Evaluation of propofol and medetomidine-ketamine for short-term immobilization of Gulf of Mexico sturgeon (Acipenser oxyrinchus de soti).

Parenteral anesthetic protocols for short-term immobilization were evaluated in twenty 4-yr-old Gulf of Mexico sturgeon (Acipenser oxyrinchus de soti). An initial dose-response trial determined the efficacy of either propofol (3.5-7.5 mg/kg. i.v.) or combinations of medetomidine (0.03-0.07 mg/kg, i.m.)-ketamine (3-7 mg/kg, i.m.). A subsequent study evaluated the physiologic effects of propofol (6.5 mg/kg, i.v.)-induced anesthesia and anesthesia induced with a medetomidine (0.06 mg/kg, i.m.)-ketamine (6 mg/kg i.m.) combination. The effects of medetomidine were reversed at 30 min with atipamezole (0.30 mg/kg, i.m.). Both drug protocols provided adequate short-term immobilization for minor diagnostic procedures. Sturgeon receiving propofol were in a light plane of anesthesia within 5 min after drug administration, whereas only 30% of the medetomidine-ketamine group reached a light plane of anesthesia in the same time period. Both propofol and medetomidine-ketamine resulted in mild bradycardia and apparent respiratory depression, with propofol producing more profound effects. At the dosages used in this study, both propofol and the medetomidine-ketamine combination effectively induced a light plane of anesthesia. Induction times were shorter in the propofol group.     

史氏鲟饲料中脂肪的最适含量

本文报道了史氏鲟饲料脂肪最适含量的结果。试验饲料是以酪蛋白、鱼粉、糊精和纤维素等为主要原料配制而成的等氮（蛋白质含量４１％）和等能量的（１１．２ＭＪ／ｋｇ饲料）半精制饲料,以等量混合的海水鱼油、豆油作为添加的脂肪源,设０、２、４、６、８和１０％６种添加浓度。试验周期为２５ｄ。试验结果显示,增重率、饲料系数和蛋白质效率均以脂肪含量７．６％～９．６％的４、５组饲料最佳,比脂肪含量分别为１．６％和３．６％的１、２组饲料差异显著,但与脂肪含量分别为５．６％和１１．６％的３、６组饲料差异不显著。如果考虑到饲料成本,把史氏鲟饲料脂肪的最适合量设定在８％左右是合适的。     

Morphological structure and peripheral innervation of the lateral line system in the Siberian sturgeon (Acipenser baerii)

Light and scanning electron microscopy (SEM) were used to study the epidermal lateral line system of the Siberian sturgeon (Acipenser baerii Brandt, 1869). This system consists of mechanoreceptive neuromasts, ampullae and the electroreceptive organ. The neuromasts are located in 5 pairs of cephalic and 1 pair of trunk canals and superficially in the middle and posterior pit lines that lie dorsomedially along the top of the skull immediately adjacent to the otic ampullae field. Both canal neuromasts and pit organ superficial neuromasts have opposite polarized hair cells that are parallel along the axis of the canal and pit line, respectively. However, they differ in both size and shape and in the density and length of the hair bundles. The ampullae are confined on the head, adjacent to the neuromast lines. The morphological structure of the ampullae in the Siberian sturgeon is similar to the ampullae in elasmobranchs and other primitive fish. Nevertheless, it has a relatively large mucus-filled ampulla, and a shorter and narrower canal leading to a small opening to the outer epidermal surface. We also present new information concerning the peripheral innervation of lateral line receptors in sturgeons. The receptors of the lateral line system are innervated by 2 pairs of cranial nerves: anterior and posterior lateral line nerves. The peripheral processes of the anterior lateral line nerve form superficial ophthalmic, buccal, otic and anteroventral rami. The peripheral processes of the posterior lateral line nerve form middle, supratemporal and lateral rami.     

