Diaphragmatic hernia in a two-year-old alpaca (Vicugna pacos)

A 2-yr-old male intact alpaca (Vicugna pacos) was admitted for a 4-day history of anorexia and colic. Five months prior, the alpaca had undergone surgical removal of a duodenal trichophytobezoar and had recovered uneventfully. The alpaca died under anesthesia, and diaphragmatic herniation of the third gastric compartment (C3) was diagnosed at necropsy. A defect was identified in the left dorsal hemidiaphragm accompanied by herniation of 80% of C3 and the aboral portion of the second gastric compartment into the pericardial sac. The smooth margins and dorsal location of the diaphragmatic defect suggested a congenital origin. Diaphragmatic herniation is uncommon in camelids, and only one other case has been reported. Due to the dorsal location of the diaphragmatic defect in this animal, positioning during the previous surgery may have initiated a partial entrapment of gastric compartments, leading to a more complete incarceration between when the animal was discharged and presented again.     

Histological characterization of umbilical cord in alpaca (Vicugna pacos)

The histomorphometric features of umbilical cord constituents in seven foetuses of alpaca (Vicugna pacos) from Cerro de Pasco, Department, Peru, were determined. Sections of 2–5 cm of umbilical cord were fixed in 10% neutral buffered formalin and processed for light microscopy. Standard histological slides stained with haematoxylin and eosin, Masson's trichrome and Van Gieson's trichrome were obtained. Histologically, common features of umbilical artery and vein were observed as well as mucous connective tissue, some cell features that compound this tissue constituted by cells presented features of myofibroblasts. Among most important findings that were observed, the lumen of umbilical vein was obliterated into star‐shaped form with the thinner umbilical artery wall; the smooth muscles and fibroblast were comparatively more in number in umbilical artery than that of umbilical vein, and the tunica media was larger in dimension than the tunica adventitia in umbilical vein. Conclusively, this histological study features an observation of the umbilical cord of alpaca foetuses and shows the similarity between them and those of other mammal species, including dromedaries and South American camelids.     

Treatment of a periradicular lesion in an alpaca (Vicugna pacos)

This case report describes the diagnosis and surgical treatment of a cyst-like periradicular lesion in an alpaca.     

Morphology of alpaca (Vicugna pacos) embryos in the first third of pregnancy

The breeding of South American camelids is the main economic activity of the high Andean region of South America and it, is potentially, the most profitable resource in of the Puna environmental conditions of the Puna. The duration of the gestation in alpaca is 339.7 ± 12 days. The objective of the present work was to macroscopically and microscopically describe the ontogenic development of the splanchnic cavities of the alpaca and to determine the gestational time in which the post‐cranial ossification centers are observed in the embryos/fetuses of this species, from day 21 to 107 of gestation. The documentation of normal ontogenic development, which is vacant for this period, is of the utmost importance to understand the consequences of the alterations at the different gestational times, as well as for the estimation of the gestational age in the case of abortions. Forty‐seven alpaca specimens of both sexes, at different times of their gestational development, collected during slaughter at local slaughterhouses of the Department of Huancavelica, Peru, were evaluated. Specimens were assigned to seven groups according to their morphological characteristics. The embryogenesis in the alpaca was characterized by a series of changes comparable to those occurring in other mammals with similar gestational periods. Despite these similarities, species differences were found in some organs as stomach, which are observed too in adult individuals.     

Bovine xenograft application for treatment of a metatarsal nonunion fracture in an alpaca (Vicugna pacos)

CASE HISTORY: A 15-year-old female huacaya alpaca (Vicugna pacos) was referred because of a non-weight-bearing lameness (4/4) in the left pelvic limb caused by a grade three open metatarsal fracture. The referring veterinarian treated the fracture with conservative management using bandages, but it progressively evolved to a non-union.

