Lats1 and Lats2 regulate YAP and TAZ activity to control the development of mouse Sertoli cells

Recent reports suggest that the Hippo signaling pathway regulates testis development, though its exact roles in Sertoli cell differentiation remain unknown. Here, we examined the functions of the main Hippo pathway kinases, large tumor suppressor homolog kinases 1 and 2 (Lats1 and Lats2) in developing mouse Sertoli cells. Conditional inactivation of Lats1/2 in Sertoli cells resulted in the disorganization and overgrowth of the testis cords, the induction of a testicular inflammatory response and germ cell apoptosis. Stimulated by retinoic acid 8 (STRA8) expression in germ cells additionally suggested that germ cells may have been preparing to enter meiosis prior to their loss. Gene expression analyses of the developing testes of conditional knockout animals further suggested impaired Sertoli cell differentiation, epithelial-to-mesenchymal transition, and the induction of a specific set of genes associated with Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ)-mediated integrin signaling. Finally, the involvement of YAP/TAZ in Sertoli cell differentiation was confirmed by concomitantly inactivating Yap/Taz in Lats1/2 conditional knockout model, which resulted in a partial rescue of the testicular phenotypic changes. Taken together, these results identify Hippo signaling as a crucial pathway for Sertoli cell development and provide novel insight into Sertoli cell fate maintenance.

Cancer Spheroids Embedded in Tissue-Engineered Skin Substitutes: A New Method to Study Tumorigenicity In Vivo

Tumorigenic assays are used during a clinical translation to detect the transformation potential of cell-based therapies. One of these in vivo assays is based on the separate injection of each cell type to be used in the clinical trial. However, the injection method requires many animals and several months to obtain useful results. In previous studies, we showed the potential of tissue-engineered skin substitutes (TESs) as a model for normal skin in which cancer cells can be included in vitro. Herein, we showed a new method to study tumorigenicity, using cancer spheroids that were embedded in TESs (cTES) and grafted onto athymic mice, and compared it with the commonly used cell injection assay. Tumors developed in both models, cancer cell injection and cTES grafting, but metastases were not detected at the time of sacrifice. Interestingly, the rate of tumor development was faster in cTESs than with the injection method. In conclusion, grafting TESs is a sensitive method to detect tumor cell growth with and could be developed as an alternative test for tumorigenicity.

A retrospective study of equine perinatal loss in Canada (2007 to 2020)

Objective

This study aims to identify the most common causes of equine perinatal loss up to 7 d of age in Canada.

Animal

Equine.

Procedure

Necropsy reports from 360 equine perinatal loss cases were acquired from provincial veterinary diagnostic labs across Canada. Each case was classified into a basic cause (noninfectious, infectious, or unidentified) of perinatal loss, then further classified into primary and secondary categories for analysis.

Results

Of the basic causes of perinatal loss, noninfectious causes were the most common. Bacterial causes, such as septicemia, were the most common primary diagnosis overall. Actinobacillus was the most commonly identified bacterial species.

Conclusion

This study showed similar results to those of studies conducted in other countries, including having similar etiologic agents identified. The high prevalence of thyroid hyperplasia identified in this study is notable and was not reported in other, similar retrospective studies, despite being reported in locations other than Canada.

Clinical relevance

Perinatal loss can have important economic consequences for horse breeders; thus, identification of the most common causes is of interest to both veterinarians and breeders.

Is the Hippo Pathway Effector Yes-Associated Protein a Potential Key Player of Dairy Cattle Cystic Ovarian Disease Pathogenesis?

Cystic ovarian disease (COD) in dairy cattle is characterized by preovulatory follicles that become cysts, fail to ovulate and persist in the ovary; consequently, interfering with normal ovarian cyclicity. The intraovarian key players that orchestrate the alterations occurring in the preovulatory follicle and that culminate with cyst formation and persistence, however, remain uncertain. Interestingly, the Hippo pathway effector yes-associated protein (YAP) has been described in humans and mice as a key player of anovulatory cystic disorders. To start elucidating if YAP deregulation in ovarian follicle cells can be also involved in the pathogenesis of COD, we have generated a series of novel results using spontaneously occurring cystic follicles in cattle. We found that mRNA and protein levels of YAP are significantly higher in granulosa (GCs) and theca cells (TCs) isolated from cystic follicles (follicular structures of at least 20 mm in diameter) in comparison to respective cell types isolated from non-cystic large follicles (≥12 mm). In addition, immunohistochemistry and Western blot analyses used to determine YAP phosphorylation pattern suggest that YAP transcriptional activity is augmented is cystic GCs. These results were confirmed by a significant increase in the mRNA levels encoding for the classic YAP-TEAD transcriptional target genes CTGF, BIRC5 and ANKRD1 in GCs from follicle cysts in comparison to non-cystic large follicles. Taken together, these results provide considerable insight of a completely novel signaling pathway that seems to play an important role in ovarian cystic disease pathogenesis in dairy cattle.

T cell-loaded injectable chitosan scaffold shows short-term efficacy as localised cancer immunotherapy in mice

Adoptive cell therapy (ACT) shows success against treatment-resistant cancers, but is limited by the large number of intravenously-delivered T cells required and toxicity related to systemic administration. In this work,...

Energy balance and hippo effector activity in endometrium and corpus luteum of early pregnant ewes

CONTEXT

The establishment of pregnancy in cows requires uterine activity regulation of the main Hippo signalling effector yes-associated protein 1 (YAP). It remains unknown (1) how YAP activity at the corpus luteum (CL) correlates with early pregnancy-related events in ruminants; and (2) if YAP activity in the uterus and CL can be affected by metabolic disorders that may lead to pregnancy failure in ruminants.

AIMS AND METHODS

To determine the effect of early pregnancy on total and phospho-YAP expression and its transcriptional activity in the CL, we compared non-pregnant vs pregnant ewes. To understand the YAP activity dysregulation with disorders that may result in pregnancy loss, we induced negative energy balance in pregnant ewes.

KEY RESULTS AND CONCLUSIONS

Our main results indicate that early pregnancy alters the expression and activity patterns of YAP in the ovine CL but not in the endometrium. In addition, while our NEB-induced model fails to alter YAP activity at the endometrium level, we found that fasting during the first but not second week of pregnancy affects YAP activity in the CL of pregnant ewes.

IMPLICATIONS

The data presented herein provide considerable insight into the activity of a signalling pathway that may be a key player in pregnancy recognition and establishment in ewes.

Effect of inactivation of Mst1 and Mst2 in the mouse adrenal cortex

Recent conditional knockout of core components of the Hippo signaling pathway in the adrenal gland of mice has demonstrated that this pathway must be tightly regulated to ensure proper development and maintenance of the adrenal cortex. We report herein that the most upstream kinases of the pathway, the mammalian STE20-like protein kinases 1 and 2 (MST1and MST2, respectively), are expressed in the mouse adrenal cortex with MST2 expression being restricted to the zona glomerulosa (zG). To further explore the role of Hippo signaling in adrenocortical cells, we conditionally deleted Mst1/2 in steroidogenic cells using an Nr5a1-cre strain (Mst1flox/flox; Mst2flox/flox; Nr5a1-cre). Our results show that the loss of MST1/2 leads to the premature and progressive accumulation of subcapsular GATA4+, WT1 + adrenal gonadal primordium (AGP)-like progenitor cells starting at 2 months of age without affecting aldosterone and corticosterone secretion. To help us understand this phenotype, microarray analyses were performed on adrenal glands from 2-month-old mutant and control mice. Gene expression analyses revealed that loss of Mst1/2 leads to the overexpression of known downstream target genes (Ajuba, Aqp1, Fn1, Ibsp, Igf1, Igfbp2, Mmp2, Thbs1) of the main effector of Hippo signaling, YAP; and underexpression of genes (Agtr1b, Ecgr4, Hsd3b6, Nr0b1, Tesc, Vsnl1) that are normally specifically expressed in the zG or overexpressed in the zG compared to the zona fasciculata (zF). Together, these results suggest that MST1/2 regulates Hippo signaling activity in the adrenal cortex and that these two kinases are also involved in the fine tuning of zG cell function or differentiation.

