EFFECTS OF WATERSHED LIMING ON PICEA RUBENS SEEDLING BIOMASS AND NUTRIENT ELEMENT CONCENTRATION

Effects of watershed liming on the biomass and tissue chemistry of planted Picea rubens Sarg. (red spruce) seedlings were investigated for two growing seasons after two subcatchments in a forested Adirondack, New York (U.S.A.) watershed were limed aerially with 6.89 t ha^-1 of calcitic limestone (CaCO₃). Picea rubens has been the focus of numerous atmospheric deposition research studies, but less well investigated for responses to amelioration. Picea rubens seedlings were planted in limed and reference subcatchments and harvested the first and second growing season after liming to measure total, foliar, and stem (i.e., branch) biomass, and concentrations of Ca, Mg, K, Al, Na, and P in the annual growth increment of foliage and branches. In the second year after liming, both foliage and stem biomass of seedlings from reference plots were at least 50% greater than seedling biomass from limed plots. Seedlings in limed areas had significantly greater foliar concentrations of Mg and P in the first year after liming, but not in the second year. Foliar Ca was not significantly different in limed than reference seedlings. Foliar Al concentrations were greater in reference than limed seedlings, but still below documented toxicity levels. Stem concentrations of Mg, K, and P in seedlings from limed areas decreased significantly between the first and second growing season after liming, while reference seedling stem concentrations either increased or declined only slightly. Correlations among foliar nutrients and foliar biomass from limed plots were negative and suggest an inverse dilution effect. Foliar Al concentrations were negatively correlated with Ca, Mg, K, and P in seedlings from reference plots, but positively correlated in limed plots. The adverse response of P. rubens seedlings to lime may reflect changes in nutrient availability associated with changes in soil pH.     

Putative Diethylcarbamazine-induced Urticaria with Eosinophilic Dermatitis in a Dog

Résumé— Une urtricaire due à la diethylcarbamazine associée à une dermite prurigineuse a été suspectée chez un chien mâle castré croisé Retriever. L'animal présentait des lésions d'urticaire multiples qui avaient tendance à fusionner au niveau des paupières, des lèvres, les conques auriculaires et du prépuce. Les biopsies cutanées ont révélé un infiltrat périvasculaire et périannexiel intense riche en polynucléaires éosinophiles. Parfois les polynuclaires éosinophiles étaient “dégranulés” ou présentaient des formes “en flamme”. La suppression de l'administration de diethylcarbamazine a été suivie d'une disparission rapide de toutes les lésions cutanées. L'hypothèse d'une réaction immune à la diethylcarbamazine est proposée. [Vitale, C. B., Ihrke, P. J., Gross, T. L. Putative diethylcarbamazine-induced uticaria with eosinophilic dermatitis in a dog. (Probable urticaire et dermite éosinophilique induites par la diethylcarbamazine chez un chien). Resumen— Se describe el caso de un perro macho castrado, cruzado de retriever que presentaba una dermatitis pruritica con urticaria supuestamente inducida por dietilcarbamacina. El perro mostraba multiples habones, principalmente alrededor de los ojos, la boca, los pabellones auriculares y el prepucio. El estudio histológico mostró un infiltrado perivascular y perianexal, con predominancia de eosinófilos. Ocasionalmente los eosinófilos degranulaban formando “figuras en llama”. La retirada de la terapia con dietilcarbamacina fue seguida por una mejoria rápida y espectacular de todas las lesiones cutáneas. Se postula una reacción adversa a la dietilcarbamacina mediada por factores inmunológicos. [Vitale, C. B., Ihrke, P. J. and Gross, T. L. Putative diethylcarbamazine-induced urticaria with eosinophilic dermatitis in a dog (Urticaria con dermatitis eosinofilica supuestamente inducida por dietilcarbamacina en un perro). Zusammenfassung— Es wird über eine vermutlich Diethylcarbamazin-verursachte Urtikaria mit Juckreiz bei einem männlich-kastrierten Retrievermischling berichtet. Der Hund wies generalisiert multifokale Striemen auf, die dazu tendierten um Augen, Mund, Ohrmuscheln und Präputium zusammenzulaufen. Die Hautbiopsie zeigte ein starkes perivaskuläres und periadenxales Infiltrat mit vorwiegend eosinophilen Granulozyten. Gelegentlich degranulierten die Eosinophilen zu “Flammenform”. Das Absetzen von Diethylcarbamazin führte zu einer dramatischen und raschen Abheilung aller Hautveranderungen. Es wird eine immunologischvermittelte Arzneimittelreaktion auf Diethylcarbamazin vermutet. [Putative diethylcarbamazine-induced utricaria with eosinophilic dermatitis in dogs (Vermutlich Diethylcarbamazin-verursachte Urtikaria mit eosinophiler Dermatitis beim Hund). Abstract— A suspected diethylcarbamazine-induced urticarial dermatitis with associated pruritus is reported in a castrated male mixed breed retriever. The dog had generalized multifocal wheals that tended to cluster around the eyes, mouth, pinnae, and prepuce. Skin biopsy revealed an intense perivascular and periadnexal infiltrate with eosinophils predominating. On occasion, eosinophils degranulated to form “flame figures”. Withdrawal of diethylcarbamazine resulted in dramatic and rapid resolution of all skin lesions. An immunologically mediated adverse drug reaction to diethylcarbamazine is proposed.     

