Dermatosparaxis in two Limousin calves

Background

An unusual presentation of skin disease was identified in two related neonatal Pedigree Limousin calves presented to University Veterinary Hospital, University College Dublin, following detailed post mortem examination a diagnosis of dermatosparaxis was made. Dermatosparaxis in animals or Ehlers Danlos Syndrome, which is the analogous condition seen in humans, is a connective tissue disorder characterised by extreme skin fragility. To the authors’ knowledge this is the first report of such a diagnosis in the Limousin breed and the features of this lethal phenotype were severe in comparison to previous reports of the condition.

Case presentation

Two calves, which were full siblings, a pedigree Limousin bull (Calf A) and pedigree Limousin heifer (Calf B) were examined clinically after presenting collapsed since birth, both had grossly abnormal skin with multiple skin fissures visible and both calves were subsequently euthanised. Both calves underwent gross post mortem examination, after which histological samples were reviewed and electron microscopical examination of selected skin samples was carried out. Histological features of dysplastic dermal collagen were identified. The diagnosis of dermatosparaxis in the Limousin breed was confirmed. Genetic testing was conducted to determine if the current cases had the same mutation as has previously been described in Belgian Blue cattle. Some common parentage was traced but genetic testing did not show a similar mutation to that previously described in cattle. The specific genetic cause in this case is unknown.

Conclusions

This is the first report of dermatosparaxis in the Limousin and the presentation of the dermatosparaxis phenotype has some noteworthy features thus further genetic testing is required to pinpoint the causative mutation or other genetic defect. Given the popularity of the breed and the lethal nature of the phenotype in this case it is important to raise awareness of the condition.

     

Coat-colour dilution and hypotrichosis in Hereford crossbred calves

AIM: To investigate cases of coat-colour dilution and hypotrichosis in a group of Hereford x Friesian crossbred calves, and to define the underlying molecular genetics of the disorder. METHODS: The investigation was predicated on the hypothesis that this disorder was similar to a known dominantly inherited disorder of calves of black breeds crossed with Simmental cattle, for which there were candidate gene mutations. Sequence analyses of PCR amplicons from exon 1 and exon 11 of the premelanosome protein 17 gene (PMel17) were carried out. Restriction enzyme digestions of amplicons were followed using electrophoresis of digested fragments. RESULTS: It was shown that an affected calf and its Hereford sire were heterozygous for a three-base deletion in exon 1 of the PMel17 gene. These two animals were also heterozygous for a second mutation in exon 11 of the PMel17 gene. Four other related animals were likewise heterozygous for both mutations in the sire's herd of origin. CONCLUSIONS: Coat-colour dilution and hypotrichosis in Hereford crossbred calves in New Zealand is the same genetic disorder as that previously described in Simmental crossbred calves, and is linked to mutations in the PMel17 gene.     

Congenital white muscle disease in a Belgian blue calf

In this case report about white muscle disease (WMD) in a Belgian Blue herd, the disease is described both as an individual and as a herd problem. Aetiology, diagnosis, and therapy of WMD are discussed. WMD is a disease of animals with muscle damage due to the presence of free radicals. Unsaturated fatty acids in the cell membrane are transformed into a radical form in a chain reaction: a fatty acid next to the fatty acid radical can be transformed into another free radical. In healthy animal the chain reaction is stopped by anti-oxidants such as vitamin E and glutathione peroxidase. WMD can occur when more free radicals are produced than the available anti-oxidants can deal with. The disease occurs in calves, lambs, and foals.     

Hereditary equine regional dermal asthenia in three related Quarter horses in Brazil

Hereditary equine regional dermal asthenia belongs to a group of inherited, congenital connective tissue dysplasias usually described as hyperelastosis cutis, cutaneous asthenia, dermatosparaxis, or Ehlers-Danlos-like syndrome. This report presents the clinical and histological features of three related Quarter horses affected with regional dermal asthenia. These horses had bilateral asymmetric lesions of the trunk and lumbar regions, where the skin was hyperextensible. Handling of the skin elicited a painful response and superficial trauma led to skin wounds. The skin was thinner than normal in the affected areas, with thickened borders and harder fibrotic masses (pseudotumours). The histopathological findings included thinner and smaller collagen fibrils, and a loose arrangement of collagen fibres in the middle, adventitial and deep dermis. Masson's trichrome and Calleja stains did not reveal any abnormality of collagen and elastic fibres. Electron microscopy showed no abnormalities. As in human patients, pseudotumour histopathological findings included fibroplasia and neovascularization. The pedigree chart of these animals supports an autosomal recessive type of inheritance, which has been suggested by other studies. This is the first report of this disease in Brazil. Its clinical and histological features resemble those described in horses affected with this condition in the United States.     