CLINICAL FINDINGS AND DIAGNOSIS: Clinical examination revealed external wounds on the medial and lateral surfaces of the metatarsus. Radiographs confirmed an open, nonarticular, displaced, diaphyseal fracture of the left metatarsus.

TREATMENT AND OUTCOME: Cancellous bone was sourced from bovine proximal and distal femur epiphyses, followed by a thermal shock procedure to achieve decellularisation, to produce a xenograft. Open reduction and internal fixation of the fracture using locking plates was performed. Alignment of the fracture fragments was corrected and the xenograft was placed at the debrided fracture site to stimulate and harness osteogenesis in situ. Clinical and radiographic follow-up was performed up to 40 weeks postoperatively. Clinical evaluations revealed that the alpaca gradually increased weight bearing following bandage removal 10 days after surgery. Serial radiographs showed correct alignment of the left metatarsus, progressive bone modelling and, complete bone union at 12 weeks. Ten months postoperatively the alpaca showed no signs of lameness and resumed normal activity.

CLINICAL RELEVANCE: For management of a metatarsal non-union, a combination of bovine xenograft application and angular stable internal fixation progressed toward an excellent long-term recovery.     

Surgical treatment of scapulohumeral subluxation in an alpaca (Vicugna pacos) using osteotomy of the acromion,open reduction and extracapsular tension sutures

CASE HISTORY AND CLINICAL FINDINGS: A 3.3-year-old male alpaca, weighing 60?kg was referred for investigation of a severe left forelimb lameness of 4 weeks duration. A scapulohumeral subluxation had been diagnosed radiographically by the referring veterinarian.

CLINICAL FINDINGS AND DIAGNOSIS: Based on clinical, ultrasonographic and radiographic findings the diagnosis of cranio-lateral subluxation of the left humeral head was confirmed. In addition, a full thickness lesion (approximately 1?×?1?cm) of the articular cartilage on the caudomedial aspect of the humeral head was diagnosed by arthroscopy.

TREATMENT AND OUTCOME: Treatment included open reduction with internal fixation. Severe muscle contraction and local tissue fibrosis around the scapulohumeral joint (SHJ) required osteotomy of the acromion 3?cm proximal to the distal acromial edge, to allow adequate access. Internal stabilisation was achieved by placing tension band sutures between one cortical screw in the scapular neck and two cortical screws, with washers, craniolaterally on the greater tubercle of the humerus. Post-surgery, a carpal flexion sling was applied with the carpus maintained in 70° flexion for 4 weeks to avoid postoperative weight-bearing. An exercise programme was started 8 days after surgery and continued for 12 weeks. The alpaca had an uneventful postsurgical recovery and showed no lameness after 8 weeks. The long-term outcome was excellent; 21 months after surgery the alpaca was sound and the range of movement of the left SHJ was equal to the right SHJ.

CLINICAL RELEVANCE: Even in this chronic case of subluxation of the SHJ of 4 weeks duration, surgical treatment using osteotomy of the acromion, open reduction and internal fixation with extracapsular scapulohumeral tension sutures resulted in an excellent long-term outcome in this alpaca, despite the presence of a cartilage lesion.     

Skin diseases in the alpaca (Vicugna pacos): a literature review and retrospective analysis of 68 cases (Cornell University 1997–2006)

This retrospective study describes 68 alpacas with skin diseases investigated from 1997 through 2006 at Cornell University. During this time period, 40 of 715 (5.6%) alpacas presented to the university hospital had dermatological diseases. In addition, skin‐biopsy specimens accounted for 86 of 353 (24.4%) of alpaca biopsy specimens submitted to the diagnostic laboratory, and of these 86 specimens, follow‐up was available for 28 cases. The following diseases were most common: bacterial infections (22%); neoplasms, cysts and hamartomas (19%); presumed immunological disorders (12%); and ectoparasitisms (10%). Conditions described for the first time included intertrigo, collagen and hair follicle hamartomas, lymphoma, hybrid follicular cysts, melanocytoma, anagen defluxion, telogen defluxion, presumed insect‐bite hypersensitivity, ichthyosis, and possible hereditary bilateral aural haematomas and chondritis. The results of the retrospective study are compared and contrasted with the results of a literature review.     

