Darryl N. Biery

Scintigraphic detection of acute gastrointestinal bleeding.

In induced bleeding experiments on dogs, 99mTc-sulfur colloid was a suitable agent for detecting the bleeding site in the small intestine, providing that the site was distant from the liver and spleen. Bleeding sites were detectable at rates as low as 0.1 ml/min. When induced in the sigmoid or descending colon, the site was demonstrated by scintigraphy with 99mTc-sulfur colloid. Unsatisfactory images were obtained in the esophagus and stomach, however, when 131I-ortho-iodohippurate or 99mTc-DTPA was used.

Diet restriction and ageing in the dog: major observations over two decades

This report reviews decade two of the lifetime diet restriction study of the dog. Labrador retrievers (n 48) were paired at age 6 weeks by sex and weight within each of seven litters, and assigned randomly within the pair to control-feeding (CF) or 25 % diet restriction (DR). Feeding began at age 8 weeks. The same diet was fed to all dogs; only the quantity differed. Major lifetime observations included 1.8 years longer median lifespan among diet-restricted dogs, with delayed onset of late life diseases, especially osteoarthritis. Long-term DR did not negatively affect skeletal maturation, structure or metabolism. Among all dogs, high static fat mass and declining lean body mass predicted death, most strongly at 1 year prior. Fat mass above 25 % was associated with increasing insulin resistance, which independently predicted lifespan and chronic diseases. Metabolizable energy requirement/lean body mass most accurately explained energy metabolism due to diet restriction; diet-restricted dogs required 17 % less energy to maintain each lean kilogram. Metabonomics-based urine metabolite trajectories reflected DR-related differences, suggesting that signals from gut microbiota may be involved in the DR longevity and health responses. Independent of feeding group, increased hazard of earlier death was associated with lower lymphoproliferative responses to phytohaemagglutinin, concanavalin A, and pokeweed mitogen; lower total lymphocytes, T-cells, CD4 and CD8 cells; lower CD8 percentages and higher B-cell percentages. When diet group was taken into account, PWM responses and cell counts and percentages remained predictive of earlier death.

Angioplasty-induced vasospasm in rabbit model. Mechanisms and treatment.

Angioplasty of the distal iliac and proximal femoral arteries in rabbits resulted in focal and diffuse vasospasm similar to that seen in humans. The focal vasospasm occurred in all experiments immediately distal to the site of angioplasty. Occasional diffuse vasospasm was preceded by intravascular thrombosis or extravasation. Heparin reduced the incidence of diffuse vasospasm and reduced the severity of focal vasospasm. Verapamil and Dazoxiben reversed focal vasospasm, but only Verapamil in the presence of heparin prevented vasospasm. Prazocin had no effect on vasospasm.

Un-United Medial Epicondyle of the Humerus: Radiographic Prevalence and Association with Elbow Osteoarthritis in a Cohort of Labrador Retrievers

OBJECTIVE To longitudinally characterize the radiographic appearance of un-united medial epicondyle (UME) of the humerus, evaluate UME association with osteoarthritis (OA) and consider its relevance to the elbow dysplasia complex. STUDY DESIGN Longitudinal cohort study. ANIMALS Labrador retrievers (n=48) from 7 litters. METHODS Forty-eight same-sex littermates were paired for this lifetime feeding study. One of each pair was control-fed; the pair mate was fed 25% less than the control each day. Elbows of 46 surviving dogs were radiographed at ages 6 and 8 years, and/or at end-of-life (EOL). Elbow histopathology was done EOL, although UME lesions were not evaluated histologically. RESULTS Seven dogs (15%) had UME, representing 5 litters; 4 were control-fed, 3 diet-restricted. Six (86%) dogs had unilateral lesions; 1 was bilateral. UME was evident on craniocaudal (CrCd) radiographic projections by 8 years in all dogs. UME was detected in only 1 elbow by mediolateral radiographic projection. Elbow OA frequency in UME affected dogs was not significantly different from the remaining study population. Histopathologic lesions were bilateral in dogs with unilateral UME. CONCLUSIONS UME may be more common than previously thought. Most cases were unilateral and diet restriction had no effect on frequency. The CrCd view was critical for diagnosis. Elbow OA was not directly associated with UME. CLINICAL RELEVANCE Infrequent diagnosis of UME could result from infrequent radiography and use of only the flexed lateral radiographic projection required by the Orthopedic Foundation for Animals for elbow screening. Like hip evaluations, screening for UME should be continued for life, until genetics are better understood. Lack of association between UME and elbow OA suggests that UME is not likely a component of elbow dysplasia.

DOUBLE CONTRAST GASTROGRAPHY IN THE CAT

Radiographic diagnosis of gastric mucosal disease has not been reported in the cat. This may be due to the difficulty in making these diagnoses with survey or single contrast radiography. Double contrast gastrography (DCG) allows direct visualization of gastric mucosal surfaces. The DCG technique in the cat is described, and the normal radiographic appearance is illustrated.

Contrast studies of the urogenital system

Traditional contrast radiographic techniques for evaluation of the urogenital system are reviewed. Specific procedural protocols are suggested. The indications, limitations, and interpretation of the studies are discussed.

Intrathecal dextrose to prevent seizures after metrizamide myelography in dogs.

Seizures are possible complications of metrizamide myelography. The protective effect (as measured by reduction in seizure incidence) of dextrose in solution with metrizamide was studied by conducting a double-blind trail. Fourteen dogs each had two myelograms at five- to 16-day intervals in a crossover study, while ten additional dogs each had a single myelogram. Metrizamide alone and metrizamide in dextrose were used for the myelograms. No significant protective effect of dextrose was found.

Use of in vivo Magnification Renal Arteriography to Study Cadmium Effects on Vasoactive Responses

Abstract Antiotensin, norepinephrine, and epinephrine administered into the renal artery produced mild to marked renal vasoconstriction in 15 dogs. Cadmium acetate administered in association with the vasoactive drugs (agonists) resulted in mild to complete inhibition of the agonist-induced renal vasoconstriction; this effect was reversible, reproducible, and dose-related. Decreased intrarenal vascular resistance secondary to the inhibition of vasoactive responses by cadmium may play a role in the pathophysiology of cadmium hypertension.