Parapoxvirus infections in New Zealand farmed red deer (Cervus elaphus)

Outbreaks of infection due to a parapoxvirus were reported on eight New Zealand deer farms. Scabby lesions were seen variably on the muzzle, lips, face, ears and neck of red deer (Cervus elaphus) with morbidity rates reaching 100%. On three farms multifocal lesions were also present on the velvet. Deaths were reported on two properties where the lesions were extensive and secondary bacterial infections had occurred. On one of these farms multifactorial disease was suspected. Poxvirus particles were seen by negative contrast electron microscopy in scab material from all eight properties. Morphologically the deer virus resembled a parapoxvirus, but restriction endonuclease analysis showed its DNA fragment patterns were distinct from those of orf (contagious ecthyma) virus.     

Diagnosis of tuberculosis due to Mycobacterium bovis in New Zealand red deer (Cervus elaphus) using a composite blood test and antibody assays

A blood test for tuberculosis in deer was developed as an ancillary test to clarify the status of skin test-positive deer, with non-specific sensitisation following exposure to saprophytic mycobacteria. The blood test incorporates the measurement of the relative humoral and cellular immunological responses to Mycobacterium bovis and M. avium antigens to provide a composite test with high levels of sensitivity (>95%) and specificity (>98%). The specificity of the test has allowed it to be used in parallel with the skin test to salvage thousands of tuberculosis-free deer with non-specific skin test-positive reactions, while its high sensitivity has consistently identified M. bovis-specific reactivity in tuberculous skin test-positive animals. The rules for establishing the diagnostic parameters for the cellular and antibody assays were developed by retrospective analysis of the laboratory results using blood samples from many thousand tuberculous or disease-free deer. The sensitivity of the blood test was tested in this study using 150 animals with tuberculosis diagnosed by the isolation of M. bovis. It had sensitivity values of 95.7-95.9% in herds with a low (<2.0%) or a high (>30.0%) incidence of tuberculosis. The test had a specificity of 98.0% when tested on 218 disease-free animals, 118 of which were skin test-positive. An antibody test was developed to diagnose M. bovis in skin test-negative anergic deer from tuberculosis infected herds. When this test was used with deer blood taken 10 days after reading the skin test, it had a sensitivity of 85.3% for 102 M. bovis-positive deer. When used in combination with skin test, the antibody test complemented the skin test to raise the sensitivity of the combined tests to 95.0%, when antibody-positive or skin test-positive tests were used to diagnose tuberculosis. The specificity of the antibody test was 100% when used to evaluate 218 disease-free deer from non-infected herds.     

Diagnosis of tuberculosis due to Mycobacterium bovis in New Zealand red deer (Cervus elaphus) using a composite blood test and antibody assays

A blood test for tuberculosis in deer was developed as an ancillary test to clarify the status of skin test-positive deer, with non-specific sensitisation following exposure to saprophytic mycobacteria. The blood test incorporates the measurement of the relative humoral and cellular immunological responses to Mycobacterium bovis and M. avium antigens to provia composite test with high levels of sensitivity (>95%) and specificity (>98%). The specificity of the test has allowed it to be used in parallel with the skin test to salvage thousands of tuberculosis-free deer with non-specific skin test-positive reactions, while its high sensitivity has consistently identified M. bovis-specific reactivity in tuberculous skin test-positive animals. The rules for establishing the diagnostic parameters for the cellular and antibody assays were developed by retrospective analysis of the laboratory results using blood samples from many thousand tuberculous or disease-free deer. The sensitivity of the blood test was tested in this study using 150 animals with tuberculosis diagnosed by the isolation of M. bovis. It had sensitivity values of 95.7–95.9% in herds with a low (<2.0% ) or a high (>30.0%) incidence of tuberculosis. The test had a specificity of 98.0% when tested on 218 disease-free animals, 118 of which were skin test-positive.

An antibody test was developed to diagnose M. bovis in skin test-negative “anergic” deer from tuberculosis infected herds. When this test was used with deer blood taken 10 days after reading the skin test, it had a sensitivity of 85.3% for 102 M. bovis-positive deer. When used in combination with skin test, the antibody test complemented the skin test to raise the sensitivity of the combined tests to 95.0%) when antibody-positive or skin test-positive tests were used to diagnose tuberculosis. The specificity of the antibody test was 100% when used to evaluate 218 disease-free deer from non-infected herds.     

