Joseph Taboada

Antigen and antibody testing for the diagnosis of blastomycosis in dogs.

BACKGROUND Early diagnosis and treatment are associated with an improved prognosis in blastomycosis. The diagnosis of blastomycosis may be missed by cytology, histopathology, culture, or serology. An enzyme immunoassay (EIA) for detection of Blastomyces dermatitidis galactomannan antigen in body fluids has been used for rapid diagnosis of blastomycosis in humans. HYPOTHESIS Measurement of Blastomyces antigen in urine or serum by the MVista Blastomyces antigen EIA is more sensitive than measurement of anti-Blastomyces antibodies for diagnosis of blastomycosis in dogs. METHODS Serum and urine samples from 46 dogs with confirmed blastomycosis were tested for Blastomyces antigen and serum was tested for anti-Blastomyces antibodies. RESULTS The sensitivity for the detection of antigen in urine was 93.5% and it was 87.0% in serum. The sensitivity of antibody detection by agar gel immunodiffusion (AGID) was 17.4% and it was 76.1% by EIA. Antigen and antibody decreased during itraconazole treatment. CONCLUSIONS AND CLINICAL IMPORTANCE Antigen detection is a more sensitive test for diagnosis of blastomycosis than antibody testing by AGID, the only commercially available method. Antigen concentrations decreased with treatment.

Transdermal methimazole treatment in cats with hyperthyroidism

The objectives of this study were to assess serum thyroxine concentrations and clinical response in hyperthyroid cats to treatment with transdermal methimazole, and to determine if further investigation is indicated. Clinical and laboratory data from 13 cats with hyperthyroidism were retrospectively evaluated. Methimazole (Tapazole, Eli Lilly) was formulated in a pleuronic lecithin organogel (PLO)-based vehicle and was applied to the inner pinna of the ear at a dosage ranging from 2.5 mg/cat q 24 h to 10.0 mg/cat q 12 h. During the treatment period, cats were re-evaluated at a mean of 4.3 weeks (recheck-1), and again at a mean of 5.4 months (recheck-2). Clinical improvement was observed, and significant decreases in thyroxine concentrations were measured at recheck-1 (mean: 39.57 nmol/L, SEM: 14.4, SD: 41.2) and recheck-2 (mean: 36.71 nmol/L, SEM: 13.9, SD: 45.56) compared to pretreatment concentrations (mean: 97.5 nmol/L, SEM: 11.42, SD: 39.5). No adverse effects were reported.

Effects of Long-Term Phenobarbital Treatment on the Liver in Dogs

Long‐term administration of phenobarbital has been reported to cause hepatic injury in dogs. Phenobarbital induces hepatic enzymes, and it may be difficult to distinguish the effect of enzyme induction on serum liver enzyme activities from actual hepatic damage. The hepatotoxicity of phenobarbital and the impact of enzyme induction on serum liver enzyme activity were investigated prospectively in 12 normal dogs. Phenobarbital was administered for 29 weeks at 5 mg per kilogram of body weight (range, 4.8— 6.6 mg/kg) PO q12h, resulting in therapeutic serum phenobarbital concentrations (20–40 μg/mL). Serum alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST), γ‐glutamyltransferase (GGT), fasted bile acids (fBA), total bilirubin, and albumin were determined before and during treatment. Lateral abdominal radiographs, abdominal ultrasounds, and histopathologic examinations of liver tissue obtained by ultrasound‐guided biopsy were performed before and during treatment. Radiographs revealed a moderate increase in liver size in most dogs. Ultrasonographic examination revealed no change in liver echogenicity or architecture. No evidence of morphologic liver damage was observed histopathologically. ALP and ALT increased significantly (P < .05), GGT increased transiently, and albumin decreased transiently during the study. There were no significant changes in AST, bilirubin, and fBA. These results suggest that increases in serum ALP, ALT, and GGT may reflect enzyme induction rather than hepatic injury during phenobarbital treatment in dogs. Serum AST, fBA, and bilirubin, and ultrasonographic evaluation of the liver are not affected by the enzyme‐inducing effect of phenobarbital and can therefore be helpful to assess liver disease in dogs treated with the drug.