Cannabinoid receptors are expressed in equine synovium and upregulated with synovitis

BACKGROUND

Osteoarthritis (OA) is a major cause of equine lameness. Cannabinoid receptors (CB) are now considered to be promising therapeutic targets in human rheumatology for pain and inflammation, however little is known about the equine endocannabinoid system.

OBJECTIVES

The primary goal was to assess the presence and expression pattern of CB1 and CB2 in the synovium of healthy joints. A secondary goal was to explore the relationship between the CB expression, degree of synovitis and OA pathology.

STUDY DESIGN

Ex vivo experimental study.

METHODS

Metacarpophalangeal joints (n=25) from a tissue bank were studied. The joints were dissected, and the articular cartilage lesions were scored. Synovial membrane specimens (n=45) were harvested, fixed and the degree of synovitis was graded on histological sections. Co-localised synovial sections were also immunostained with antibodies to CB1 and CB2. Five regions of interest (ROIs) were randomly selected from digital images of manually segmented synovial intima and scored blindly for positive cellular immunoreactive staining by 2 independent observers. Interobserver agreement was calculated with an intraclass correlation coefficient (ICC). Relationships between CB1 and CB2 immunoreactive scores and synovitis or joint OA grade were explored with mixed linear models.

RESULTS

CB1 was expressed in synovial intimal cells in all specimens studied whereas CB2 expression was identified in 94%. Both receptors were also expressed in the subintimal blood vessel walls. ICCs were 84.6% (CB1) and 92.9% (CB2) for the immunoreactivity scores. Both CB1 and CB2 expression were significantly upregulated (p=0.04 and p=0.03 respectively) with increasing degree of synovitis. Conversely, CB1 expression significantly decreased (p=0.03) with increasing severity of OA.

MAIN LIMITATIONS

The type of synovial cell expressing CB1 or CB2 was not investigated.

CONCLUSIONS

Equine synovial intimal cells constitutively express both CB1 and CB2 receptors that are upregulated with synovitis and may have a role in joint pain. They are potential targets for therapy with cannabinoid molecules or their derivatives. This article is protected by copyright. All rights reserved.

A 13-year retrospective study of equine abortions in Canada

OBJECTIVE

The purpose of this study was to identify the most common causes of equine abortion in Canada, and to compare findings to similar reports from other countries.

ANIMAL

Equine.

PROCEDURE

Necropsy reports from 901 equine abortion cases were acquired from provincial veterinary diagnostic laboratories across Canada. The final diagnosis was classified into basic abortion causes (infectious, non-infectious, unknown) and into primary and secondary categories for analysis.

RESULTS

Non-infectious causes of abortion were the most frequently identified in Canada, with fetoplacental causes, including umbilical cord torsion or placental insufficiency, being the most common primary diagnosis category. Streptococcus and Escherichia were the bacterial species most often identified as causing infectious abortions, whereas equine herpesvirus-1 was implicated in all viral abortions identified.

CONCLUSION

The high rate of non-infectious causes of abortion was similar to previous studies conducted in the United Kingdom. This finding was somewhat dissimilar to the USA, which had higher rates of infectious abortions, despite Canada's geographic proximity to the USA. The reason for variations among countries in equine abortion causes is unknown.

CLINICAL RELEVANCE

The large number of fetoplacental-related abortions identified in this study emphasized the need for submission of both the fetus and placenta, if possible, to increase the probability of a diagnosis. In addition, the high rate of unidentified diagnoses suggests a need for further study into both non-infectious and infectious causes of equine abortion, including potential development of new diagnostic tests or markers.

Constitutive activation of CTNNB1 results in a loss of spermatogonial stem cell activity in mice

Spermatogenesis requires that a careful balance be maintained between the self-renewal of spermatogonial stem cells (SSCs) and their commitment to the developmental pathway through which they will differentiate into spermatozoa. Recently, a series of studies employing various in vivo and in vitro models have suggested a role of the wingless-related MMTV integration site gene family/beta-catenin (WNT/CTNNB1) pathway in determining the fate of SSCs. However, conflicting data have suggested that CTNNB1 signaling may either promote SSC self-renewal or differentiation. Here, we studied the effects of sustained CTNNB1 signaling in SSCs using the Ctnnb1^tm1Mmt/+; Ddx4-Cre^Tr/+ (ΔCtnnb1) mouse model, in which a stabilized form of CTNNB1 is expressed in all germ cells. ΔCtnnb1 mice were found to have reduced testis weights and partial germ cell loss by 4 months of age. Germ cell transplantation assays showed a 49% reduction in total functional SSC numbers in 8 month-old transgenic mice. In vitro, Thy1-positive undifferentiated spermatogonia from ΔCtnnb1 mice formed 57% fewer clusters, which was associated with decreased cell proliferation. A reduction in mRNA levels of genes associated with SSC maintenance (Bcl6b, Gfra1, Plzf) and increased levels for markers associated with progenitor and differentiating spermatogonia (Kit, Rarg, Sohlh1) were detected in these cluster cells. Furthermore, RNAseq performed on these clusters revealed a network of more than 900 genes regulated by CTNNB1, indicating that CTNNB1 is an important regulator of spermatogonial fate. Together, our data support the notion that CTNNB1 signaling promotes the transition of SSCs to undifferentiated progenitor spermatogonia at the expense of their self-renewal.

Targeted Disruption of Lats1 and Lats2 in Mice Impairs Adrenal Cortex Development and Alters Adrenocortical Cell Fate

It has recently been shown that the loss of the Hippo signaling effectors Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) in adrenocortical steroidogenic cells impairs the postnatal maintenance of the adrenal gland. To further explore the role of Hippo signaling in mouse adrenocortical cells, we conditionally deleted the key Hippo kinases large tumor suppressor homolog kinases 1 and -2 (Lats1 and Lats2, two kinases that antagonize YAP and TAZ transcriptional co-regulatory activity) in steroidogenic cells using an Nr5a1-cre strain (Lats1flox/flox;Lats2flox/flox;Nr5a1-cre). We report here that developing adrenocortical cells adopt characteristics of myofibroblasts in both male and female Lats1flox/flox;Lats2flox/flox;Nr5a1-cre mice, resulting in a loss of steroidogenic gene expression, adrenal failure and death by 2 to 3 weeks of age. A marked accumulation of YAP and TAZ in the nuclei of the myofibroblast-like cell population with an accompanying increase in the expression of their transcriptional target genes in the adrenal glands of Lats1flox/flox;Lats2flox/flox;Nr5a1-cre animals suggested that the myofibroblastic differentiation could be attributed in part to YAP and TAZ. Taken together, our results suggest that Hippo signaling is required to maintain proper adrenocortical cell differentiation and suppresses their differentiation into myofibroblast-like cells.

