Health comparison between guinea pigs raised in uncontrolled and controlled environments

Abstract

Background and aim:
Guinea pigs (GPs) (Cavia porcellus) are not only kept as pets but also widely used in biological and biomedical research. At present, GPs are also used as a species for animal-assisted therapy (AAT). Consequently, assessing their health status is vital to determining their quality of life, usability for research, and prevention of spread of potential zoonotic diseases to patients using them for AAT. GPs are mainly sourced from animal markets supplied by traditional farms, where environmental factors and sanitation are not properly controlled. This study aimed to compare health status between GPs raised in uncontrolled (conventional farm) and controlled (animal facility) environments.

Materials and methods:
Sample animals were obtained from a local animal market and transported to an animal facility. After 1 week of acclimatization, the health status of the animals, including general health condition, body weight, body temperature, complete blood count, liver function (alanine aminotransferase and bilirubin), renal function (blood urea nitrogen and creatinine), and presence of ectoparasites and endoparasites, was assessed. Then, the animals were maintained in the animal facility following the standard procedure for laboratory animals. After 2 months, the animals' health status was re-examined, assessing the same parameters.

Results:
Based on the evaluated parameters, GPs raised in an uncontrolled environment were found to have poorer health status than those raised in a controlled environment. There were significant differences in almost all parameters between GPs raised in controlled and uncontrolled environments. We found that the populations of two ectoparasites, Gyropus ovalis and Gliricola porcelli, and one endoparasite, Eimeria caviae, decreased significantly following the movement of the animals from an uncontrolled to a controlled environment.

Conclusion:
GPs raised in an uncontrolled environment have poor health status. However, a controlled environment with better care management can improve the health status of GPs.

Full text

Veterinary World, EISSN: 2231-0916 1575
Veterinary World, EISSN: 2231-0916
Available at www.veterinaryworld.org/Vol.15/June-2022/22.pdf
RESEARCH ARTICLE
Open Access
Health comparison between guinea pigs raised in uncontrolled and
controlled environments
Laksmindra Fitria1, Nastiti Wijayanti1, Tuty Arisuryanti2 and Siti Isrina Oktavia Salasia3
1. Laboratory of Animal Physiology, Department of Tropical Biology, Faculty of Biology, Universitas Gadjah Mada,
Yogyakarta, Indonesia; 2. Laboratory of Genetics and Breeding, Department of Tropical Biology, Faculty of Biology,
Universitas Gadjah Mada, Yogyakarta, Indonesia; 3. Department of Clinical Pathology, Faculty of Veterinary Medicine,
Universitas Gadjah Mada, Yogyakarta, Indonesia.
Corresponding author: Siti Isrina Oktavia Salasia, e-mail: isrinasalasia@ugm.ac.id
Co-authors: LF: laksmindraf@ugm.ac.id, NW: nastiti_wijayanti@ugm.ac.id, TA: tuty-arisuryanti@ugm.ac.id
Received: 25-01-2022, Accepted: 13-05-2022, Published online: 29-06-2022
doi: www.doi.org/10.14202/vetworld.2022.1575-1582 How to cite this article: Fitria L, Wijayanti N, Arisuryanti T,
Salasia SIO (2022) Health comparison between guinea pigs raised in uncontrolled and controlled environments,
Veterinary World, 15(6): 1575–1582.
Abstract
Background and Aim: Guinea pigs (GPs) (Cavia porcellus) are not only kept as pets but also widely used in biological and
biomedical research. At present, GPs are also used as a species for animal-assisted therapy (AAT). Consequently, assessing
their health status is vital to determining their quality of life, usability for research, and prevention of spread of potential
zoonotic diseases to patients using them for AAT. GPs are mainly sourced from animal markets supplied by traditional
farms, where environmental factors and sanitation are not properly controlled. This study aimed to compare health status
between GPs raised in uncontrolled (conventional farm) and controlled (animal facility) environments.
Materials and Methods: Sample animals were obtained from a local animal market and transported to an animal facility.
