Osteoporosis and growth arrest in illthriven Scottish hoggs
2021; Wiley; Volume: 188; Issue: 4 Linguagem: Inglês
10.1002/vetr.223
ISSN2042-7670
Tópico(s)Effects of Environmental Stressors on Livestock
ResumoVeterinary RecordVolume 188, Issue 4 p. 142-146 SurveillanceFree Access Osteoporosis and growth arrest in illthriven Scottish hoggs First published: 20 February 2021 https://doi.org/10.1002/vetr.223AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat THE mean temperature in Scotland for December 2020 was 0.6°C above the long-term average. Rainfall was near normal in the west and above normal elsewhere, with Scotland as a whole having 120 per cent of average rainfall. Sunshine was 87 per cent of average, with only the Northern Isles and parts of the far north sunnier than average. Cattle Generalised and systemic conditions A three-year-old Aberdeen Angus cow from a group of 17 was reported to have a poor appetite for around 12 hours before becoming recumbent. Clinical findings of firm faeces and poor gut motility suggested the possibility of hypocalcaemia, which was confirmed on biochemistry. Intravenous calcium was administered but death occurred soon afterwards. Postmortem examination found the carcase to be jaundiced and ascitic. A 4 cm diameter firm pale lesion surrounded by a wider area of haemorrhage was identified in the liver and a fluorescent antibody test for Clostridium novyi was positive. Histopathology detected lesions of severe extensive acute-subacute necrotising and leucocytoclastic hepatitis, with extensive areas of coagulative necrosis and expansion of sinusoids by small gas pockets, bordered by a zone of intense cytoclastic debris accumulation, accompanied by numerous intralesional stout sporulated bacilli, typical of clostridial hepatitis. Elsewhere, acute zonal periacinar necrotising hepatopathy and moderate mature portal fibrosis were present. ABOUT THIS REPORT This monthly summary is produced for Vet Record by Scotland's Rural College Veterinary Services (SRUC VS) and is based on reports from its surveillance centres in Edinburgh, Perth, St Boswells, Ayr (Auchincruive), Dumfries, Aberdeen, Inverness and Thurso and in collaboration with the Moredun Research Institute and the University of Glasgow School of Veterinary Medicine. SRUC VS monthly reports are available online at www.sruc.ac.uk/downloads/120613/monthly_reports from the first of every month. SRUC VS DISEASE SURVEILLANCE HEADLINES, DECEMBER 2020 Further cases of Histophilus somni septicaemia in weaned beef calves. Congenital cerebellar abiotrophy in Aberdeen Angus calves. Suspected postoperative ileus in a Texel ewe. Protein deficiency/undernutrition resulting in osteoporosis and growth arrest in Scottish blackface and mule hoggs Respiratory disease in crows due to Pasteurella multocida. “Clinical findings of firm faeces and poor gut motility suggested hypocalcaemia The zonal necrosis was more recent, consistent with a secondary event. The portal fibrosis was most likely secondary to chronic fluke exposure; however, there was no evidence of acute fluke migration. The group had been treated with nitroxynil one week earlier. Necrotising laryngitis in association with Histophilus somni septicaemia was recorded twice during December 2020. The first outbreak of disease occurred in a group of 200 fattening animals purchased from various sources. Ten per cent had been treated with antibiotics and non-steroidal anti-inflammatory drugs after presenting with lethargy and anorexia. One animal with a history of ataxia and recumbency died and was submitted for investigation of the problem. The carcase exhibited haemorrhages throughout, with multiple petechiae on the mucosa of the larynx (Fig 1), trachea and bronchi. Histopathology revealed lesions in multiple tissues, including a severe necrotising laryngitis, consistent with systemic localisation of H somni. The second case involved a seven-month-old Aberdeen Angus suckled calf, which was submitted for investigation of respiratory and neurological signs. This animal initially developed pyrexia and respiratory signs before progressing to lateral recumbency with opisthotonos and nystagmus. Necrotising laryngitis, patchy lung congestion and polyarthritis were detected on postmortem examination. Histopathology confirmed a thrombotic meningoencephalitis, explaining the neurological signs, in addition to multisystemic leucocytoclastic inflammation, including myocarditis typical of H somni septicaemia. Fig 1Open in figure viewerPowerPoint Laryngeal haemorrhage in a case of Histophilus somni septicaemia in a fattening cow Alimentary tract disorders A herd submitted one beef and two dairy