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Neurologic dysfunction in a ball python (python regius) color morph, and Implications for welfare


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There is widespread and growing public and professional awareness of genetic disorders associated with artificial breeding, and its implications on the health and welfare of companion animals. Despite increased captive breeding and popularity of atypical color/pattern variants, little research has been conducted, to date, into genetic variants of reptiles, relative to common domestic (e.g., dogs, cats). This work aims to raise awareness among the animal welfare science community of the potential for welfare problems in inbred reptiles, and to stimulate further research in this field. A survey of expert opinion was used to establish a description of a heritable disorder, the “wobble syndrome”, associated with a widely propagated phenotype, the “spider” morph of the ball python (Python regius), a common “pet” snake species. This information was used to provide an assessment of animal welfare impacts of the “wobble syndrome” condition.
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Mark P. Rose, BSc, MSc, CBiol, MSB, and David L. Williams, MA, VetMD, PhD, CertVOphthal,
There is widespread and growing public and professional awareness of genetic disorders associated with
articial breeding selection, and their implications on the health and welfare of companion animals.
Despite increased captive breeding and the popularity of atypical colour/pattern variants, little research
has been conducted, to date, into genetic variants of reptiles relative to common domestic animals (e.g.,
dogs and cats). This article aims to raise awareness in the animal welfare science community of the
potential for welfare problems in genetic variant reptiles and to stimulate further research in this eld. A
survey of expert opinion was used to establish a description of a heritable disorder, the wobble
syndrome,associated with a widely propagated phenotype, the spidermorph of the ball python
(Python regius), a common petsnake species. This information was used to provide an assessment of
animal welfare effects of the wobble syndrome condition. Copyright 2014 Elsevier Inc. All rights reserved.
Key words: animal welfare; articial selection; ball python; captive reptiles; genetic mutation; heritable
Genetic disorders in captive-bred animals are acknowledged as a leading welfare concern
among animal welfare and veterinary professionals.
Growing public awareness,
facilitated by mainstream media,
has promoted advances in animal genetic disease
identication, reduction and remediation.
The need for continued and enhanced
public education has been emphasised to promote informed choices when purchasing
companion animals.
To date, there has been a focus towards disorders
in pedigree dogs and cats with little consideration
of the health and welfare consequences of
selectively breeding captive wild animals,
including reptiles. However, in the United
Kingdom (UK) there are now comparable, if not
collectively greater, numbers of captive reptiles
than dogs (Clark B: A report looking at the reptile
keeping hobby, those who want it banned and
why? University of Kent, BSc Thesis,
There are 8 million reptiles kept as
pets across 1.1 million UK households,
with a
further 13.6 million across 4.7 million American
(US) households.
A signicant driver of growth in
the captive-bred reptile industry is the
development of novel colour/pattern strains, or
morphs,through articial breeding selection of
gene mutations. This is a lucrative business, where
naturally occuring base morphsare combined to
produce designer morphs,reaching values in
excess of US $20,000.
Despite the numbers of reptile species
maintained in captivity and the growth in
selection for novel phenotypes, a literature review
reveals scant reference to health and wefare in this
context. However, the web-based hobbyist media
Ó2014 Elsevier Inc. All rights reserved.
From enims, Burcot Farm, East Stratton, Hampshire, UK; and Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
Address correspondence to: Mark P. Rose, enims, Burcot Farm, East Stratton, Hampshire SO21 3DZ, UK. E-mail:
234 Journal of Exotic Pet Medicine 23 (2014), pp 234239
includes numerous anecdotal reports of potential
welfare issues linked to genetic manipulation. In
their report on the welfare of nondomestic
companion animals, the Companion Animal
Welfare Council recommended that, selection for
specictraitsshould be undertaken only with careful
regard to the possibility of overt or covert adverse
welfare consequences.
The report further
recommends research into breeds where there is
reason to believe that welfare may have been
affected during selection for desired traits.
This article aims to (i) raise awareness of the
potential for genetic disease in reptiles among the
veterinary and welfare science communities, and
(ii) establish a description of a heritable disorder
in a captive-bred reptile species and consider its
effect on animal welfare.
MATERIALS AND METHODS __________________
This study focuses on a single genetic disorder
associated with a widely propagated phenotype of
the ball python (Python regius)(Fig. 1). This species
has gained widespread popularity among pet
owners, hobbyists and commercial breeders. The
spider morph (Fig. 2) is a dominant gene trait
characterised by a pattern alteration where the
distribution of dorsal melanophores is altered,
forming a web-like mesh.