Mortality and recovery of runt white sturgeon (Acipenser transmontanus) in a commercial farm in California, USA

We investigated the effect of raising runt white sturgeon (Acipenser transmontanus) separately from dominant fish during the initial stages of grow-out in a commercial farm. Runt fish are poor-growers, have underdeveloped muscle mass, swim slowly and are more-frequently found at the top of the water column. The objective of the study was to describe the mortality and recovery rates (and their determinants) of white-sturgeon runts after separating them from dominant fish. Runt white sturgeon were stocked into twelve 2 m × 2 m rectangular tanks and graded periodically during a follow-up of 46–102 days. Overall mortality rates ranged from 0.3 to 7 dead fish per 1000 sturgeon-days at risk and overall recovery rates from 3.9 to 13.5 recovered fish per 1000 sturgeon-days at risk. Period-specific mortality and recovery rates increased over time. The period-specific mortality rates for all three periods were significantly higher for tanks of runts originating from grow-out tanks with high mortality (p-values: first period = 0.06; second period = 0.09; third period = 0.03), but were similar for tanks of runts of high- and low-mean initial weight. The period-specific recovery rates were significantly higher in runts originating from high-mortality grow-out tanks only for the third period (p = 0.05) but not the first and second periods (p-values = 0.33 and 0.25, respectively). Recovery rates were significantly higher in the higher-mean-weight runts tanks for the first and third period but not for the second (p-values: first period = 0.02; second period = 0.65; third period = 0.06). We concluded that the proportion of runts that recover during a 46–89 day period is substantial (16–58%); therefore, it might be worthwhile growing such fish separately in a fish farm for about three months. Financial analysis showed that this practice was profitable, if the value of white sturgeon fish for the farm exceeded $2.05 per kg.     

Cecal impaction due to dysautonomia in a llama (Lama glama).

A llama (Lama glama) died after 1 wk of obstipation, lethargy, and rolling. Necropsy showed that the stomach and small intestine were distended with gas and fluid. The cecum was impacted with dry contents and the colon was empty. No gross lesions were found in the wall of the gastrointestinal tract or other organs. Histologic changes consisted of chromatolysis of neurons of autonomic ganglia, enteric plexi, and the accessory cuneate nucleus, consistent with lesions associated with dysautonomia in other domestic animals.     

不同年龄的养殖中华鲟和野生洄游亲鱼组织脂肪酸组成

对3个年龄(0.5、3和16龄)的养殖中华鲟(摄食鲟鱼饲料)和28龄野生洄游亲鱼肌肉和肝脏中14种常规脂肪酸相对含量和组成进行了分析比较.结果表明:各龄中华鲟肌肉和肝脏中,单不饱和脂肪酸含量最高(32.8%～38.7%及30.6%～46.9%),以18:(n-9)为主;饱和脂肪酸中含量最高的是16:,多不饱和脂肪酸中含量最高的是20:(n-6)和18:(n-6);20:(n-9)含量随年龄增大而减小,20:(n-6)含量随年龄增大而增大.28+洄游中华鲟肌肉中18:(n-9)、20:(n-6)和单不饱和脂肪酸总量高于养殖鱼,而多不饱和脂肪酸总量最低.养殖中华鲟肌肉中16:高于肝脏,28龄野生鱼则肌肉中低于肝脏.通过系统聚类,0.5+与16+中华鲟肌肉和肝脏中脂肪酸舍量最为接近,0.5+与3+鲟较为接近,其中鱼的营养状况起主导作用,年龄差距起辅导作用.比较结果提示:在人工养殖中华鲟时,有必要在其饲料中添加适量含18:(n-9)MUFA的植物油或投喂富含18:(n-9)鲤、鲫鱼可能会达到较好的效果.     