Targeted ablation of Wnt4 and Wnt5a in Müllerian duct mesenchyme impedes endometrial gland development and causes partial Müllerian agenesis

Wnt4 and Wnt5a have well-established roles in the embryonic development of the female reproductive tract, as well as in implantation, decidualization, and ovarian function in adult mice. Although these roles appear to overlap, whether Wnt5a and Wnt4 are functionally redundant in these tissues has not been determined. We addressed this by concomitantly inactivating Wnt4 and Wnt5a in the Müllerian mesenchyme and in ovarian granulosa cells by crossing mice bearing floxed alleles to the Amhr2cre strain. Whereas fertility was reduced by ∼50% in Wnt4flox/flox; Amhr2cre/+ and Wnt5aflox/flox; Amhr2cre/+ females, Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ mice were either nearly or completely sterile. Loss of fertility was not due to an ovarian defect, as serum ovarian hormone levels, follicle counts, and ovulation rates were comparable to controls. Conversely, the uterus was abnormal in Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ mice, with thin myometrial and stromal layers, frequent fibrosis and a >90% reduction in numbers of uterine glands, suggesting redundant or additive roles of Wnt4 and Wnt5a in uterine adenogenesis. Loss of fertility in Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ mice was attributed to defects in decidualization, implantation, and placental development, the severity of which were proportional to the extent of gland loss. Furthermore, a third of Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ females had a partial agenesis of Müllerian duct-derived structures, but with normal oviducts and ovaries. Together, our results suggest that Wnt4 and Wnt5a play redundant roles in the development of the female reproductive tract, and may provide insight into the etiology of certain cases of Müllerian agenesis in women.

Lats1 and Lats2 are required for the maintenance of multipotency in the Müllerian duct mesenchyme

WNT signaling plays essential roles in the development and function of the female reproductive tract. Although crosstalk with the Hippo pathway is a key regulator of WNT signaling, whether Hippo itself plays a role in female reproductive biology remains largely unknown. Here, we show that conditional deletion of the key Hippo kinases Lats1 and Lats2 in mouse Müllerian duct mesenchyme cells caused them to adopt the myofibroblast cell fate, resulting in profound reproductive tract developmental defects and sterility. Myofibroblast differentiation was attributed to increased YAP and TAZ expression (but not to altered WNT signaling), leading to the direct transcriptional upregulation of Ctgf and the activation of the myofibroblast genetic program. Müllerian duct mesenchyme cells also became myofibroblasts in male mutant embryos, which impeded the development of the male reproductive tract and resulted in cryptorchidism. The inactivation of Lats1/2 in differentiated uterine stromal cells in vitro did not compromise their ability to decidualize, suggesting that Hippo is dispensable during implantation. We conclude that Hippo signaling is required to suppress the myofibroblast genetic program and maintain multipotency in Müllerian mesenchyme cells.

Mycobacterium xenopi systemic infection in a domestic fiery-shouldered conure bird (Pyrrhura egregia)

Introduction

Mycobacterium xenopi is a rare opportunistic pathogen mainly causing infections in immunocompromised human patients or those with underlying chronic structural lung disease. Cases of disease in veterinary medicine remain scarce. Few animal species, including birds, are suspected of being vectors of the disease and there has not yet been a report of clinical disease in birds. We report the first case, to our knowledge, of systemic infection in a domestic bird.

Case presentation

A female fiery-shouldered conure was submitted after death for necropsy following episodes of heavy breathing. The necropsy revealed multiple granulomatous lesions within the liver, air sacs and kidneys. Ziehl–Neelsen stains demonstrated the presence of numerous intralesional acid-fast bacilli. PCR assays and culture confirmed the presence of M. xenopi.

Conclusion

Through this case we hope to describe the characteristics of M. xenopi disease in birds and the possible close relationship between animal and human infections.

Holding Power of Orthopaedic Screws in Femora of Young Calves

The holding power and holding power per mm bone width of 4.5 mm and 5.5 mm cortical and 6.5 mm cancellous orthopaedic screws were obtained by load-to-failure studies in excised femora of young female Holstein calves. Mean ( ± SD) holding power (HP), holding power per mm bone width (HPBW), and holding power per cortical bone width (HPCW) of 4.5 mm (179.67 ± 59.74 kg), 5.5 mm (171.46 ± 76.52 kg), and 6.5 mm orthopaedic screws (191.10 ± 56.67 kg) were not significantly different. The HP, HPBW, HPCW, bone width (BW), and cortical width (CW) were not different between left and right femora. The greatest HP was obtained in the proximal femoral diaphysis, while the smallest HP was observed in the proximal and distal metaphysis. The increase in HP was related to the increase in CW, but was not related to the BW. The CW at the insertion sites of orthopaedic screws in femora was significantly less than in metacarpi and metatarsi. The limiting factor of holding power in all tests was the shear strength of the bone.

This study compares the holding power, holding power per mm bone width, and holding power per mm cortical width of 4.5 mm and 5.5 mm cortical and 6.5 mm cancellous orthopaedic screws in excised femora of young female Holstein calves. The holding power, holding power per mm bone width, and holding power per mm cortical width of different screws were not significantly different.

Targeted Disruption of YAP and TAZ Impairs the Maintenance of the Adrenal Cortex

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are functionally redundant transcriptional regulators that are downstream effectors of the Hippo signaling pathway. They act as major regulators of stem cell maintenance, cell growth, and differentiation. To characterize their roles in the adrenal cortex, we generated a mouse model in which Yap and Taz were conditionally deleted in steroidogenic cells (Yapflox/flox;Tazflox/flox;Nr5a1cre/+). Male Yapflox/flox;Tazflox/flox;Nr5a1cre/+ mice were characterized by an age-dependent degeneration of the adrenal cortex associated with an increase in apoptosis and a progressive reduction in the expression levels of steroidogenic genes. Evaluation of the expression levels of stem and progenitor cell population markers in the adrenal glands of Yapflox/flox;Tazflox/flox;Nr5a1cre/+ mice also showed the downregulation of sonic hedgehog (Shh), a marker of the subcapsular progenitor cell population. Gross degenerative changes were not observed in the adrenal glands of Yapflox/flox;Tazflox/flox;Nr5a1cre/+ females, although steroidogenic capacity and Shh expression were reduced, suggesting that mechanisms of adrenocortical maintenance are sex specific. These results define a crucial role for YAP and TAZ in the maintenance of the postnatal adrenal cortex.

Surgical treatment of lameness

Digital diseases are commonly seen in cattle. Cattle affected by digital disorders do not always respond to conservative therapy and require surgery. Surgical procedures for the common digital disorders are described, with emphasis on the different approaches to the distal interphalangeal joint.

Lameness examination in cattle

Veterinarians are often asked to examine cattle for lameness. A good history, observation of stance and stride, and physical examination are critical to the diagnosis of lameness in cattle. Methods of examination, including observation of the animal at a distance and during movement, are described. Lameness grading systems and ancillary diagnostic tests are also discussed.

Synovial fluid analysis in cattle: a review of 130 cases

OBJECTIVE

To compare synovial fluid characteristics of cattle with infectious and noninfectious arthritis.

STUDY DESIGN

Retrospective cohort study.