Prevalence of Candidatus Mycoplasma haemolamae,bovine viral diarrhoea virus,and gastrointestinal parasitism in a sample of adult New Zealand alpaca (Vicugna pacos)

AIM: To determine the prevalence of infection with Candidatus Mycoplasma haemolamae (Mhl), antibodies to bovine viral diarrhoea virus (BVDV), and BVDV antigen, and the prevalence of animals with elevated faecal nematode egg counts (FEC) in a sample of adult New Zealand alpaca (Vicugna pacos).

METHODS: Blood samples were obtained from 175 alpaca, collected from 15 farms around New Zealand, and from 31 samples sent to a diagnostic laboratory for routine haematology. Blood smears (n=170) were examined microscopically for the presence of haemoplasma, and DNA was extracted from whole blood (n=206) for real-time PCR testing for Mhl. Packed cell volume (PCV) was determined for 193 samples. Serum samples (n=195) were tested for BVDV antibody using ELISA, and for BVDV antigen using a real-time PCR assay. Faecal samples were collected from 143 animals; FEC were measured, and samples pooled for larval culture.

RESULTS: No haemoplasma organisms were present on blood smear examination. Of the 206 blood samples, two (from the same farm) were positive for Mhl by real-time PCR testing, giving a prevalence of infection with Mhl of 0.97%. Of the 195 serum samples tested, four (2.1%) were positive for antibodies to BVDV; animals with BVDV antibodies were from 3/15 (20%) farms, none of which farmed cattle. None of the serum samples were positive by PCR for BVDV antigen. The median FEC was 50?epg (min 0, max 4,700), with 55/143 (38.5%) samples having 0?epg, and 33/143 (23.1%) having ≥250?epg. Haemonchus spp. were the most common nematodes present in faecal larval cultures from the North Island. Log₁₀ FEC was negatively associated with PCV (p=0.02), and was higher in males than females (p<0.001), and in animals that were positive compared with negative for Mhl (p=0.022).

CONCLUSIONS AND CLINICAL RELEVANCE: The number of alpaca infected with Mhl was low, as was the seroprevalence of BVDV. Gastrointestinal parasitism was, however, a common finding in this sample of New Zealand alpaca.     

Effect of Foetal Bovine Serum on sperm motility,acrosome reaction and spermatic interaction to zona pellucida in alpacas (Vicugna pacos)

The use of foetal bovine serum (FBS) in cell culture media is quite common. However, little is known about the effect of FBS on sperm. The severe difficulties in alpaca reproduction demand the search of new methods for in vitro reproductive management. In the present study, we use for the first time FBS as a supplement in the culture medium for sperm in alpaca, and the effect of FBS on motility, acrosome reaction and sperm binding to the zona pellucida in this species was evaluated. A concentration of 10% v/v FBS was used. The sperm motility with FBS at the first hour was 32.8% (vs. control = 30.0%), whereas at the second hour sperm motility with FBS was 30.2% (vs. control = 28.8%). The acrosome reaction reached an average of 44.0% for treatment with FBS (vs. control = 30.1%). The sperm‐zona pellucida binding assay showed that the samples incubated with FBS had an average of 2.7 bound sperm (vs. control = 1.7). Only a significant difference was observed for sperm motility at the first hour and for the acrosome reaction. It is concluded that FBS favours the capacitation of sperm in alpaca.     

