Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 April 2020 | 12(5): 15646–15650
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
doi: https://doi.org/10.11609/jott.4411.12.5.15646-15650
#4411 | Received 17 July 2018 | Final
received 09 March 2020 | Finally accepted 28 March 2020
Piroplasmosis in a captive
Grant’s Zebra Equus quagga boehmi (Mammalia: Perissodactyla: Equidae) - a case
study
Sarat Kumar Sahu
1, Niranjana Sahoo 2, Bijayendranath
Mohanty 3 & Debabrat Mohapatra 4
1,4 Nandankanan Zoological Park, Po-Barang,
Khordha District, Odisha 754005, India.
2
Department of Preventive Veterinary Medicine and Epidemiology, College of
Veterinary Science & Animal Husbandry, Odisha University of Agriculture
& Technology, Unit-8, Surya Nagar, Bhubaneswar, Odisha 751003, India.
3
Department of Veterinary Parasitology, College of Veterinary Science &
Animal Husbandry, Odisha University of Agriculture & Technology, Unit-8,
Surya Nagar, Bhubaneswar, Odisha 751003, India.
1 sahu.sarat77@gmail.com
(corresponding author), 2 niranjanasahoo@hotmail.com, 3
bijayendranath@gmail.com, 4 debabrat73@gmail.com
Editor: Rajeshkumar G. Jani, Anand Agricultural University, Anand, India. Date
of publication: 26 April 2020 (online & print)
Citation: Sahu, S.K., N. Sahoo, B. Mohanty & D. Mohapatra (2020). Piroplasmosis in a captive Grant’s Zebra Equus quagga boehmi (Mammalia: Perissodactyla:
Equidae) - a case study. Journal of
Threatened Taxa 12(5): 15646–15650. https://doi.org/10.11609/jott.4411.12.5.15646-15650
Copyright: © Sahu et al. 2020. Creative
Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction,
and distribution of this article in any medium by providing adequate credit to
the author(s) and the source of publication.
Funding: This study is a part of normal healthcare activity of the zoo (Nandankanan Zoological Park)
which is under the control of ‘Forest and Environment Department, Government of Odisha’. No separate
fund has been received from any agency for this study.
Competing interests: The authors declare no competing interests.
Acknowledgements: The authors express their deep sense of thanks and
gratitude to the Director, Nandankanan Biological
Park, Forest and Environment Department, Government of Odisha, for his kind
support during the entire period of study.
Abstract: An apparently healthy 2½-year-old
male Grant’s Zebra weighing approximately 200kg located at Nandankanan
Zoological Park, Odisha, India, procured from Zoological Centre, Tel Aviv-
Ramat Gan, Israel during September 2015 was noticed in a sitting position
making frequent attempts to get up. The
zebra was immobilised the same day with a combination of 1.96mg etorphine
hydrochloride, 8.0mg of acepromazine and 40.0mg of xylazine hydrochloride to
facilitate diagnosis and treatment.
Clinical examinations did not reveal any signs suggestive of disease or
disorder of the musculoskeletal system.
Microscopic examination of blood smears stained in Giemsa’s stain
revealed the presence of
intra-erythrocytic inclusions, either single or pairs, suggestive of haemoprotozoans, i.e., B. caballi
and/or T. equi. The zebra was administered with two divided
doses of imidocarb injection @4.0mg/kg b.wt. deep
intramuscularly in the neck region with supportive therapy. Progressive improvement in posture, gait, and
appetite were noticed following 24h of medication. Three more doses of imidocarb were
administered at 72h intervals, each time after immobilisation.
Keywords: Babesia caballi,
imidocarb, immobilisation, sub-clinical carriers, Theileria equi.
‘Equine piroplasmosis’, a
tick borne haemoparasitic
disease of Equidae (horses, mules, donkeys, and
zebras), is widely distributed across the globe including tropical and
subtropical areas, and some temperate zones (Alhassan et al. 2005; Acici et al. 2008). Piroplasmosis is prevalent amongst Burchell’s Zebra Equus
quagga burchellii and Cape Mountain Zebra Equus
zebra zebra in southern Africa (Lampen et al. 2009; Bhoora et al.