The genetic dominance
of the trait means that the morph can be readily
outcrossed to introduce spider patterning into
designer morphs (Fig. 3). The spider morph is
linked to a neurological disorder, the wobble
syndrome.Examples of the condition may be
observed in open-access, online videos, for
watch?v=zA4lBpoPIWY and
An online survey of expert opinion targeting
hobbyist and commercial breeders was used to
establish a description of the clinical signs of the
wobble syndromecondition, and breeder
perceptions on prevalence, cause and possible welfare
effects. A second survey presented these ndings to
animal welfare scientists and veterinary professionals,
targeting members of the Animal Welfare Science,
Ethics and Law Veterinary Association. Each survey
employed an e-questionnaire. The group of animal
welfare specialists was asked to give their perception
of the welfare effect, if any, of the wobble condition
on affected snakes. Quantitative methods of statistical
analysis were not employedowingtothelowsample
sizes achieved; rather qualitative analysis was
FIGURE 1. Typical wild-type colour/pattern of the ball
FIGURE 2. Ball python with the spider colour/pattern
mutation or morph.
FIGURE 3. Adesigner morphball python expressing
the spider morph in combination with the
pastel morph.
Rose and Williams/Journal of Exotic Pet Medicine 23 (2014), pp 234239 235
RESULTS ______________________________________
Breeder Group
A total of 100 breeders were contacted, with
13 responses received. All respondents were
aware of the spider wobble condition. Of them,
8 respondents commented on the clinical signs
associated with the syndrome, describing side-to-
side head tremors (5), incoordination (4), erratic
corkscrewing of the head and neck (4), inhibited
righting reex (3), torticollis (2), poor muscle tone
(1), and loose grip with the tail (1).
The clinical signs are more pronounced or
appear only during states of arousal (e.g., feeding),
with a widely acknowledged scale in the severity of
clinical signs between affected individual animals.
Breeders disagreed on the proportion of spider
morphs that present with the condition, to some
degree, at some point during their lives (Fig. 4).
However, there was a general consensus that a low
proportion of these snakes were severely affected
(Fig. 5).
Breeders generally reported a minimal effect
on quality of life in most snake cases in which
clinical signs of wobble syndrome were
detected, with typical statements including
Most I see lead a comparable life to a normal ball
python except the obvious differences in grace of
motionand Even severely affected adults eat great,
breed and will lay good eggs.Feeding response is
frequently stated as good (6 responses; 46%),
although owing to poor motor skills, strike
accuracy is often poor (4 responses; 30%).
Euthanasia of 2 individuals was reported, with
poor feeding cited as the primary reason for the
decisions, though it is unclear whether poor
feedingwas related to physical ability or
willingness to feed unassisted. Fecundity was
also reported unaffected, excepting 1 report of
severely affected individuals experiencing
difculty with the physical act of copulation.
There is no evidence to suggest an effect of the
wobble condition on longevity. One respondent
reported that a spider-spider morph mating
results in a higher incidence of egg failures,
suggesting that the gene mutation may be lethal
when homozygous.
The wobble condition appears to be linked to
the gene mutation causing the spider pattern, but
breeders disagreed on the potential for
disassociation of the condition from the morph
(Fig. 6). Spider offspring that lack the pattern
mutation do not express wobble symptoms.
Further, unaffected hatchlings may be born to
severely affected females and affected offspring
born to adults that have never displayed
observable clinical signs.
Welfare Scientist Group
Respondents (n¼28) typically perceived a
moderate to high welfare effect associated with the
clinical signs of the wobble condition (Table),
based on the feelings of frustration and stress that,
intuitively in their opinion, might be
associated with impaired ability to perform
species-appropriate behaviours (e.g., feeding).
The question of ethical defensibility of
continued propagation of the spider morph, in
light of the available evidence, evoked a mixed
response (Fig. 7). Further research was called for, to
address (i) the effect, if any, of the mutation on
longevity relative to that of the wild phenotype; (ii)
the underlying pathology, including any latent
physiological manifestations that may accompany
the neurological symptoms of the condition; and,
(iii) an extensive dataset of standardised clinical
assessments, gathered by a nonbiased exotic
FIGURE 4. Breeder-reported prevalence of the wobble condi-
tion in spider morph ball pythons (n¼13).