Dictyocaulus infection in farmed red deer (Cervus elaphus)

Post mortem examination of red deer calves on a deer farm situated on hill ground in north-east Scotland revealed infection by a lungworm morphologically similar to Dictyocaulus viviparus. Trials were conducted to monitor the natural development of D viviparus infection in red deer, to investigate the value of a commercial lungworm vaccine and to evaluate methods of treating clinical cases. The findings indicate that the syndrome may be less apparent in red deer than it is in cattle, protection might be gained by vaccination and that housing and medication provide useful therapy. The extent of clinical disease is likely to depend on the general health, bodily condition and nutritional status of the animals versus the weight of infection acquired from the pasture. However, various factors can affect both sides in this confrontation.     

Short interval intradermal skin testing in farmed red deer (Cervus elaphus) inoculated with Mycobacterium bovis

Two groups of 26 red deer (Cervus elaphus) were tuberculin skin tested for 41 weeks at three and six week intervals respectively, except at 17 weeks when the internal was two and five weeks. Seventeen weeks after the start of the experiment 36 deer were inoculated intratracheally with Mycobacterium bovis, and the remaining 16 were run in-contact. At six weeks post inoculation, 35 of the 36 inoculated deer reacted to the skin test with a mean skin thickness difference (STD) of 6.3 mm. In inoculated deer further testing led to a suppression of skin sensitivity which was significantly greater in the three-weekly tested group. There was no statistical difference in skin thickness response between 1 and 2 mg/ml bovine purified protein derivative (PPD). Of 454 tests on noninoculated deer (noninfected), 107 produced reactions. These reactions were small and 96% had a STD of less than 2 mm.     

A malignant catarrhal fever-like disease in red deer (Cervus elaphus) in New Zealand

Two case histories are presented to illustrate the clinical and pathological findings of a malignant catarrhal fever-like disease as seen in farmed red deer in New Zealand. Attention is drawn to the similarities with some exotic diseases and the suggestion is made that deer may act as a reservoir for the aetiological agent.     

A malignant catarrhal fever-like disease in red deer (Cervus elaphus) in New Zealand

Two case histories are presented to illustrate the clinical and pathological findings of a malignant catarrhal fever-like disease as seen in farmed red deer in New Zealand. Attention is drawn to the similarities with some exotic diseases and the suggestion is made that deer may act as a reservoir for the aetiological agent.     

Experimental tuberculosis in red deer (Cervus elaphus)

This study was designed to investigate experimental Mycobacterium bovis infection of red deer (Cervus elaphus). Three intravenously inoculated deer (dose 10 microg-1000 microg) developed miliary tuberculosis of the lungs and all died within 28 days of being infected. No clinical illnesses were observed in four subcutaneously (dose 1 microg-1000 microg) and three intratracheally (dose 10 microg-100 microg) inoculated deer. At the conclusion of the experiment six weeks post inoculation, these seven animals reacted to 2 mg/ml of bovine purified protein derivative. The principal lesions in the intravenously inoculated deer were in the lungs which had multiple foci of necrosis containing very large numbers of acid fast bacilli. A gradation of changes was seen in the subcutaneously inoculated deer. The animal receiving the 1 microg dose only had lesions at the injection site and the draining prescapular lymph node. Deer receiving higher doses also had histopathological changes in the lungs and liver. Microscopic changes in the intratracheally infected animals were restricted to the thoracic cavity. The ability of the deer to controlled infection was related to the route of inoculation.     

Tuberculosis in imported red deer (Cervus elaphus)

An outbreak of tuberculosis due to Mycobacterium bovis in farmed red deer imported from an eastern European country is described. Twenty-six of the 106 deer examined at autopsy were found to be infected and 19 had visible lesions of tuberculosis. Single comparative intradermal tuberculin tests on 51 deer showed that the test had a specificity of 61.3 per cent and a sensitivity of 80 per cent relative to subsequent biological and cultural tests on tissues taken at autopsy. Three hundred and seventy eight culled fallow and sika deer which had been running in a park in contact with some of the infected animals were found to be free of tuberculosis.     

