Characterization of early-stage lesions and investigation on the role of mucosal trauma in hemorrhagic bowel syndrome in cattle.

Hemorrhagic bowel syndrome (HBS) is characterized by a dissecting intramucosal hematoma at the small bowel, causing obstruction and severe hemorrhage in dairy cattle. Recent investigation revealed the presence of early-stage lesions in cows affected by HBS. These are presumed to be the initial stage of the hematoma, as both share unique dissection of the lamina muscularis mucosae (LMM) as histological hallmark. Early-stage lesions of HBS have not been characterized in greater detail, and neither has the hypothesis of mucosal abrasion as etiology been explored. Therefore, the first objective of the present study was to characterize the morphology of early-stage lesions, by gross examination, histochemistry, immunohistochemistry and transmission electron microscopy. The second objective was to determine the effect of mucosal abrasion to the small intestine in an ex vivo model. A total of 86 early-stage lesions from 10 cows with HBS were characterized. No underlying alterations at the LMM were evident which could explain their occurrence. However, degeneration at the ultrastructural level of the LMM smooth muscle cells was present in 3 of 4 lesions, it is however unclear whether this is primary or secondary. Bacteriological examination did not reveal any association with a specific bacterium. Experimental-induced and early-stage lesions were gross and histologically evaluated and scored in three cows with HBS and seven controls. Experimentally induced lesions in both affected cows and controls, were histologically very similar to the naturally occurring early-stage lesions. Altogether, the results are suggestive for mucosal trauma to play a role in the pathogenesis of HBS.

Foot-and-mouth disease-associated myocarditis is age dependent in suckling calves.

Myocarditis is considered a fatal form of foot-and-mouth disease (FMD) in suckling calves. In the present study, a total of 17 calves under 4 months of age and suspected clinically for FMD were examined for clinical lesions, respiratory rate, heart rate, and heart rhythm. Lesion samples, saliva, nasal swabs, and whole blood were collected from suspected calves and subjected to Sandwich ELISA and reverse transcription multiplex polymerase chain reaction (RT-mPCR) for detection and serotyping of FMD virus (FMDV). The samples were found to be positive for FMDV serotype "O". Myocarditis was suspected in 6 calves based on tachypnoea, tachycardia, and gallop rhythm. Serum aspartate aminotransferase (AST), creatinine kinase myocardial band (CK-MB) and lactate dehydrogenase (LDH), and cardiac troponins (cTnI) were measured. Mean serum AST, cTn-I and LDH were significantly higher (P < 0.001) in < 2 months old FMD-infected calves showing clinical signs suggestive of myocarditis (264.833 ± 4.16; 11.650 ± 0.34 and 1213.33 ± 29.06) than those without myocarditis (< 2 months old: 110.00 ± 0.00, 0.06 ± 0.00, 1050.00 ± 0.00; > 2 months < 4 months: 83.00 ± 3.00, 0.05 ± 0.02, 1159.00 ± 27.63) and healthy control groups (< 2 months old: 67.50 ± 3.10, 0.047 ± 0.01, 1120.00 ± 31.62; > 2 months < 4 months: 72.83 ± 2.09, 0.47 ± 0.00, 1160.00 ± 18.44). However, mean serum CK-MB did not differ significantly amongst the groups. Four calves under 2 months old died and a necropsy revealed the presence of a pathognomic gross lesion of the myocardial form of FMD known as "tigroid heart". Histopathology confirmed myocarditis. This study also reports the relevance of clinical and histopathological findings and biochemical markers in diagnosing FMD-related myocarditis in suckling calves.

Prevalence and characterisation of band-shaped tail lesions in Holstein cows.

The aim of the study was to characterise and determine the prevalence of band-shaped tail lesions in Holstein cows. Lesions were present either as wounds or by epithelised granulation/connective tissue formations. Both types were characterised by a median localisation 7 cm from the tip of the tail, and they occurred on the dorsal aspect of the tail. From here they encircled the tail either completely or in varying degrees, and they were often present as isolated lesions (93%). The prevalence of band-shaped tail lesions was found to be 25% among 2099 cows examined in 16 Danish Holstein herds with a variation from 18 to 40% between herds. In the herds, the wound lesions and the connective tissue formations accounted for 22% and 78% of all band-shaped tail lesions, respectively. Among 458 Holstein cows examined at an abattoir the prevalence of band-shaped tail lesions was 23%, i.e. similar to the prevalence within the herds. At the abattoir the share of band-shaped wound lesions was 67% and the band-shaped connective tissue formation 33%. Associations between the occurrence of band-shaped tail lesions and parity and lack of the tail tip were observed.