FIGURE 5. Breeder-reported proportion of spider morph ball
pythons severely affected by the wobble condition (n¼12).
236 Rose and Williams/Journal of Exotic Pet Medicine 23 (2014), pp 234239
veterinary team, focusing on sensory and motor
performance, divergences from normal behaviour
patterns, and general physical and physiological status.
Others stated that sufcient information was
available to conclude a signicant welfare
compromise associated with the wobble condition
(e.g., Even from the brief description provided by this
survey it is easy to see that this condition has a
signicant impact on the day to day life quality of
affected individuals.).
DISCUSSION _________________________________
Clinical signs of the wobble condition are
indicative of a central nervous system disorder.
Although prevalence of the condition among
spider morphs remains unclear, with many experts
stating that all are affected, there is consensus that
a minority are severely affected in their ability to
perform species-appropriate behaviours, relative to
wild-type, captive pythons. No data are available
on longevity of these morphs, given the relatively
recent discovery of the spider morph in ball
pythons, a species recorded to reach 47.5 years.
Although breeders generally agreed that quality
of life was not signicantly affected, 89% (25/28)
of welfare scientists concluded a moderate to high
welfare effect based on the information available.
This disparity may reect biases inherent in the
respective groups.
One animal welfare respondent stated, Mild
torticolliswould still be quite uncomfortable, according
to the how would that make me feel?principle.Such
anthropomorphism is clearly subject to
limitations; however, common sense and empathy
can, in some cases, provide insight into an animals
welfare state. Human and nonhuman animals exist
on an evolutionary continuum, where sentience
increases with physiological complexity.
historical failure to identify signs of potential
welfare compromises in reptiles is probably best
explained by their alien morphology and
If supercially mechanistic, reptiles in
fact have complex neural architecture
and are
collectively capable of sophisticated
communication, problem solving, parental care
and play behaviours.
Fecundity was widely
reported as unaffected by the wobble condition,
excepting 1 report of animals experiencing
difculty with the physical act of copulation, and
FIGURE 6. Breeder conclusions on the potential for
disassociation of the wobble condition from the spider
morph, with a widely implemented programme of
selective breeding (n¼13).
TABLE. Reported perception of welfare effect (intensity and duration) of the wobble condition among the
Welfarist Group (n ¼28)
Perceived Welfare Impact: Intensity
Negligible Minimal Moderate High
Perceived Welfare Impact: Duration
Negligible 0 0 0 0
Short 0 1 1 0
Moderate 0 1 2 2
Prolonged 0 1 11 10
FIGURE 7. Welfarist conclusions on whether it is
ethically defensible to continue to propagate the ball
python spider morph (n¼43).
Rose and Williams/Journal of Exotic Pet Medicine 23 (2014), pp 234239 237
herpetoculturists implicitly considered this
demonstrated the absence of effect on quality of
life. This may not be the case, as even in stressful
situations, sexual activity is likely to be maintained
in reptiles where the negative inuences of
corticosteroids on sexual endocrine function
seen in many mammals do not seem to be
Aspects of reptile welfare may have beneted from
the growth of captive breeding. In the past, it has
been more nancially viable to replace a diseased
reptile than to seek veterinary intervention.
This is
no longer the case owing to greater veterinary
expertise and growing commercial value of reptiles.
However, any such favourable factors do not detract
from our ethical responsibilty to address potential
sources of poor welfare where they are identied. A
true assessment of effect on quality of life should be
based on complete information on the effects of the
condition. Other neuropathies presenting
comparable behavioural symptoms to the wobble
syndrome are often found to be accompanied by
physiological clinical signs during cytology, biopsy
and necropsy investigation.
pathological analysis of ball python spider morph
specimens may therefore identify latent physiological
manifestations of the wobble condition, which may
themselves open further avenues of investigation.
Where welfare science respondents perceived a
moderate-high welfare impact intensity associated
with the wobble condition, the rationale was often
stated as likely frustration associated with impaired
ability to perform species-appropriate behaviours,
with strike accuracy in affected pythons reportedly
reduced during feeding. Further study to quantify any
increase in stress experienced during feeding is
therefore warranted, to support a robust assessment
of the welfare implications of the condition. The
neuroendocrine stress response in affected snakes
could be assessed through the measurement of
plasma corticosterone level. The corticosterone levels
may be employed to identify chronic stress
measuring basal and feeding stress levels in spider
morph ball pythons presenting with signs of the
wobble syndrome relative to wild phenotype control
CONCLUSIONS _______________________________
Although further research is necessary for
improved understanding, there is clear potential
for signicant welfare compromises to result from
articial breeding selection of reptiles. The 2003
Companion Animal Welfare Council report
highlights the ethical importance of prevention of
captivity-related diseases but emphasises the need
for a measured response.
legislative control may not promote optimum
welfare and can have unforeseen consequences.
