit insulin resistance, both of which are risk factors for diabetes in non-carnivores. Similarly, carnivores develop naturally occurring diseases such as hemochromatosis, fatty liver, obesity, and diabetes that have strong parallels with the same disorders in humans. Understanding how evolution, environment, diet, and domestication may play a role with nutrient metabolism in the dolphin and cat may also be relevant to human diabetes.

Feline dysautonomia in the Midwestern United States: a retrospective study of nine cases

Dysautonomia of domestic animals is pathologically characterized by chromatolytic degeneration of the neurons in the autonomic nervous ganglia that results in clinical signs related to dysfunction or failure of the sympathetic and parasympathetic nervous systems. The exact cause is unknown. It has a poor prognosis among all species reported and no definitive treatment is available currently. To date, most reported feline cases have occurred in the United Kingdom and Scandinavia. The cases reported here highlight the clinical signs, physical examination findings, and results of autonomic nervous system function testing in nine cats with dysautonomia in the US. Feline dysautonomia is uncommon in the US, but may have a regional prevalence, as is seen in dogs with most cases reported in Missouri and Kansas.

Splenectomy as an adjunctive treatment for dogs with immune-mediated hemolytic anemia: ten cases (2003-2006).

OBJECTIVEnTo describe the patient population, disease severity, and outcome in dogs with immune-mediated hemolytic anemia (IMHA) that underwent splenectomy. To compare presurgical and postsurgical data.nnnDESIGNnRetrospective case series.nnnSETTINGnEmergency clinic/referral hospital.nnnANIMALSnTen dogs diagnosed with IMHA.nnnINTERVENTIONSnSplenectomy in addition to standard medical management for IMHA.nnnMEASUREMENTSnMedical records of 10 dogs with IMHA, in which a splenectomy was performed were reviewed. The population was analyzed with regards to physical and clinicopathologic data, severity, treatment, and outcome. Outcome was defined as survival at 30 days, percentage of dogs on medications at 30 days, and number of relapses documented by 30 days. The presurgical and postsurgical PCV and transfusion requirements were documented and compared for each dog.nnnRESULTSnNine of 10 dogs survived to 30 days. Four of the 9 that survived were not on any immunosuppressive medications. There were no relapses during the 30 days. The 3-day postsplenectomy PCVs were significantly higher than presplenectomy. The number of transfusions administered postsplenectomy was significantly less than those administered presplenectomy.nnnCONCLUSIONnThe use of splenectomy may be associated with an improved outcome in dogs with IMHA.

Assessment of a point‐of‐care cardiac troponin I test to differentiate cardiac from noncardiac causes of respiratory distress in dogs