Tuberculosis in alpaca (Lama pacos) on a farm in Ireland. 2. Results of an epidemiological investigation

Tuberculosis (TB), due to infection with Mycobacterium bovis was diagnosed in a flock of alpaca in Ireland in 2004. An epidemiological investigation was conducted to identify the risk of TB for farmed alpaca where TB is endemic, the origin of the infection, the potential for alpaca-to-alpaca transmission and appropriate control measures. The investigation focused on the alpaca flock (including the farm, animal movements and breeding, feeding and flock health practice), the disease episode (including animal disease events and subsequent control measures) and TB infection risk in the locality. The TB risk to alpaca is high in areas where infection is endemic in cattle and badgers and where biosecurity is inadequate. It is most likely that the source of infection for the alpaca was a local strain of M. bovis, present in cattle in this area since at least 2001. Genotyping of isolates identified a single variable number tandem repeat (VNTR) profile in both cattle and alpaca in this region. Although a tuberculous badger was also removed from the vicinity, bacterial isolation was not attempted. On this farm, infection in alpaca was probably derived from a common source. Alpaca-to-alpaca transmission seems unlikely. Two broad control strategies were implemented, aimed at the rapid removal of infected (and potentially infectious) animals and the implementation of measures to limit transmission. Tests that proved useful in detecting potentially-infected animals included measurement of the albumin-to-globulin ratio and regular body condition scoring. Skin testing was time consuming and unproductive, and early detection of infected animals remains a challenge. The flock was managed as a series of separate groupings, based on perceived infection risk. No further TB cases have been detected.     

Assessment of buffalo (Bubalus bubalis) sperm DNA fragmentation using a sperm chromatin dispersion test

Chromosomal fragmentations or damage in sperm DNA has considerable value in determination of semen quality. However, rapid and/or simple method to assess sperm DNA integrity in buffalo has apparently not been reported. In the present study, SCD was used for the first time in buffalo bulls for assessment of sperm DNA fragmentation. A modified SCD protocol, under bright field microscope was developed and validated by comparison with other routine tests which can be used for processing of samples. The DNA fragmentation index (DFI) from SCD was correlated with semen quality parameters viz. viability (r=-0.68, p<0.05), membrane integrity (r=-0.74, p<0.05) and capacitation status (r=-0.69, p<0.05). The amount of DNA fragmentation assessed by SCD was highly correlated (R=0.874, p<0.05) with results of acridine orange test (AOT), a traditional method of assessing DNA damage. There were no significant differences between two observers with regards to scoring dispersion patterns. Therefore, the SCD test can be routinely used for detection of DNA fragmentation in buffalo sperm, with potential for replacing conventional time consuming tests.     

In vitro effects of gonadotropin-releasing hormone (GnRH) on Leydig cells of adult alpaca (Lama pacos) testis: GnRH receptor immunolocalization, testosterone and prostaglandin synthesis, and cyclooxygenase activities

The main objective of this study was to examine the modulatory in vitro effects of gonadotropin-releasing hormone (GnRH) on isolated Leydig cells of adult alpaca (Lama pacos) testis. We first evaluated the presence of GnRH receptor (GnRHR) and cyclooxygenase (COX) 1 and COX2 in alpaca testis. We then studied the in vitro effects of buserelin (GnRH analogue), antide (GnRH antagonist), and buserelin plus antide or inhibitor of phospholipase C (compound 48/80) and COXs (acetylsalicylic acid) on the production of testosterone, PGE(2), and PGF(2α) and on the enzymatic activities of COX1 and COX2. Immunoreactivity for GnRHR was detected in the cytoplasm of Leydig cells and in the acrosomal region of spermatids. COX1 and COX2 immunosignals were noted in the cytoplasm of spermatogonia, spermatocytes, spermatids, Leydig cells, and Sertoli cells. Western blot analysis confirmed the GnRHR and COX1 presence in alpaca testis. The in vitro experiments showed that buserelin alone increased (P < 0.01) and antide and buserelin plus acetylsalicylic acid decreased (P < 0.01) testosterone and PGF(2α) production and COX1 activity, whereas antide and compound 48/80 counteracted buserelin effects. Prostaglandin E(2) production and COX2 activity were not affected by buserelin or antide. These data suggest that GnRH directly up-regulates testosterone production in Leydig cells of adult alpaca testis with a postreceptorial mechanism that involves PLC, COX1, and PGF(2α).     