ANIMAL OR SAMPLE POPULATION

130 cattle.

METHODS

Synovial fluid was analyzed for total nucleated cell count (NCC), absolute number and percentages of polymorphonuclear (PMN) and mononuclear cells, total protein (TP) concentration, and specific gravity. Cattle were categorized as having infectious or noninfectious arthritis based on physical and lameness examinations, joint radiographs, and microbial culture results. Kruskal-Wallis 1-way analysis of variance was used to compare synovial fluid analysis data from different categories. Selection of cut-off values for the calculation of likelihood ratios, sensitivity, specificity, and positive and negative predictive values was based on examination of the distribution of the data using histograms.

RESULTS

Cattle with infectious arthritis had significantly higher numbers of total NNC, PMN cells, TP concentration, and specific gravity (P = .0001) and a significantly higher percentage of PMN cells compared with cattle with noninfectious arthritis (P = .0001). The percentage of mononuclear cells was significantly higher in cattle with noninfectious arthritis (P = .0001).

CONCLUSIONS

Synovial fluid analysis is useful for differentiation of infectious and noninfectious causes of joint disease in cattle.

CLINICAL RELEVANCE

Cattle with a synovial fluid total NCC > 25,000 cells/microL, a PMN cell count > 20,000 cells/microL or more than 80% PMN cells, and TP > 4.5 g/dL should be considered to have infectious arthritis.

Improved osseointeraction of calcium phosphate-coated external fixation pins. Studies in calves

We investigated osseointeraction of solution-precipitated calcium phosphate (SPCP)-coated transfixation pins used in external skeletal fixation of a calf stable fracture model. One group (SPCP) received centrally-threaded transfixation pins which had SPCP coating; the other group (control) received identical, but not coated, pins. Radiographs were obtained 1 and 40 days after surgery and examined for evidence of osteolysis. Bone phase 99mTc-MDP studies were performed 6 and 28 days after surgery. Calves were killed 40 days after surgery and mechanical tests performed. Dual-energy x-ray absorptiometry (DEXA) and histomorphometric analyses were done. A smaller proportion of SPCP pins (5/24) had evidence of discharge during the study compared with control pins (21/24). A smaller proportion of SPCP pins (4%) had radiographic evidence of osteolysis compared with control pins (42%). Uptake of 99mTc-MDP was similar for SPCP and control calves. Uptake was significantly greater in bone segments showing radiographic evidence of osteolysis than in bone segments not having osteolysis. Yield stress (MPa) for axial displacement was similar in the treatment groups. Bone mineral density was less in SPCP pins. Affinity index and interface histologic score were greater and osteoclastic index less in SPCP calves. Coating of transfixation pins with solution-precipitated calcium phosphate improved the osseointeraction of pin and bone during this 40-day study.

Use of a multifenestrated indwelling lavage system for treatment of septic digital tenosynovitis in cattle

Septic tenosynovitis was diagnosed in seven cattle on the basis of history, physical examination, radiographs, cytological examination of tendon sheath fluids, and microbial culture. A commercially available indwelling multifenestrated silicone rubber drain was used to perform frequent lavage of the flexor tendon sheaths. The sepsis resolved in all cattle. Five of six cattle for which long-term (> 1 year) follow-up information was available were clinically sound on the affected limb and had remained productive members of the herd.

Characterization of anatomic communications of the fetlock in cattle, using intra-articular latex injection and positive-contrast arthrography

OBJECTIVE

To evaluate the frequency and sites of communication between the lateral and medial synovial sacs of the metatarsophalangeal or metacarpophalangeal joints in cattle.

ANIMALS

188 limbs were obtained from 55 fresh bovine cadavers submitted for necropsy because of problems unrelated to the fetlocks.

PROCEDURE

In each ox, lateral or medial synovial sacs of each fetlock were randomly assigned. Joints were injected with a mixture of latex and barium sulfate. Communication between 2 joints was determined by presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and use of positive-contrast arthrography.

RESULTS

Communication between the 2 synovial sacs existed in 186 of 188 (98.9%) specimens. The communication site between lateral and medial synovial sacs was located at the level of the proximal sesamoid bones, between the distal aspect of the interdigital band of the axial branch of the interosseus muscle and the metacarpal or metatarsal bone.

CONCLUSIONS AND CLINICAL RELEVANCE

Although communication between the lateral and medial synovial sacs did not exist in 2 specimens, the fetlock in cattle can be treated as 1 compartment.

Sulfur amino acid utilization by growing steers

Studies were conducted to quantify sulfur amino acid requirements of growing steers. In Exp. 1, six steers (160 kg) were used to determine the methionine requirement in the presence of excess L-Cys. Treatments were abomasal infusion of water only or water plus 2, 4, 6, 8, or 10g/d of L-Met. Steers were fed 2.4 kg/d DM of a diet designed to minimize basal Met supply to the small intestine. Continuous ruminal infusions of VFA (506 g/d) and abomasal infusions of dextrose (150 g/d) increased energy supply to the abomasum. Break-point analysis estimated maximal N retention at 5.8 g/d supplemental L-Met. The basal absorbable Met supply was 2.1 g/d; therefore, the total Met requirement was 7.9 g/d when excess Cys was available. In Exp. 2, five steers (195 kg) were used to determine the efficiency of transsulfuration. Treatments were abomasal infusion of water only or water plus 1.62 or 3.25 g/d L-Cys or 2 o4 g/d L-Met. Diet and infusions were similar to those on Exp. 1, except the amino acid mixture was devoid of Cys and all steers received 4 g/d L-Met to make total sulfur amino acids, but not necessarily Met, limiting. Nitrogen retention increased in response to Met but not Cys infusion and was maximized at 2 g/d supplemental L-Met; thus, the total Met requirement was near 8.4 g/d when the Cys supply was 2.1 g/d. Supplemental Cys did not spare Met, suggesting that nonprotein functions of Met may be quantitatively important.

Characterization of anatomic communications among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle, using intra-articular latex, positive-contrast arthrography, and fluoroscopy

OBJECTIVE

To evaluate the frequency and sites of communication among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle.

ANIMALS

137 limbs were obtained from 72 fresh bovine cadavers submitted for necropsy because of problems unrelated to the carpus.

PROCEDURE

1 of the 3 injection sites was randomly assigned to both carpi of each ox, and a mixture of latex and barium sulfate was injected into the joint. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examination of frozen sections, positive-contrast arthrography, and fluoroscopy.

RESULTS

Communication existed among the 3 joints in 18 specimens (13.1%). The middle carpal joint and the carpometacarpal joint always communicated. The antebrachiocarpal joint communicated with the middle carpal joint between the ulnar and intermediate carpal bones. The middle carpal and carpometacarpal joints always communicated between the fourth and fused second and third carpal bones. In a few specimens, additional sites of communication were identified at the palmar aspect of the fourth carpal bone and the fused second and third carpal bones.

CONCLUSIONS AND CLINICAL RELEVANCE

Individual anatomic variation of the carpus in cattle should be considered when diagnostic or treatment protocols are established.