Two cases of congenital lipomatosis in calves.

Fetal tumours in domestic animals are considered rare. Congenital lipomatous changes have been sporadically reported in fetal, neonatal and young bovids. Their prognosis is often guarded compared with benign lipocytic tumours and depends on their location and degree of infiltration. They can infiltrate the subcutis, deeper musculature and even the skeleton. Four cases of congenital infiltrative lipomatosis have been described in bovine fetuses and young calves. In this report we describe an additional two cases in a neonatal Belgian Blue White calf and a fetal dairy calf. A potential role in bovine abortion needs further investigation. Furthermore, a suggestion is made to adapt the nomenclature from infiltrative lipoma to lipomatosis in order to emphasize the poor prognosis due to the local infiltrative behaviour of these lesions.

Ulcerative stomatitis associated with yellow bristle grass in New Zealand dairy cows.

CASE HISTORY: A line of 25 cull cows were all found to have ulcerative lesions of the tongue at post-mortem inspection in a New Zealand slaughter plant. A further 9 of 10 cows inspected at the farm of origin had similar oral lesions. There were no other clinical signs or indicators of ill-health observed at ante-mortem inspection in the abattoir or on the farm. The cows had been fed baleage for 3 weeks prior to slaughter, made from pasture in paddocks heavily contaminated with yellow bristle grass (Setaria pumila). CLINICAL FINDINGS: There was extensive and deep transverse linear ulceration in the lingual fossa immediately rostral to the torus linguae. At histological examination, full-thickness ulceration of the stratified squamous epithelium was observed with a bed of disorganised collagenous tissue and extensive mixed inflammatory infiltrate extending into the sub-epithelial connective tissue and skeletal muscle. Barbed plant fragments were embedded in both the superficial and deeper areas of inflammation. Detailed examination of the baleage also found that yellow bristle grass seedheads were present. DIAGNOSIS: Based on the presence of barbed plant material in the tongue and yellow bristle grass seeds in the baleage, a diagnosis of ulcerative stomatitis associated with yellow bristle grass was made. CLINICAL RELEVANCE: Clinicians should be aware of the potential for hay or baleage contaminated with yellow bristle grass to cause oral lesions in cattle.

[Successful surgical excision of a melanoma and a rare peripheral nerve sheath tumor in 2 cattle]. / Erfolgreiche chirurgische Exzision eines Melanoms und eines seltenen peripheren Nervenscheidentumors bei 2 Rindern.

A heifer and a dairy cow were presented to our practice with cutaneous masses on the left side of their necks. Each mass had a diameter of approximately 20 cm. Both tumors had increased in size in recent weeks and were now prone to injuries from the stable equipment. Both animal owners agreed to surgical removal, which was performed under sedation and local anesthesia on a bovine treatment crush. The subsequent histopathological examinations of the extirpates revealed a melanocytoma in the young heifer and a cutaneous peripheral nerve sheath tumor (PNST) in the dairy cow. Both cases were benign tumors. The postoperative course was without complications and no recurrences were observed even more than a year later. No comparable tumors were found in related animals or in the offspring.

A rare case of adventitious placentation (diffuse semi-placenta) in a Jersey cow.

Placental abnormalities more frequently occur during pregnancy of somatic cell clones and may lead to pregnancy loss or dystocia. Adventitious placentation, or diffuse semi-placenta, is determined by the development of areas of accessory placentation between the cotyledons due to the abnormal growth of placentomes.After a full-term pregnancy, a 3-year-old Jersey heifer was referred for dystocia which resulted in the delivery of a dead calf. The cause of dystocia was found to be foetal malposition, while the placenta was physiologically expelled after dystocia resolution.Grossly, cotyledons appeared reduced in size and number in one placental horn, while the surface of the other horn was covered with microplacentomes. Numerous villous structures without trophoblastic coating were highlighted after histopathology. The dominant sign was an inflammatory reaction. The findings were consistent with inter-cotyledonal placentitis, which led to adventitial placentation.Diffuse semi-placenta compensates for the inadequate development of placentomes and may occur as a congenital or acquired defect. The outcome depends on its severity: in the worst scenario, pregnancy may not proceed beyond midterm and may be complicated by hydrallantois. In the case under examination, the dimensions of the cotyledons (from 2 to 10 cm) allowed for the natural course of pregnancy.