After 1 week of acclimatization, the health status of the animals, including general health condition, body weight, body
temperature, complete blood count, liver function (alanine aminotransferase and bilirubin), renal function (blood urea
nitrogen and creatinine), and presence of ectoparasites and endoparasites, was assessed. Then, the animals were maintained
in the animal facility following the standard procedure for laboratory animals. After 2 months, the animals’ health status was
re-examined, assessing the same parameters.
Results: Based on the evaluated parameters, GPs raised in an uncontrolled environment were found to have poorer health
status than those raised in a controlled environment. There were significant differences in almost all parameters between
GPs raised in controlled and uncontrolled environments. We found that the populations of two ectoparasites, Gyropus ovalis
and Gliricola porcelli, and one endoparasite, Eimeria caviae, decreased significantly following the movement of the animals
from an uncontrolled to a controlled environment.
Conclusion: GPs raised in an uncontrolled environment have poor health status. However, a controlled environment with
better care management can improve the health status of GPs.
Keywords: clinical biochemistry, environment, guinea pig, health status, hematology, parasites.
Introduction
Cavia porcellus, or guinea pigs (GPs), are tropi-
cal animals that originated from the Andes Mountains,
South America. The species we are familiar with today
was derived from wild animals domesticated some-
time between 6000 and 2000 BC by Central Andeans,
who raised GPs, particularly to serve as the main
source of protein in their daily diet and for medicinal
purposes [1]. Cavy is the proper but less popular name
for GP; they are also known as Dutch rats because
Dutch and Spanish traders introduced these animals
to Europe, Africa, and the rest of the world, includ-
ing Indonesia, in approximately 1554 [2, 3]. Outside
South America, GPs are kept as exotic pets [4]. GPs
have been used as experimental animals since 1780
for research on pathology, nutrition, genetics, phar-
macology, allergies, radiology, immunology, and
other fields [5]. Furthermore, GPs are used as animal
models in dentistry, osteology, nutrition, and physiol-
ogy and as models for various infectious diseases [6].
Recently, GPs have been involved in animal-assisted
therapy (AAT) for physical and mental treatment,
similar to cats, dogs, and horses. GPs have been used
for therapeutic purposes in geriatrics-gerontology
patients, individuals with chronic diseases, and chil-
dren with typical development and autism spectrum
disorders [7, 8].
Whether kept as pets, used for research, or
used for AAT, the health status of GPs must be ver-
ified because it determines their quality of life and
the validity of research data. In addition, preventing
infections in owners, caretakers, and patients are also
crucial because GPs are suspected of transmitting
infections to humans, particularly dermatophytosis,
Copyright: Fitria, et al. Open Access. This article is distributed under
the terms of the Creative Commons Attribution 4.0 International
License (http://creativecommons.org/licenses/by/4.0/), which
permits unrestricted use, distribution, and reproduction in any
medium, provided you give appropriate credit to the original
author(s) and the source, provide a link to the Creative Commons
license, and indicate if changes were made. The Creative Commons
Public Domain Dedication waiver (http://creativecommons.org/
publicdomain/zero/1.0/) applies to the data made available in this
article, unless otherwise stated.

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which can pose a serious zoonotic risk to individu-
als who actively interact with GPs [9]. Environmental
factors and husbandry/care management practices
influence the physiological condition of animals and
their health status [10]. Parameters that do not meet
the requirements may adversely affect animal health.
Unfortunately, some animals, including GPs, do not
always show visible signs of illness when casually
observed or clinically examined [11]. Blood tests
can be used to study the physiological condition and
health status of animals, including disease diagnosis,
and these tests include hematology and clinical bio-
chemistry parameters [12]. Detecting parasites in GPs
will help interpret results from blood tests, both ecto-
parasites [13, 14] and endoparasites [15, 16].
Therefore, this study aimed to compare the health
status of GPs raised in an uncontrolled environment
with that of those moved to a controlled environment.
Materials and Methods
Ethical approval
All procedures regarding animal handling, care,
and sampling methods were approved by Research Ethics
Committee of Faculty of Veterinary Medicine, Gadjah
Mada University at Yogyakarta, Indonesia, issued with
Ethical Clearance No. 0016/EC-FKH/Eks./2020.
