Cutaneous Mastocytosis and Mucinosis with Gross Deformity in a Shar pei Dog

Abstract— An 8-year-old Chinese Shar pei dog was examined because of gross deformity of the hind limbs. The deforming soft tissue swellings were associated with mucinosis and mastocytosis.
Résumé— Un Shar Peï de 8 ans a été examiné pour une déformation au niveau des membres postérieurs. Les épaissiessements des déformations des tissus mous étaient associés à une mucinose et une mastocytose.
Zusammenfassung— Ein 8 Jahre alter Chinesischer Shar Pei wurde wegen makroskopischer Verformung der Hintergliedmaßen untersucht. Die deformierenden Weichteilschwellungen standen in Zusammenhang mit einer Muzinose und Mastozytose.
Resumen  Un perro Shar pei de 8 años de edad se examinó, debido a la presencia de vastas deformidades de los cuartos traseros. La deformidad de los tejidos blandos se asoció con mastocitosis y mucinosis.     

Absorption and pharmacokinetics of phenylbutazone in Welsh Mountain ponies

The disposition of phenylbutazone (4.4 mg/kg), administered intravenously to six Welsh Mountain ponies, was described by a two-compartment open model. Pharmacokinetic parameters were not significantly different after morning dosing in comparison with afternoon dosing. When phenylbutazone (4.4 mg/kg) was administered orally to the same ponies, marked variations in time to peak concentrations were produced with different feeding schedules. When access to hay was permitted before and after dosing, the mean time to peak concentration was 13.2 +/- 1.2 h and double peaks in the plasma concentration-time curve were common. Double peaks were also encountered when phenylbutazone was given to ponies deprived of food prior to, and allowed access to hay after, dosing. In this circumstance, mean times to peak concentration were much shorter (3.8 +/- 1.3 h after morning dosing and 5.3 +/- 1.5 h followed afternoon dosing). Absorption was more regular and double peaks were less apparent when food was withheld both before and after dosing. In order to explain these findings, it is tentatively postulated that, whereas some of the administered dose of phenylbutazone may be absorbed quickly, some may become adsorbed on to the feed and subsequently released by fermentative digestion in the large intestine and/or caecum. The consequences of delayed absorption in fed animals for toxicity and clinical efficacy, and for the use of phenylbutazone in equestrian sports, are considered. Delayed absorption in ponies given access to hay was not accompanied by a significant reduction in total absorption. Bioavailability was estimated to be approximately 69% in fed and 78% in unfed ponies. Estimates of bioavailability gave similar values for morning (72%) and afternoon (71%) dosing.     

CHANGES IN ECHOCARDIOGRAPHIC VARIABLES OF LEFT VENTRICULAR SIZE AND FUNCTION IN A MODEL OF CANINE NORMOVOLEMIC ANEMIA

The objective of this study was to document changes in echocardiographic variables of left ventricular size and function noninvasively during acute normovolemic anemia. This model was developed as a pilot study with the purpose of providing baseline information to investigate the pathophysiology, and more specifically the effect on the heart, of canine babesiosis-induced anemia. The study group comprised of 11 mature healthy Beagle dogs that weighed between 9 and 15 kg. Severe normovolemic anemia was induced over a 3-4-day period by serial bleeding while maintaining normovolemia by autotransfusing plasma and infusing crystalloids. The dogs were then allowed to recover. Preanemic (mean Hct 46.7%, standard deviation [SD] 2.4%) echocardiographic variables of left ventricular performance (Fractional shortening, ejection fraction, end-systolic and end-diastolic ventricular volumes, cardiac index, and heart rate) were compared with those in the severely (mean Hct 15.3%, SD 1.1%), moderately (Hct mean 24.7%, SD 1.5%), and mildly (mean Hct 33.5%, SD 2.5%) anemic states, and between the anemic states. With the exception of end diastolic volume, there was a statistically significant (P < 0.05) increase in all variables in the severely anemic state vs. the preanemic and the mild and moderate anemic states. In concordance with previous invasive models, a hyperdynamic state of the left ventricle develops in response to experimentally induced acute canine normovolemic anemia in the conscious dog. Echocardiography has promise as a noninvasive technique of evaluating the cardiac changes in dogs having canine babesiosis.     