2010). It is caused by two
morphologically distinct intra erythrocytic protozoans, viz., Theileria equi
(formerly known as Babesia equi) and/or Babesia
caballi. T.
equi infection having shorter incubation period
is more pathogenic than B. caballi (de Waal
& van Heerden 2004). The disease appears in acute, sub-acute, and
chronic forms with signs of fever, anaemia, icterus,
hepatomegaly, edema, intravascular haemolysis, and haemoglobinuria.
Mortality may reach up to 50% (de Waal 1992). Laminitis is one of the clinical signs of
secondary complications (de Waal 1992). Antiprotozoan drugs are quite effective in bringing
clinical recovery but fail to make the infected animal sterile. Hence, infected animals may remain life-long
carriers of T. equi infections while B. caballi for up to four years (de Waal & van Heerden
2004). Thirty species of ixodid ticks of the genera Dermacentor,
Hyalomma, and Rhipicephalus
have been identified as vectors (de Waal 1992). It is also not possible to distinguish
between T. equi and B. caballi
infections based on clinical signs alone and mixed infections do occur (de
Waal 1992). Available literature is
silent about documentation of these infections amongst Grant’s Zebras in Indian
zoos. The present case describes a case
report of Piroplasmosis in a Grant’s Zebra Equus
quagga boehmi at Nandankanan
Zoological Park.
Case history
On 28 December 2016 (15.30h Indian time), a 2½-year
old apparently healthy male Grant’s Zebra (approx. body weight 200kg) of Nandankanan Zoological Park (NKZP) was noticed in a sitting
position making repeated attempts to get up.
But the zebra failed to bear its weight on the hind limbs. When approaching close to the animal, it
moved with difficulty and dragged its right hind limb fetlock on the
ground. Initial attempt with an intramuscular
injection of NSAID (non-steroid anti-inflmmatory
drug) of 10ml Melonex Power (M/S Intas
pharmaceuticals Ltd, Ahmedabad, Gujarat, India) through a blow pipe did not
result in any remission even after three hours post-administration.
Four zebras (two males + two females) including the
present ailing one were procured from Zoological Center, Tel Aviv- Ramat Gan,
Israel. As per health records, the
zebras were apparently healthy during the time of procurement as well as on
arrival at Nandankanan Zoological Park on 13
September 2015. The zebras were kept in
‘pre-export’ quarantine at Ramat Gan, Israel for a period of 30 days. During the quarantine period at Israel, they
were screened against Theileria equi and Babesia caballi
by complement fixation test (CFT) and test reports were negative for both. At NKZP, these zebras were housed in an open
air exhibit enclosure of 3,510m2 area.
Of these four zebras, two females died on 20 August
2016 and 29 October 2016 with the predominant signs of limping in one or more
limbs that continued for a period of 20–60 days in spite of supportive
treatment consisting of nervine stimulants, NSAID, and broad spectrum
antibiotics (BSA), all given with the help of a blow pipe. Further investigations could not be initiated
due to non-availability of supporting facilities during that concerned
period.
Earlier painful experience of casualties in two
valuable animals triggered efforts to immobilise the
sick zebra in the late evening (20.00h) to extend all possible therapeutic
measures.
Clinical investigation
The zebra was darted using a drug mixture of 0.8ml of
large animal immobilon (Novartis Animal Health, UK Limited, Frimley, South
Africa) containing 1.96mg etorphine hydrochloride & 8.0mg of acepromazine
and 0.4ml of Xylazil 100 (Troy Lab Pty Ltd, 35
Glendenning Road, Australia) containing 40.0mg of xylazine hydrochloride. This drug mixture was administered
intramuscularly to the thigh muscle through ‘Dist-Inject
Syringe Projector Mod30N’ from a distance of about 10m using a blue cartridge.
Detailed clinical examination was carried out
including examination of hooves, joints, and other vulnerable body
regions. Blood samples were collected
with anticoagulants (EDTA & fluoride) and clot activator in three different
sterile vials for further investigation.
Laboratory investigation was performed the same night
with respect to haemato-biochemical and parasitological examinations to
initiate a specific line of treatment.