The strength of the herpetocultural industry is in its
community of enthusiasts, closely connected by
web-based media. It is self-evident from a review of
such media that most herpetoculturists care greatly
for the health and welfare of their companion
animals and/or breeding stock. This aspect of the
herpetoculturist community should be supported
and used to fuel further research into the welfare
consequences of heritable disorders in reptile
species, effectively disseminate ndings, and
improve self-regulation by community leaders.
We thank the Universities Federation for Animal
Welfare (UFAW) who funded this work, and
Dr Fritha Langford (University of Edinburgh),
James Yeates and Vanessa Ashall (Animal Welfare
Science, Ethics and Law Veterinary Association) for
their support and assistance.
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... Much of this international trade can be traced back to a number of registered reptile "farms" that are in operation across West Africa, most notably Benin, Togo and Ghana [13,23,24]. However, a significant proportion of the captive-bred reptile industry is based on the development of novel colour/pattern strains (also known as morphs) through artificial breeding selection [25]. ...
... There is a growing awareness and concern regarding several genetic disorders associated with artificial selection for colour and pattern morphs, and the negative impacts that this may be having on the health and welfare of Ball pythons [25]. For example, "wobble head" syndrome is a central nervous system disorder that occurs primarily in "spider" morph ball pythons [48]. ...
... For example, "wobble head" syndrome is a central nervous system disorder that occurs primarily in "spider" morph ball pythons [48]. Reported clinical signs include side-to-side head tremors, incoordination, erratic corkscrewing of the head and neck, inhibited righting reflex, torticollis, poor muscle tone, and loose grip with the tail [25]. ...
Full-text available
Ball pythons (family Pythonidae) remain a commonly exploited species, readily available for purchase in North America and Europe. We assessed the housing conditions of more than 5000 Ball pythons across six exotic pet expositions and 113 YouTube videos. We scored provisions for hygiene, mobility, shelter, substrate and water provision, based on the Royal Society for the Protection of Animals (RSPCA) minimum guidelines. We found most entities involved in this commercial enterprise are not providing housing conditions that meet the minimum welfare recommendations for Ball pythons, either publicly or privately. We found that breeders and vendors typically utilised small and highly restrictive enclosures, with dimensions that prevented occupants from extending their bodies to full and unrestricted natural length. Our study also highlights that most vendors are not providing adequate written husbandry guidance to potential consumers, either at exotic pet expositions, on their commercial website, or on associated social media pages. Furthermore, our study also indicates that most potential consumers may themselves be unable to recognise unsuitable housing conditions that do not meet minimum animal welfare standards for Ball pythons. We suggest that more consistent guidance, adherence to agree principles and more potent operating models that are formally incorporated into relevant legislation would greatly aid existing and future efforts to safeguard animal welfare in this regard.
... The scale of the trade is likely to be even greater than current estimates due to incomplete record-keeping and widespread illegal activity throughout the industry [1,9]. Increasing consumer demand for novel colour and pattern strains produced by artificial breeding selection is driving industry growth for the captive breeding sector [10]. ...
... From 1978 to 2017, between 0.9 million and 1.6 million live individuals were exported from Togo alone, 99% of which were for commercial purposes (presumably as exotic pets) [11]. The emergence of novel colour and pattern strains known as 'morphs' has also been a significant driver of growth in demand for captive bred Ball pythons by creating competition among breeders and owners for the most unusual and exotic characteristics [10]. Their popularity has been attributed in part to their docile nature, long lifespans and small size, deemed by some as suitable for terrariums [12,13]. ...
... It is not only the welfare of wild caught and ranched snakes that requires further scientific attention. To date, very little formal research has been undertaken to understand the health and welfare consequences of selectively breeding wild sourced and captive reptiles [10]. Anecdotal reports of potential welfare issues linked to genetic manipulation can be found in hobbyist media (e.g., duckbills [42]), but only one study in the published scientific literature focuses on a single genetic disorder (wobble head syndrome) associated with a widely propagated phenotype of the Ball python [10]. ...