IDENTIFYING REMOVABLE RADIOACTIVITY ON THE SURFACE OF CATS DURING THE FIRST WEEK AFTER TREATMENT WITH IODINE 131

Because radioiodine (1-131) is excreted in urine and saliva, treated cats can accumulate I-131 on their coats from contacting soiled litter and grooming. This could result in removable radioactivity, which is a potential source of human exposure to radiation and specifically to internal contamination. The purpose of this study was to determine if there is removable radioactivity on cats treated with I-131. Daily wipe tests were performed for 7 days at two sites (both flanks, one site; and all four paws, one site) on six hyperthyroid cats treated with I-131. A y counter was used to determine the counts per minute (cpm) of the samples, which were converted to disintegrations per minute (dpm) to estimate activity. The results were compared to the New York State limits of removable activity for a non-controlled area (<1000dpm/100 cm2) to determine if the amount of removable activity was acceptable for a member of the public. The median value of removable activity was 241 dpm (range from 34 to 4184 dpm) for the flanks, and 308 dpm (range from 60 to 1890 dpm) for the paws. The amount of removable radioactivity on the surface of hospitalized cats treated with I-131 during the first week after treatment, occasionally and without obvious pattern, exceeded the New York State limit. Sporadic activity as high as 4148 dpm was found. It is prudent to advise owners to observe routine hygiene when handling cats after discharge to minimize the risk of internal contamination.     

MAGNETIC RESONANCE IMAGING OF SUBARTICULAR BONE MARROW LESIONS IN DOGS WITH STIFLE LAMENESS

A bone bruise is a magnetic resonance (MR) imaging sign thought to signify acute traumatic microfracture of trabecular bone with hemorrhage and edema in the marrow that may occur without grossly visible disruption of the adjacent cortices or overlying cartilage. In approximately 75% of people with acute anterior-cruciate ligament tears, bone bruises are detected in characteristic locations within the femur and tibia and are best seen as high-signal lesions using fat-suppression sequences. We questioned whether this is a component of naturally acquired stifle lameness in dogs and obtained short-tau inversion recovery (STIR) images of six dogs with stifle lameness. High-signal STIR lesions were detected in five of six (83%) dogs and eight of 12 (67%) limbs. We observed these lesions deep to the intercondylar fossa of the femur and intercondylar eminence of the tibia, which are atypical locations in people. High-signal STIR lesions were detected in dogs with only synovitis, partial tear of the cranial cruciate ligament (CCL) and complete tear of the CCL. One of these lesions was seen in the lateral tibial condyle, a typical location in humans with acute anterior cruciate ligament tear. As the MR imaging appearance of stress fractures and bone bruises are similar, and the high-signal STIR lesions are at attachment sites of the CCL, this finding may be due to stress disease or other unknown causes, rather than bone bruising. High-signal STIR lesions may be a common sign in naturally acquired canine stifle disease, but the pathogenesis, prognostic and diagnostic values need further investigation.     