calves following the acute deaths of five calves in three days. The beef and dairy herds were managed separately, but with shared personnel and equipment. All affected calves were less than three days of age and appeared healthy at birth before rapidly becoming cold and recumbent. Postmortem examination confirmed dehydration and watery diarrhoea in all cases. Faecal samples tested positive for Escherichia coli K99 and concurrent colisepticaemia was also diagnosed. Histopathology was carried out on tissues from one calf and revealed changes consistent with a severe form of K99 E coli colonisation and secondary septicaemia/bacteraemia. SRUC VS commented that generally the E coli strains identified in colisepticaemia and enterotoxigenic E coli are different, but the latter can become systemic in the agonal phase of disease.1 Respiratory tract diseases Two two-week-old Holstein Friesian heifer calves were presented alive to investigate respiratory disease in young dairy calves. Both calves were normothermic and moderately dyspnoeic and tachypnoeic. One calf had an additional right-sided head tilt and ear droop. Postmortem examination confirmed a diagnosis of pneumonia: Mannheimia haemolytica was isolated and respiratory syncytial virus detected by PCR. Examination of the middle ear of the calf with the head tilt revealed a purulent otitis media on the right side (Fig 2). The clinical signs in these cases were due to peripheral vestibular disease and cranial nerve dysfunction, including compression of the facial nerve (Bell's palsy) secondary to the bacterial otitis. M haemolytica was also isolated from the affected middle ear and is a recognised cause of otitis media2 as a result of ascending infection from the nasopharynx. No evidence of Mycoplasma bovis infection was identified in either case. “Sudden death is an unusual presentation for pyelonephritis Fig 2Open in figure viewerPowerPoint Otitis media due to infection with Mannheimia haemolytica in a neonatal dairy calf Nervous system disorders Two Aberdeen Angus calves were submitted to investigate an issue with severe congenital neurological disease affecting two of four calves born to a group of 10 heifers calving ahead of the main herd. Both calves presented with a slight head nod and had difficulty maintaining sternal recumbency. They were unable to stand when assisted and had complete loss of proprioception in all four limbs. No abnormalities were observed on gross postmortem examination. Neuropathology detected cerebellar cortical degeneration involving multifocal vacuolation of the basal molecular layer, scattered Purkinje neuronal fine cytoplasmic vacuolation, chromatolysis and nuclear pyknosis, occasional Purkinje axonal spheroids and an impression of paucity of internal granule layer neurones. Pestivirus involvement was considered unlikely and excluded by additional testing. A diagnosis of congenital cerebellar abiotrophy was reached. Congenital or neonatal onset of neurological signs associated with cerebellar cortical degeneration is recorded in Angus and Angus cross calves; however, the clinical and neuropathological features in these cases differed in some respects – for example, no seizures were reported. However, the characteristics and progressive nature of the lesions were consistent with an inherited condition. Accidental inbreeding had occurred, with three of the heifers found to be granddaughters of the sire used. Renal diseases A four-year-old shorthorn cow was found dead with no history of clinical illness. Severe bilateral pyelonephritis was identified on postmortem examination (Fig 3). The renal pelvises and proximal ureters were distended with haemorrhagic, purulent urine and bacteriology produced a pure, profuse growth of Corynebacterium renale. C renale is a common inhabitant of the lower reproductive tract and is an opportunistic pathogen that takes advantage of tissue damage and/or immunosuppression, with ascending infection occurring most frequently in the periparturient period. Sudden death is an unusual presentation for pyelonephritis and despite chronic renal pathology the cow was in good condition and had been eating. The same condition was diagnosed on a second holding in a 13-year-old beef cow that had been purchased three weeks earlier for fattening. This animal was more typical, being thin with a history of malaise and reduced appetite in the week before death. Cases of pyelonephritis are usually sporadic, but it is worth checking that access to water is adequate as poor intake in housed cattle is a possible predisposing factor. Fig 3Open in figure viewerPowerPoint Pyelonephritis due to Corynebacterium renale in a