Suspected intoxication by Kikuyu grass (Cenchrus clandestinus) of dairy cattle in the Azores, Portugal.

CASE HISTORY: An outbreak of suspected Kikuyu grass (Cenchrus clandestinus) intoxication among dairy cattle occurred on the island of Terceira in the Azores (Portugal), in October 2022. The animals affected were non-lactating dairy cows and heifers from five small farms grazing (free or tethered) a Kikuyu-dominant pasture. Of the 29 animals exposed, 17 were affected, and eight (five heifers and three adult cows) died, resulting in a morbidity rate of 58%, a mortality rate of 28% and a case mortality rate of 47%. CLINICAL FINDINGS AND TREATMENT: The clinical signs were non-specific and inconsistent, and included dry faeces, some with dark red blood; apathy and prostration; abdominal dilatation; tachycardia; tachypnoea; pale or jaundiced mucous membranes; sham drinking; sialorrhoea; and moderate to severe dehydration. Symptomatic treatment was provided but was ineffective. Haematology and serum biochemistry revealed an acute inflammatory leukogram, increased alkaline phosphatase (ALP) activity, decreased gamma-glutamyl transferase (GGT) activity, and azotaemia.The most consistent necropsy findings were haemorrhages in the epicardium and endocardium, an enlarged liver with rounded edges, non-perforated abomasal ulcers, and haemorrhagic lesions in the small and large intestines. Histopathology indicated myocarditis, hepatitis, interstitial nephritis, enteritis and colitis.Several fungal species were isolated from grass samples taken from affected pastures including several Fusarium spp., the genus implicated in Kikuyu toxicosis. Immediate removal of the animals from the pasture with Kikuyu was the only measure that prevented new cases and resulted in the recovery of some of the less affected animals. DIAGNOSIS: The epidemiological features of this outbreak and the clinical signs and micro- and macroscopic lesions observed were highly suggestive of Kikuyu grass poisoning. CLINICAL RELEVANCE: Although the weather conditions varied from other published cases, the grazing conditions (almost exclusive Kikuyu grass) and the post-mortem findings were very similar to those described in the literature, particularly the haemorrhages in the epicardium and endocardium. Kikuyu grass is very invasive and presents many desirable characteristics as cattle feed. Thus, an increase in cases of intoxication may be expected. Practitioners and farmers in areas where Kikuyu grass is abundant should be aware of the potential risks of grazing cattle exclusively on these pastures. They should also be aware of the early and subtle signs of Kikuyu intoxication to allow for timely removal of the animals from pasture.

A scoring system for grading corkscrew claws in dairy cattle.

Corkscrew claw (CC) in dairy cattle is increasingly reported in dairy herds. CC is a progressive deformity of the claw capsule with uncertain aetiology and pathogenesis. Genetics and specific environmental factors are suspected of contributing to the development of this irreversible condition. CC has been found in lame cows; however, the cause and effect has not been established. To perform analysis of risk factors, treatment and pathogenesis, a definition of severity scores is called for. The aim of this study was to measure and analyse CC characteristics from photos of cows' feet to describe and evaluate a scoring system for CC. Width of the visible part of the axial wall, degree of contact between the toe and the floor and angle of the distal part of the abaxial wall as a proxy for the deviation of the abaxial wall was measured from 393 pictures of CC. Based on the measurements on the claws, the parameter "width of the axial wall" was chosen to define the scores. The parameter was divided into three intervals to define either mild CC 0.3-2.0 cm, moderate CC 2.1-3.5 cm or severe CC>3.5 cm and correlation between the parameters; level of contact between the toe and the floor and the angle of the distal abaxial wall was evaluated. There was a significant positive linear correlation between width of the axial wall and angle of the distal part of the abaxial wall (r=0.91), the wider the axial wall, the more the abaxial wall deviated in the distal part. As the width of the axial wall increased the toe increasingly lost contact with the floor, this association was significant for mild CC and moderate CC but not for severe CC. The Interobserver agreement of the CC Scoring system was tested by 30 claw trimmers each scoring 32 cadaver feet and by 2 trained observers on 28 photos of feet using Cohen´s weighted kappa and showed substantial to almost perfect agreement between untrained and trained observers, respectively.