Use of Doppler ultrasonography and positive-contrast corpus cavernosography to evaluate a persistent penile hematoma in a bull

A 32-month-old Angus bull was evaluated because of a 2-month history of a slowly progressive swelling located cranial to the base of the scrotum. The mass was 8 x 8 x 6 cm, and was causing phimosis. The mass was determined to be a penile hematoma on the basis of results of ultrasonography and exploratory surgery. Surgical evacuation was not performed initially because the deep fascia of the penis was intact and the hematoma was small; however, the hematoma enlarged slowly during the ensuring 2 months, despite sexual rest and isolation from other livestock. Doppler ultrasonography and positive-contrast corpus cavernosography were performed, and the hematoma was seen as a space-occupying mass within the corpus cavernosum penis; vascular anomalies were not found. The penile hematoma was surgically excised, and the bull was isolated for 60 days. At follow-up, the owner indicated that the bull had returned to pasture-breeding soundness and was still being used 2 years after surgery. The small penile hematoma in this bull was unusual in that it did not respond to medical treatment. Surgical treatment was apparently curative, even though surgery was not performed until 4 months after the hematoma was first detected.

Efficiency of D- vs L-methionine utilization by growing steers

Five ruminally cannulated Holstein steers (180 kg) were used in a 5 x 5 Latin square design experiment to evaluate the efficiency of D- vs L-methionine (Met) utilization in growing steers. Treatments were continuous abomasal infusions of water or water with 2 or 4 g.steer-1.d-1 L-Met or 2 or 4 g.steer-1.d-1 D-Met. All steers were fed 2.7 kg/d (DM basis) of a soyhull-based diet to minimize basal Met flow to the small intestine to create a paradigm by which responses to Met supplementation could be measured easily. To ensure that amino acids other than Met did not limit animal performance, an essential amino acid mixture simulating the nonsulfur amino acid profile of ruminal bacteria was infused abomasally. Energy supply to the steers was increased by continuously infusing acetate, propionate, and butyrate into the rumen at rates of 150, 150, and 37.5 g.steer-1.d-1, respectively. Abomasal infusions of dextrose (300 g/d) also provided an additional energy source. Nitrogen retention increased linearly (P < .05) in response to both L-Met and D-Met infusions, with responses being similar between the two Met isomers. Regression of N retention against Met supplementation yielded: Nitrogen retention (g/d) = 19.2 + 1.81 D-Met (g/d) + 1.90 L-Met (g/d). By slope ratio analysis, the efficiency of D-Met utilization relative to L-Met was 95.5%. In a concurrent study using intestinally cannulated steers, both D- and L-Met were absorbed essentially completely from the small intestine. These results show that D-Met can be utilized efficiently as a Met source by cattle.

Effect of increasing degradable intake protein on intake and digestion of low-quality, tallgrass-prairie forage by beef cows

Five ruminally and duodenally fistulated Angus x Hereford cows were used in a 5 x 5 Latin square to monitor intake, ruminal fermentation responses, and site and extent of digestion associated with providing increasing amounts of supplemental degradable intake protein (DIP). Cows had ad libitum access to low-quality, tallgrass-prairie forage (1.9% CP, 77% NDF) that was fed twice daily. The supplemental DIP (sodium caseinate; 90% CP) was infused intraruminally at 0630 and 1830 immediately before feeding forage. Levels of DIP were 0, 180, 360, 540, and 720 g/d. Each period consisted of 14 d of adaptation and 6 d of sampling. Forage OM intake increased quadratically (P < .01) with increasing supplemental DIP reaching a peak at the 540 g/d level. True ruminal OM and NDF digestion increased with the addition of 180 g/d supplemental DIP, but exhibited only moderate and somewhat variable responses when greater amounts of supplemental DIP were infused (cubic, P < or = .03). Microbial N flow and efficiency increased linearly (P < .01) with increasing supplemental DIP. However, a quadratic effect (P < .01) was observed for total duodenal N flow, which was maximized at 540 g/d supplemental DIP. A linear (P = .02) treatment effect was observed for ruminal fluid dilution rate. Total ruminal VFA and ammonia concentrations increased (P < .01) in response to DIP supplementation. In conclusion, increasing supplemental DIP generally improved forage utilization; intake of digestible OM was maximized when it contained approximately 11% DIP.

Comparative evaluation of two surgical scrub preparations in cattle

One hundred seventeen cattle that had undergone surgery were assigned randomly to two preoperative skin preparation protocols. Group 1 (60 animals) skin preparation was with povidoneiodine soap and isopropyl alcohol, whereas group 2 (57 animals) had skin preparation with chlorhexidine gluconate and isopropyl alcohol. Quantitative microbial culture plates were used to estimate the number of colony forming units (CFUs) before skin preparation (prescrub), after skin preparation (postscrub), after surgery (postoperative), and in room air (environment). A significant decrease in CFU occurred postscrub for both skin preparations (P < .05). Chlorhexidine and alcohol preparation resulted in significantly fewer CFUs (LSMean +/- SE = 2.79 CFU +/- 1.74) and a greater percentage reduction in CFUs (98.64% +/- 2.01) postscrub than providone and alcohol (LSMean +/- SE = 10.27 CFUs +/- 1.51, 93.29% +/- 1.85); (P < .005). Group 2 had a significantly higher frequency of negative cultures postscrub (49.1%) compared with group 1 (18.3%) (P < .001). The number of postoperative CFUs were not significantly different between the two treatment groups. Wound infection frequency for clean surgical procedures was not significantly different between the two skin preparation protocols (group 1 = 9.8%, group 2 = 10.7%), however, infection frequency was significantly higher for surgical procedures with a ventral abdominal approach (5 of 14, 35.7%,) compared with a flank approach (1 of 41, 2.4%) or other approaches (orthopedic procedures) (1 of 16, 6.3%) (P < .05). Both skin preparation protocols were effective and safe in decreasing the skin microflora population of cattle before surgery and although preparation with chlorhexidine gluconate and alcohol resulted in less CFUs immediately postscrub, the frequency of surgical wound infection was similar for both protocols.

Traumatic flexor tendon injuries in 27 cattle

Information for all cattle with a diagnosis of tendon injury entered into the Veterinary Medical Data Base (VMDB) was retrieved and selected medical records reviewed. The proportional morbidity rate for tendon disruption was 0.89 cattle/1,000 cattle admissions and 95 of 99 cattle survived. Female and dairy cattle had a greater risk of tendon disruption than male or beef cattle, respectively. Also, cattle 6 months to 7 years old had a greater risk than cattle younger than 6 months old. Complete medical records were examined for 27 cattle. Affected cattle were 2.5 +/- 1.8 years old and weighed 593.6 +/- 315.6 kg. Injuries were most commonly caused by accidents involving farm machinery (72%). Unilateral superficial digital flexor tendon injury occurred in 8 cattle (30%); multiple tendon injury occurred in the other 19 cattle (70%). A single limb was involved in 25 cattle, a rear limb was involved in 24 cattle, and an open wound was associated with the injury in 26 cattle. Wounds were identified most commonly at the mid (13 cattle) and proximal metatarsus (4 cattle). Treatment of tendon disruption included tenorrhaphy and casting (9 cattle), external coaptation, alone, (14 cattle), stall confinement, alone, (1 cow), and euthanasia or salvage (3 cattle). External coaptation was maintained for 74.4 +/- 34.3 days, and total confinement period was 88.3 +/- 59.5 days. Short-term complications included severe tendon laxity (one cow) and fatal septic peritonitis (one bull). Twenty-two of 24 cattle treated for tendon disruption survived. Follow-up information was available for 16 cattle; 14 cattle (87%) returned to productivity and 11 of 15 cattle with long-term follow-up (73%) were considered productive. Long-term complications included persistent lameness (56%) and persistent hyperextension of the digits (19%).