Experimental tuberculosis in red deer (Cervus elaphus)

This study was designed to investigate experimental Mycobacterium bovis infection of red deer (Cervus elaphus). Three intravenously inoculated deer (dose 10µg–1000µg) developed miliary tuberculosis of the lungs and all died within 28 days of being infected. No clinical illnesses were observed in four subcutaneously (dose 1 uµg–100uµg) and three intratracheally (dose lµg–100µg) inoculated deer. At the conclusion of the experiment six weeks post inoculation, these seven animals reacted to 2 mg/ml of bovine purified protein derivative. The principal lesions in the intravenously inoculated deer were in the lungs which had multiple foci of necrosis containing very large numbers of acid fast bacilli. A gradation of changes was seen in the subcutaneously inoculated deer. The animal receiving the 1µg dose only had lesions at the injection site and the draining prescapular lymph node. Deer receiving higher doses also had histopathological changes in the lungs and liver. Microscopic changes in the intratracheally infected animals were restricted to the thoracic cavity. The ability of the deer to control infection was related to the route of inoculation.     

Mycobacterium bovis infection in North American elk (Cervus elaphus).

A naturally occurring outbreak of Mycobacterium bovis infection in captive wild elk (wapiti) in Montana was confirmed by mycobacteriologic examination. Twenty-eight of 143 elk responded to M. bovis purified protein derivative (PPD) tuberculin injected intradermally in the cervical region (SCT). The results of comparative cervical tuberculin skin tests conducted within 9 days of SCT revealed greater responses to M. bovis PPD tuberculin than to M. avium PPD tuberculin in 23 of 28 elk responding. At necropsy, several grossly visible tuberculous lesions were observed in the parenchyma of the lung, thoracic lymph nodes, and submandibular lymph nodes. Microscopic examination of appropriately stained tissue sections revealed the presence of granulomatous lesions containing acid-fast bacilli. An enzyme-linked immunosorbent assay (ELISA) was developed using a sarkosyl extract of M. bovis (antigen) and peroxidase-labeled protein G (conjugate); reactions were detected in the sera of 8 of 9 elk responding to M. bovis PPD tuberculin. Lymphocyte blastogenic assay responses were detected using M. bovis antigens in 7 of 9 elk positive on skin tests using M. bovis PPD.     

Electrical stunning of red deer (Cervus elaphus)

Eighteen of 23 red deer (Cervus elaphus) at a deer slaughtering premises were successfully stunned with an apparatus modified from that normally used to stun sheep. The five unsuccessful electrical stuns were associated with poor head restraint and poor head contact by the electrodes. The median stunning current was 0.9 A, and in the majority of cases the duration of stunning was less than 1 second. The signs of the electrically induced epileptiform seizures in the deer were dissimilar to those seen in sheep, cattle and pigs, in that the initial tonic phase was less marked, and of shorter duration. A similar shorter and less obvious tonic phase was noted in four deer shot with a captive bolt pistol. Two animals which were electrically stunned, and bled within 10 seconds, showed no signs of recovery while bleeding. The electroencephalograms of four deer stunned with currents of 1.3 A for a duration of either 0.5 or 1.0 seconds were recorded under more controlled conditions. All four animals developed electroencephalograms typical of an epileptiform seizure. The animals exhibited behavioural reactions similar to the other 18 animals in the trial at the deer slaughtering premises and were rendered unconscious for between 54 and 122 seconds. The electroencephalogram activity amplitude was greater than that recorded immediately before stunning and took between 6 and 9 seconds to build up to maximum value. It is concluded that, providing the heads of deer are adequately restrained, head-only electrical stunning can be incorporated into a humane method of slaughter for deer.     

Pathology of Brucella ovis infection in red deer stags (Cervus elaphus)

Abstract

AIM: To describe the pathology of the reproductive tract of red deer stags with active Brucella ovis infection and in stags in which B. ovis infection had resolved.

METHODS: Twenty-three red deer stags of varying history were slaughtered and their epididymides and accessory sex glands examined grossly and by histopathology. At the time of slaughter five of the stags had an active B. ovis infection of 24–55 days duration following exposure to infected rams, 10 stags had been experimentally infected with B. ovis by intravenous inoculation 649 days previously and had developed an active infection but the bacterial infection had resolved at least 308 days prior to slaughter, and eight stags had not been exposed to B. ovis at any time.

RESULTS: Of the five stags with an active infection, one had gross enlargement of the epididymides that could be detected by scrotal palpation. Histological lesions in all five stags included mild to severe, predominantly non-suppurative epididymitis, vesiculitis, prostatitis and ampullitis, with neutrophil exudation in associated glandular ducts. Additional lesions in the epididymides were spermatic granulomas and epithelial hyperplasia with intra-epithelial cyst formation. Of the 10 stags in which the bacterial infection had resolved, two had gross enlargement of the epididymides. The histological lesions were similar to those in stags with active infection but were generally milder, with increased periductal scar tissue in the epididymides. The lesions seen in stags resembled those seen in rams with B. ovis infection but they were usually less florid and had fewer plasma cells. No gross abnormalities or histopathological lesions were detected in the non-infected stags.