Breed differences in the pharmacokinetics of ivermectin administered subcutaneously to Holstein and Belgian Blue calves

Belgian Blue (BB) cattle are very sensitive to mange caused by Psoroptes ovis and, in contrast to the case in Holstein cattle, single treatments with ivermectin do not result in complete elimination of the parasite. The objective of the present study was to determine the concentration of ivermectin in plasma, skin and hair following subcutaneous administration to Holstein and BB calves and to assess the influence of breed on drug pharmacokinetics and availability. Two groups of six healthy female Holstein and BB calves were treated with ivermectin (SC formulation) at a dose of 0.2 mg/kg. Blood, skin and hair were collected before treatment and up to 21 days after treatment. Ivermectin was analyzed in plasma and tissue by high-performance liquid chromatography (HPLC). The peak concentrations (Cmax), time-peak concentrations (Tmax), the area under the plasma concentration-time curves (AUC) and the mean residence time (MRT) were determined. The patterns of plasma and tissue ivermectin concentrations were similar in the two breeds of animals, however, the AUC and Cmax levels for plasma and skin were significantly higher in the BB calves. In hair, ivermectin was detected later than in plasma and skin, with the Tmax ranging between 4 days (Holstein group) and 6 days (BB group). The possible reasons for the significantly higher levels in plasma and skin in BB calves compared to Holstein calves are discussed.     

Echocardiographic evaluation of cardiac morphologic and functional variables in double-muscled calves.

We studied, by means of echocardiography in vivo, the cardiac consequences of the double-muscled character selection in beef cattle. Morphologic and functional echocardiographic variables were regularly estimated in 17 Friesian and 8 Belgian White and Blue calves during their growth. A total of 50 and 44 sets of data were collected in each group, respectively. Recordings were obtained, using 2-dimensional and M-mode echocardiography, and included measurements in long- and short-axis views of the heart. Most of the diastolic measurements of the left ventricle were not significantly different between breeds when normalized for body weight. To the contrary, systolic measurements of left ventricular wall thickness and dimensions were significantly (P less than or equal to 0.001) lower and greater, respectively, in Belgian White and Blue calves than in Friesian calves. This was interpreted as a result of significantly (P less than or equal to 0.001) lower left ventricular systolic functional indices in Belgian White and Blue than in Friesian calves. Echocardiographic evidence that the double-muscled selection in cattle induces alteration in morphologic variables of left ventricle was not found. However, results indicate that indices of left ventricular systolic function are lower in double-muscled calves than in calves with standard conformation.     

Hereditary parakeratosis in shorthorn beef calves

Parakeratosis was diagnosed in 9 Shorthorn beef calves over a 4-year period. When pedigrees of these calves were analyzed, familial associations were strong. Thirty-six coefficients of relationship among all possible combinations of the 9 affected calves ranged from 0.5 to 39.8% and averaged 15.6%. All affected calves were descendants of bull A. Of 9 affected calves, 6 had bull A in their paternal and maternal pedigrees. The 3 remaining affected calves had bull A in their sire's pedigree and were born to 2 full-sib dams. Seemingly, parakeratosis in this Shorthorn herd was hereditary with the mode of inheritance being that of a simple autosomal recessive.     

A genetic, pathological and virological study of congenital hypotrichosis and incisor anodontia in cattle

Two Friesian cows, half-sibs by a common dam, produced four bull calves with severe congenital hypotrichosis and incisor anodontia and three normal heifers by six unrelated Holstein, Friesian, Devon and Hereford bulls. The two dams, and their dam, had coats of a short, stubbly nature and the pigmented areas appeared rusty grey rather than black. Pathological examination of skin samples taken from multiple standardised sites from two of the affected calves showed a reduction in the number of large first-formed hair follicles. Smaller calibre hair follicles were present but, unlike those of normal neonatal calves, all were in the telogen (inactive) phase. Although the herd was infected with bovine virus diarrhoea virus there was no convincing evidence that the virus was implicated in the pathogenesis of these cases of congenital hypotrichosis with incisor anodontia. The family breeding information on the few severely affected and normal progeny and mildly affected and normal parents may be explained by the genetic hypothesis of an X-linked incompletely dominant gene.     