SKELETAL LESIONS OF HISTIOCYTIC SARCOMA IN NINETEEN DOGS

The purpose of this study was to describe the clinical and radiographic findings in dogs with bone lesions secondary to histiocytic sarcoma. Nineteen dogs with radiographically identified bone lesions that were histologically diagnosed as histiocytic sarcoma were assessed. The medical records, all available radiographs and histologic sections were reviewed retrospectively. Dogs were subcategorized into localized or disseminated histiocytic sarcoma groups. Golden Retrievers or Rottweilers greater than 5 years of age, with a history of lameness or neurologic deficits localized to the spinal cord was the most common presentation. Fifteen of 19 dogs had a radiographically detectable soft tissue mass associated with bone destruction. The bone lesions had aggressive characteristics and the sites of involvement included periarticular bones (n = 11), vertebrae (n = 6), proximal humerus (n = 5), and rib (n = 2). Fifteen of 19 dogs had disseminated histiocytic sarcoma, and four had localized histiocytic sarcoma. All Rottweilers had disseminated histiocytic sarcoma. Histiocytic sarcoma should be considered as a differential diagnosis for aggressive periarticular, vertebral, or proximal humeral bone lesions identified on radiographs. The index of suspicion should be increased in greater than 5-year-old Golden Retrievers and Rottweilers when a soft tissue mass is associated with the bone lesion on radiographs or myelography. Bone involvement with histiocytic sarcoma, and the Rottweiler breed, was associated with the disseminated form of the disease.     

EFFECTS OF MEASUREMENT OF PLASMA ACTIVITY INPUT ON NORMALIZATION OF GLOMERULAR FILTRATION RATE TO PLASMA VOLUME IN DOGS

Glomerular filtration rate (GFR) normalized to body fluid volumes to adjust for differing body size and conformation is more physiologically correct than a relationship with body weight (BW). GFR can be normalized to plasma volume by a renographic method that uses the Rutland-Patlak plot with plasma activity and kidney activity inputs. A plasma time-activity curve is obtained from a region of interest (ROI) of the left ventricle (LV), the size of which is in theory not critical. The aims of the study were to evaluate the effect of different LV ROI sizes, the effect of extravascular activity in the thorax over the LV ROI, and different time intervals for the semilogarithmic LV plot. Seventy-two scintigrams were used, with three different-sized automatic and a manual LV ROI, all with and without subtracting extravascular activity, and with LV curve time intervals of 30-120 s and 60-240 s. GFR/plasma volume was not affected by LV ROI sizes but significantly affected by extravascular activity subtraction and different time intervals. Subtracting extravascular activity from the LV ROI did not improve precision, but increased variability caused by different LV ROI sizes and time intervals chosen for the LV plot. The ROI for measuring extravascular activity apparently contained a considerable and variable intravascular component, which when subtracted, created noisy and unreliable LV curves. Manual LV ROI, without extravascular subtraction, and a time interval for LV input between 1 and 4 min are recommended as they gave the least variability determined by statistical analysis. With these methods, normal individual GFR/plasma volume in normal beagle dogs was 29.2 +/- 6.5 ml/min/l.     

Comparison of four dog diets (including nitrogen balance study)

Four pairs of Beagle dogs received in rotation, a specially prepared purified diet in powder form (reference diet), a semi-solid (SS) diet and two complete dry diets in expanded-pellet form (Dry-S and Dry-P). Finally, all dogs received a nitrogen-free diet. The diets were offered in equi-caloric quantities (175 kcal/kg body weight/day) and consumed for 14-day periods. Nitrogen balance was determined during the last 5 days of each period. Clinical observations (clinical signs, body weight, food and water consumption) revealed no differences between the semi-solid and two dry diets. On the reference diet, however; food consumption was poor, no weight was gained and water intake was increased. Nitrogen balance studies revealed that:

• (i). The relative biological values (BV) of the reference diet protein (casein) and that in the Dry-S diet were similar and greater than those of the other two products. The value for the Dry-S diet (BV = 58) was significantly greater than that on the Dry-P diet (BV = 50) at almost the 5 per cent level of probability.
• (ii). The apparent digestibility of nitrogen was greatest on the reference diet, however any advantage that this may have entailed was reversed by the low food intake, so that significantly greater quantities of nitrogen were absorbed by the same dogs, when offered the dry diets (0–1 per cent level of significance) and also the semi-solid diet (5 per cent level of significance).
• (iii). Nitrogen retention within the body was significantly greater on the Dry-S diet, but analysis of covariance showed that the group differences were entirely dependent on the amounts of nitrogen absorbed.