Effects of long-term phenobarbital treatment on the thyroid and adrenal axis and adrenal function tests in dogs.

Phenobarbital can interfere with the thyroid axis in human beings and rats by accelerating hepatic thyroxine metabolism because of enzyme induction. In human beings, it also can interfere with the low-dose dexamethasone suppression test (LDDST) used to assess adrenal function by accelerating dexamethasone metabolism. This effect can cause a lack of suppression of pituitary ACTH and subsequent adrenal cortisol release after dexamethasone administration. The effects of phenobarbital on the thyroid axis, the adrenal axis, and adrenal function tests were prospectively investigated in 12 normal, adult dogs. Phenobarbital was administered at 5 mg per kilogram of body weight (range, 4.8-6.6 mg/kg) PO q12h for 29 weeks, resulting in therapeutic serum concentrations (20-40 microg/mL). Serum total thyroxine (TT4), free thyroxine (FT4) by equilibrium dialysis, total triiodothyronine (TT3), thyrotropin (TSH), and cholesterol were determined before and during phenobarbital treatment. LDDST, ACTH stimulation tests, and ultrasonographic evaluation of the adrenal glands were performed before and during treatment. TT4 and FT4 decreased significantly (P < or = .05), TT3 had minimal fluctuation, TSH had only a delayed compensatory increase, and cholesterol increased during phenobarbital treatment. The delayed increase in TSH, despite persistent hypothyroxinemia, suggests that accelerated hepatic thyroxine elimination may not be the only effect of phenobarbital on the thyroid axis. There was no significant effect of phenobarbital on either of the adrenal function tests. With the methods employed, we did not find any effects of the drug on the hormonal equilibrium of the adrenal axis.

American Association of Feline Practitioners: Senior Care Guidelines

Background Cats are the most popular pet in the United States and much of Northern Europe. Although 78% of owners consider their cats to be family members, many cats, particularly seniors, do not receive appropriate preventive care.1–3 One of the main obstacles to owner compliance is the lack of a clear recommendation by the veterinary team. 4 Guidelines can help veterinarians to minimize this obstacle, strengthen the human-pet-veterinary bond, and improve the quality of life of cats. Goals The goals of this article are to assist veterinarians to: Deliver consistent high-quality care to senior cats. Promote longevity and improve the quality of life of senior cats by: recognizing and controlling health risk factors; facilitating and promoting early detection of disease; improving or maintaining residual organ function; and delaying the progression of common conditions. Define aspects of screening, diagnosis, treatment and anesthesia of senior cats.

Thyroid Function and Serum Hepatic Enzyme Activity in Dogs after Phenobarbital Administration

Phenobarbital is the drug of choice for control of canine epilepsy. Phenobarbital induces hepatic enzyme activity, can be hepatotoxic, and decreases serum thyroxine (T4) concentrations in some dogs. The duration of liver enzyme induction and T4 concentration decreases after discontinuation of phenobarbital is unknown. The purpose of this study was to characterize the changes in serum total T4 (TT4), free T4 (FT4), thyroid‐stimulating hormone (TSH), cholesterol and albumin concentrations, and activities in serum of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma‐glutamyl transferase (GGT) after discontinuation of long‐term phenobarbital administration in normal dogs. Twelve normal dogs were administered phenobarbital at a dosage of approximately 4.4–6.6 mg/kg PO ql2h for 27 weeks. Blood was collected for analysis before and after 27 weeks of phenobarbital administration and then weekly for 10 weeks after discontinuation of the drug. The dogs were clinically normal throughout the study period. Serum ALT and ALP activity and TSH and cholesterol concentrations were significantly higher than baseline at week 27. Serum T4 and FT4 were significantly lower. Serum albumin and GGT were not changed from baseline at week 27. Changes in estimate of thyroid function (TT4, FT4, TSH) persisted for 1–4 weeks after discontinuation of phenobarbital, whereas changes in hepatic enzyme activity (ALT, ALP) and cholesterol concentration resolved in 3–5 weeks. To avoid false positive results, it is recommended that thyroid testing be performed at least 4 weeks after discontinuation of phenobarbital administration. Elevated serum activity of hepatic enzymes 6–8 weeks after discontinuation of phenobarbital may indicate hepatic disease.