The Analgesic Effects of Administering Fentanyl or Medetomidine in the Lumbosacral Epidural Space of Cats

The analgesic effects of fentanyl (4 μg/kg) and medetomidine (10 μg/kg) in 1 mL saline injected epidurally were measured in 15 cats. The response to an electrical cutaneous stimulus from a constant current generator was used as the index of analgesia. The stimulus was applied to a forelimb before epidural injection, and at 15, 30, 60, 90, 120, 180, 240, and 300 minutes post-injection (PI). The hindlimb was tested 5 minutes later. One mL saline only was used to control for volume of injection and saline. Medetomidine significantly increased the pain threshold for the hindlimb at 20 to 245 minutes PI compared with the preinjection level. Fentanyl significantly increased the pain threshold at 20 minutes PI only compared with preinjection levels. Medetomidine significantly increased the pain threshold of the forelimb at 15 to 120 minutes PI compared with the preinjection levels. Fentanyl did not significantly increase the pain threshold of the forelimb. Administration of medetomidine produced emesis in 12 of 15 cats in an average of 6.4 minutes PI (range, 3 to 11 minutes) and mild sedation in all cats. Injection of fentanyl produced no visible side effects in any of the cats.     

Phenylbutazone in the horse: a review

Phenylbutazone is an acidic, lipophilic, non-steroidal anti-inflammatory drug (NSAID). It is extensively metabolized in the horse. The metabolites so far identified, oxyphenbutazone, gamma-hydroxyoxyphenbutazone, account for some 25-30% of administered dose over 24 h. The plasma half-life of phenylbutazone and termination of its pharmacological action are determined primarily by its rate of hepatic metabolism. Phenylbutazone acts by inhibiting the cyclooxygenase enzyme system, which is responsible for synthesis of prostanoids such as PGE2. It appears to act on prostaglandin-H synthase and prostacyclin synthase, after conversion by prostaglandin-H synthase to reactive intermediates. It markedly reduces prostanoid-dependent swelling, edema, erythema, and hypersensitivity to pain in inflamed tissues. Its principal use in the horse is for treatment of soft tissue inflammation. Phenylbutazone is highly bound (greater than 98%) to plasma protein. After i.v. injection, blood levels decline with an elimination half-life of 3-10 h. The plasma kinetics of phenylbutazone may be dose dependent, with the plasma half-life increasing as the drug dosage level increases. Plasma residues of the drug at 24 h after a single i.v. dose of 2 g/450 kg average about 0.9 microgram/ml, but considerable variation occurs. If dosing is repeated, the plasma residue accumulates to give mean residual blood levels of approximately 4.5 microgram/ml on Day 5 after 4 days of dosing. Approximately similar blood levels are found after a combination of oral and i.v. dosing. Experiments on large numbers of horses in training have been undertaken to ascertain the population distributions of residual blood levels after such dosing schedules. Absorption of phenylbutazone from the gastrointestinal tract is influenced by the dose administered and the relationship of dosing to feeding. Access to hay can delay the time of peak plasma concentration to 18 h or longer. Under optimal conditions, the bioavailability of oral phenylbutazone is probably in the region of 70%. Paste preparations may be more slowly absorbed than other preparations and yield higher residual plasma levels at 24 h after dosing, but further controlled studies are required. Phenylbutazone is easily detected in the plasma and urine of horses but concentrations in saliva are low. It is quantitated for forensic purposes by HPLC. The variability of this method between laboratories is about +/- 25%. Increasing urinary pH increases the urinary concentration of phenylbutazone and its metabolites up to 200-fold.(ABSTRACT TRUNCATED AT 400 WORDS)     