four-year-old beef cow Small ruminants Alimentary tract disorders Postoperative ileus was suspected in a two-year-old Texel ewe that had died a few days after an embryo transfer flushing procedure. Postmortem examination findings included marked distension of the large intestine by liquid contents (Fig 4) and haemorrhage within the adrenal glands. Haemorrhages in the adrenal glands in people may be associated with acute illness or stressful events such as surgery and are thought to be the result of sympathetic nervous system activation.3 There is experimental evidence in sheep that postoperative ileus is mediated by the sympathetic nervous system, as ileus secondary to laparotomy and surgical procedures was prevented by splanchnicectomy. Fig 4Open in figure viewerPowerPoint Distension of the large intestine in a ewe with suspected postoperative ileus Stress-mediated changes were therefore thought to be the most likely explanation for the unusual findings in the ewe. Musculoskeletal conditions Six weeks after moving to winter grazing 20 per cent of a group of 165 Scottish blackface and mule hoggs were reported to be dull and illthriven. One blackface hogg was euthanased for investigation and the remainder were housed. The carcase weighed 17 kg and was very thin with no body fat. Significant pneumonia due to M haemolytica and Trueperella pyogenes was detected but not considered to be the main issue. The femoral cortex was thinner than average with a diameter of 1.5 to 2 mm and the frontal bone was paper thin and translucent. The brain and growth plates were grossly normal. INVESTIGATING CONGENITAL NEUROLOGICAL PRESENTATIONS IN LAMBS – PART 1 In-utero copper deficiency (congenital swayback) and the teratogenic effects of transplacental border disease virus infection are well-recognised causes of neurological presentations in lambs. However, in a neuropathological survey of neonatal lambs, superficial laminar cerebrocortical neuronal necrosis (SLCCN) was detected more frequently than these conditions.1 This article summarises the clinical and laboratory investigation of SLCCN. The differential diagnoses and investigation of other causes of congenital neurological presentations in lambs will be included in a future article. Lambs with SLCCN often present with other lesions, most commonly cerebellar Purkinje neuronal necrosis (Fig A), with deep laminar cerebrocortical neuronal necrosis, vacuolar leucoencephalopathy, brainstem neuronal chromatolysis and long fibre tract degeneration being present in a smaller proportion of cases. The severity of the clinical signs is correlated with the extent and severity of the neuropathology. Fig AOpen in figure viewerPowerPoint Typical neuropathological findings in lambs born to ketotic ewes. (a) Superficial laminar cerebrocortical necrosis with individual necrotic neurones (arrowheads) in the superficial laminae of the frontal cortex. (b) Individual Purkinje neuronal degeneration (arrowhead) and necrosis in the cerebellar vermis The most severely affected lambs were stillborn or extremely weak, preventing the detection of other neurological disease. The less severely affected lambs were often weak, dull, unable to stand, fell to one side and some had a head tremor. A number of these lambs succumbed to secondary infections. In some flocks, lambs that were born with neurological signs (usually dullness, tremor and ataxia) that resolved over several days, and, occasionally, presumed affected surviving lambs, had residual non-progressive cerebellar deficits. The flocks involved reported less than 10 per cent morbidity. All lambs were from multiple births, with triplets being overrepresented; however, variation in the severity of the clinical signs between sibling lambs was common. In two flocks, maternal serum beta-hydroxybutyrate (BHB) concentrations were determined within 24 hours of parturition and were markedly elevated in four ewes that had given birth to affected lambs. However, BHB concentrations were within the reference range at intervals greater than one day postpartum. The presence of maternal ketonaemia together with the clinical observations indicate that in-utero energy deprivation consequent to late gestational maternal negative energy balance is the likely cause of the necrotising encephalopathy in at least some of these lambs. In one flock, maternal illness resulting in inanition was the explanation; however, in most flocks management factors were considered to be the underlying cause. Checking ewe BHB levels three to four weeks prelambing is a useful guide to dietary energy sufficiency. In all cases of neurological diseases in lambs, the nature of the