Growth of white sturgeon (Acipenser transmontanus) following recovery from the stunted stage in a commercial farm in California, USA

Runt white sturgeon (Acipenser transmontanus) develop during grow-out and are characterized by atrophied muscles and decreased growth. Our first objective was to compare the growth (and body condition) of previously-runt white sturgeon after they recovered from the runt state and sturgeon that had never been runts. On 12 occasions, recovered runts and age- and size-matched controls that had never been runts were tagged and put in a tank that already contained fish of similar age and size. Tagged groups were followed for 119–134 days. Median relative growth rates (RGRs) of the recovered runts were significantly (p ≤ 0.05) higher than those of the controls in three tanks. Multiple linear regression was used to model final weight as a function of initial weight and status (recovered runt or control). Status was not significantly related (p = 0.71) to final weight, after adjusting for initial weight, “tank” and time of follow-up. Our second objective was to determine factors that influenced the loss of tags by white sturgeon during the follow-up period. Logistic regression analysis indicated that higher initial weight and being a control fish might have been associated with losing both tags. We concluded that once white sturgeon runts recovered and started growing, they grew at least as well as fish that had never been runts.     

Partial tracheal obstruction due to chondromas in ball pythons (Python regius).

Over a 9-mo period, three adult ball pythons (Python regius) (one male, two females) were evaluated for severe dyspnea. Partial obstructions of the tracheal lumen were identified radiographically and/or visualized with a 3.0-mm rigid laparoscope inserted into the tracheal lumen in all three snakes. Administration of systemic antibiotics and nebulization resulted in partial improvement of the dyspnea. In two snakes, the tracheal lesions were removed with a rigid laparoscope and a flexible biopsy instrument inserted into the tracheal lumen. The other snake died and was necropsied. Histologically, the lesions from two snakes were determined to be benign chondromas. The chondromas were composed of a variably disorganized chondroid matrix populated by quiescent, normal-appearing chondrocytes within lacunae, although the chondrocytes were increased in density compared with normal hyaline cartilage and contained rare mitotic figures. The tracheal masses in one snake grew by expansion, not invasion, and were focally continuous with a mineralized cartilage tracheal ring, suggesting a benign nature. This is the second report of tracheal chondroma in ball pythons. Tracheal chondromas are exceedingly rare in humans and domesticated animals, suggesting a possible predisposition of ball pythons for this neoplasm.     

Compressive myelopathy due to intervertebral disk extrusion in a llama (Lama glama).

A 12-year-old intact female llama was euthanized following acute onset of spastic tetraparesis and recumbency with inability to rise. Postmortem examination revealed caudal cervical spinal cord compression due to a mass within the ventral spinal canal arising from the C6-C7 intervertebral disk space and attached to an irregularly thickened annulus fibrosis. On histopathologic examination, the mass was composed of amorphous acellular basophilic to amphophilic material admixed with irregularly arranged collagen bundles. The amorphous material was metachromatic and contained multiple small foci of markedly vacuolated round cells, characteristic of origin from the nucleus pulposus. Severe necrosis of all white matter tracts with astrocytic reaction was present in the overlying spinal cord segment. Ascending and descending Wallerian degeneration and dissecting interstitial astrogliosis were present within white matter tracts above and below the lesion, respectively. The diagnosis was compressive myelopathy due to chronic extrusion of the nucleus pulposus of the C6-C7 intervertebral disk. To the authors' knowledge, this is the first report of intervertebral disk disease in a camelid.     

Disseminated mycobacteriosis due to Mycobacterium avium in captive Bengal tiger (Panthera tigris).

A 2-year-old captive female Bengal Tiger (Panthera tigris) died after prolonged anorexia in the Gwangju Uchi Park Zoo, Gwangju, Republic of Korea. Necropsy revealed multiple nodules of varying sizes in the lung, liver, kidney, and spleen. Histopathologic examination revealed a typical granuloma composed of caseous necrotic areas surrounded by lymphocytes with a few giant cells and foamy macrophages. Periodic acid-Schiff stain and Gomori methenamine silver stain did not reveal any fungal bodies. The Ziehl-Neelsen acid-fast stain revealed few acid-fast organisms in the lung, liver, kidney, and spleen. A polymerase chain reaction assay of the lung, liver, kidney, and spleen yielded a positive result for Mycobacterium avium subsp. avium. This is an unusual case of disseminated infection of a wild mammal with avian mycobacteriosis, and is believed to be most likely associated with the feeding of tigers with culled chickens infected with M. avium.     