Blood smears were stained with Giemsa’s stain and examined under oil
immersion with the objective to detect haemoparasite. It revealed the presence of pear/oval shaped
intra-erythrocytic inclusions, either single or pairs, suggestive of Babesia
organism. Haemato-biochemical parameters
with respect to Hb, TLC, DLC, sodium, potassium, ALP,
AST, total protein, urea, creatinine, cholesterol, bilirubin, glucose,
triglyceride, calcium, magnesium, and phosphorus were carried out following
standard procedures (Table 1).
Treatment
The sick zebra was administered Imicarb
8.0ml (M/S Sava Health Care Ltd. Sava House, Pune, India) deep i/m in two equally divided doses at the neck muscle. The dose was calculated @4.0mg imidocarb per
kg body weight. Additional treatment
included 1L Lactated Ringer’s and 1L 5% dextrose, 2.0g Tazar
(Piperacillin and Tazobactum from M/S Lupin Limited, Mumbai, India) and
15ml Optineurone
(M/S Lupin Ltd, Gujarat, India) .
The zebra was reversed after 40min of induction by
intravenous injection of 0.8ml of large animal revivon
(Novartis Animal Health) that contained 2.6mg of diprenorphine hydrochloride
and 0.5ml Reverzine (Bomac
Pty Limited, Hornsby, NSW 2077) that contained 5.0mg of yohimbine
hydrochloride. All the activities were
accomplished under artificial electric flood light (Image 1).
As a supportive therapy, the zebra was provided with
mineral mixture (Bestomin Gold, Provimi
Animal Nutrition India Pvt Ltd.) @ 30g/day, calcium
granules (Orcal-P, TTK Healthcare Limited, Chennai,
India) @ 50g/day and a commercially available herbal antirheumatic preparation
(R-Compound from M/S Alarsin Pharmaceuticals, Mumbai,
India) @ 10 tablets per day in its concentrate feed for a period of three
months.
The sick zebra was segregated from the other male
zebra to facilitate treatment and monitoring.
Based on the literature (Radostits et al.
2006), three more doses of imidocarb injections were administered with the same
dose and route at 72h intervals. Blood
samples were also collected during the post-treatment period to record
haemato-biochemical alterations.
Results and Discussion
The severity of clinical signs shown by the ailing
zebra coupled with the earlier tragic end of two other zebras in the same
enclosure warranted immediate intervention.
Etorphine used in this case is the most recommended drug to immobilise the zebra.
The drug combination, i.e., Etorphine, Acepromazine, and Xylazine were
also used previously by different workers to immobilise
zebras (Walzer 2003; Senthilkumar
et al. 2005; Nath et al. 2012). Following
tranquilisation the zebra started showing signs of anaesthesia four minutes post-injection period and complete
immobilisation was achieved in seven minutes.
Clinical signs of equine piroplasmosis
are often nonspecific. It may be
confused with a variety of other viral diseases like equine influenza, encephalosis virus infection and equine infectious anaemia. The
haemato-biochemical parameters analysed in the
present case were found to be within reference range (Table 1). This showed the absence of any of the viral
infections described above. Clinical
examinations did not reveal any appreciable musculo-skeletal
disorders or deformity correlating clinical signs exhibited by the zebra. Body vitals like rectal temperature,
respiration, and heart rate were recorded as 99.3°F, 12 breaths/minute, and 70
beats/minute, respectively. Both rectal
temperature and respiration rates were within the normal range. Heart beats were on a higher side as against
the reference value of 28–40 bpm. This
transient increase could be correlated with the excitement during pre and post tranquillisation procedure.
Anaemia and haemoglobinuria which
is marked in case of T. equi infection (Soulsby 1982) was not seen here and posterior paralysis
found in this case is common to B. caballi infection
and not found in T equi infection (Soulsby 1982).
Blood smear examination revealed the presence of
pear/oval shaped intra-erythrocytic inclusions, either single or pairs (Image
3), suggestive of haemoprotozoans, i.e., B. caballi and/or T.
equi. No
tetrads/ maltese cross, specific for T. equi, (Soulsby 1982) were
noticed here. Clinical signs coupled
with parasitological examination confirmed the case to be equine piroplasmosis and more likely to be B. caballi infection.