Failure of passive immunoglobulin transfer: a major determinant of mortality in newborn alpacas (Lama pacos)

Failure of passive transfer (FPT) of immunoglobulin from colostrum was demonstrated as a major determinant of mortality in newborn alpacas (Lama pacos; crias). Serum IgG concentrations of dying crias were significantly (P less than 0.0001) lower than were serum IgG concentrations of crias that lived. Of 82 crias, 10 (12%) died within 1 month of age, and 7 of these had 0 to 9 mg of IgG/ml of serum at 48 hours after birth; 5 of the 7 had evidence of infectious diseases. The serum IgG concentrations of the remaining dead crias were 12, 13, and 20 mg/ml. On the basis of serum IgG concentrations of crias that died in the first month, FPT was defined as a 48-hour serum IgG concentration less than 9 mg/ml, which was greater than 2 SD below the 48-hour mean of clinically normal crias. Using this definition, the prevalence of FPT in the 82 crias studied was 9%. Corroborative evidence of the relationship between FPT and mortality was obtained from a retrospective study of 21 dead crias. The postmortem serum IgG concentration of 5 crias that died 2 to 10 days after birth ranged from less than 1 to 3 mg/ml; all were greater than 2 SD below the mean of age matched clinically normal crias. The range of serum IgG concentration was 2.2 to 21 mg/ml in 8 crias that died 11 to 20 days after birth; serum IgG concentration in 1 cria was greater than 2 SD below the normal mean, and 6 were greater than 1 SD below the normal mean.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of chelating and antioxidant agents on morphology and DNA methylation in freeze-drying rabbit (Oryctolagus cuniculus) spermatozoa

Freeze-drying (FD) has been exhaustively tried in several mammalian species as an alternative technique to sperm cryopreservation, but few studies have been done in rabbits (Oryctolagus cuniculus). The main objective of this study was to compare the protective effect of various antioxidants added to EDTA medium on structural and functional components of FD rabbit spermatozoa and on their status of global DNA methylation. FD media used were composed of basic FD medium (10 mM Tris-HCl buffer and 50 mM NaCl) supplemented with either 50 mM EDTA alone (EDTA) or added with 105 µM of rosmarinic acid (RA, EDTA-RA) or 10 µM of melatonin (MLT, EDTA-MLT). The effect of each medium on the preservation of FD spermatozoon structure was evaluated with light and scanning electron microscopy (SEM). Global DNA methylation was quantified in all FD sperm samples as well as in fresh spermatozoa. Morphologically, fracture points were evidenced in the neck, mid and principal piece of the spermatozoon tail. No differences in spermatozoon fracture points were evidenced among FD treatments: intact spermatozoa were the largest (p < .01) category, whereas the most frequent (p < .01) injury was the neck fracture, resulting in tailless heads. At SEM, the head of spermatozoa showed a well-conserved shape and intact membrane in all treatments. DNA methylation status was the same in all FD treatments. In conclusion, supplementation of EDTA, EDTA-RA and EDTA-MLT during FD preserved rabbit sperm morphological integrity and methylation status as well. Therefore, the difficulty of getting viable offspring using FD semen is likely unrelated to the impact of the lyophilization process on DNA methylation and morphology of lyophilized spermatozoa.     