Study period and location
This study was conducted from July to
September 2020 at “Animal House”, the animal facil-
ity of Faculty of Biology, Gadjah Mada University
(UGM), for animal maintaining, weighing, and mea-
suring body temperature. Hematological analysis and
parasite identification were performed at Laboratory
of Animal Physiology, Faculty of Biology UGM.
Evaluation of liver and renal function was carried out
at The Integrated Research and Testing Laboratory
(LPPT UGM).
Animals
Eighteen GPs were obtained from a local animal
market in Yogyakarta, Indonesia, provided by multi-
ple vendors. The animals were kept in unstandardized
animal facilities according to the standard guideline
of animal welfare (uncontrolled environment). We
chose individuals of American/English shorthair tri-
color breed for uniformity. Based on morphological
observation for sex determination, we separated into
boars and sows to avoid breeding between animals.
Individuals were randomly chosen with the consider-
ation of 200–300 g for initial body weight.
Experimental design
GPs were kept in pens based on sex; each pen
consisted of three animals. One week after accli-
matization, biological and health parameters were
obtained from GPs raised in an uncontrolled environ-
ment. Then, GPs were moved into an animal room and
kept there for 2 months. Similar biological and health
parameters were obtained from GPs raised in a con-
trolled environment.
Procedures
Animals were transported from a local market to
an animal facility at the Faculty of Biology, Gadjah
Mada University, Yogyakarta, Indonesia, through
land. One week after acclimatization, all animals were
examined to determine their health status in an uncon-
trolled environment.
At the animal facility, the animals were main-
tained using the standard recommended procedure
for husbandry/care, management, and welfare of GPs,
including housing, diet, drinking water, temperature,
lighting, and sanitation [17–21]. After 2 months, the
animals were re-examined to determine their health
status in a controlled environment.
Biological and health parameters
The parameters used to assess the health status
of animals included general health condition through
physical examination, body weight, core temperature,
complete blood count, liver function (i.e., alanine
aminotransferase [ALT] and bilirubin levels), and
renal function (i.e., creatinine and blood urea nitrogen
[BUN] levels). The results were compared between
the first and second assessments and evaluated using
international/general [4] and local/Indonesian [17]
references. Furthermore, we examined the animals
for the presence of parasites. Ectoparasites were har-
vested from the skin, fur, and all body surfaces as per
the standard parasitological method [22], whereas
endoparasites were collected from fecal samples using
the flotation and sedimentation methods [23].
Blood sample collection and analysis
No more than 0.5 mL of blood was col-
lected by clipping the toenails. Next, ethylenedi-
aminetetraacetic acid was added as an anticoagulant
for the blood samples [21, 24–26]. A complete blood
count was performed using a fully automated hematol-
ogy analyzer (Sysmex® XP100, Jakarta, Indonesia).
Bleeding and coagulation times were measured man-
ually using a stopwatch. Then, the blood samples
were centrifuged at 1400× g for 15 min in a com-
mercial centrifuge (Eppendorf®5418R, Selangor,
Malaysia) to yield plasma for evaluating liver and
renal functions. The levels of ALT, bilirubin, creati-
nine, and BUN were measured using the respective
kits (DiaSys®, Jakarta, Indonesia) and a semi-auto-
mated clinical chemistry analyzer (Microlab® 300,
Puteaux, France).
Statistical analysis
Quantitative data were tabulated in a spreadsheet
using Microsoft®Excel® 2019 (Microsoft Corporation,
USA) and statistically analyzed using the Statistical
Package for the Social Sciences (SPSS) version 23
(IBM Corp., NY, USA), for descriptive statistics
(mean ± standard deviation). Data were analyzed using
a one-way analysis of variance and then Duncan’s
post hoc test (α = 0.05) to compare results among the
groups [27, 28]. Qualitative data have been reported
as figures with corresponding descriptions.