An open prospective investigation into aetiology in a group of cats with suspected allergic skin disease

Abstract This prospective study evaluated the cause(s) of dermatitis in a series of cats with signs suggestive of allergic skin disease. Twenty cases completed the díagnostic evaluation, which included intradermal skin testing, a rigorous flea-control programme, and a 4-month stabilization period on a restricted protein source commercial diet, followed by rechallenge with the cat's original diet. The most common final díagnoses included flea allergic dermatitis (seven cases), and flea allergic dermatitis together with atopy (seven cases). Three additional cases which did not complete the study were also considered to be atopic. No cases were considered to be primarily associated with food hypersensitivity, an observation supporting previous data indicating this to be a rare cause of allergic skin disease in the cat. These observations emphasize the value of a rigorous flea-control programme as part of the management of many cases of feline allergic dermatitis. Résumé Une étude étiologique prospective a été réalisée dans une population de chats suspects de dermites allergiques. Des tests cutanés intradermiques ont été réalisés ainsi qu'un contrôle antipuce rigoureux et un régime d'élimination, faisant appel à une alimentation du commerce restreinte en protéines pendant 4 mois, suivi par une réintroduction de l'alimentation initiale du chat. Le díagnostic le plus fréquent est la Dermite par Allergie à la Piqûres de Puce (DAPP) (7 cas), une DAPP associée à une atopie (7 cas). Trois cas supplémentaires sont atopiques. Aucun cas n'est en rapport avec seulement une allergie alimentaire. Cette observation montre que l'allergie alimentaire est une cause rare de dermite allergique chez le chat. Ces observations confirment par ailleurs l'intérêt d'un contrôle antipuce rigoureux dans la gestion thérapeutique des dermites allergiques du chat. [O'Dair, H.A., Markwell, P.J., Maskell, I.E. An open prospective investigation into aetiology in a group of cats with suspected allergic skin disease (Etude étiologique prospective ouverte dans une population de chats suspects de dermite allergiques). Veterinary Dermatology 1996; 7 : 193–202.] Resumen Este estudio prospective evalúa la(s) causa(s) de dermatitis en un grupo de gatos con sintomas sugestivos de dermatosis alérgica. Se evaluó el díagnóstico de veinte casos, incluyendo pruebas cutáneas intradérmicas, programa riguroso de control de pulgas y un periodo de cuatro meses de estabilización con una dieta comercial con fuente de proteina restringida, seguido de una re-exposición a la dieta original del gato. El díagnóstico final más frecuente fue de dermatitis alérgica a las pulgas (siete casos) y dermatitis alérgica a las pulgas con atopia (siete casos). Tres casos más que no completaron el estudio fueron también considerados atópicos. Ninguno de los casos fue considerado estar principalmente asociado a una hipersensibilidad alimentaria, lo que apoya hallazgos previos indicativos de que este tipo de hipersensibilidad es poco frecuente en el gato. Estos hallazgos resaltan la importancia de un programa rigurosos de control de pulgas en el protocolo de manejo de muchos casos de dermatitis alérgica felina. [O'Dair, H.A., Markwell, P.J., Maskell, I.E. An open prospective investigation into aetiology in a group of cats with suspected allergic skin disease (Investigacion prospectiva abierta de la etiologia en un grupo de gatos sospechosos de dermatosis alérgica). Veterinary Dermatology 1996; 7 : 193–202.] Zusammenfassung Diese prospektive Untersuchung wertete die Fälle von Dermatitis bei einer Reihe von Katzen aus, die Symptome aufwiesen, welche auf eine allergische Hautkrankheit deuteten. Zwanzig Fälle wiesen eine vollständige díagnostische Untersuchung äuf, die intradermale Hauttests, striktes Flohbekämpfungsprogramm und eine viermonatige Stabilisierungsphase mit einer kommerziellen Diät mit begrenzten Eiweißquellen, gefolgt von einer Provokation mit dem bisher üblichen Katzenfutter, beinhaltete. Die häufigste endgültige Diagnose bestand in Flohbißdermatitis (sieben Fälle) und Flohbißdermatitis zusammen mit Atopie (sieben Fälle). Drei weitere Fälle durchliefen die Studie nicht vollständig, wurden aber als atopisch angesehen. Kein Fall wurde primär in Verbindug mit Futtermittelhypersensibilität gesehen, eine Beobachtung, die frühere Daten unterstützt, die dies als seltene Ursache bei allergischen Hautkrankheiten der Katze nennt. Diese Beobachtungen betonen die Bedeutung des genauen Flohbekämpfungsprogramms als Teil des Management vieler Fälle von allergischen Hautkrankheiten bei der Katze. [O'Dair, H.A., Markwell, P.J., Maskell, I.E. An open prospective investigation into aetiology in a group of cats with suspected allergic skin disease (Offene prospektive Untersuchung über die Ätiologie bei einer Gruppe von Katzen mit Verdacht auf allergische Hautkrankheiten). Veterinary Dermatology 1996; 7 : 193–202.]     