Objectives – To (1) determine a reference interval for cardiac troponin I (cTnI) using a point-of-care device in normal dogs and compare the results with those published by the manufacturer and (2) determine if cTnI differs among dogs with cardiogenic and noncardiogenic respiratory distress. n nDesign – Prospective observational study. n nSetting – Emergency and referral veterinary hospital. n nAnimals – Twenty-six clinically normal dogs and 67 dogs in respiratory distress. n nInterventions – All dogs underwent whole blood sampling for cTnI concentrations. n nMeasurements and Results – Normal dogs had a median cTnI concentration of 0.03xa0ng/mL (range 0–0.11xa0ng/mL). Thirty-six dogs were diagnosed with noncardiogenic respiratory distress with a median cTnI concentration of 0.14xa0ng/mL (range 0.01–4.31xa0ng/mL). Thirty-one dogs were diagnosed with cardiogenic respiratory distress with a median cTnI concentration of 1.74xa0ng/mL (range 0.05–17.1xa0ng/mL). n nA significant difference between cTnI concentrations in normal dogs and dogs with noncardiogenic respiratory distress was not detected. Significant differences in cTnI concentrations were found between normals versus cardiogenic and cardiogenic versus noncardiogenic respiratory distress groups. Significant differences in cTnI concentrations were identified in >10 when compared with the 1.5xa0ng/mL as the optimal “cut-off point” having a sensitivity of 78% and specificity of 51.5%. The area under the receiver operating curve was 0.72. Overall test accuracy was 65%. n nConclusions – cTnI concentrations were significantly increased in dogs with cardiogenic respiratory distress versus dogs with noncardiogenic respiratory distress and normal dogs. A significant difference between normal dogs and dogs with noncardiogenic causes of respiratory distress was detected. Although highly sensitive when cTnI concentrations exceed 1.5xa0ng/mL, the test has low specificity. Assessment of cTnI by the methodology used cannot be recommended as the sole diagnostic modality for evaluating the cause of respiratory distress in dogs.OBJECTIVESnTo (1) determine a reference interval for cardiac troponin I (cTnI) using a point-of-care device in normal dogs and compare the results with those published by the manufacturer and (2) determine if cTnI differs among dogs with cardiogenic and noncardiogenic respiratory distress.nnnDESIGNnProspective observational study.nnnSETTINGnEmergency and referral veterinary hospital.nnnANIMALSnTwenty-six clinically normal dogs and 67 dogs in respiratory distress.nnnINTERVENTIONSnAll dogs underwent whole blood sampling for cTnI concentrations.nnnMEASUREMENTS AND RESULTSnNormal dogs had a median cTnI concentration of 0.03 ng/mL (range 0-0.11 ng/mL). Thirty-six dogs were diagnosed with noncardiogenic respiratory distress with a median cTnI concentration of 0.14 ng/mL (range 0.01-4.31 ng/mL). Thirty-one dogs were diagnosed with cardiogenic respiratory distress with a median cTnI concentration of 1.74 ng/mL (range 0.05-17.1 ng/mL). A significant difference between cTnI concentrations in normal dogs and dogs with noncardiogenic respiratory distress was not detected. Significant differences in cTnI concentrations were found between normals versus cardiogenic and cardiogenic versus noncardiogenic respiratory distress groups. Significant differences in cTnI concentrations were identified in > 10 when compared with the < 5 and the 5-10 years of age groups. Receiver operating curve analysis identified cTnI concentrations > 1.5 ng/mL as the optimal cut-off point having a sensitivity of 78% and specificity of 51.5%. The area under the receiver operating curve was 0.72. Overall test accuracy was 65%.nnnCONCLUSIONSncTnI concentrations were significantly increased in dogs with cardiogenic respiratory distress versus dogs with noncardiogenic respiratory distress and normal dogs. A significant difference between normal dogs and dogs with noncardiogenic causes of respiratory distress was detected. Although highly sensitive when cTnI concentrations exceed 1.5 ng/mL, the test has low specificity. Assessment of cTnI by the methodology used cannot be recommended as the sole diagnostic modality for evaluating the cause of respiratory distress in dogs.

The effect of differing Audience Response System question types on student attention in the veterinary medical classroom.

The purpose of this study was to evaluate the ability of specific types of multiple-choice questions delivered using an Audience Response System (ARS) to maintain student attention in a professional educational setting. Veterinary students (N=324) enrolled in the first three years of the professional curriculum were presented with four different ARS question types (knowledge base, discussion, polling, and psychological investment) and no ARS questions (control) during five lectures presented by 10 instructors in 10 core courses. Toward the end of the lecture, students were polled to determine the relative effectiveness of specific question types. Student participation was high (76.1%+/-2.0), and most students indicated that the system enhanced the lecture (64.4%). Knowledge base and discussion questions resulted in the highest student-reported attention to lecture content. Questions polling students about their experiences resulted in attention rates similar to those without use of ARS technology. Psychological investment questions, based on upcoming lecture content, detracted from student attention. Faculty preparation time for three ARS questions was shorter for knowledge base questions (22.3 min) compared with discussion and psychological investment questions (38.6 min and 34.7 min, respectively). Polling questions required less time to prepare (22.2 min) than discussion questions but were not different from other types. Faculty stated that the investment in preparation time was justified on the basis of the impact on classroom atmosphere. These findings indicate that audience response systems enhance attention and interest during lectures when used to pose questions that require application of an existing knowledge base and allow for peer interaction.