This corroborated the earlier report of Zweygarth
et al. (2002) who detected both B. caballi and
T. equi in zebras from two national parks in
South Africa.
The present report is substantiated by the fact that Theileria equi and Babesia
caballi infections are endemic in Israel (Levi et
al. 2018). Most of the infected animals
(equids) may remain as sub-clinical carriers of these parasites with no
clinical signs and act as a source of infection (Friedhoff & Soulè 1996). Though
these zebras were tested negative against B. caballi
& T. equi through complement fixation test
during pre-export quarantine period at Israel, the possibility of carrier state
can’t be ruled out as documented by Radostits et al.
(2006) and the zebra is suspected to have carried B. caballi
and/or T. equi from Israel in sub-clinical
stage.
Several techniques/tests are employed for the
diagnosis of equine piroplasmosis that include
clinical signs, direct demonstration of parasites in blood smears, serological
assays, cell-culture, and PCR assays, however, the present diagnosis is based
on the clinical signs, blood smear examination, and response to treatment.
Advanced molecular techniques couldn’t be carried out due to lack of facilities
at that time. The clinical signs noticed
here, i.e., sudden onset of impaired mobility with posterior paralysis were
also akin to observations by other authors (Radostits
et al. 2006; Kaandorp 2010).
Drugs available for the treatment of equine piroplasmosis are Diminazene for B.
caballi and Parvaquone for T. equi infections (de Waal 1992). Imidocarb, which is considered to be the
safest of all drugs available, is effective in treating clinical cases of both
the protozoans (Radostits et al. 2006).
Within 24 hours after administration of the first dose
of imidocarb injection, significant improvement was observed with respect to
gait, movement, and appetite. The zebra
could stand and walk with moderate speed (Image 2). The signs of limping subsided completely and
appetite was regained within 72h after the first dose of imidocarb. In order to ensure proper administration of
the required drug, the zebra was immobilised every
time using the same drug and dose schedule.
This favourable response to
imidocarb confirmed our diagnosis of piroplasmosis. Imidocarb is the most trusted drug for the
treatment of equine babesiosis (Radostits et al.
2006; Donnellan & Marais 2009). To
the best of our knowledge, this seems to be the first report of the piroplasmosis in Grant’s Zebra in Indian zoos.
Table 1. Haemato-biochemical values of a 2½-year-old
ailing male Grant’s Zebra on different days of illness.
Parameters |
Haemato-biochemical values on
different days of treatment |
Reference values of horse (Radostits et
al. 2006) |
|
28.xii.2016 |
01.i.2017 |
||
Haemoglobin (g%) |
15.5 |
15.4 |
11–19 |
TLC (cu mm) |
14,350 |
11,600 |
5400–14300 |
DLC(%) |
|||
Neutrophil |
78 |
70 |
52–70 |
Eosinophil |
02 |
01 |
0–7 |
Lymphocyte |
18 |
26 |
21–42 |
Monocyte |
02 |
03 |
0–6 |
Sodium (mEq/L) |
134.5 |
131.6 |
132–146 |
Potassium (mEq/L) |
4.1 |
4.0 |
3.0–5.0 |
ALP (IU/L) |
225.6 |
210.9 |
140–4003 |
ALT (IU/L) |
6.0 |
5.8 |
3.0-23 |
Total
Protein (g/dl) |
6.5 |
6.4 |
6.0–7.7 |
Urea
(mg/dl) |
59.7 |
70.2 |
10–24 |
Creatinine
(mg/dl) |
1.81 |
1.25 |
0.9–1.9 |
Cholesterol
(mg/dl) |
132.9 |
107.4 |
46–180 |
Bilirubin
(mg/dl) |
0.95 |
1.01 |
1.0–2.0 |
Glucose
(mg/dl) |
163.0 |
102.1 |
75–115 |
Triglyceride (mg/dl) |
67.5 |
67.5 |
4.0–44.0 |
Calcium
(mg/dl) |
12.1 |
11.1 |
11.2–13.6 |
Magnesium
(mg/dl) |
2.2 |
2.2 |
2.2–2.8 |
Phosphorous
(mg/dl) |
3.7 |
4.1 |
3.1–5.6 |
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