An outbreak of Akabane virus—induced abnormalities in calves after agistment in an endemic region

SUMMARY: During 1988, 2 farmers in the Bega district agisted pregnant cattle in the Hunter Valley of New South Wales. On return to the district to calve, 54% of calves from herd 1 and 30% of calves from herd 2 were affected with congenital arthrogryposls or hydranencephaly caused by Akabane virus infection. Field observations and laboratory findings from this outbreak are presented, illustrating the danger of moving immunologlcally naive animals into areas where Akabane virus is endemic.     

Javelin diagrams: applications in veterinary medical decision analysis

This paper introduces javelin diagrams as an innovative way for depicting the results of medical decision analyses. The methods were used to determine whether, and at which values, blood lactate in Belgian White and Blue or maximum tidal volumes in Holstein calves should be measured before deciding to treat or not a calf suffering from the bovine respiratory disease complex. The different alternatives depended upon the probabilities of survival with and without treatment and upon the costs associated with a possible death, the test and the treatment. The chosen alternative was the one with the lowest expected costs. From data collected on the treated calves, the expected costs of measuring lactate (198.01 euro) and tidal volumes (27.38 euro) before deciding to treat or not were lower than the expected costs of directly treating sick Belgian Blue (215.39 euro) and Holstein (51.55 euro) calves, respectively. The treatment should be applied to sick Belgian Blue calves with blood lactate < or = 7.8 mmol/L and to Holstein calves with a maximum tidal volume > or = 1.81 L. At such test values, the treatment expected costs were lower than the expected costs associated with no treatment of calves with other test values. Probabilistic sensitivity analyses showing benefits in treating animals with a positive test (over not treating the animals with a negative test) were mostly invariant to changes in any cost value but were sensitive to uncertainties in probabilities of survival with or without treatment. The javelin diagrams provided a clear visual indication of such results. They depicted how and by how much the benefits were affected by uncertainties in probabilities, they proposed different information values associated with the chosen alternative, and identified directions for further research.     

High mortality rate associated with bovine respiratory syncytial virus (BRSV) infection in Belgian white blue calves previously vaccinated with an inactivated BRSV vaccine

In a group of 60 Belgian White Blue calves less than 8 months old still housed in barns, a bovine respiratory syncytial virus (BRSV) outbreak was revealed on the basis of a direct diagnosis (immunofluorescence and virus isolation) performed on the lungs of dead animals, and the kinetics of BRSV neutralizing antibodies. Clinical signs, macroscopical and microscopical pulmonary lesions were also compatible with a BRSV infection. This outbreak is peculiar because the 35 oldest calves (204 +/- 29 days old) had been vaccinated 3-4 months before with an inactivated BRSV vaccine and 30% of these animals had died of respiratory distress. While they experienced a mild respiratory symptomatology, no death was recorded among the 25 youngest calves (69 +/- 29 days old) which had been left unvaccinated. Another peculiarity was found at the histological level where a massive infiltration of eosinophils was demonstrated in the pulmonary tissues of the dead animals. Together these data parallel the dramatic story described 30 years ago in children previously vaccinated with a formalin-inactivated human RSV (HRSV) vaccine upon a natural HRSV challenge. This illustrates that an immunopathological phenomenon also takes place after BRSV vaccination in cattle.     

CEREBELLAR HYPOPLASIA OF GENETIC ORIGIN IN CALVES

Within 2 years, following the introduction of 2 Shorthorn bulls from the same stud into an Australian Illawarra Shorthorn (AIS) herd, 16 calves were born with cerebellar hypoplasia. All affected calves were the progeny of one bull mated to the daughters of the other. All other progeny of these bulls, most of which were from AIS dams, were normal. Affected calves exhibited severe ataxia, consistent head movement and abduction of the forelimbs. Microscopic changes in the cerebellum included sparsity of cells of the granular layer, loss of Purkinje cells and narrowing of the molecular layer. Observations on the frequencies of normal and abnormal calves are consistent with the hypothesis that the condition is caused by an autosomal recessive gene for which affected calves were homozygous and which was introduced into the herd in heterozygous condition by both of the Shorthorn bulls. Evidence is given for an unusually high frequency of the gene in the stud of origin of the Shorthorn bulls and a procedure for reducing its frequency is outlined. The possibility of a viral or toxic aetiology is discussed but is considered to be an unlikely explanation for the condition in this herd.     