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Results
General appearance
The GPs in the market were classified as the
uncontrolled environment group. The vendors used
wire cages as GPs enclosures, which are commonly
used to house dogs and cats. GPs were crowded inside
the enclosure; the entire cage floor was occupied
with no vacant spaces. When visitors approached the
cage, GPs rushed to a corner and gathered together.
Furthermore, boars (male GPs) and sows (female
GPs) and individuals of different ages were placed
inside the same cage. When the animals were pal-
pated/examined, we felt their spines and ribs, with
their hips being prominent. This result corresponds
to the emaciated criteria based on GPs body condi-
tion scoring [29]. Their fur or coat looked dull and
felt rough, and on some parts of the body, lesions,
such as sores or scabs, were observed. Healthy GPs
have clean coats because of their intense grooming
behavior. In dirty environments, they groom more
frequently. Grooming is also the expression of dis-
tress and response to ectoparasites, which cause
itchiness on the skin [30]. The poor appearance of
GPs in the markets was probably because of poor
health conditions; thus, they did not properly groom.
Interviews with stall owners revealed that the ani-
mals were fed only a modest diet of vegetables or
fruits. Traditional GPs farmers usually do not know
the impact of environmental parameters, nutrition,
sanitation, and housing on the health and well-being
of the animals they sell. The condition of the GPs
in the uncontrolled environment group is shown in
Figure-1a.
Figure-1b shows the controlled environment
group, which consisted of three GPs of the same sex.
The animals were placed in a pen (cage without a lid)
with a size of 60 × 60 × 23 cm, which was equipped
with wood shaving as bedding, a feeder, and a water
bottle with a tube sipper and enriched with a tunnel,
shelter, twigs or other media for gnawing, and hay
or straw. These components were provided based on
recommendations for standard GPs housing to meet
animal welfare. Environmental parameters for the
animal room, as per standard recommendations, were
as follows: Room temperature, 25°C–27°C; relative
humidity, 60–77%; closed circulation system with air
conditioner and exhaust fan; illumination with artifi-
cial light from a 7-watt LED lamp; light intensity, 130
lux (room) and 30–60 lux (inside pen); photoperiod,
12 h dark:12 h light; and noise intensity, 30–102 dB
(0.01–12.5 kHz) and 50–75 dB (12.5–70 kHz). For
sanitation, we replaced the bedding twice a week.
Once a week, the pens were cleaned and sanitized with
detergent and disinfectant. We fed GPs with washed/
rinsed cleaned fresh vegetables (i.e., cucumber, carrot,
cabbage, and green leaves), grass, and hay, combined
with commercial pellets. Commercial mineral drink-
ing water was provided ad libitum. Furthermore, we
added Vitamin C to drinking water to meet the daily
ascorbic acid requirement (5–30 mg/kg/day) [31].
Similar to humans, GPs cannot synthesize endoge-
nous Vitamin C; thus, an unbalanced diet will affect
their health status (resulting in “scurvy”) and prolong
the recovery process in case of an infection or dis-
ease [31, 32].
Biological data and blood analysis
Through general health examination from phys-
ical observation and blood analysis, we compared the
health status between GPs from the market and those
that were moved to an animal facility (Table-1).
Parasites
We examined the animals for the presence of
ectoparasites and endoparasites. Ectoparasites cause
skin diseases, such as scabies and infections related
to environmental hygiene, such as fungal infections
or dermatophytosis [13, 14]. Endoparasites mainly
live in the gastrointestinal environment or bile ducts.
Excessive population leads to diarrhea, bloating, and
weight loss because of decreased appetite [15, 16].
We found two ectoparasites, Gyropus ovalis (chew-
ing lice) and Gliricola porcelli (yellow lice), and one
endoparasite, Eimeria caviae (Figure-2).
Discussion
General appearance
For 2 months, we raised GPs as the controlled
environment group in the animal facility, following
the standard guidelines for care and management that
refer to their basic needs, particularly housing, envi-
ronmental factors, sanitation, and welfare [17–21].