Full-text available
Extensive numbers of Ball pythons are caught, bred, traded and subsequently kept in captivity across the world as part of the exotic pet industry. Despite their widespread availability as pets, relatively little is known about the potential welfare challenges affecting them. We reviewed the literature for research focused on the health and welfare of Ball pythons in the international pet trade. From a total of 88 articles returned from the search criteria, our analysis showed that very few actually focused on trade (10%) or animal welfare (17%). Instead, the majority (64%) of articles focused on veterinary science. There was a considerable bias towards physical health, with most studies neglecting the four other domains of animal welfare (behaviour, nutrition, environment and mental health). Furthermore, very few studies considered Ball pythons prior to resulting pet ownership, during wild capture and transportation or captive breeding operations. Our review demonstrates that our current understanding of welfare for Ball pythons traded as exotic pets is limited. We recommend that future research should focus on aspects of the industry that are currently overlooked, including the potential consequences of genetic selection during captive-breeding and the conditions provided for snakes prior to and during international transportation.
... Although there has been much concern in the academic community over the welfare of other captive-bred animals that are highly derived in relation to their 'wild-type' (e.g. bulldogs) (Aromaa et al., 2019;Hopkins, 2015;O'Neill et al., 2018;Packer et al., 2012;Palmer, 2012;Sandøe et al., 2017), there has been less focus on the welfare of unusual reptile phenotypes (Rose and Williams, 2014). The silkback and leatherback data from the present study will hopefully form a scaffold to promote best practice for the care of lepidosaurs with reduced scalation for dissemination among reptile keepers, veterinarians and animal welfare groups. ...
Whether scales reduce cutaneous evaporative water loss in lepidosaur reptiles (Superorder Lepidosauria) such as lizards and snakes has been a contentious issue for nearly half a century. Furthermore, while many studies have looked at whether dehydration affects thermal preference in lepidosaurs, far fewer have examined whether normally hydrated lepidosaurs can assess their instantaneous rate of evaporative water loss and adjust their thermal preference to compensate in an adaptive manner. We tested both of these hypotheses using three captive-bred phenotypes of bearded dragon (Pogona vitticeps) sourced from the pet trade: ‘Wild Types’ with normal scalation, ‘Leatherbacks’ exhibiting scales of reduced prominence, and scaleless bearded dragons referred to as ‘Silkbacks’. Silkbacks on average lost water evaporatively at about twice the rate that Wild Types did. Leatherbacks on average were closer in their rates of evaporative water loss to Silkbacks than they were to Wild Types. Additionally, very small (at most ∼1°C) differences in thermal preference existed between the three phenotypes that were not statistically significant. This suggests a lack of plasticity in thermal preference in response to an increase in rate of evaporative water loss, and may be reflective of a thermal ‘strategy’ as employed by thermoregulating bearded dragons that prioritises immediate thermal benefits over the threat of future dehydration. The results of this study bolster an often-discounted hypothesis regarding the present adaptive function of scales and have implications for the applied fields of animal welfare and conservation.
... Over 13,000 species across all major animal classes are thought to be involved [15]. As with any successful market, the lucrative nature of the exotic pet trade has created financial opportunities for introducing new commodities [16], such as the introduction of novel colour and pattern strains in reptiles [17], as well as new species with morphology and behaviour considered as rare, unique, charismatic or otherwise appealing to consumers [2,18,19]. While the growth and diversification of the industry has likely been largely driven by increasing desire for exotic pets [2,20], it is thought to have been further compounded by the greater availability of wild animal species through online markets [4,[21][22][23], along with increasing wealth and the commercialization of wild animals in popular media [4,18,24]. ...
Full-text available
Keeping exotic pets has become a popular habit in the UK in recent decades. Yet, information on the current scale of the trade and the diversity of animals involved is lacking. Here, we review the licensed sale of amphibians, reptiles, birds, and mammals as exotic pets in the UK, identifying current geographical hotspots of trader activity, data gaps, and compliance issues related to this trade. In terms of trade volume, records showed large numbers of individual wild animals, across a wide range of species groups, are being legally sold in the UK. Maximum numbers of exotic pets permitted for sale included 54,634 amphibians, 64,810 reptiles, 23,507 birds, and 6,479 mammals. Moreover, nearly 2000 pet traders located in 283 different local authority areas had permission to sell exotic pets. The scope and scale of the trade draws additional attention to the substantial animal welfare challenges associated with it, and our review serves to highlight several shortcomings associated with the licensed exotic pet trade in the UK. Pet shop licences often lacked detailed information about the specific type and number of animals permitted for sale, which raises compliance concerns and hinders efforts to carry out adequate inspection and monitoring. Ninety five pet traders in England had been given a one star rating, indicating ‘minor failings’ in animal welfare, and some local authorities in England were still operating under the old Pet Animals Act (1951). We recommend that resources should be prioritised and focused towards local authorities in England that are not operating under the new Animal Welfare (Licensing of Activities Involving Animals) (England) Regulations (2018), and that local authorities should improve data reporting on all licenses issued to aid inspection and monitoring.