neurological deficits, information on the clinical progression in lambs, the presence or absence of clinical signs in siblings, clinical examination of the dams, blood samples (plasma and serum) from dams within 24 hours of parturition and neuropathological examinations are helpful when investigating the cause. Analysis of BHB levels in dams within 24 hours of parturition is especially important in the investigation of lambs with suspected SLCCN. Copper deficiency and lead toxicity were ruled out as the cause of the osteoporosis. Histopathology detected established abomasitis and enteritis consistent with a chronic response to parasitism despite the worm burden being low at the time of death. Evidence of a vacuolar encephalomyelopathy was also considered to be secondary to metabolic disturbances associated with the gastroenteritis. Examination of the frontal bone and long bones confirmed pronounced osteoporosis with premature closure of growth plates and growth arrest lines in the proximal diaphyses. These findings indicated that the bones had stopped growing at least twice, most likely as a result of protein deficiency/general undernutrition. Osteoporosis of the frontal bone in illthriven hoggs has been recognised for many decades.4 Renal diseases A beltex tup with a two-week history of rapid weight loss was euthanased and an on-farm postmortem examination performed. Before death the urea value was noted to be elevated at 115 mmol/l (reference range 4–8 mmol/l) and the albumin result of 28 g/l was slightly low (reference range 30–40 g/l). Both kidneys were reported to be pale and swollen and representative sections were fixed in formalin. A severe chronic global diffuse glomerulopathy together with variable plasmalymphocytic and neutrophilic tubulointerstitial nephritis was described on histopathology. Abundant tubular luminal hyaline cast formation was evident particularly within the medulla and a Congo red preparation viewed under polarised light revealed apple green birefringence particularly within glomeruli. These findings confirmed glomerular amyloidosis as the cause of the nephropathy. Amyloidosis occurs secondary to chronic inflammation, the source of which was not clear in this case. Fig 5Open in figure viewerPowerPoint Fibrinous pericarditis due to Pasteurella multocida infection in a carrion crow Skin diseases Samples were submitted from two separate outbreaks of lower leg lesions during December. In the first case affected sheep were reported to be lame. Biopsies were taken and histopathology confirmed epidermal hyperplasia and pronounced dermal vascular proliferation suggestive of orf; however, no lesion typical of parapoxvirus was detected. PCR testing for parapoxvirus DNA was not carried out. There was also evidence of superficial bacterial infection and Streptococcus dysgalactiae was detected in pure culture from one of three swabs and in mixed growth from another. In the second outbreak lesions were present between the coronary band and fetlock of affected sheep. Spread within the flock had occurred over a period of three months but lameness was not reported and there was no response to foot bathing. Both ulcerative and granulomatous lesions were described. Histopathology found extensive dermal vascular proliferation and granulation tissue, indicating that the lesions were well-established. Purulent exudation extended beyond the surface into deeper tissues, suggesting that bacterial infection was contributing to the lesions. Staphylococcus aureus was isolated but parapoxvirus DNA was not detected by PCR testing. Outbreaks of similar lesions have previously been reported5 and the aetiology remains to be clarified. Birds Pigeons Fixed and fresh viscera were submitted following the death of eight adult pigeons from a group of 25. Affected birds had reduced appetites with associated weight loss and green diarrhoea. Histological evidence of interstitial nephritis with tubular degeneration and necrosis plus lymphocytic pancreatitis were highly suggestive of pigeon paramyxovirus (PPMV). The APHA was notified and further testing was initiated. The clinical presentation in outbreaks of PPMV can be variable and classical neurological signs such as torticollis and paralysis may not be observed. PPMV is a notifiable disease and suspect cases, including incidents where the possibility of PPMV cannot be excluded, should be reported immediately to APHA. Wild birds A member of the public reported finding five dead carrion crows (Corvus corone) and two were submitted for postmortem examination. White mucus was found within the pharynx and there was a severe fibrinous airsacculitis in both birds. A fibrinous