Résumé. Quatre paires de chiens Beagles reqoivent tour à tour un régime spécialement purifié préparé sous forme de poudre (régime de référence), un régime semi-solide (SS) et dew régimes complètement secs, sous forme de tablettes (Dry-S et Dry-P). Puis, tous les chiens reçoivent un régime totalement dépourvu d'azote. La nourriture était administrée en des quantités équicaloriques (175 calories/kg de poids corporel et par jour) et poursuivie pendant 14 jours. Le bilan azoté était déterminé au cours des 5 derniers jours de chaque période. L'observation clinique (signes cliniques, poids, consommation de nourriture et doses) n'a montré aucune différence entre le régime semi-solide et les deux régimes secs; cependant, avec le régime de référence, la consommation de nourriture était réduite, celle de l'eau augmentée, et le poids est resté stationnaire. L'étude du bilan azoté a donné les résultats suivants:

• (i). Les valeurs biologiques relatives (BV) concernant la protéine du régime de référence (caséine) et celle du régime Dry-S étaient similaires et supérieures à ce qui était observé avec les deux autres produits. Les valeurs pour le régime Dry-S (BV = 58) étaient significativement plus grandes que celles du regime Dry-P (BV = 50) à un niveau de presque 5% de probabilité.
• (ii). La digestibilité apparente de l'azote était la plus grande avec le régime de référence, cependant les avantages qui pouvaient en être tirés étaient réduits par la faible prise de nourriture, d'où absorption de quantités significativement plus grandes d'azote chez le meme chien soumis ultérieurement au régime sec (niveau de signification = 0,1%) et aussi au régime semi-solide (niveau de signification = 5%).
• (iii). La retention azotée dans l'organisme était significativement plus grande avec le régime Dry-S, mais l'analyse des covariances a montré que les différences de groupes dépendaient totalement des quantités d'azote absorbées.

Zusammenfassung. Vier Paare von Beaglehunden erhielten in planmässigem Wechsel ein besonders hergestelltes gereinigtes Futter in Pulverform (Reference Diet), ein halbfestes Futter (SS) und zwei völlig trockene Futtertypen in Form expandierter Pellets (Dry-S und Dry-P). Schliesslich erhielten alle Hunde ein stickstomreies Futter. Die Futtertypen wurden den Tieren in kalorisch gleichwertigen Mengen (175 cal/kg Körpergewicht/Tag) geboten und jeweils 14 Tage lang gefressen. Während der letzten 5 Tage jeder Periode wurde die Stickstoffbilanz bestimmt. Die klinischen Beobachtungen (klinische Zeichen, Körpergewicht, Futter- und Wasserverbrauch) ergaben keine Unterschiede zwischen dem halbfesten Futter und den zwei trockenen Futtertypen. Bei der Reference Diet war jedoch der Futterverbrauch gering, es erfolgte keine Gewichtszunahme und der Wasserverbrauch war erhöht. Die Stickstoff bilanzbestimmungen zeigten, dass:

• (i). Die relativen biologischen Werte (BW) des Reference-Diet-Proteins (Casein) und des Proteins im Dry-S-Futter ähnlich und grösser als die der beiden anderen Produkte waren. Der Wert für das Dry-S-Futter (BW = 58) war wesentlich grösser als der für das Dry-P-Futter (BW = 50) bei fast 5% Probabilität.
• (ii). Die scheinbare Verdaulichkeit des Stickstoffs war am grössten bei der Reference Diet, jedoch wurde jeder dadurch mögliche Vorteil durch die geringe Futteraufnahme aufgehoben, so dass die gleichen Hunde wesentlich grössere Stickstoffmengen absorbierten, wenn sie die trockenen Futtertypen erhielten (0,1% Signifikanz) oder auch das halbfeste Futter (5% Signifikanz).
• (iii). Die Stickstoffspeicherung im Körper war beim Dry-S-Futter wesentlich grösser, aber die Kovarianzanalyse zeigte, dass die Gruppenunterschiede völlig von den absorbierten Stickstoffmengen abhingen.