Lack of glucokinase regulatory protein expression may contribute to low glucokinase activity in feline liver

In most mammals, glucokinase (GK) acts as a hepatic “glucose sensor” that permits hepatic metabolism to respond appropriately to changes in plasma glucose concentrations. GK activity is potently regulated by the glucokinase regulatory protein (GKRP), which is encoded by the GCKR gene. GKRP binds GK in the nucleus and inhibits its activity. GK becomes active when it is released from GKRP and translocates to the cytosol. Low glucokinase (GK) activity is reported to be a principal feature of feline hepatic carbohydrate metabolism but the molecular pathways that regulate GK activity are not known. This study examined the hypothesis that species-specific differences in GKRP expression parallel the low GK activity observed in feline liver. Hepatic GKRP expression was examined using RT-PCR, immunoblot, and confocal immunomicroscopy. The results show that the GCKR gene is present in the feline genome but GCKR mRNA and the GKRP protein were absent in feline liver. The lack of GKRP expression in feline liver indicates that the low GK activity cannot be the result of GKRP-mediated inhibition of the GK enzyme. However, the absence of the permissive effects of GCKR expression on GK expression and activity may contribute to reduced GK enzyme activity in feline liver. The study results show that the cat is a natural model for GCKR knockout and may be useful to study regulation of GCKR expression and its role in hepatic glucose-sensing and carbohydrate metabolism.

Tissue expression of ketohexokinase in cats

Ketohexokinase (KHK) metabolizes dietary fructose and is an important regulator of hepatic glucose metabolism. The veterinary literature contains conflicting data regarding the role of KHK in feline fructose metabolism. The study objectives were to determine tissue expression of KHK mRNA and protein in cats, with special emphasis on hepatic expression. KHK mRNA and protein expression were determined using routine RT-PCR and immunoblot techniques. KHK mRNA was detected in feline liver, pancreas, spleen and striated muscle but not in lung. The partial sequence of feline KHK mRNA obtained was highly similar to known KHK mRNA sequences. Immunoblot studies confirmed KHK protein expression in the feline liver. The tissue distribution of KHK mRNA in cats is similar to KHK expression in other species. KHK mRNA and protein expression in feline liver is consistent with previous reports of hepatic fructokinase activity in this species.

Evaluation of a real-time, continuous monitor of glucose concentration in healthy dogs during anesthesia

OBJECTIVEnTo evaluate the accuracy of a real-time, continuous glucose monitoring system (CGMS) in healthy dogs undergoing anesthesia for elective ovariohysterectomy or orchiectomy.nnnANIMALSn10 healthy dogs undergoing routine elective surgery.nnnPROCEDURESnA CGMS was placed and used to obtain calculated glucose measurements before, during, and after anesthesia in each dog. Periodically, CGMS measurements were compared with concurrent measurements of glucose concentration in peripheral venous blood obtained with a portable chemistry analyzer (PCA).nnnRESULTSnCGMS-calculated glucose measurements were significantly different from PCA blood glucose measurements during most of the anesthetic period. The CGMS values differed from PCA values by > 20% in 54 of 126 (42.9%) paired measurements obtained during the anesthetic period. Hypoglycemia was evident in CGMS measurements 25 of 126 (19.8%) times during anesthesia. By comparison, only 1 incident of hypoglycemia was detected with the PCA during the same period.nnnCONCLUSIONS AND CLINICAL RELEVANCEnUse of the CGMS for routine monitoring of interstitial glucose concentration as an indicator of blood glucose concentration during anesthesia cannot be recommended. Additional investigation is necessary to elucidate the cause of discrepancy between CGMS results and PCA data during anesthesia.

Effects of feline hyperthyroidism on kidney function: a review

Chronic kidney disease and hyperthyroidism are two commonly diagnosed conditions in the geriatric feline population, and are often seen concurrently. Management of both diseases is recommended; however, the physiologic implications of both diseases must be understood to ensure the most favorable outcome for each patient. This report reviews the complex interplay between hyperthyroidism and kidney function, as well as the effects of hyperthyroid therapy on kidney function.