Congenital Cerebellar Cortical Degeneration in Holstein Cattle in Southern Brazil

A congenital progressive cerebellar disorder is described in Holstein calves. The clinical signs were progressive and were characterized by ataxia, hypermetria, a wide stance and fine head tremors. When the affected cattle were forced to run, the signs were exacerbated, leading to epileptiform attacks. Histological lesions consisted of a very selective cerebellar cortical degeneration, almost exclusively affecting the Purkinje cells. The disease affected 6 out of 200 Holstein calves from the same bull. However, results of mating tests of the bull with his daughters and granddaughters suggested that it was not hereditary (p = 0.0062) although an environmental–genetic interaction could not be ruled out.     

Comparative study of the body surface electrocardiogram in double-muscled and conventional calves.

The purpose of this work was to study electrocardiographic features of double-muscled beef cattle. Electrocardiograms were recorded on one to six occasions from each of a group of 18 conventional calves of the Friesian breed and 29 double-muscled calves of the Belgian White and Blue breed. Ages of the calves at the times of examination ranged from eight to 348 days. The Holmes semi-orthogonal lead system was used. The waves and interval durations and the tridimensional P, QRS, and T modal vector orientation and amplitude were calculated. The magnitude of the cardiac vectors was significantly lower and the ventricular waves and QT interval duration significantly shorter in the double-muscled than in the conventional calves. The P modal vector pointed significantly less downwards and the QRS modal vector pointed significantly more forwards and less up- and rightwards in the Belgian White and Blue, than in the Friesian group. Most of the observed differences might be a consequence of the bodily, and more specifically the thoracic, conformation of the former calves. However, the lower cardiac vector magnitude and shorter wave and interval durations might also reflect lower cardiac mass in the double-muscled subjects.     

An investigation of the causes of parturient calf mortality in Shorthorn heifers

A study of parturient calf mortality in a herd of 250 Shorthorn cattle on the Southern Tablelands of New South Wales is reported. Death rates as high as 44% from heifer groups are described. There were 30 parturient deaths of which 27 were confirmed as due to maternal dystocia. Pathological changes in many of the dystocia-caused deaths were minimal, but a congested, swollen tongue was a definitive lesion. The death rate was not significantly higher in heifers mated at 14 to 16 months of age than in those mated at 20 to 22 months, but significantly more male than female calves died from maternal dystocia. As two dead calves were affected with goitre, a comparative trial using parenteral iodine was designed. Ratios of thyroid weight to calf body weight were examined for 24 of the calves where the mean was 0.52 gm/kg. Goitre was found not to be a contributing factor to the calving mortality problem. The use of a Jersey bull for heifer matings eliminated the dystocia problem. The Jersey cross allowed safe, early mating at 14 months of age.     

Somatic cell mapping and restriction fragment length polymorphism analysis of bovine insulin-like growth factor I.

The DNA isolated from cow-hamster hybrid somatic cells segregating bovine chromosomes was analyzed by Southern blotting and hybridization with a heterologous [32P]-labeled porcine cDNA probe encoding insulin-like growth factor I (IGF-I). Thirteen of 25 cow-hamster hybrid cell lines exhibited the bovine-specific IGF-I fragment. Analysis for the retention or loss of bovine IGF-I with markers previously screened against the same panel of hybrid cells revealed a 100% concordance with lactate dehydrogenase B of bovine syntenic group U3 located on bovine chromosome 5. Restriction fragment length analyses of genomic DNA from animals representing five breeds (Angus, Polled Hereford, Simmental, Gelbvieh, and Belgian Blue) and from seven half-sib Angus calves indicated that polymorphisms for the genomic composition of the bovine IGF-I gene may exist in cattle populations.     

Abnormal skin fragility in a cat with cnolangio-carcinoma

An eight-year-old shorthaired cat which presented with a five-month history of bouts of anorexia and vomiting, developed a large spontaneous skin tear over the left shoulder when manipulated for clinical workup. The cat had no previous history of abnormal skin fragility and clinical examination of the skin revealed a general thinning but no scarring or hyperextensibility. After one day of hospitalisation the animal was euthanased because of its poor condition and on post mortem examination a cholangiocarcinoma with distant metastasis was identified. The skin biopsy specimens obtained from different sites revealed dermal atrophic changes, characterised in electron microscopy by disorganisation in the packing of both collagen fibrils and fibres, and by collagen fibrils with an abnormally wide range of diameters and with an irregular shape in cross section. Although no specific cause of the dermal lesions was suggested, this case differed greatly from the fragile skin conditions previously described in the cat.     