Surgical correction of polydactyly in a camel (Camelus dromedarius).

A 2-mo-old, 90-kg, intact male camel (Camelus dromedarius) was admitted for surgical removal of a supernumerary digit associated with the medial aspect of the right carpus and metacarpus. Radiographic views of the carpus and metacarpus revealed the supernumerary digit articulating with the middle carpal joint via an extra carpal bone. The supernumerary digit consisted of three bones. Surgical removal of the supernumerary digit was recommended to restore normal limb conformation, limit the possibility of future lameness, and improve the cosmetic appearance of the limb. Complete surgical removal of the digit was performed by disarticulating the extra carpal bone from its attachments to the second and radial carpal bones. One year after surgery, the leg appeared grossly normal and the camel showed no sign of lameness.     

Development of glaucoma after phacoemulsification for removal of cataracts in dogs: 22 cases (1987-1997)

OBJECTIVE: To determine factors contributing to glaucoma after lens extraction via phacoemulsification in dogs. DESIGN: Retrospective study. ANIMALS: 22 dogs (29 eyes) with glaucoma and 21 dogs (30 eyes) without glaucoma after phacoemulsification. PROCEDURE: Medical record review. RESULTS: Eyes at increased risk for glaucoma included those of Boston Terriers, those with uveal or retinal abnormalities before surgery, and those with intraoperative intraocular hemorrhage. Significant differences between groups were not detected for incidence of preoperative lens-induced uveitis, presence of an intraocular lens, or frequency of an acute postoperative increase in intraocular pressure. Glaucoma developed (mean +/- SD) 12.8+/-14.1 months (median, 10 months; range, 0.25 to 55 months) after surgery. Eighteen of 29 (62%) eyes with potential for vision after onset of glaucoma retained vision for a mean of 16.5+/-12.8 months (median, 10.8 months; range, 1.5 to 37 months) after glaucoma was diagnosed. Most of these eyes still had vision at the conclusion of the study period. CONCLUSIONS AND CLINICAL RELEVANCE: Risk factors identified by this study will aid in preoperative counseling of clients and refining selection criteria for candidates for phacoemulsification. Careful follow-up for the remainder of the dog's life after surgery may improve long-term success rates by permitting early intervention before intraocular pressure increases substantially and vision is irreversibly lost. Surgery for cataracts may still be worthwhile in dogs with increased risk of glaucoma, especially if elderly, because of the lengthy period to onset of glaucoma after surgery and the beneficial effects of treatment after glaucoma develops.     

Zinc toxicosis due to ingestion of a penny in a gray-headed chachalaca (Ortalis cinereiceps).

Zinc toxicosis was diagnosed in a gray-headed chachalaca (Ortalis cinereiceps) due to ingestion of a copper-plated zinc penny. Histopathological lesions were most marked in the pancreas. These lesions included apoptosis, zymogen granule depletion, and loss of normal acinar architecture. There was also severe gizzard erosion. Heavy metal analysis revealed abnormal levels of zinc and iron in the liver. Iron pigment in the liver was most concentrated in Kupffer cells. This, along with evidence of erythrophagocytosis in the spleen, suggested that extravascular hemolysis was also associated with zinc toxicosis in this case.     

Cholelithiasis in four callitrichid species (Leontopithecus, Callithrix).