Systemic Diseases with Cutaneous Manifestations

The purpose of this article is to briefly discuss the following cutaneous manifestations of selected systemic diseases: poxvirus; feline leukemia virus (FeLV); feline immunodeficiency virus (FIV); herpesvirus; calcivirus; pseudorabies; plague; tularemia; toxoplasmosis; leishmania; hypothyroidism; hyperthyroidism; hyperadrenocorticism; diabetes mellitus; acromegaly; thallium poisoning; pancreatic disease; hypereosinophilic syndrome; mucopolysaccharidosis; and pansteatitis. Recognition of these cutaneous signs may help alert the clinician to the possibility of an internal disorder so that the appropriate diagnostic tests can be considered.

Hypernatremia and Hypertonic Syndromes

Hypernatremia is the most common cause of hypertonicity in small animal medicine. Despite this fact, severe hypernatremia is an uncommon clinical entity in dogs and cats. The causes of hypernatremia are excessive water loss and increased sodium intake. Clinical signs are most often related to CNS dysfunction. Severe hypernatremia should be considered a life-threatening situation and treated as such. Initial fluid therapy should be given with care according to the rate of onset of hypernatremia, as deterioration of the animals condition is a common sequela. The determination of the cause of hypernatremia and the treatment can be both challenging and rewarding. The other notable hypertonic syndrome in small animal medicine is hyperosmolar nonketotic diabetes mellitus. Judicious management of this disease with fluid therapy and insulin is the standard therapy. An understanding of the pathophysiology is essential to their diagnosis and appropriate medical management.

Phenol poisoning in three dogs.

Three adult dogs were evaluated following oral administration of phenol by the owner. All three dogs experienced severe oral and gastric ulceration. Hematological abnormalities included neutropenia with the presence of toxic neutrophils, thrombocytopenia, and increased muscle enzymes. Endoscopic examination was performed, and biopsies yielded a diagnosis of gastric mucosal necrosis in two of the dogs. Following supportive care, the dogs recovered completely. Phenol is a caustic, highly poisonous derivative of coal tar. The dogs of this report were poisoned inadvertently by their owner who received misinformation concerning the use of this chemical via the Internet.

An anatomy precourse enhances student learning in veterinary anatomy

Veterinary anatomy is often a source of trepidation for many students. Currently professional veterinary programs, similar to medical curricula, within the United States have no admission requirements for anatomy as a prerequisite course. The purpose of the current study was to evaluate the impact of a week‐long precourse in veterinary anatomy on both objective student performance and subjective student perceptions of the precourse educational methods. Incoming first year veterinary students in the Louisiana State University School of Veterinary Medicine professional curriculum were asked to participate in a free precourse before the start of the semester, covering the musculoskeletal structures of the canine thoracic limb. Students learned the material either via dissection only, instructor‐led demonstrations only, or a combination of both techniques. Outcome measures included student performance on examinations throughout the first anatomy course of the professional curriculum as compared with those who did not participate in the precourse. This study found that those who participated in the precourse did significantly better on examinations within the professional anatomy course compared with those who did not participate. Notably, this significant improvement was also identified on the examination where both groups were exposed to the material for the first time together, indicating that exposure to a small portion of veterinary anatomy can impact learning of anatomical structures beyond the immediate scope of the material previously learned. Subjective data evaluation indicated that the precourse was well received and students preferred guided learning via demonstrations in addition to dissection as opposed to either method alone. Anat Sci Educ 9: 344–356.