... This is the case of spider ball pythons and jaguar carpet pythons (Morelia spilota), which develop a wobble syndrome of genetic origin characterized by head tremors, incoordination, and lack of righting reflex. 29 Head tilt may be of behavioral or neurologic origin in certain lizards. If the origin is behavioral, this sign will be intermittent. ...
Reptile behavior varies widely among the approximately 11,000 species of this class. The authors' objective is to allow practitioners to discriminate between normal and abnormal behaviors in reptiles. Some of the most common reasons for presentation of behavioral issues are discussed, including hyperactivity, self-mutilation, biting, repetitive behaviors, and postural abnormalities. Medical problems and suboptimal husbandry causing abnormal behaviors should be ruled out by attending veterinarians. Addressing behavior issues involves determining a differential diagnosis through a systematic approach, which then allows implementation of necessary environmental changes including enrichment, developing plans for behavior modification and biomedical training, and medication when appropriate.
... Las serpientes tienen necesidades espaciales muy superiores a las que se pensaba, incluso en el caso de las especies consideradas sedentarias, que se mantienen habitualmente mediante el sistema de "Racks" (Figura 3). En un trabajo realizado con diferentes especies de serpientes, se puso de manifiesto que la mayoría de individuos ampliaban la variedad de tipos de locomoción y adoptaban posturas rectilíneas o casi rectilíneas si disponían de espacio suficiente para ello 31 . El enriquecimiento ambiental basado en la ecología y la historia natural potencia el desarrollo del comportamiento típico de la especie, afectando positivamente a su salud y bienestar. ...
Clinetovet: Revista Clínica de Etología Veterinaria, 16: 10-17. Ethology as a tool to understand the sentience, welfare and emotions in reptiles.
There is general awareness of artificial selection and its potential implications on the health and welfare of animals. Despite growing popularity and increasing numbers of reptile breeds of atypical colour and pattern variants, only a few studies have investigated the appearance and causes of diseases associated with colour morphs. Ball pythons (Python regius) are among the most frequently bred reptiles and breeders have selected for a multitude of different colour and pattern morphs. Among those colour variants, the spider morph of the ball python is frequently associated with wobble syndrome. The aim of this study was to determine whether a morphological variant can be found and associated with the clinical occurrence of wobble syndrome in spider ball pythons, using computed tomography and magnetic resonance imaging as in-vivo diagnostic methods. Data from five spider and three wild type ball pythons was assessed and evaluated comparatively. We were able to identify distinctive structural differences in inner ear morphology in spider ball pythons, which were highly likely related to wobble syndrome. To our knowledge, this is the first report of these anomalies and provides a basis for further anatomical and genetic studies and discussion of the implications for animal welfare in reptile breeding.
Background Renal dysplasia is a rare, progressive and fatal disease in mammals characterized by disorganized maturation of renal tissue. Survival with this condition has been limited to human patients with unilateral disease or those receiving advanced therapies such as dialysis and/or kidney transplants. Case description A 2.5-year-old, male, super dwarf reticulated python (Python reticulatus) was presented for evaluation of coelomic masses located in the caudal third of the body. Ultrasound was consistent with multifocal masses within the renal parenchyma. A coeliotomy was conducted and numerous uroliths were observed within a grossly abnormal left kidney. The uroliths were removed and a biopsy of the left kidney was consistent with renal dysplasia. Aerobic culture of the uroliths and renal tissue was negative for bacterial growth. The patient remained clinically well for 10 months until masses were once again observed, consistent with recurrent urolithiasis. Pre-operative plasma biochemical analysis was unremarkable. A nephrectomy of the left kidney was performed and a biopsy of the right kidney revealed histologically normal renal parenchyma. The patient continues to do well almost one year after nephrectomy. Conclusion and case relevance This is the first report of renal dysplasia and ureterolithiasis in a reptile. Renal dysplasia is often associated with a grave prognosis in mammals; however, unilateral disease may result in a more favorable outcome. Clinicians should be aware of renal dysplasia in snake species, especially if urolithiasis is also noted.