During the study, the boars and sows in the controlled
environment group significantly gained weight and
Figure-1: Housing of guinea pigs (GPs). (a) GPs in uncontrolled environment and (b) GPs in controlled environment.
b
a

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exhibited improvement in their appearance. At first,
the GPs from the market frequently scratched their
body; however, this habit decreased gradually after
moving and maintaining them in a controlled envi-
ronment. This activity is related to the population of
ectoparasites in their body [4, 33]. Although they are
easily startled and scared, GPs can adapt well when
handled well. GPs are inquisitive animals by nature
but dislike changes in their environment. However,
they learn quickly after observing the behavior of
other individuals [4, 17]. For instance, when we pro-
vided pellets, they required a few days to begin eat-
ing and enjoying them eventually. Furthermore, they
required a longer period to familiarize themselves
with drinking water from bottles. Feral GPs in their
natural environment neither eat pellets nor drink water
because they already get water from consuming veg-
etables or fruits.
Table-1: Comparison of values of several variables for health status indicators between GP from uncontrolled
environment (animal market) and after being moved to controlled environment (animal room).
Variables Boars (n = 9) Sows (n = 9)
Animal market Animal room Animal market Animal room
BW (g) 250.00 ± 12.50a446.67 ± 22.33b291.67 ± 14.58a436.67 ± 21.83b
BT (°C) 37.87 ± 1.89b36.30 ± 1.82a37.53 ± 1.88a37.67 ± 1.88a
Erythrocyte profile
RBC (×106/µL) 4.48 ± 0.22ab 4.54 ± 0.23ab 4.90 ± 0.25b4.28 ± 0.21a
HGB (g/dL) 11.72 ± 0.59a12.30 ± 0.62b13.12 ± 0.66ab 11.90 ± 0.60a
HCT (%) 39.08 ± 1.95b37.37 ± 1.87a39.62 ± 1.98b36.70 ± 1.84a
MCV (fL) 87.23 ± 4.36bc 82.31 ± 4.12ab 80.86 ± 4.04a85.75 ± 4.29b
MCH (pg) 26.16 ± 1.31a27.09 ± 1.35b26.78 ± 1.34a27.80 ± 1.39b
MCHC (g/dL) 29.99 ± 1.50a32.91 ± 1.65b33.11 ± 1.66b32.43 ± 1.62b
Leukocyte profile
WBC (×103/µL) 6.50 ± 0.33b5.60 ± 0.28a6.70 ± 0.34b6.20 ± 0.31ab
NEU (×103/µL) 3.60 ± 0.18c2.20 ± 0.11ab 3.40 ± 0.17 c1.00 ± 0.05a
LYM (×103/µL) 2.90 ± 0.15a3.40 ± 0.17b3.30 ± 0.17b5.20 ± 0.26c
NEU (%) 55.38 ± 2.77d39.29 ± 1.96b50.75 ± 2.54c16.13 ± 0.81a
LYM (%) 44.62 ± 2.23a60.71 ± 3.04b49.25 ± 2.46ab 83.87 ± 4.19c
N/L 1.24 ± 0.06c0.65 ± 0.03b1.03 ± 0.05c0.19 ± 0.01a
Thrombocyte profile
PLT (×103/µL) 200.33 ± 10.02a394.67 ± 19.73b323.50 ± 16.18b260.00 ± 13.00a
BT (s) 403.33 ± 20.17b350.00 ± 17.50a337.50 ± 16.88a360.00 ± 18.00ab
CT (s) 140.00 ± 7.00b110.00 ± 5.50a127.50 ± 6.38a125.00 ± 6.25a
Evaluation of liver functions
ALT (U/L) 68.70 ± 3.44b64.20 ± 3.21b80.80 ± 4.04c46.10 ± 2.31a
BIL (mg/dL) 1.38 ± 0.07c0.63 ± 0.03b0.75 ± 0.04b0.36 ± 0.02a
Evaluation of renal functions
CRE (mg/dL) 1.56 ± 0.08c1.05 ± 0.05b0.71 ± 0.04a0.64 ± 0.03a
BUN (mg/dL) 26.22 ± 1.31b14.66 ± 0.73a40.14 ± 2.01c11.91 ± 0.60a
Parasites
Gyropus ovalis +++ + +++ +
Gliricola porcelli ++++ ++ ++++ ++
Eimeria caviae +++ - +++ -
BW=Body weight, BT=Body temperature, RBC=Red blood cell, HGB=Hemoglobin, MCV=Mean corpuscular volume,
MCH=Mean corpuscular hemoglobin, MCHC=Mean corpuscular hemoglobin concentration, WBC=White blood cell,
NEU=Neutrophil, LYM=Lymphocyte, N/L=Neutrophil/lymphocyte ratio, PLT=Platelet, BT=Bleeding time, CT=Coagulation
time, ALT=Alanine aminotransferase, BIL=Bilirubin, CRE=Creatinine, BUN=Blood urea nitrogen, The same letter
following the value in a row indicates no significant difference (p > 0.05) compared to other values of the similar
variable in the row
Figure-2: Parasites in guinea pigs (GPs) from uncontrolled environment and after moved to controlled environment.