Characterization of anatomic communications between the femoropatellar joint and lateral and medial femorotibial joints in cattle, using intra-articular latex, positive contrast arthrography, and fluoroscopy

OBJECTIVE

To evaluate the frequency of communication between the lateral and medial femorotibial joints and the femoropatellar joint in cattle.

DESIGN

1 of 3 injection sites was randomly assigned to each ox.

ANIMALS

102 limbs were obtained from 55 fresh bovine cadavers presented for necropsy with problems unrelated to the stifle.

PROCEDURE

The joints were injected with a mixture of latex and barium sulfate. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and positive-contrast arthrography.

RESULTS

Communication between the 3 joints was present in 58 (56.9%) limbs. The femoropatellar and the medial femorotibial joints always communicated. Thirteen of 38 (34.2%) specimens injected in the lateral femorotibial joint did not communicate with the 2 other joints. The femoropatellar joint communicated with the lateral and medial femorotibial joints on the distal abaxial aspect of the trochlear ridge.

CONCLUSION

Individual anatomic variation of the stifle in cattle should be considered when diagnostic or treatment protocols are established.

CLINICAL RELEVANCE

The lateral femorotibial joint should be treated separately because it does not consistently communicate with the femoropatellar or medial femorotibial joint.

Surgical management of preputial injuries in bulls: 51 cases (1986-1994)

The purpose of this study was to compare success rates for preputial surgery depending on the initial diagnosis, ability to extend the penis, use of sedation and local anesthesia versus general anesthesia for surgery, and surgical technique. Medical records of 51 bulls treated surgically for preputial injury were reviewed. The mean age of the bulls was 2.5 years ranging from 1 to 5 years. Bos taurus breeds (82.3%) were more often affected than Bos indicus breeds (17.7%). The most common breeds represented in this study were Angus (45.1%), Simmental (11.8%), and brangus (9.8%). The seasonal incidence of preputial injuries was higher during the period of May-July (52.9%) and November-February (33.3%). The overall success rate was 70%. Posthioplasty was more successful than circumcision (90% to 43%) (P < 0.05). The success rate for surgeries performed under inhalation anesthesia in the surgery suite was 100% compared with a success rate of 63% for those animals operated on with injectable and local anesthesia in a rotary chute (P < 0.05). The success rate was 88% if the penis could be extended before the surgery and 36% if extension was not achieved (P < 0.05).

Comparative analyses of peritoneal fluid from calves and adult cattle

Reference values for hematologic variables change with increasing age in cattle. Therefore, the purpose of the study reported here was to describe the peritoneal fluid constituents of clinically normal young calves, and to compare cellular concentration and distribution in blood and peritoneal fluid of young calves with those of adult cattle. Eight healthy 8-week-old male Holstein calves and 8 healthy 3- to 8-year-old Holstein cows were studied. Peritoneal fluid was collected from calves along the ventral midline, 4-cm cranial to the umbilicus. Abdominocentesis was performed in the region of the lower right flank in adult cattle. Correlation analysis, using the Pearson's correlation coefficient, and regression analysis were performed for blood and peritoneal fluid data from calves. Data from calves were compared with those of cows, using Wilcoxon's rank sum test. A P value < 0.05 was considered significant for all tests. Calves had significantly lower blood eosinophil count (P < 0.003) and plasma protein concentration (P < 0.001) than did cows. Calves had significantly higher peritoneal fluid nucleated cell (P < 0.05) and mononuclear cell (P < 0.05) counts, but lower peritoneal fluid eosinophil cell count (P < 0.003) than did cows. For calves, nucleated cell and lymphocyte cell counts in the blood had a high, positive correlation with those of peritoneal fluid. However, the prediction equation for nucleated cell count accounted for a modest proportion of variability. A prediction equation for peritoneal fluid lymphocyte cell count was established.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of facilitated ankylosis in the treatment of septic arthritis of the distal interphalangeal joint in cattle: 12 cases (1987-1992)

Medical records were reviewed for 12 cattle with septic arthritis of the distal interphalangeal joint that were treated by use of facilitated ankylosis. Information on signalment, clinical signs, digit affected, radiographic findings, and type and duration of treatment were compiled. Owners were contacted for information about the convalescent period, reasons for culling, productivity, and outcome. Outcome was classified as successful or unsuccessful on the basis of lameness, growth pattern, and whether the cattle were subsequently productive. Cause of the septic arthritis was unknown in 9 of 12 (75%) cattle. Eleven of 12 (92%) cattle represented beef breeds. Cattle were lame for a mean of 5.3 weeks before admission. In 8 of 12 (67%) cattle, a trephine was used in the creation of an arthrostomy, the middle and distal phalanges were curetted, and the joint was lavaged with isotonic solution. A drill bit was used in 4 of 12 (33%) cattle to remove articular cartilage and facilitate ankylosis. Convalescent period after discharge from the hospital was 1 to 7 months (mean, 4 months; median, 4 months). After that period, all cattle had an apparently normal gait. Eight of 12 (67%) cattle were maintained in their herd of origin. None of the cattle were culled because of lameness. Two of 12 (17%) cattle had a deformation of the affected digit. According to the criteria for successful outcome that were used in the study reported here, the success rate was 100%. Treatment of septic arthritis of the distal interphalangeal joint by use of facilitated ankylosis is an alternative to digit amputation and is recommended to promote longevity and productivity.

Comparison of peritoneal fluid analysis before and after exploratory celiotomy and omentopexy in cattle

The effect of right paralumbar fossa exploratory celiotomy and omentopexy on peritoneal fluid constituents was studied in 22 adult dairy cows. Six cows were eliminated on the basis of physical examination findings (n = 2), surgical findings (n = 2), or inability to obtain a sufficient volume of peritoneal fluid (n = 2). Sixteen cattle had normal results of CBC and serum biochemical analysis, and a minimum of 1 ml of peritoneal fluid was obtained by abdominocentesis. Abdominocentesis was repeated on days 1, 2, and 6 after surgery. Statistical analysis for repeated measures was performed, using a significance level of P < 0.05. Stage of gestation was evaluated for interaction with time. Mean total nucleated cell count was 3,200 cells/microliters before surgery, was significantly increased 2 days after surgery (16,336 cells/microliters), and continued to increase through day 6 (20,542 cells/microliters). Mean polymorphonuclear cell count was 1,312 cells/microliters before surgery and was significantly higher at 2 (11,043 cells/microliters) and 6 (10,619 cells/microliters) days after surgery. Mean lymphocyte count was 254 cells/microliters before surgery and was significantly increased 2 days (1,911 cells/microliters) after surgery. By day 6, lymphocyte numbers were similar to preoperative values. Mean mononuclear cell count was 770 cells/microliters before surgery and was significantly increased on days 1 (3,084 cells/microliters), 2 (3,285 cells/microliters), and 6 (2,349 cells/microliters) after surgery. Mean eosinophil numbers were 1,388 cells/microliters before surgery and were significantly increased on day 6 (6,347 cells/microliters) only. Interaction between time and stage of gestation was found only for specific gravity and total protein concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Type I congenital cystic adenomatoid malformation of the lungs in a Hereford calf

A 3-day-old Hereford calf was presented for general weakness and severe dyspnoea. Lateral radiographs projections showed several compartmentalized gas filled structures in the caudodorsal thorax. At necropsy each diaphragmatic lung lobe contained a large cyst. Gross and histopathologic findings were consistent with a congenital type I cystic adenomatoid malformation of the lungs.