Bovine astrovirus and its role in lymphocytic encephalitis in cattle in Ontario, Canada, 1988-2019.

Astroviruses have been found in cattle and other species with encephalitis. Our objective was to determine the frequency of neurotropic bovine astrovirus (BoAstV) in cases of encephalitis in cattle ≥ 4-mo-old. Of 56 cases of idiopathic lymphocytic encephalitis examined retrospectively (1988-2019), fixed brain from 11 cases (19%) tested positive by semi-quantitative RT-PCR for BoAstV CH13/NeuroS1. None of the control cases tested positive, including 32 with other forms of encephalitis and 40 with no neurologic disease. Most astrovirus-positive cases were 1-2-y-old, with a range of 7 mo to 7 y, and affected both beef and dairy breeds with wide geographic distribution. BoAstV-positive cases had acute onset of neurologic signs of 12 h to 7 d before death or euthanasia. Affected cattle had lymphocytic inflammation throughout the brain including cerebrum, thalamus, midbrain, cerebellum, medulla oblongata, and spinal cord, and affecting gray and white matter. Further PCR testing identified a possible cause in 9 of the 45 (20%) remaining idiopathic cases of lymphocytic encephalitis, including eastern equine encephalitis virus, Listeria monocytogenes, bovine viral diarrhea virus, bovine alphaherpesvirus 1, and ovine gammaherpesvirus 2 (malignant catarrhal fever); we found no cases of infection by West Nile virus, rabies virus, or Chlamydia spp. No cause was identified in 36 of 56 (64%) cases of lymphocytic encephalitis. We frequently identified neurotropic BoAstV in cases of lymphocytic encephalitis that had no previously identified cause. Neurotropic BoAstV infections had gone undetected for decades, but the frequency of BoAstV infections has not increased among contemporary cases.

A recessive CLN3 variant is responsible for delayed-onset retinal degeneration in Hereford cattle.

Thirteen American Hereford cattle were reported blind with presumed onset when ~12-mo-old. All blind cattle shared a common ancestor through both the maternal and paternal pedigrees, suggesting a recessive genetic origin. Given the pedigree relationships and novel phenotype, we characterized the ophthalmo-pathologic changes associated with blindness and identified the responsible gene variant. Ophthalmologic examinations of 5 blind cattle revealed retinal degeneration. Histologically, 2 blind cattle had loss of the retinal photoreceptor layer. Whole-genome sequencing (WGS) of 7 blind cattle and 9 unaffected relatives revealed a 1-bp frameshift deletion in ceroid lipofuscinosis neuronal 3 (CLN3; chr25 g.26043843del) for which the blind cattle were homozygous and their parents heterozygous. The identified variant in exon 16 of 17 is predicted to truncate the encoded protein (p. Pro369Argfs*8) battenin, which is involved in lysosomal function necessary for photoreceptor layer maintenance. Of 462 cattle genotyped, only blind cattle were homozygous for the deletion. A query of WGS data of > 5,800 animals further revealed that the variant was only observed in related Hereford cattle. Mutations in CLN3 are associated with human juvenile neuronal ceroid lipofuscinosis (JNCL), or Batten disease, which results in early-onset retinal degeneration and lesions similar to those observed in our cases. Our data support the frameshift variant of CLN3 as causative of blindness in these Hereford cattle, and provide additional evidence of the role of this gene in retinal lesions, possibly as a model for human non-syndromic JNCL.

Surgical treatment of bovine nasal granuloma and an allergological exploration.