CEREBROSPINAL FLUID SIGNAL-VOID SIGN IN DOGS

The cerebrospinal fluid signal-void sign is an observable signal loss from cerebrospinal fluid (CSF), especially on T2-weighted magnetic resonance (MR) images. In people, this sign is attributed to rapid CSF flow or turbulence from arterial pulsations and occurs more frequently with reduced intracranial compliance. The purposes of this study were to describe the CSF signal-void sign, document whether a similar sign occurs in dogs and investigate associations between it and other conditions. The sample population consisted of 327 dogs admitted for neurocranium evaluation using a 0.2 T system. Review of the medical records and MR images was performed to characterize the presence and location of a CSF signal-void sign, ventricular size, syringomyelia, and other lesions. A CSF signal-void sign was detected in at least the mesencephalic aqueduct in 59/327 (18.0%) dogs, including some with no morphologic brain abnormality. The majority of these dogs (45/59% or 76%) weighed <15 kg. In two other dogs, a CSF signal-void sign was detected only in a cervical syrinx. In dogs weighing >15 kg, a CSF signal-void sign was seen with various conditions. In 137/327 (41.9%) dogs weighing <15 kg, the presence of a CSF signal-void sign in the aqueduct (45 dogs) was associated with syringomyelia ( P =0.0468) and increased ventricular size ( P =0.0054): syringomyelia also was associated with increased ventricular size ( P =0.0009). In conclusion, a CSF signal-void sign was seen in dogs with various conditions. In small-breed dogs, a CSF signal-void sign in the aqueduct was associated with ventricular enlargement and syringomyelia.     

Cefadroxil in the horse: pharmacokinetics and in vitro antibacterial activity

Sodium cefadroxil was administered as a single intravenous dose (25 mg/kg) to six healthy adult mares. Plasma samples were collected over a 24-h period and cefadroxil concentrations were measured by microbiological assay. The pharmacokinetic behavior of the drug was appropriately described in terms of a one-compartment open model. Values for the major pharmacokinetic terms were: extrapolated initial plasma concentration = 59.2 +/- 15.0 micrograms/ml; half-life = 46 +/- 20 min; apparent volume of distribution = 462 +/- 191 ml/kg; and body clearance = 7.0 +/- 0.6 ml/min.kg. In a subsequent study, a suspension of cefadroxil monohydrate was administered intragastrically (25 mg/kg) to the same six horses. Plasma concentrations of the drug peaked at 1-2 h but, in general, absorption was both poor and inconsistent. The data were unsuitable for determination of cefadroxil bioavailability from this oral dosage form. Ninety-nine isolates of eleven bacterial species obtained from clinically ill horses were tested for susceptibility to cefadroxil. All strains of Streptococcus equi, Streptococcus zooepidemicus, coagulase-positive staphylococci, Corynebacterium pseudotuberculosis and five out of six strains of Actinobacillus suis were highly susceptible to the drug (MIC less than 4 micrograms/ml). Escherichia coli, Klebsiella pneumoniae and Salmonella sp. showed intermediate susceptibility (MIC 4-16 micrograms/ml), while all isolates of Corynebacterium (Rhodococcus) equi, Enterobacter cloacae and Pseudomonas aeruginosa proved to be highly resistant to cefadroxil (MIC greater than 128 micrograms/ml).