The influence of age on patellar reflex response in the dog

The patellar tendon reflex is a clinical parameter commonly used to assess neurological status. Factors such as quadriceps muscle fiber composition, femur length, and patient age have been reported to influence total and fractionated reflex times in human beings. The purpose of this blinded, cross-sectional study was to examine the effect of age on the patellar reflex in the dog. Eighty-six dogs without evidence of neurological impairment or orthopedic disease of the stifle (eg, patellar luxation or cranial cruciate ligament rupture) were assigned to 1 of 2 groups on the basis of age: group 1, <10 years old (n = 72); or group 2, > or =10 years old (n = 14). Patellar reflexes were elicited in both pelvic limbs by a reflex hammer while the dog was in lateral recumbency. The reflex was scored as present or absent by a blinded individual. Two dogs in group I had reflexes absent in both limbs, 3 dogs in group 2 had reflexes absent in both limbs, and 1 dog in group 2 lacked a response in 1 limb. The proportion of dogs with absent patellar reflexes in group 2 (4 of 14, 95% CI, 8-58%) was significantly higher than the proportion of dogs with absent patellar reflexes in group 1 (2 of 72, 95% CI, 0-10%) (P < .006). Furthermore, dogs lacking at least 1 patellar reflex were older than those having both reflexes present (P = .04). Weight was not related to the presence of both reflexes (P = .49). These findings suggest that neurologically normal dogs may have an age-dependent decline in patellar reflex magnitude or a prolongation of total reflex time (TRT).     

Primary cutaneous plasmacytomas in the dog and cat

The clinical, light microscopic and ultrastructural features of twelve cases of primary cutaneous plasmacytomas are described (11 dogs and one cat). The tumours were solitary in all but one case, tended to grow rapidly but did not recur after removal and had a predilection for the feet, lips and ear canal. Primary cutaneous plasmacytomas should be considered in the differential diagnosis of round cell tumours of the canine and feline skin. They appear to be benign tumours unrelated to the malignant disease of myelomatosis.     

Feasibility and repeatability of cold and mechanical quantitative sensory testing in normal dogs

Feasibility and inter-session repeatability of cold and mechanical quantitative sensory testing (QST) were assessed in 24 normal dogs. Cold thermal latencies were evaluated using a thermal probe (0 °C) applied to three pelvic limb sites. Mechanical thresholds were measured using an electronic von Frey anesthesiometer (EVF) and a blunt-probed pressure algometer (PA) applied to the dorsal aspect of the metatarsus. All QST trials were performed with dogs in lateral recumbency. Collection of cold QST data was easy (feasible) in 19/24 (79%) dogs. However, only 18.4%, 18.9% and 13.2% of cold QST trials elicited a response at the medial tibia, third digital pad and plantar metatarsal regions, respectively. Collection of mechanical QST data was easy (feasible) in 20/24 (83%) dogs for both EVF and PA.At consecutive sampling times, approximately 2 weeks apart, the average EVF sensory thresholds were 414 ± 186 g and 379 ± 166 g, respectively, and the average PA sensory thresholds were 1089 ± 414 g and 1028 ± 331 g, respectively. There was no significant difference in inter-session or inter-limb threshold values for either mechanical QST device. The cold QST protocol in this study was achievable, but did not provide consistently quantifiable results. Both mechanical QST devices tested provided repeatable, reliable sensory threshold measurements in normal, client-owned dogs. These findings contribute to the validation of the EVF and PA as tools to obtain repeated QST data over time in dogs to assess somatosensory processing changes.     

Anal sphincter pressure and the rectosphincteric reflex in the dog

Anal sphincter pressure (ASP) was measured in healthy conscious dogs, and the rectosphincteric reflex that causes inhibition of the internal sphincter was identified. Pressures were measured in 6 dogs by use of a perfused miniature 4-lumen catheter. To identify the rectosphincteric reflex, a balloon (fitted over the distal opening of the catheter) was insufflated with 25 ml of air. Mean (+/- SE) ASP was 74.7 +/- 4.2 mm of Hg. When the rectosphincteric reflex was stimulated by balloon distension, ASP decreased to 35.9 +/- 4.9 mm of Hg. The reduction in pressure persisted for 22 +/- 1.5 s, and ASP returned to predistension values, despite the maintenance of balloon distension. Atropine did not affect ASP or its reduction during balloon distension.     