Nasal granuloma in cattle results from inflammation within, and attendant proliferation of, the nasal mucosa possibly in response to an allergic response. However, the relationship between nasal granuloma and allergies remains unclear. Furthermore, severe cases have a poor prognosis because there is currently no effective treatment. Herein, we report three cases of nasal granuloma with severe stertorous breathing that were treated surgically. We also conducted an allergological exploration. Following surgical removal clinical signs did not recur in two of the three cases; however, stertorous breathing persisted in one case, and the cow was sacrificed 4 months later. A histopathological examination revealed that all nasal granulomas featured varying infiltrations of macrophages eosinophils, mast cells, and lymphocytes. The number of mast cells and the proportion of these cells that had degranulated were significantly higher in the granulomas than in normal nasal mucosae. In addition, serum histamine levels were higher in nasal granuloma cases than in normal cows, although serum immunoglobulin E levels were similar, and lymphocyte infiltration in the submucosal layer suggested type I and type IV allergies. Collectively, the results indicate the efficacy of complete surgical curettage for the treatment of allergic nasal granuloma in cattle. Further studies are required to identify the causes and risk factors of allergic nasal granuloma in cows.

Abomasal lesions found in postmortem examination of fattening Holstein-Friesian bulls from central Poland.

The health of the gastrointestinal tract in cattle is one of the factors influencing adequate nutrient absorption and body weight gain. This study aimed to evaluate the prevalence of lesions found in the abomasum of Polish fattening Holstein-Friesian bulls. A total of 149 abomasa from adult bulls from two voivodeships of central Poland were inspected for pathologicalanatomic position (displacement, volvulus), impaction, mucosal membrane lesions (inflammation, hyperplasia), and signs of parasite infestation(Moroccan leather, worm nodules) in one of the Polish abattoirs just after slaughter. Among all the examined males no lesions were observed in only 8 individuals. The most common findings were erosions (75.8%) and type 1 ulcerations (48.3%) of the body, pylorus, or both locations. Signs of parasite infestations were observed in 78.5% of the inspected animals. Significant differences correlated with age were found in the prevalence of healed ulcers, and between voivodeships in the prevalence of type 2 ulcers. The findings of this study indicate that most fattening bulls in Poland suffer from subclinical forms of abomasa inflammation (both diffuse and focal) and middle-large abomasum parasites invasions, which can influence the economics and profitability, as well as welfare, of livestock production.

Evaluation of selected risk factors for different stages of digital dermatitis in Dutch dairy cows.

Digital dermatitis (DD) is a painful infectious disease in dairy cattle that causes ulcerative lesions of the skin just above the coronary band, mainly of the hind legs. Estimates for DD prevalence at cow level in the Netherlands range from 20% to 25%. In this study, risk factors for the various stages of DD were identified and quantified. The hind legs of 6766 cows on 88 farms were scored by trained interns, using the M-scoring system (M0-M4.1). Farms in this study were a convenience sample, based on the prevalence of DD as recorded at the latest herd trim, geographical location and willingness of the farmers to participate. A survey with questions about cow environment and herd management was conducted by the intern at the day of scoring. The data were collected between August 2017 and January 2018. DD was found on 38.6% of the scored legs; 49.8% of the cows had DD on at least one leg and M4 was the most frequent stage (20.9%). Not removing manure on a regular basis resulted in lower odds for M2, M4 and M4.1 compared to cleaning by automatic scrapers ten times a day or more (odds ratio [OR]= 0.16, 0.49 and 0.18, respectively). The odds for M2 and M4 lesions were higher in cows aged 3-5 years than in first-calved cows (OR> 1.5 and > 1.7, respectively). Rubber flooring in the passageways resulted in lower odds for both M1 and M2 (OR, 0.06 and 0.32, respectively). Prophylactic use of footbaths treatment with an alternative active compound resulted in significant higher odds for M4 lesions than formalin and a combination of formalin and copper sulphate (OR= 1.69 and 2.04 respectively). The odds for an M4.1 lesion were lower in cows from smaller herds (n = 50-100) compared to large herds (n >100; OR= 0.67).

Granulomatous pneumonia in a cow infected with Toxoplasma gondii.

We report a confirmed case of Toxoplasma gondii infection in the lungs of a cow exhibiting respiratory symptoms. At slaughter, white nodules were discovered in lung tissue, accompanied by enlarged hilar lymph nodes. Histological examination revealed the disappearance of alveolar structures in nodular areas, replaced by granulomas containing inflammatory cells. Immunohistochemical staining with anti-T. gondii antibody and nucleotide sequencing of 18S rDNA confirmed T. gondii infection. However, the link between T. gondii and observed symptoms remains unclear. Various factors, including host genetics, underlying diseases, infection route, and exposure level, may contribute to these uncommon symptoms. Although T. gondii infections in cattle are traditionally considered asymptomatic, our study suggests the possible existence of clinical symptoms associated with Toxoplasma infection. Beef cattle are generally not assumed to be a relevant source of human T. gondii infection; however, sporadic transmission by infected edible beef to humans cannot be completely excluded and deserves further studies.