(a) Gyropus ovalis, (b) Gliricola porcelli, and (c) Eimeria caviae.
c
b
a

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Housing
The habitat or environment where an animal
lives, including housing and environmental param-
eters, predisposes its physiological condition and
behavior, which determines its health status and wel-
fare [34–36]. Transportation, transfers from one envi-
ronment to another, cage structure, or housing method
can trigger stress as indicated by weight loss and
elevated blood cortisol levels. The population or col-
ony size per pen also affects the welfare of GPs [36].
GP as a social animal, cannot be kept alone; at least
two individuals or a group of the same sex should
be housed in each pen for maintenance purposes.
For breeding purposes, GPs can be caged in a pair
or harem [17–20, 34]. GP is a rodent, similar to rats
and mice, which keep moving about for exploration
and foraging, as well as gnawing, digging, and hiding.
Therefore, cages must be designed and enriched with
media to facilitate these behaviors. The number of
individuals in one cage must be managed, for example,
avoiding overcrowding, to ensure that there is enough
area for doing activities and expressing normal behav-
ior. The pen that we modified for the controlled envi-
ronment group meets the basic requirements for GPs
(Figure-1b). The number of animals per pen is consid-
ered ideal for applying as a reference for keeping GPs
indoor as pets or in animal facilities for research pur-
poses [34–36], compared with the uncontrolled envi-
ronment group (Figure-1a). Stress and overpopulation
reduce immunity and resistance to diseases, which can
be observed as elevated body temperature. Elevated
core temperatures significantly indicate fever and
systemic inflammation. In addition, the total and dif-
ferential leukocyte counts provide data for assessing
infection and immune responses [37, 38].
Body weight and body temperature
Results showed that the body weight of the
boars and sows in the controlled environment group
increased significantly compared to those of the boars
and sows in the uncontrolled environment group.
Raised body weight indicates that animals were
not stressed; they were able to express their normal
behavior, including feeding well in order to grow nor-
mally. Body weight represents animal physiological
status and is an important indicator for their normal
growth. Naturally, animals gain weight as they age.
Feed adequacy, including types of food and nutri-
tional contents, health conditions, stress, welfare,
and environmental factors, affects the feed intake
and thus alters the growth rate of animals [39]. We
cannot provide information on the exact age of the
GPs we used in this study as the vendor did not have
the birth record of their animals – a common prob-
lem in the conventional animal farming system. GPs
weighing 250–350 g are approximately 2–3 months
old [39–41]. GPs can be bred when their body weight
reaches 400–450 g [17, 41, 42].
In the uncontrolled environment group, the
boars had higher body temperature than the sows.
After being moved to a controlled environment, their
body temperature was significantly lower than that of
the sows. Normally, male mammals have lower body
temperature than females. Female sex hormones, such
as estrogen and progesterone, are responsible for reg-
ulating and maintaining warm temperature in female
mammals [43]. High body temperature in boars in
uncontrolled environments could occur because of
stress, crowdedness, and diseases. Proper care man-
agement helped regulate their body temperature back
to normal ranges [36].