Accuracy and repeatability of beef carcass longissimus muscle area measurements

This study was conducted to determine the accuracy and repeatability of beef carcass longissimus muscle area (LMA) measurements obtained by three different methods. Longissimus muscle area for beef carcass sides (n = 100) randomly selected in a commercial packing plant was determined: 1) independently by three USDA grading supervisor "experts" using the grid method to obtain triplicate measurements of the same longissimus muscle (LM); 2) by three different Colorado State University personnel tracing the LMA on acetate paper and subsequently measuring the area via a polar planimeter three different times (total of 3 x 3 = 9 observations/LM); and 3) by use of two identical video image analysis (VIA) instruments making triplicate measurements for each LM using three different procedures. Video image analysis Procedure 1 required that LMA be measured by placing the camera head unit over the LM and collecting three sequential images without moving the camera head unit while carcasses were in a stationary position; Procedure 2 required measurement of LMA by placing the camera head unit over the LM and collecting three images, but removing and repositioning the camera head unit between collection of each image while carcasses were in a stationary position; and Procedure 3 required that LMA be measured by placing the camera head unit over the LM and obtaining an image while carcasses were in continuous motion (chain speed of 360 carcasses/ h) during three different circulations past the grading stand. Overall, VIA-derived LMA measurements were highly accurate for all three procedures compared with expert-gridded (R2 = 0.92, 0.90, and 0.84 for Procedures 1, 2, and 3, respectively) and acetate/planimeter-traced (R2 = 0.94, 0.93, and 0.86 for Procedures 1, 2, and 3, respectively) LMA measurements. Instrument LMA repeatability also was comparable to expert-gridded and acetate/planimeter-traced LMA repeatability, as the means of the absolute differences between individual measurements and the average of those same measurements per LM were 1.29, 1.35, 0.52, 0.84, and 1.87 cm2 for expert-gridded, acetate/planimeter-traced, and VIA Procedures 1, 2, and 3, respectively. Therefore, VIA instrumentation can be used to assess beef carcass LMA in both a stationary and operational scenario with high levels of accuracy and repeatability.     

古典式条件反射原理在工作犬训练中的应用

生理学家巴甫洛夫以犬为对象，通过采用一种原来与犬无关的条件刺激(如灯光)，与另一种对犬有生物学意义的非条件刺激(如食物)结合作用，引起犬出现食物反应(唾液分泌)，并经过多次重复结合后，只要单独使用灯光刺激而不用再结合食物，同样能引起食物反应，这说明灯光对犬已具有食物信号意义。犬的这种行为的产生把它称为条件反射。它的反应程序是刺激在前，行为在后，行为是刺激的结果，犬对刺激的反应是既定的。它的联系表现为：刺激——动作——强化——条件信号活动。     

Significance of the oculocardiac reflex during ophthalmic surgery in the dog

Antimuscarinic drugs were intentionally excluded from the anaesthetic protocol used in 72 dogs undergoing a variety of ophthalmic surgical procedures. Following premedication with acepromazine and morphine, anaesthesia was induced with thiopentone and maintained with halothane vaporised in oxygen and nitrous oxide. Muscle relaxation was achieved in all dogs using either vecuronium or atracurium and ventilation was controlled to produce mild hypocapnia. Only one patient showed electrocardiographic and arterial blood pressure changes that could be attributed to the oculocardiac reflex. This indicates that the reflex is of minor clinical importance when anaesthesia results in good muscle relaxation, mild hypocapnia and adequate unconsciousness. When these conditions are present the routine use of atropine or glycopyrrolate is unwarranted during ocular surgery in the dog.     

The intra‐ and intertester repeatability of radiographic elbow incongruity grading is high in chondrodystrophic dog breeds

Elbow incongruity is a form of elbow dysplasia that causes osteoarthritis, pain, and lameness, and it is common in chondrodystrophic dog breeds. The objective of this retrospective secondary analysis study was to evaluate the intra‐ and interobserver repeatability of a novel radiographic incongruity grading system for assessing elbow incongruity in three chondrodystrophic dog breeds—the dachshund, Skye Terrier, and Glen of Imaal Terrier. We conducted an observer agreement study that included 220 mediolateral antebrachial radiographs from 110 dogs with the elbow in 90° flexion. The radiographs were independently assessed by three observers at three time points, using a four‐stepped grading scale. The proportion of agreement and Kappa coefficient were calculated. Both the intra‐ and interobserver proportions of agreement were substantial when three grades were required to be identical (.705‐.777 and .609, respectively), and almost perfect for two identical grades (.991‐1.000 and .991, respectively). Some differences in repeatability between breeds were noted; specifically, the intraobserver repeatability was higher in the dachshund, and the interobserver repeatability was lower in the Glen of Imaal Terrier. Our study showed that the radiographic imaging protocol and incongruity grading system have high repeatability when assessing elbow incongruity in chondrodystrophic dog breeds.     

The development of multiple cutaneous inverted papilloma following ovariohysterectomy in a dog

Abstract

CASE HISTORY: Ovariohysterectomy was performed on an adult Cavalier King Charles Spaniel. The skin that had been clipped for surgery was noticed to be erythematous 8 days later.