Congenital cutaneous papillomatosis in a one-year-old Holstein

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Endoscopic evaluation of the nasopharynx, pharynx, and larynx of Jersey cows

Endoscopy of the nasopharynx, pharynx, and larynx was performed in each of 25 adult Jersey cows, age and body weight of which ranged from 2 to 6 years and 300 to 365 kg, respectively. The endoscopic appearance of normal anatomic structures of the proximal portion of the airway were described. Observations specific to female dairy cattle were: the nasal septum, which tapered caudodorsally in the distal third of the nasal passage; the ability to observe both ethmoturbinates from the same viewing side; presence of a pharyngeal septum; the nasopharyngeal opening of the auditory tubes dorsolateral to the pharyngeal septum; and the appearance of the larynx--a triangular epiglottis with round borders and prominent corniculate process of the arytenoid cartilages. Tracheoscopy was performed in 13 cows. Of 11 cows for which the soft palate could be observed immediately after withdrawing the endoscope, 7 had dorsal displacement of the soft palate.

Hyperlipemia and ketonuria in an alpaca and a llama

An alpaca and a llama in late stages of gestation were evaluated for lethargy, anorexia, and recumbency. Both camelids had cloudy, white, turbid serum, elevated serum triglyceride (1564, 5658 mg/dL, respectively) and cholesterol (158, 297 mg/dL, respectively) concentrations, and ketonuria. Signs of fetal stress were evident ultrasonographically in the alpaca, and a live cria was delivered by Cesarean section performed under general anesthesia. The alpaca developed severe metabolic acidosis, hepatic lipidosis, and acute renal failure secondary to renal lipidosis and died 36 hours after admission despite medical therapy. Histopathology revealed renal and hepatic lipidosis and neutrophilic pancreatitis. The cria died 72 hours after birth. The llama responded to IV electrolyte, dextrose, and regular crystalline insulin therapy. The pregnancy was maintained, and the llama was discharged from the hospital 20 days after admission. Two months after discharge, the llama gave birth to a live, 5 kg cria. Findings of hypertriglyceridemia, hypercholesterolemia, elevated sorbitol dehydrogenase activity, metabolic acidosis, azotemia, and ketonuria occurred in these two camelids. Based on this report, camelids appear to be similar to both horses and cattle in their response to severe energy imbalances in late gestation.

Repair of fractures of the radius and ulna in a ewe using positive profile transfixation pins and casting

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Isolation of Mycobacterium paratuberculosis from mononuclear cells in tissues, blood, and mammary glands of cows with advanced paratuberculosis

Seven mature dairy cows from 6 herds were obtained with history, clinical signs of disease, and laboratory findings suggestive of advanced paratuberculosis. A surgically implanted collection chamber was used to obtain peripheral tissue fluid. Blood, mammary gland flush fluid, and collection chamber flush fluid (CCFF) samples were obtained 6 times over a 2-week period from each cow. Mononuclear cell-rich portions of these fluids obtained by gradient centrifugation were submitted for bacteriologic culture of Mycobacterium paratuberculosis and for total and differential cell counts. Bacteriologic culture of feces for M paratuberculosis and complete necropsy performed on each cow at the conclusion of the study confirmed the diagnosis of paratuberculosis. Numbers of tissue macrophages obtained from CCFF samples were lower than expected. Mean (+/- SD) differential count of tissue macrophages collected from CCFF was 65.57 (+/- 23.39). Mean calculated tissue macrophages (total cell count x differential count) collected from CCFF samples was 623.1 (+/- 784.55) cells/microliters. Mycobacterium paratuberculosis was isolated from 1 of 42 (2.4%) collections of mononuclear cell-rich portions of plasma and from 2 of 42 (4.8%) CCFF samples. Mycobacterium paratuberculosis was not isolated from any collections of mammary gland flush fluid. The collection and processing techniques used in this study did not enhance detection of M paratuberculosis infection in cows with advanced paratuberculosis, beyond that of ileocecal lymph node biopsy or fecal culture.

Normal laparoscopic anatomy of the bovine abdomen

Three laparoscopic procedures were performed on each of 6 adult Jersey cows in the first trimester of gestation to describe normal laparoscopic anatomy of the bovine abdomen. Also, a technique for laparoscopy of the cranioventral portion of the abdomen was described. Right paralumbar fossa, left paralumbar fossa, and cranioventral midline laparoscopy were performed 72 hours apart of each cow. Physical examination findings, CBC, serum biochemical analysis, and peritoneal fluid analysis before and 72 hours after the first surgery were used to assess the effects of the procedures on the cows. Exploratory celiotomy was performed 2 weeks after the last laparoscopy. The cows were then reexamined 6 weeks after the last procedure. The t-test for paired data was used for statistical analysis; the level of significance was P < 0.05. Laparoscopy was performed without complication in all cows. Adverse effects of laparoscopy, individually or serially, were not observed. Significant differences were not found between CBC, serum biochemical, and peritoneal fluid variables taken before and 72 hours after surgery.

Importance of platelets in myocardial injury after reperfusion in the presence of residual coronary stenosis in dogs

Residual coronary stenosis is common after successful thrombolysis for acute infarction. We investigated the role of platelets and the influence of a residual critical stenosis during early reperfusion in survival of reperfused myocardium. The left anterior descending coronary artery was occluded for 90 minutes and reperfused for 6 hours in 5 groups of dogs, 3 with a residual critical stenosis (groups 1 through 3) and 2 without (groups 4 and 5). Thrombocytopenia was produced by an antiserum in groups 2, 3, and 5; group 3 was also made neutropenic by another antiserum. Platelets (groups 1 and 4) and neutrophils (groups 1, 2, 4, and 5) labeled with indium 111 were reinjected at occlusion. Collateral flow was estimated with radioactive microspheres and was statistically similar among groups. Infarct size (percentage of area at risk), revealed by triphenyltetrazolium, was more severe (49.4% +/- 4.0%; p < 0.05) with stenosis (group 1) than without stenosis (group 4: 29.5% +/- 4.6%). Platelet depletion reduced infarct size in group 2 (28.6% +/- 6.3%; p < 0.05 vs group 1) with stenosis, but not in group 5 without stenosis (24.5% +/- 6.2% vs group 4: 29.5% +/- 4.6%). Neutropenia (group 3) did not decrease infarct size in thrombocytopenic dogs. Neutrophil accumulations in reperfused myocardium were similar among groups, but platelets accumulated in greater numbers in reperfused infarcts with stenosis (group 1: 338,581 +/- 52,857/gm; p < 0.05) than without stenosis (group 4: 153,445 +/- 23,949/gm). Therefore a critical stenosis at reperfusion compromises myocardial salvage and increases infarct size by means of a platelet-mediated mechanism.

Squamous cell carcinoma of the anal and perianal area in a bull

A squamous cell carcinoma located adjacent to the anus was diagnosed in a 15-year-old light colored Longhorn bull. The tumor restricted the anal orifice to a diameter of 3 cm. Upon histological evaluation, islands of squamous cells were present deep in the dermis and the submucosal connective tissue. It was not possible to determine whether the tumor originated from the perianal region or the anus. This is the first diagnosed and reported occurrence in North America of squamous cell carcinoma in the anal region of a bull.