Blood parameters
Blood, including both cell components and the
plasma/serum, is important biological samples. Blood
plays a key role in animal physiology, including the
exchange of respiratory gases (oxygen and carbon
dioxide), transportation of nutrients and metabolic
wastes, and distribution of various endogenous prod-
ucts, such as enzymes, hormones, and other sub-
stances, to support an individual’s normal physiology.
Circulating blood also distributes exogenous sub-
stances or xenobiotics, such as drugs, toxicants, and
contaminants. Therefore, blood reflects the physiolog-
ical condition and health status of animals [44, 45].
Our results demonstrated alterations in almost all
blood parameters, which indicated the improvement
in the health of the GPs in the controlled environ-
ment group. Values showing significant differences
between the uncontrolled and controlled environment
groups reassured that care and management play a
major role in the health status of GPs. Hematology
analysis showed some changes in the values of eryth-
rocytes, leukocytes, and platelets. Variations in hema-
tology and biochemical parameters are sex and age
related. The values are significantly different between
young and adult individuals, which can be determined
as below and over 300 days [46]. Because some val-
ues in this study were significantly different and were
maintained within the normal range and the growth is
< 300 days, the difference reflected normal physiolog-
ical dynamics.
In addition to assessing the physiological
condition of animals (physical health), hematology
profiles can also be used to determine their psy-
chological condition (mental health) through indica-
tors of stress, by calculating the ratio of neutrophils
to lymphocytes (N/L). Physiological stress because
of changes in environmental conditions, diseases, or
other interventions will affect the psychological status
of animals, manifested as distress. In general, stress
in vertebrates decreases the number of lymphocytes,
with a concomitant increase in the number of neu-
trophils; therefore, stressed animals have a high N/L
ratio [47, 48]. Land transportation and the transfer
of GPs from their old habitat (uncontrolled environ-
ment) to a new habitat (controlled environment), as
well as changes in lifestyle and diet had the potential
to cause distress [49]. Our results showed that GPs in

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the controlled environment group did not experience
stress during the experiment, indicated by an increase
in lymphocyte count and percentage, whereas neutro-
phil count and percentage decreased; thus, the N/L
value was lower.
Liver and renal functions had decreasing val-
ues for all indicators. This is probably because cells
making up both organs of GP in the controlled environ-
ment group have improved, in consequence, optimiz-
ing their normal functions. The liver is an important
organ for assessing the health status of both humans
and animals as it detoxifies toxic substances that
enter the body and excrete waste products of the body
during normal metabolism. However, these processes
cause several damage to the liver structure, which can
be indicated by elevating intracellular enzymes, such
as ALT, because many liver cells experience necrosis.
Furthermore, this injury leads to liver dysfunctions,
which can be detected by elevating plasma bilirubin.
The kidney is also an essential organ for determining
the health status of an individual because of its func-
tions for ultrafiltration, reabsorption, and excretion.
Therefore, disruption to these processes indicates
deterioration in renal function, which can be observed
structurally and/or functionally. Creatinine and BUN
are two main indicators for evaluating renal func-
tion [44, 50].
Published reference values for normal or healthy
GPs in Indonesia are still rare. The only source was
written by Smith and Mangkoewidjojo [17], which
aged more than three decades ago, and does not include
a wide range of parameters. International publications
provide newer and more complete values and are con-
stantly updated; however, the data were GPs that were
housed in conditions that are different from husbandry
and management practiced in Indonesia [4].
Parasites
Endoparasitic infection and ectoparasitic infesta-
tion can be found in conventionally sourced and housed
GPs [4, 17, 50]. In the animals we studied, we found
two ectoparasites, namely, G. ovalis (chewing lice)
and G. porcelli (yellow lice), and one endoparasite,
namely, E. caviae (Figure-2). G. ovalis and G. porcelli
are common ectoparasites found in GPs. Trixacarus
caviae, Chirodiscoides caviae, and Demodex caviae
are also specific ectoparasites in GPs [13, 14]; how-
ever, they were not found in the animals we studied.
E. caviae, the main protozoa causing coccidiosis in
GPs [4, 51], has been reported in Indonesia [17] and
Brazil [52]. However, this parasite has not been found
in African GPs; the most common infection in African
GPs is caused by Giardia spp. and Cryptosporidium
spp. [15] and Paraspidodera spp. [16].