CLINICAL AND PATHOLOGICAL FINDINGS: Poorly defined patches containing multiple papules were visible bilaterally within the clipped skin. These became larger over the following 2 weeks, and samples were collected for histology. Seven days later, the lesions were multiple raised masses, up to 5 cm in diameter. Histology revealed numerous cup-shaped epidermal proliferations extending into the dermis. The presence of keratinocytes with increased quantities of blue-grey cytoplasm, and koilocytosis suggested papillomavirul infection; Canis familiaris papillomavirus (CfPV-2) DNA was amplified from two separate samples. Complete regression was observed 8 weeks after the lesions had been initially observed.

DIAGNOSIS: Multiple inverted papilloma confined to skin that had been clipped for surgery.

CLINICAL RELEVANCE: This is the first time that the development of canine cutaneous papillomas has been associated with surgery. The nature of the association between surgery and development of the papillomas is uncertain. However, it is possible that damage to superficial skin could promote the formation of papillomas. This is the first identification of CfPV-2 in New Zealand.     

Use of innate behaviors to evaluate sensory function in the dog

The need to evaluate sensory function in the dog is discussed. A group of techniques that use innate behaviors (species-typical behaviors) and are effective in the evaluation of sensory function of domestic animals are described. Techniques to measure olfactory, gustatory, auditory, and visual function are included.     

Cutaneous smooth muscle tumors in the dog and cat

Cutaneous smooth muscle tumors may arise from arrector pili muscles and from smooth muscles of the dermal vasculature. This report describes histologic and immunohistochemical features of eight arrector pili hamartomas in 8 dogs, 15 piloleiomyomas in 10 dogs and 3 cats, 10 piloleiomyosarcomas in 9 dogs and 1 cat, 1 angioleiomyoma in 1 cat, and 9 angioleiomyosarcomas in 6 dogs and 3 cats. Hamartomas and tumors arising from arrector pili muscles preferentially originated from the dorsal trunk. 5/5 (100%) arrector pili hamartomas, 10/12 (83%) piloleiomyomas, 4/5 (80%) piloleiomyosarcomas, 1/1 (100%) angioleiomyoma, and 6/7 (86%) angioleiomyosarcomas were positive for smooth muscle actin. 5/5 (100%) arrector pili hamartomas, 10/12 (83%) piloleiomyomas, 4/5 (80%) piloleiomyosarcomas, 1/1 (100%) angioleiomyoma, and 1/7 (14%) angioleiomyosarcomas were positive for desmin. Two incompletely excised canine angioleiomyosarcomas recurred locally. Metastases were not reported.     

Hypotension and cutaneous reactions associated with intravenous administration of etoposide in the dog

A study was undertaken to determine the pressor and toxic effects of etoposide, an antineoplastic agent, when administered IV in 0.9% sodium chloride solution (0.4 mg of etoposide/ml) over a 30-minute period to dogs at a dosage of 40 mg/m2 of body surface. On day 1, 6 adult German Shorthaired Pointers were anesthetized with halothane, and blood pressures were measured via a femoral artery catheter before, during, and after the etoposide was administered. Systolic, diastolic, and mean blood pressures of each dog decreased [corrected] significantly (P less than 0.01) within 30 minutes after initiation of etoposide infusion. On day 3, when the dogs were not anesthetized, etoposide was again administered to each dog, using the same dosage. Each dog developed a moderate to severe cutaneous reaction characterized by moderate to severe pruritus, urticaria, and swelling of the head and extremities that began during the second infusion of etoposide. These same cutaneous reactions were seen on day 30, when etoposide was administered to 3 of the previously treated dogs and 2 previously untreated Beagles. We concluded that the administration of the commercial preparation of etoposide is likely to cause a significant reduction in blood pressure of anesthetized dogs, and that the drug is likely to induce a moderate to severe cutaneous reaction when administered to unanesthetized dogs.     

Unusual muscle and tendon disorders of the forelimb in the dog

Five dogs with unusual muscle and tendon disorders of the forelimb are described. In one dog, mineralisation of the tendon of insertion of the supraspinatus muscle was treated surgically but lameness returned following the resumption of exercise. Of two cases of avulsion of the origin of the extensor carpi radialis muscle, one was successfully managed conservatively while the other needed surgical intervention to resolve the lameness. A single case of chronic avulsion/rupture of the tendon of insertion of the extensor carpi radialis muscle was successfully managed conservatively while a case of medial displacement of the biceps brachii tendon was surgically corrected by repair of the transverse humeral ligament. The aetiology, diagnosis and management of the above conditions is discussed.