Retracted: Reliable collection of Caspian brown trout (Salmo trutta caspius) sperm using a catheter

The traditional stripping procedure for collecting fish semen is associated with the risk of urine contamination, which may significantly affect semen quality and quantity. The use of a catheter as an alternative method for semen collection may overcome this problem. Therefore, this study compared Caspian brown trout (Salmo trutta caspius) semen parameters (i.e. sperm density, seminal plasma osmolality, motility parameters of spermatozoa analysed using computer‐assisted sperm analysis and fertility) between the traditional stripping method and the use of a catheter. All parameter values of the semen collected with a catheter were significantly higher (p < .05; density = 7.67 ± 1.02 × 10⁹ ml^?1 and osmolality = 279.28 ± 32.84 mOsm kg^?1) than those collected with stripping method (density = 4.85 ± 0.47 × 10⁹ ml^?1 and osmolality = 216.42 ± 20.75 mOsm kg^?1). Semen collected with a catheter was characterized by higher spermatozoa motility compared with sperm collected via stripping. Similarly, the fertilization ability of sperm collected with a catheter was significantly greater (p < .05) than sperm collected with the traditional stripping method. In conclusion, collection of sperm with a catheter was shown to effectively reduce urine contamination and is therefore recommended for the collection of Caspian brown trout sperm.     

Evaluation of decision criteria for detection of spinal cord compression based on cervical myelography in horses: 38 cases (1981-2001)

REASONS FOR PERFORMING STUDY: Different criteria have been described based on height reduction of the total myelographic contrast column and components of it as tests for compression of the spinal cord due to cervical stenotic myelopathy (CSM). Fifty percent height reduction of the dorsal myelographic column (DMC), <2 mm empiric height of the DMC and a 40% reduction of the ratio of stenosis calculated based on the height reduction of the entire dural diameter (DD) have been described as decision criteria for considering the test result positive. The reasons for selecting these decision criteria or their accuracies have rarely been reported. OBJECTIVES: To evaluate the accuracy of diagnostic criteria based on reduced height of the total myelographic column and components of it for diagnosing extradural spinal cord compression using different decision criteria, and make recommendations for consistent myelographic interpretation in horses suspected of having CSM. METHODS: Four measurements were obtained by 2 readers in a retrospective sample population of 38 horses in which both cervical myelography and histopathological examination of the cervical spinal cord were performed. The prevalence of CSM in the sample was 50%. At intervertebral sites, the minimum heights of the DD and DMC were measured. At intravertebral sites, the maximum heights of the entire DD and DMC were obtained. Percent height reductions of the DMC and DD were determined as the ratio of minimum intervertebral height to maximum intravertebral height within the next cranial vertebra. Histological examination was used as the gold standard for determining the actual site of spinal cord compression. Sensitivity and specificity for the diagnostic criteria were estimated at each site in neutral and flexed neck positions using several different decision criteria. CONCLUSIONS: At C6-C7, in neutral or flexed neck position and using 20% reduction of DD, the test was highly sensitive and specific for CSM. At other sites, reduced height of the myelographic column generally was not accurate for diagnosing extradural spinal cord compression. Using 20% reduction of DD in neutral position at the mid-cervical sites, the test had only low sensitivity and high specificity. Flexion of the neck appeared to increase detection of spinal cord compression in the mid-cervical region, but also substantially increased the frequency of false-positive diagnoses. POTENTIAL RELEVANCE: By using the reported sensitivity and specificity estimates, readers may decide on a decision criterion for diagnosis of extradural spinal cord compression due to CSM. However, in planning a surgical correction, it is difficult to define a decision criterion that combines acceptable sensitivity and specificity, especially at the mid-cervical sites.     

Assessment of susceptibility of the poultry red mite Dermanyssus gallinae (Acari: Dermanyssidae) to some acaricides using an adapted filter paper based bioassay

A previously described bioassay was modified to assess the response of the poultry red mite, an important ectoparasite of fowl, to a selected group of acaricides. The adapted bioassay is simple to use, escape-proof and provides data that can be subjected to probit analysis. The reproducibility of the method was assessed by three tests with alpha-cypermethrin against a reference strain, which produced dose-response lines that did not differ significantly (chi(2)=1.39, 2 d.f., p=0.50), and had a derived common slope of 1.89. In addition, a limited evaluation study enabled assessment of response to commercial formulations of bifenthrin, bifenthrin+malathion and cypermethrin by field populations of the poultry red mite.