Within-herd contact structure and transmission of Mycobacterium avium subspecies paratuberculosis in a persistently infected dairy cattle herd

Within-herd transmission of pathogens occurs either by direct or by indirect contact between susceptible and infected animals. In dairy herds that are structured into groups, the way in which animals encounter each other and share an environment can affect pathogen transmission. Dairy cattle are heterogeneous in terms of susceptibility and infectivity with respect to Mycobacterium avium subspecies paratuberculosis (Map) transmission. It is mainly young animals that are susceptible and adults that are infectious. Both vertical and horizontal transmission through the ingestion of Map shed into the environment by adults and transiently infected calves can occur. Our objective was to assess the effect of contact structure on Map transmission in persistently infected dairy herds and to examine the effect of isolating calves from other calves or from adults before weaning. We developed a stochastic compartmental model of Map transmission in a closed dairy herd. The model reflects the Map infection process and herd management characteristics. Indirect transmission via the environment was modelled explicitly. Six infection states (susceptible, resistant, transiently infectious, latently infected, subclinically infected, and clinically affected) and two contaminated farm area environments (whole farm and calf area) were modelled. Calves were housed in hutches, individual indoor pens, or group indoor pens. Two different levels of exposure of calves to a farm environment contaminated by adults were possible: no exposure and indirect exposure through fomites. Three herd sizes were studied. We found that contacts between calves before weaning did not influence Map transmission in a herd, whereas the level of exposure of calves to an environment contaminated by adults and the starting age of exposure of calves to adults were pivotal. Early culling of clinically affected adults led to a lower prevalence of infectious adults over time. The results were independent of herd size. Despite the many transmission routes that are known, the best control approach is to limit the exposure of calves to adult faeces through the systematic separation of adults and calves in combination with hygiene measures. Reducing contact between calves does not appear effective.     

A triad of bovine inherited diseases (abstract)

Three inherited diseases of cattle seen in the past 2 years were described. Familial acantholysis of Angus cattle was seen in 9/54 calves born to cows inadvertently mated to a full sibling bull. Sloughing skin from the joints, nose and palate were seen at 1 day of age, confirmed as suprabasilar clefts on histopathology. A 2-year-old Charolais steer was noted at ante-mortem slaughter inspection with a whole body tremor and nystagmus. Histopathologically, eosinophilic plaques expanded white matter throughout the brain, consistent with a syndrome of 'progressive ataxia' of Charolais cattle. Two calves born from Red Devon cattle had marked hyperkeratosis, microtia and periocular reddening with deep fissuring of the keratin, characteristic of congenital ichthyosis.     

Influence of age,sex and herd characteristics on the occurrence of Verocytotoxin-producing Escherichia coli O157 in Danish dairy farms

Verocytotoxin-producing Escherichia coli (VTEC) O157 is an important emerging human pathogen. Cattle are considered to be the main reservoir for VTEC O157. The objectives of this study were to determine the prevalence of VTEC O157 in Danish dairy herds and to investigate the relationship between shedding of VTEC O157 and a number of animal and herd characteristics. Sixty dairy farms were visited once in August-October, and from each herd faecal samples from up to 50 animals were analysed for VTEC O157 by enrichment, immunomagnetic separation (IMS), and plating on selective agar. In total, 2419 animals were sampled, and 3.6% of these excreted VTEC O157. These animals were located on 10 farms (17%). On average, 21% of the sampled animals in the positive herds excreted VTEC O157. Register data, including age, sex, breed, housing conditions and herd composition, were extracted from a database. No influence of herd size or housing conditions was found. A strong effect of age was seen with 2-6-month-old calves as the high-risk age group (8.6% positive) in contrast to calves <2 months (0.7%) and cows (2.4%). There was a non-significant tendency of bull calves to have a higher prevalence than heifers within the age group of 2-6 months. Significantly, more of the herds characterised by having relatively many bull calves or many animals bought into the herd were positive for VTEC O157. Despite the low incidence of human VTEC O157 infections in Denmark, the prevalence in Danish dairy herds was found to be at a similar level as in many other countries.