Abdominal pain associated with an umbilical abscess in a llama

A 3-month-old llama with a presenting complaint of lethargy, anorexia, and a painful, distended abdomen was evaluated. The llama had intermittently strained to defecate during the 3 days prior to admission. Physical examination results, hematologic data and lateral abdominal radiographs were used to diagnose a large umbilical abscess, which was causing a partial obstruction of the gastrointestinal tract. Under general anesthesia, 3 liters of purulent exudate were drained from the abscess. The abscess cavity was then lavaged with saline solution and its capsule was marsupialized to the skin. Cultures of the abscess content yielded Proteus sp, Streptococcus equisimilis, and Clostridium septicum. Two days after surgery, the llama was drinking, eating, and passing feces. The abscess was lavaged daily for a total of 11 days. Six months after surgery, the llama was the same size as other llamas of the same age, and the owners were pleased with the cosmetic appearance of the ventral abdomen. Umbilical abscesses can vary in size and clinical presentation; they should be recognized as a possible cause of abdominal pain with a potential for causing intestinal obstruction in llamas.

Collection of pancreatic exocrine secretions by formation of a duodenal pouch in cattle

Collection of exocrine pancreatic secretions from cattle by use of a single-unit cannula was performed. The major advantage of the cannula was simple technical management. A small pouch of the duodenum into which the major pancreatic duct drains was formed. Continuity of the duodenum was reestablished by end-to-end anastomosis. A side arm of the cannula was inserted into the pouch to collect exocrine secretions, and the main portion of the cannula was placed cranial to the anastomosis to return pancreatic secretions to the small intestine between collection periods. The accessory pancreatic duct was ligated in 2 of 4 cattle to evaluate possible secretory contribution from this source. All cattle remained healthy after cannulation, and cattle gained approximately 100 kg of body weight in the 5 months after surgery. The mean secretory rate for exocrine pancreatic secretion in cattle was 106 +/- 6.8 ml/h. There was no effect of feeding on the pattern of secretion nor were there significant differences between cattle. A fistula formed between the pouch and duodenum approximately 120 days after surgery in the first 2 cattle used. Development of fistulas was prevented for 300 days in subsequently prepared cattle by use of surgical mesh around the cannulas, leading to functional cannulation sites. Preparation of a duodenal pouch appeared useful for long-term studies of pancreatic exocrine secretion in cattle.

Abomasal luminal pressure in cattle with abomasal volvulus or left displaced abomasum

The abomasal luminal pressure was determined during surgery in 54 dairy cows with abomasal volvulus (AV) and another 50 dairy cows with left displaced abomasum. The luminal pressure was high in all cattle with AV and 49 (98%) cattle with left displaced abomasum. Luminal pressure was significantly higher in cattle with AV (median, 11.7 mm of Hg; range, 4.1 to 32.4 mm of Hg) than cattle with left displaced abomasum (median, 8.7 mm of Hg; range, 3.5 to 20.7 mm of Hg). Among cattle with AV, abomasal luminal pressure was significantly higher in cattle that died or were sold for slaughter following surgery (median, 20.6 mm of Hg; n = 8) than in cattle that were retained in the herd (median, 11.0 mm of Hg; n = 46). The luminal pressure was weakly correlated with the preoperative serum alkaline phosphatase activity but not correlated with duration of inappetence before surgery. Calculation of likelihood ratios and construction of a response operating characteristic curve for cattle with AV indicated that a cut-off value of 16 mm of Hg for luminal pressure optimized the distribution of cattle into productive and nonproductive groups. The sensitivity, specificity, positive predictive value, and negative predictive value of a luminal pressure < 16 mm of Hg in predicting a productive outcome were 0.83, 0.75, 0.95, and 0.43, respectively.

Penile hematoma in bulls: 60 cases (1979-1990)

Sixty bulls with penile hematomas were examined from 1979 through 1990. Thirty-eight bulls underwent surgical correction, 17 bulls were managed by medical treatment, and 5 bulls were not treated. Hereford and Polled Hereford breeds represented the majority (n = 37, 62%) of the bulls, with 10 other breeds representing the remainder (n = 21, 35%) in this study; breed was not reported in 2 bulls. Follow-up information was obtained from owners (40/60) through conversation on the success or failure of treatment, interval of sexual rest, duration of breeding soundness, and final outcome of the bull. Surgical correction was successful in 19 (70%) of 27 cases; medical treatment was successful in 6 (46%) of 13 cases. Of the 8 bulls that had penile hematomas with swelling measuring > 20 cm in width, 6 were successfully treated surgically, compared with 1 of 3 successfully treated medically. Of the bulls with penile hematomas having a swelling measuring < or = 20 cm in width, 7 of 9 were successfully treated surgically, compared with 4 of 5 successfully treated medically. Duration of the penile hematoma had little effect on the success of surgical correction. Of the bulls allowed sexual rest for > 2 months after treatment was initiated, 6 (25%) of 24 had a recurrence of penile hematoma. Four (40%) of 10 bulls allowed sexual rest for < or = 2 months had a recurrence of penile hematoma.

Repair of a proximal diaphyseal femoral fracture in a calf, using intramedullary pinning, cerclage wiring, and external fixation

Repair of a comminuted, spiral oblique, proximal diaphyseal femoral fracture in a 7-day-old calf was achieved by use of an intramedullary pin, cerclage wires, and external fixator. Six stainless steel wires were used for full cerclage to secure a long butterfly fragment and multiple incomplete and complete nondisplaced fragments to the femur in order to create 2 principal fragments. Axial alignment and resistance to bending was provided by a round, double-pointed, end-threaded intramedullary pin (6.35 mm in diameter), which was inserted in a retrograde fashion. A type-1, double-connecting-bar external fixator, using 4 round pins (4.8 mm in diameter), was used to provide supplemental stabilization against shear and torsional forces. At 45 days after surgery, healing at the fracture site was seen on radiography of the limb, and the external fixator was removed. Eight months after surgery, the calf had a normal gait.

Intramedullary pinning of femoral diaphyseal fractures in neonatal calves: 12 cases (1980-1990)

Medical records of 12 calves less than or equal to 1 month old, with fracture of the femoral diaphysis, were reviewed. Ten calves were within 1 week of birth at the time of diagnosis. Open reduction was accomplished by use of a lateral approach. Retrograde intramedullary pinning was accomplished in all calves, using 2 (n = 4 calves) or 3 (n = 8 calves) pins. Cerclage wire was used to supplement fixation in 7 calves. A closed continuous suction drain was placed along the lateral aspect of the femur in every calf. Postsurgical complications included seroma formation over the middle gluteal musculature (n = 5 calves), pin migration (n = 6 calves), and osteomyelitis (n = 1 calf). Pin migration was observed in 4 calves that had been treated with nonthreaded trochar point pins. Fractures in 10 of 12 calves (83%) were considered to have healed satisfactorily. One calf was euthanatized because of septic osteomyelitis of the femur. One calf was euthanatized because of persistent lameness and pin migration. Pins were removed in 8 of 12 calves (67%) between the 13th and 90th postoperative days. Results of this study indicate that application of intramedullary pins may be a useful solution for management of femoral diaphyseal fracture in young calves.