CONCLUSIONS: Only a small percentage of red deer stags infected with B. ovis develop lesions of epididymitis that can be detected by scrotal palpation. Gross and histological lesions of the genital tract of stags associated with B. ovis infection are similar to the lesions seen in rams. Lesions in stags persist for >300 days after the bacterial infection has resolved.

CLINICAL RELEVANCE: Brucella ovis infection should be considered when there are gross lesions of epididymitis or histological evidence of inflammation in the epididymides or accessory sex glands of red deer stags. Retrospective diagnosis of B. ovis in stags could be achieved by histological examination of the reproductive organs.     

Pharmacokinetics of ceftiofur in red deer (Cervus elaphus)

Twelve adult female red deer (Cervus elaphus) were given 250 mg of ceftiofur sodium by intramuscular injection (i.m.) and ballistic implant in a crossover design. Blood samples were taken from an in-dwelling jugular catheter prior to drug administration and at 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, and 72 h postadministration of the drug. Samples were centrifuged and plasma kept frozen at -70 degrees C until analysis for ceftiofur and active metabolites using an HPLC method. The pharmacokinetics of ceftiofur and metabolites after i.m. dosing and following ballistic implant were quite different. Absorption after i.m. injection was rapid; whereas following ballistic implant there was a lag-time until concentrations were detectable in plasma. The maximum concentration reached in plasma was higher following injection compared with ballistic implant, however the AUC calculated after ballistic implant was almost identical to the mean AUC found after i.m. dosing. The results indicate that i.m. administration of ceftiofur maintains adequate plasma levels for most susceptible bacterial pathogens for at least 12 h; therefore twice daily administration is needed in red deer. Ballistic implants produced plasma concentrations above the MIC for most bacterial pathogens from 4 to 24 h in most animals after administration; however, absorption of the drug was variable and some did not maintain effective concentrations for more than a few hours. Ceftiofur is a useful drug in red deer and twice daily i.m. administration dosing should allow treatment for susceptible bacterial pathogens.     

Pharmacokinetics of oxfendazole in red deer (Cervus elaphus)

The pharmacokinetics of oxfendazole (OFZ) in red deer (Cervus elaphus) was examined. OFZ, administered per os at 4.53 mg kg-1, was extracted in ether from plasma and identified and concentrations estimated by high pressure liquid chromatography. Irrespective of whether the animals were fed concentrates indoors as pellets or grass while on pasture, OFZ was absorbed rapidly. Concentrations of OFZ in plasma reached maxima within 20 hours (0.83 and 1.005 mg litre-1 respectively) and were undetectable 36 hours after administration. Fenbendazole was not detected at any time in the chromatograms. Metabolism of OFZ occurred rapidly producing the sulphone metabolite. In comparison with published data for OFZ in sheep, red deer appear to metabolise OFZ and excrete OFZ sulphone at much faster rates. Consequently, anthelmintic efficacy is likely to vary from species to species.     

Babesias of red deer (Cervus elaphus) in Ireland

ABSTRACT: Blood samples were obtained from 38 wild red deer (Cervus elaphus) at two sites in Ireland and subjected to PCR analysis of the 18S rRNA gene followed by sequencing. Two fragments of the 18S rRNA gene were generated by two different PCR protocols and subsequent sequencing suggested that at least six of the deer were infected by a babesia that, in those loci, is indistinguishable from Babesia divergens, an important tick-borne pathogen of cattle and of zoonotic significance. Additionally, a B. odocoilei-like parasite was detected in three samples and a babesia that did not match any sequences in the GenBank database was found in five samples. Neither B. capreoli nor B. venatorum (EU1) were found. There have been several reports of B. divergens occurring in deer species, including red deer, roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus). However, in view of recent re-sequencing of bovine-origin samples deposited previously in GenBank, it is unlikely that any of these sequences from deer are B. divergens. The present study describes the only deer piroplasm detected so far that shows complete identity with B. divergens, in just over half of the 18S rRNA gene. The entire gene of this deer parasite should be analysed and transmission experiments undertaken before the infectivity of B. divergens for red deer can be confirmed.