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The trading and keeping of exotic pets are associated with animal welfare, conservation, environmental protection, agricultural animal health, and public health concerns and present serious regulatory challenges to legislators and enforcers. Most legislation concerning exotic pet trading and keeping involves restricting or banning problematic species, a practice known as “negative listing”. However, an alternative approach adopted by some governments permits only the keeping of animals that meet certain scientifically proven criteria as suitable in respect of species, environmental, and public health and safety protections. We conducted an evaluation of positive lists for the regulation of pet trading and keeping within the context of the more prevalent system of restricting or prohibiting species via negative lists. Our examination of international, national, and regional regulations in Europe, the United States, and Canada found that criteria used for the development of both negative and positive lists were inconsistent or non-specific. Our online surveys of governments received limited responses, although telephone interviews with officials from governments either considering or developing positive lists provided useful insights into their attitudes and motivations towards adopting positive lists. We discuss key issues raised by civil servants including perceived advantages of positive lists and anticipated challenges when developing lists of suitable species. In addition, we compare functions of negative and positive lists, and recommend key principles that we hope will be helpful to governments concerning development and implementation of regulations based on positive lists.
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13 Captive-bred ball pythons (Python regius) represent a powerful model system for studying the 14 genetic basis of colour variation and Mendelian phenotypes in vertebrates. Although hundreds 15 of Mendelian phenotypes (colour morphs) affecting colouration and patterning have been 16 described for ball pythons, the genes causing these colour morphs remain unknown. Here, we 17 used crowdsourcing of samples from commercial ball python breeders to investigate the 18 genetic basis of a classic phenotype found in the pet trade, the piebald [characterized by 19 dorsolateral patches of unpigmented (white) skin]. We used whole-genome sequencing of 20 pooled samples followed by population genetic methods to delineate the genomic region 21 containing the causal gene. We identified TFEC of the MIT-family of transcription factors as a 22 candidate gene. Functional annotation of SNPs identified a nonsense mutation in TFEC, which 23 we conclude is the likely causal variant for the piebald phenotype. Our work shows that ball 24 python colour morphs have the potential to be an excellent model system for studying the 25 genetic basis of pigment variation in vertebrates, and highlights how collaborations with 26 commercial breeders can accelerate discoveries. 27 28 29 30 31 32
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Four handling techniques commonly used with snakes and lizards in zoological park reptile collections were evaluated with respect to animal well-being. Adult male blue-tongued skinks (n = 3) and ball pythons (n = 4) were either handled gently, restrained manually, or container restrained for 10 min. The animals were then released into their enclosures for 15 min and blood sampled. At each sampling period, one animal served as an unhandled control. Plasma corticosterone (CS) levels, pre-and post-treatment locomotor and consummatory activities, and heterophil/lymphocyte ratios were determined. None of the parameters evaluated differed significantly among treatments with the exception of CS levels in container-restrained pythons (56.2 + 6.7 ng ml-l), which were higher (P < 0.05) than those of controls (37.6 + 6.1 ng ml-1). Brief periods of handling in captivity thus do not appear to cause chronic stress in the study species, although container restraint did appear to result in short-term stress in pythons.
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The role of behavioural flexibility in responding to new or changing environmental challenges is a central theme in cognitive ecology. Studies of behavioural flexibility have focused mostly on mammals and birds because theory predicts that behavioural flexibility is favoured in species or clades that exploit a diversity of habitats or food sources and/or have complex social structure, attributes not associated with ectothermic vertebrates. Here, we present the results of a series of experiments designed to test cognitive abilities across multiple cognitive modules in a tropical arboreal lizard: Anolis evermanni. This lizard shows behavioural flexibility across multiple cognitive tasks, including solving a novel motor task using multiple strategies and reversal learning, as well as rapid associative learning. This flexibility was unexpected because lizards are commonly believed to have limited cognitive abilities and highly stereotyped behaviour. Our findings indicate that the cognitive abilities of A. evermanni are comparable with those of some endothermic species that are recognized to be highly flexible, and strongly suggest a re-thinking of our understanding of the cognitive abilities of ectothermic tetrapods and of the factors favouring the evolution of behavioural flexibility.