Medical records of three male and three female callitrichids of four species (Leontopithecus chrysopygus, Leontopithecus rosalia, Callithrix argentata argentata, Callithrix kuhlii) diagnosed with cholelithiasis were reviewed. Ages of affected animals at the time of diagnosis ranged from 2-14 yr. Definitive antemortem diagnosis of cholelithiasis was made in four of the six cases. Chronic weight loss, lethargy, and weakness were seen in all cases. Chronic intermittent diarrhea was seen in three cases. Icterus and abnormal gait were each present in two of the animals. Hematologic and serum biochemical abnormalities included leukocytosis in five cases, elevated bilirubin (direct and indirect) in four cases, and anemia in four cases. Radiographic evidence of choleliths was observed in three cases. Surgical removal of choleliths was successfully performed on two animals. Full necropsies were performed on all cases, and choleliths were believed to contribute to morbidity in all cases. However, inflammatory bowel disease was determined to be the primary cause of weight loss and mortality in at least three animals. All choleliths analyzed were pigment stones, two being primarily composed of cystine.     

Outbreaks of egg drop syndrome due to EDS-76 virus in quail (Coturnix coturnix japonica).

Two outbreaks of the egg drop syndrome were observed in quail flocks maintained on a farm together with chickens. The decrease in egg production ranged from 10.6 per cent to 50.6 per cent, and the number of soft-shelled eggs increased with the decline in egg production. In both the outbreaks haemagglutination inhibiting antibodies to EDS-76 virus were detected. Fluorescent viral antigen specific to EDS-76 virus was also detected in the lining epithelial and glandular cells of the uterus.     

Surgical technique for tubal ligation in white-tailed deer (Odocoileus virginianus).

Surgical tubal ligation was used to sterilize urban free-ranging white-tailed deer (Odocoileus virginianus) as a methodology of a larger study investigating the influences of intact, sterile females on population dynamics and behavior. Deer were either trapped in clover traps (n = 55) and induced with an i.m. injection of xylazine and tiletamine/zolazepam or induced by a similar protocol by dart (n = 12), then intubated and maintained on isoflurane in oxygen. Over 3 yr, individual female deer (n = 103) were captured in Highland Park, Illinois, with a subset of females sterilized using tubal ligation by ventral laparotomy (n = 63). Other sterilization procedures included tubal transection by ventral (n = 1) or right lateral (n = 2) laparoscopy and ovariohysterectomy by ventral laparotomy (n = 1). One mortality (1/ 67, 1.5%) of a doe with an advanced pregnancy was attributed to a lengthy right lateral laparoscopic surgery that was converted to a right lateral laparotomy. The initial surgical modality of laparoscopy was altered in favor of a ventral laparotomy for simplification of the project and improved surgical access in late-term gravid does. Laparotomy techniques included oviductal ligation and transection (n = 14), application of an oviductal mechanical clip (n = 9), ligation and partial salpingectomy (n = 40), and ovariohysterectomy (n = 1). As of 2 yr poststerilization, no surgical does were observed with fawns, indicating that these procedures provide sterilization with low mortality in urban white-tailed deer.     

Intracapsular lens removal in a Przewalski's wild horse (Equus caballus przewalskii).

A 11.5-yr-old female Przewalski's wild horse (Equus caballus przewalskii) presented for unilateral blepharitis and drainage from the left eye. The left cornea was not ulcerated, and intraocular evaluation was hampered by severe corneal edema. The left eye appeared to respond positively to treatment with anti-inflammatories and a topical mydriatic agent. During the ensuing 2 yr, there were minor episodes of epiphora from the left eye. The discharge then increased, and a luxated lens was noted during an examination by a veterinary ophthalmologist as part of the preshipment examination. Initially, the lens was located in the anterior compartment but was in the vitreal compartment at the time of surgery, complicating the intracapsular extraction. After successful removal of the lens, the horse was transferred to a new institution without incident, where it appears to have adapted well to its probable loss of vision in the left eye. No further episodes of uveitis, corneal edema, or epiphora have been reported, and the horse has successfully foaled at the new institution.