Clinical, pathologic, and molecular characterization of a non-metastatic multicentric cutaneous mast cell tumor in a cow.

Cutaneous mast cell tumors are rarely reported in cattle. Although mutations in the c-KIT gene have been shown to play a central role in the oncogenesis of canine mast cell tumors, few data are available in cattle. This report describes the clinical, histologic, immunohistochemical, and genetic features of a multicentric cutaneous mast cell tumor in an adult cow. An 11-year-old Prim'Holstein cow was presented for a 5-month history of multiple skin nodules. Cytologic and histologic analyses of the nodules led to a diagnosis of mast cell tumors. Immunohistochemical analysis for KIT expression showed a moderate to strong signal in neoplastic mast cells with a cytoplasmic and membranous pattern. Sequencing of the c-KIT gene coding sequence revealed no mutation. Despite partial response after corticosteroid treatment, euthanasia was elected. No metastases to the lymph nodes, spleen, and liver were identified at post-mortem and histologic examinations.

An abattoir study of the prevalence of foot lesions and claw measurements in water buffalo in Egypt.

BACKGROUND: Lameness has been associated with compromised animal welfare and reduced productivity in dairy cattle herds worldwide. However, little is known about the prevalence of claw lesions in the dairy buffalo population in Egypt. Furthermore, the optimum measurements for claw trimming in buffalo are unknown. A cross-sectional cadaver study was conducted where 135 pair buffalo hind feet were collected from 4 slaughterhouses and examined for the presence of claw lesions. The proportion and associated 95% confidence interval (CI) of each type of lesion were calculated. A separate set of healthy claws (n = 26) underwent ultrasonography (US) and computed tomography (CT). The agreement between US and CT measurements was assessed using Passing-Bablok regression and intraclass correlation coefficient. The CT measurements were used to calculate trimming recommendations. RESULTS: At least one lesion was identified in 242 claws (89.6%, 95% CI = 85.4-93.0). In healthy claws, poor to moderate agreement was identified between US and CT measurements which could be due a sample size of the study. The average ± standard deviation (SD) minimum recommended external wall length of the lateral and medial claws in heifers was 7.1 ± 0.36 cm and 7.5 ± 0.35 cm, respectively. The average ± SD minimum recommended external wall length in buffaloes over five years of age was 8.2 ± 0.27 cm and 8.4 ± 0.39 cm for the lateral and medial claws, respectively. CONCLUSIONS: The study found a high prevalence of claw lesions in buffalo in Egypt, the clinical significance of which requires further elucidation. Recommended measurements will help guide claw trimming in buffalo to minimise lesions.

Granulomatous dermatitis caused by Exserohilum mcginnisii infection in a cow.

A 5-y-old, Piedmontese cow had a 4-mo history of ongoing development of skin masses. This was the only cow affected in a herd of 20 cows. Up to 12, hairless, red-to-black, raised nodules-to-plaques were distributed along the dorsum and tail head. Biopsies were taken for histopathology and ancillary testing. An ulcerated skin section contained dermal infiltrates of eosinophils, plasma cells, neutrophils, macrophages, lymphocytes, and multinucleate giant cells, and pyogranulomas. Fungal hyphae were seen within the dermis, multinucleate giant cells, and pyogranulomas. In pyogranulomas, fungi were surrounded by a Splendore-Hoeppli reaction. Dematiaceous (pigmented) hyphae were rarely observed with H&E-stained and unstained (cleared and mounted) sections, but stained well with a Fontana-Masson stain. Exserohilum mcginnisii was identified by fungal culture, followed by PCR assay and sequencing. Exserohilum is a dematiaceous fungus that causes disease in humans and rarely in animals. The use of unstained sections and Fontana-Masson stain are important to demonstrate pigment because dematiaceous fungi have little melanin and appear as hyaline hyphae histologically. PCR assay and sequencing aid in the differentiation and classification of fungal species. To our knowledge, E. mcginnisii dermal granulomas have not been reported previously in cattle.