Reptiles and amphibians have been neglected in research on cognition, emotions, sociality, need for enriched and stimulating environments, and other topics that have been greatly emphasized in work on mammals and birds. This is also evident in the historic lack of enriching captive environments to reduce boredom and encourage natural behavior and psychological well-being. This paper provides those responsible for the care of reptiles and amphibians a brief overview of concepts, methods, and sample findings on behavioral complexity and the role of controlled deprivation in captive herpetological collections. Most work has been done on reptiles, however, and so they are emphasized. Amphibians and reptiles, though not admitting of easy anthropomorphism, do show many traits common in birds and mammals including sophisticated communication, problem solving, parental care, play, and complex sociality. Zoos and aquariums are important resources to study many aspects of these often exotic, rare, and fascinating animals, and rich research opportunities await those willing to study them and apply the wide range of methods and technology now available. (c) 2013 Elsevier B.V. All rights reserved.
The purpose of this chapter is to present various considerations, not necessarily related, that may directly or indirectly have a significant bearing on reptile health and welfare. It is hoped that at the very least their inclusion may create or stimulate an awareness of these and other issues which affect the well-being of captive reptiles.
Squamate reptiles generally have been ignored in the search for a unified theory for the evolution of sociality due to the perception that they exhibit little social behavior beyond territoriality and dominance hierarchies and display polygynous mating systems. However a growing body of research has revealed unsuspected levels of social complexity and diversity in mating systems within the squamate lineage, particularly among the members of the Australian Scincid genus Egernia. Several species of Egernia are amongst the most highly social of all squamate reptiles, exhibiting stable social aggregations and high levels of long-term social and genetic monogamy. Social complexity is widespread within the Egernia genus, with reports of social aggregations in 23 of the 30 described species. The purpose of this review was to examine the potential for the Egernia genus as a model system for study of the evolution of sociality and monogamy within squamate reptiles. Current evidence indicates there is substantial variability in social complexity both within and between species, with social organization covering the spectrum from solitary to highly social. Four highly social Egernia species are known to live in stable social aggregations consisting of closely related individuals (adults, subadults, juveniles; i.e., 'family' groups) that appear to utilize chemical cues to recognize group members (kin recognition). Enhanced vigilance against predators is one presumed benefit of group membership. Additionally, juveniles within social groupings appear to receive low levels of indirect parental care. Several Egernia species create scat piles that mark group territories. Three Egernia species exhibit long-term social and genetic monogamy and several inbreeding avoidance strategies have been documented. However, it is currently unknown whether monogamy is widespread within Egernia. Egernia species occupy a broad range of habitats, although most are terrestrial, saxicolous or semi-arboreal. Several species display an attachment to a permanent home site, generally a rock crevice, burrow or tree hollow. Egernia species take 2–5 years to mature, live for 5–25 years, and are viviparous with litter size positively correlated with body size. Several Egernia species are herbivorous, with the degree of herbivory increasing with body size and during ontogeny in larger species. Most smaller species are either insectivorous or omnivorous. Species of Egernia have a wide range of reptilian, avian, and mammalian predators. Several larger species possess several behavioral and morphological features to prevent their extraction from rock crevices, including highly modified keeled scales and numerous defensive behaviors. Color pattern polymorphism is present in five Egernia species. Potential ecological correlates of sociality and monogamy are discussed. The life-history hypothesis predicts long-lived, late-maturing species should evolve complex sociality. The habitat availability hypothesis relies on the assumption that refugia may be limited in some ecological settings, and group formation is a consequence of co-habitation of available refugia. These hypotheses are not mutually exclusive, and testable predictions are formulated and discussed. Specific future research directions are outlined to take advantage of Egernia as a model system for comparative research on a lineage that represents an independent origin of social organization comparable to that found in birds and mammals. THE Australian Scincid genus Egernia com-prises some of Australia's largest, more ubiq-uitous and easily identifiable lizards (Cogger, 2000; Greer, 1989). Several species of Egernia are among the most highly social of all squamate reptiles, and recent research has suggested that studies focused on this genus could provide a valuable contribution to our understanding of the evolution of complex sociality and monogamous mating systems in reptiles. Complex sociality appears to be widespread within the Egernia lineage, with anecdotal reports of social aggregations docu-mented for 23 of the 30 currently recognised species. The size, complexity, and stability of these aggregations appear to vary noticeably both among species, and among populations of the same species, indicating diversity of social organization within the genus.