G. ovalis and G porcelli live beneath the skin,
eating epithelial cells, digging holes, and sucking
blood. When consuming the epidermis, they secrete
substances that induce inflammation. The itchy sen-
sation causes GPs to scratch their skin intensively,
which results in patchy hair loss, ulcerative lesions,
and redness of the skin. The skin may appear dry or
oily, thickened, and crusted. Severely infected ani-
mals can develop secondary infections, get stressed,
and lose weight. These lice may predispose ani-
mals to health deterioration due to internal parasites,
infectious diseases, poor nutrition, and poor sanita-
tion [53]. E. caviae is a coccidia found specifically
in GPs, with infections established through contam-
inated food. Eimeria is found in the epithelial lining
or tissues in the digestive tract; sometimes, it is also
found in the bile duct or renal tubules. This genus is
relatively harmless; however, if the population of the
organisms increases, clinical signs may occur, such as
mucus in feces, diarrhea, bloody feces, colitis, ane-
mia, and weight loss. This coccidia is not zoonotic and
can be prevented with the provision of clean food and
sterile bedding [17, 53]. These three parasites were
found in GPs that had just arrived from the market
(uncontrolled environment), during acclimatization,
and also after 2 months of housing in the animal facil-
ity (controlled environment). The difference was the
total number of parasites. After housing and mainte-
nance in our controlled animal room, the population
of ectoparasites dropped significantly; meanwhile, the
population of endoparasite was eliminated. Sanitation
plays a major role in the level of parasitic infestations
and infections in GPs. Better management of animal
husbandry/care and health monitoring and appropriate
medical treatments by the attending veterinarians also
affect the health status of animals.
G. ovalis, G. porcelli, and E. caviae are natural
infective organisms in GPs that have occurred for a
long time since domestication. As these parasites are
very infectious among GP populations, good man-
agement are essential to prevent and control the dis-
eases in GPs, including proper housing, ventilation,
cleanliness, temperature, humidity, and well-balanced
diets [35, 36, 53]. Multivitamins were administered
to GPs that appeared weak, passive, or unhealthy.
For parasites, we treated GPs with the administration
of antiparasitics, such as ivermectin, combined with
anti-inflammatory agents and vitamins [51, 54].
Biological data for health monitoring in GPs are
already available from various countries. However,
no publications have provided comprehensive data for
comparing the biological and health profiles of GPs
based on different environments. Our study provides
new insight that differences in environmental factors
and care methods greatly affect the health status of
animals, which is related to sex. Our study could be
used to prepare the health status of animals ready to
be used as experimental animals for various research
purposes.
Conclusion
GPs raised in an uncontrolled environment (con-
ventional farms) have poor health status according to
the evaluated parameters. Moving them to a controlled

Veterinary World, EISSN: 2231-0916 1581
Available at www.veterinaryworld.org/Vol.15/June-2022/22.pdf
environment (animal facilities) with better care man-
agement can improve their health status.
Authors’ Contributions
SIOS and LF: Conceived and designed the study
and wrote and revised the manuscript. LF: Conducted
the experiments, collected samples, and analyzed the
data. TA and NW: Analyzed the data. All authors have
read and approved the final manuscript.
Acknowledgments
This study was funded by Gadjah Mada University
through “Rekognisi Tugas Akhir” Research Grant
(No.2488/UN1.P.III/DIT-LIT/PT/2020). The authors
acknowledge Prof. Em. drh. Soesanto Mangkoewidjojo,
for sharing knowledge on guinea pigs, Mark A. Suckow,
and David Moore, for making suggestions for this study
and manuscript. We also thank Dian Kristiawati,
Diandra Vildainy Amalo, Lina Noor Na’ilah, Lisa
Handayani, and Rika Nirmasari, for their assistance in
laboratory works.
Competing Interests
The authors declare that they have no competing
interests.
Publisher’s Note
Veterinary World remains neutral with regard
to jurisdictional claims in published institutional
affiliation.
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