pericarditis was also noted in one bird (Fig 5). Both birds were very thin and no food was detected within their digestive tracts. Small numbers of tapeworm were present in the small intestine and considered an incidental finding. Bacteriology was carried out after testing to exclude infection with avian influenza virus had been completed. Pasteurella multocida was cultured from the airsac of one bird. This is a recognised cause of respiratory disease in corvids and losses can be high due to the large numbers of birds congregating at roosts.6 Miscellaneous species Deer A seven-month-old female red deer calf was found dead and presented for postmortem examination. Thirteen deaths had occurred in the three weeks since the group of 130 were weaned and housed and the keeper reported a lot of coughing. The carcase was thin with a severe, predominantly cranioventral, pneumonia characterised by multiple, often coalescing, firm, slightly raised areas. Dictyocaulus species were detected in the bronchi. Other findings included a 10 cm length of necrotic colon with secondary peritonitis, a single rumen ulcer and several renal infarcts. Histopathology confirmed a granulomatous pneumonia associated with numerous lungworm larvae and eggs and multifocal mycotic pneumonia. Fungal hyphae were also identified in association with the rumen ulcer and renal infarcts, indicating systemic mycosis. Thrombosis associated with fungal colonisation was also considered to be the cause of the devitalised colon wall, which was the ultimate cause of death. The rumen ulcer was thought to be the most likely source of the mycotic infection. The calves had been treated with an ivermectin/triclabendazole product eight weeks earlier which would have allowed reinfection with lungworm before housing. Further anthelmintic treatment was recommended. DISEASE ALERTS The following conditions were reported by SRUC VS disease surveillance centres in March 2020. Given similar climatic and production conditions, they could also be important this year. Osteodystrophy in rapidly growing beef fattening animals Nutritional osteodystrophy can present with a range of clinical signs which may include lameness, stiffness, joint or epiphyseal swelling, fracture or gastrocnemius tendon rupture. Cases may come to light several months after introduction of an intensive ration and are a serious welfare issue when they occur. It is important to supply a mineral/vitamin supplement that is appropriate to the ration being fed. Necrotising encephalopathy in neonatal lambs secondary to inadequate ewe nutrition Prolonged maternal energy deficiency may lead to neurological disease in neonatal lambs, with less severely affected animals slow to stand or suck. Ewes may be in suboptimal body condition and blood samples collected in the periparturient period may reveal hypoglycaemia and subclinical ketosis. Histopathology of lamb brains is required to confirm the diagnosis. Assessing dietary energy adequacy by measuring ewes' serum beta-hydroxybutyrate three to four weeks prelambing is recommended (see the box on p 144 for further information). CONTACTING SRUC VS SRUC Veterinary Services can be contacted by telephone on 0131 535 3130 or by email: vcedinburgh@sac.co.uk Contact details for local SRUC VS disease surveillance centres are available at www.sruc.ac.uk/contactvetservices References 1Acres SD. Enterotoxigenic Escherichia coli infections in newborn calves: a review. J Dairy Sci 1985; 68: 229– 56CrossrefCASPubMedWeb of Science®Google Scholar 2Duarte ER, Hamdan JS. Otitis in cattle, an aetiological review. J Vet Med B 2004; 51: 1– 7Wiley Online LibraryCASPubMedWeb of Science®Google Scholar 3Simon DR, Palese MA. Clinical update on the management of adrenal haemorrhage. Curr Urol Rep 2009: 10: 78– 83CrossrefPubMedGoogle Scholar 4Nisbet DI, Butler EJ, Bannatyne CC, et al. Osteodystrophic diseases of sheep 1. An osteoporotic condition of hoggs known as double scalp or cappi. J Comp Path 1962; 72: 270– 80CrossrefCASPubMedWeb of Science®Google Scholar 5van der Burgt GM, Ward T, Codner J. Unusual skin lesions in sheep. Vet Rec 2011; 168: 569– 70Wiley Online LibraryPubMedWeb of Science®Google Scholar 6Strugnell BW, Dagleish MP, Bayne CW, et al. Investigations into an outbreak of corvid respiratory disease associated with Pasteurella multocida. Avian Pathol 2011; 40: 329– 36CrossrefCASPubMedWeb of Science®Google Scholar 1Scholes SFE, Watson PJ. Congenital necrotising encephalopathy in lambs. Vet Rec 2004; 154: 32CASPubMedWeb of Science®Google Scholar Volume188, Issue4February 2021Pages 142-146 FiguresReferencesRelatedInformation
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