Neuronal-Visceral GM1 Gangliosidosis in Portuguese Water Dogs

Three female siblings in a litter of seven Portuguese Water dogs (PWDs) showed clinical signs of ataxia and/or lameness at 5 months of age. Signs of cerebellar dysfunction (intention tremors, ataxia, widebased stance, dysmetria, and/or nystagmus) and mild limb weakness developed rapidly. Results of hemograms (three dogs), blood chemistry profiles (two dogs), urinalyses (two dogs), electroencephalograms (two dogs), and radiographs of the limbs or pelvis (three dogs), vertebrae (two dogs), and skull (one dog) were unremarkable except for an absolute lymphocytosis in one dog. Routine cerebrospinal fluid (CSF) analyses were normal in all three dogs. However, the CSF creatine kinase concentration was elevated in the one dog in which it was measured. Mucopolysacchariduria was present in all three dogs. Due to the rapid progression of clinical signs and a poor prognosis, all three dogs were euthanatized between 6 and 7 months of age. Histopathologic and electron microscopic studies showed neuronal cytoplasmic inclusions, vacuolated hepatocytes, and vacuolated renal tubular epithelial cells, compatible with the diagnosis of a storage disease. Beta-galactosidase activities in leukocytes, serum, and brain homogenates were reduced when compared with that in normal dogs and the stored product was identified as GM1 ganglioside, confirming GM1 gangliosidosis.     

Effect of desmopressin on von Willebrand factor multimers in Doberman Pinschers with type 1 von Willebrand disease

OBJECTIVE: To assess the effect of desmopressin (DDAVP) administration in Doberman Pinschers with type 1 von Willebrand disease (vWD) on plasma von Willebrand factor (vWF) multimers through determination of vWF collagen binding activity (vWF:CBA; a functional vWF assay dependent on the presence of high-molecular-weight [HMWI multimers), comparison of vWF antigen concentration (vWF:Ag) to vWF:CBA, and vWF multimer size distribution. ANIMALS: 16 Doberman Pinschers with type 1 vWD and 5 clinically normal control dogs. PROCEDURE: Plasma vWF:Ag and vWF:CBA assays and vWF multimer analysis were performed before and 1 hour after administration of DDAVP (1 microg/kg, SC). RESULTS: Following DDAVP administration, dogs with type 1 vWD had an increase in mean baseline values of plasma vWF:Ag and vWF:CBA from 10% to 17% for both variables. The mean vWF Ag:CBA ratio at baseline (0.95) was similar after DDAVP administration (0.97), indicating concordant increases in plasma vWF concentration and activity. In control dogs, mean plasma vWF:Ag and vWF:CBA increased from baseline values of 64% to 113% and 58% to 114%, respectively, and the vWF Ag:CBA ratios were unchanged (1.1 vs 1.0) after DDAVP administration. Plasma vWF multimer analysis revealed proportional increases in band intensity for all multimer sizes following DDAVP administration, in comparison to baseline for the control dogs and Doberman Pinschers with vWD, consistent with vWF Ag:CBA ratios of approximately 1. CONCLUSIONS AND CLINICAL RELEVANCE: Beneficial effects of DDAVP on primary hemostasis in Doberman Pinschers with type 1 vWD cannot be explained by preferential increases in HMW vWF multimers.     

Comparison of various canine blood-typing methods

OBJECTIVE: To compare canine blood-typing results determined by use of the card (CARD), gel (GEL), Michigan State University (MSU), and tube (TUBE) tests. SAMPLE POPULATION: Blood samples from 23 healthy dogs. PROCEDURES: Blood samples anticoagulated with EDTA were screened by use of each blood-typing method according to manufacturers' protocols. RESULTS: Strong RBC agglutination reactions were observed with dog erythrocyte antigen (DEA) 1.1 reagents of the CARD and GEL tests as well as MSU test (only after adding Coombs' reagent) in 9 blood samples. By use of the CARD test, RBCs from 4 additional dogs agglutinated weakly; on the basis of MSU test results, these 4 dogs were classified as DEA 1.2 positive. All blood samples agglutinated with the B antigen reagent of the TUBE test. All but 2 blood samples had strong positive reactions with the DEA 4 reagent of the MSU test. All but 3 blood samples reacted with the E antigen reagent of the TUBE test. Three blood samples agglutinated with the DEA 3 reagent of the MSU test and A antigen reagent of the TUBE test. Five blood samples had strong agglutination reactions with the DEA 5 reagent of the MSU test. CONCLUSIONS AND CLINICAL RELEVANCE: Use of the CARD test allows for rapid identification of DEA 1.1 but may produce weak reactions with blood from DEA 1.2-positive dogs. The GEL test is a reliable and rapid clinical laboratory method for identification of DEA 1.1. The MSU test requires Coombs' reagent for identification of DEA 1.1 and 1.2.     

Effect of romifidine on the nociceptive withdrawal reflex and temporal summation in conscious horses

OBJECTIVE: To investigate the action of a single IV administration of romifidine on the thresholds of the nociceptive withdrawal reflex (NWR) and temporal summation in conscious horses. ANIMALS: 10 adult horses. PROCEDURE: Single electrical stimulations were applied on the digital nerves to evoke NWR from the left forelimb and hind limb. Repeated electrical stimulations (10 stimuli, 5 Hz) were given to obtain temporal summation. Surface electromyographic reflex activity was recorded from the common digital extensor and cranial tibial muscles. After baseline assessment of NWR and temporal summation thresholds, romifidine (80 microg x kg(-1), IV) was administered. Successive determinations of NWR and temporal summation thresholds were performed 5, 25, and 55 minutes after administration. RESULTS: Romifidine significantly increased the current intensities necessary to evoke NWR and temporal summation in forelimbs and hind limbs of horses. Values were significantly higher than baseline values 55 minutes after romifidine administration. After administration of romifidine, a facilitation of reflex components of tactile origin was observed when repeated stimulations were applied. CONCLUSIONS AND CLINICAL RELEVANCE: Results confirm antinociceptive activity of romifidine and may represent an objective demonstration of the well-known hypersensitivity to tactile stimuli observed in horses receiving alpha2-adrenoreceptor agonists in clinical practice. Romifidine can be included in analgesic and anesthetic protocols to provide additional analgesia in horses.     

Understanding Management Decisions of Absentee Landowners: More Than Just Presence-Absence

Ownership and management of North American rangelands has become increasingly diverse, prompting a need to better understand how changing demographics and values relate to individual land management decisions and land cover. Absentee landowners, who reside away from their rural property, are a growing segment of this changing social landscape. The implications of absentee ownership are not clearly understood, perhaps because the absentee concept is ambiguously defined and inconsistently specified. We introduce the construct of involvement with one’s land to clarify and reframe the absentee landowner concept. We analyzed data from a mail survey of rangeland owners in central Texas to explore the relationship between absentee land ownership and the use of brush management to restore woody-plant invaded grasslands. We employed an information-theoretic approach to compare candidate models using indicators of absenteeism (permanent residence on land and distance of permanent residence from land) and involvement. We measured involvement with one’s land as hours per week operating or working one’s land. We conducted path analysis to examine the relationship between absenteeism and brush management as a function of involvement. Involvement in land management was the best predictor of brush management behavior. Absenteeism, as measured through presence-absence or as distance from land, had no relationship with brush management unless mediated by the involvement construct. Segmenting landowners based solely on the location of their full-time residence provides little information on brush management behavior because it neglects the relationship that landowners may have with their land, regardless of residency. The absentee landowner concept is central to understanding the dynamics of rangeland management and important to get right. Our analysis suggests that getting it right means knowing more than the location of the residence of the landowner.