Exotic animal integument Flashcards
What is the natural colour of a ferret?
Polecat
What does ferret fur comprise of?
Fur comprises a soft, short undercoat and long coarse guard hairs
What does ferret skin comprise of?
Skin is very thick with numerous sebaceous glands which give a musky smell (different from anal gland musk)
No skin sweat glands so they overheat easily
How do ferrets moult?
Seasonal moults thinner and lightens in spring, thicker and darkens in autumn
Moult may be affected if indoors
What does rabbit fur comprise of?
Long and short guard hairs and an undercoat
What is the natural colour of a rabbit, guinea pig, rat and gerbil?
Agouti
When do rabbits moult?
Moult in Spring & Autumn
Mature females have a……..
dewlap
Rabbits large ears play a role in …..
role in thermoregulation
Where are rabbits scent glands?
submental, anal and inguinal
Name some adaptations and possible problems associated with: Rex rabbits Angora Himalayan Giant breeds Lops
Rex has short guard hairs Angora longer undercoat Himalayan dark extremities Giant breeds skin folds Lops deformed ear canal
A guinea pigs thick foot pads are prone to what problem?
prone to urine scald/infection
Is it normal for a guinea pig to be hairless behind the ears?
yes
Where do guinea pigs have prominent sebaceous glands?
Sebaceous gland approx 1cm dorsal to anus often matted and sticky in entire males.
What type of coat should the following breeds of guinea pig have? Self Abyssinian Himalayan Naked
Self = smooth coated Abyssinian = whorls Peruvian & Texel = coat 20cm+ Himalayan = colour point Naked or Skinny Pigs = hairless
What is a chinchilla coat like?
Very dense, soft coat with up to 60 hairs/follicle
Need regular dust baths to maintain coat
What is the natural coat colour of a chinchilla?
Natural colour is blue-grey
What can chinchillas do if handled too roughly?
Fur-slip defense when handled roughly
Do chinchillas have strong claws?
No
Describe the hair coat and foot pads of rats
Guard hairs and undercoat
Feet hairless, thick pads and Rats sweat glands only on feet
What gland do rats have at the base of their ear?
Zymbal’s Gland at base of ear
A rats tail is large and hairless, why is this clinically important?
Important in thermoregulation (heat loss during anaesthesia) – Care ‘Tail-slip’
How big is rat mammary tissue?
Extensive mammary tissue (2/3 of rat) but only females have visible nipples
Can gerbils tail slip?
Yes
Where is the most prominent scent gland in the gerbil?
Ventral scent gland
What is a sugar glider?
A marsupial females have a pouch with 4 teats
Patagium stretching between front & hind legs
Where is the scent gland on a sugar glider?
Scent glands on forehead (males) + throat and paracloacal scent glands
Do hedgehog spines have sebaceous glands?
Hair and sebaceous glands absent in the spiny skin
Many sweat and sebaceous glands in haired skin and feet
Where is the glandular tissue in reptiles?
Glandular tissue is confined to femoral and pre-cloacal pores in some lizards
The reptile epidermis can be separated into what three layers?
Stratum germinatum which divides and produces keratin
Intermediate layer which contains lipid
Stratum corneum which forms scales and scutes
What are the two types of keratin found in reptiles?
Alpha-keratin: Flexible, Found between scales & scutes and in hinges (Often sites of infections and mites)
Beta-keratin: Unique to reptiles, is hard and forms scutes, horns and scales
Describe the dermis of reptiles
Contains pigment cells, nerves & vessels
The dermis contains bony plates (osteoderms) in some species e.g. crocodile, tortoise, skink
The chelonian shell is formed from about 60 osteoderms which are fused with the ribs and parts of the spine and covered by epidermal scutes or leathery skin
What are the 4 types of pigment containing cell in the reptile?
Chromatophores lie between the dermis and epidermisand are influenced by autonomic nervous system, hormones, light and temperature. Used in camouflage, display and thermoregulation
Melanophores – black, brown, yellow & grey
Carotenoid cells – yellow, red & orange
Iridophores (guanophores) lie in the dermis, contain the semi-crystalline product guanine that reflects light. Blue waves are reflected more thus giving skin a blue colour. When combined with yellow carotenoids green colour is formed
What is the parietal eye?
Found in many lizards and is connected to the pineal gland and thought to help with regulating body temperature
What are spectacles in reptiles?
clear scales over eyes of snakes and some geckos
What are cloacal spurs in reptiles?
retained pelvic vestiges found in boas, used in courtship. More pronounced in males
What are gastropeges?
A single row of large ventral scales in snakes that aid locomotion
How do gecko footpads work?
Composed of rows of tiny overlapping scales called lamellae. Each lamella in turn covered in tiny branching hairs called setae
What does the chelonian shell consist of?
The shell consists of a dome shaped carapace dorsally and a flattened plastron ventrally
What gives the chelonian osteoderms and scutes such strength?
Osteoderms and scutes do not overlap exactly which gives the shell additional strength
How do scutes grow?
Scutes grow by the addition of new keratin layers to the base of each scute
What causes pyramiding of chelonian shells?
A multi-factorial disease resulting from inadequate diet & husbandry
What is ecdysis?
Shedding of the skin (under influence of the thyroid gland)
Do geckos eat their skin after shedding?
Yes
Do terrestrial tortoises shed?
Terrestrial tortoises shed legs, tail and neck skin only (piecemeal)
Do aquatic chelonians shed?
Aquatic chelonia also shed individual scutes
Describe the stages of ecdysis
The cells of the intermediate layer replicate to form a new three-layer epidermis
Lymph and enzymes diffuse between the old and new layers to form a cleavage zone
The old skin is then shed
The new skin hardens
What are the problems associated with a more permeable skin post shed?
During ecdysis the skin becomes more permeable and therefore vulnerable to parasites and infection. Absorption of topical medications may also be enhanced potentially causing toxicity
During ecdysis what do reptiless seek?
During ecdysis many reptiles will seek out areas of increased humidity to facilitate proper shedding.
Snakes especially may require a rough object to rub up against in order to initiate final shedding
Failure to provide adequate humidity and/or a rough surface to rub against is a very common cause of dysecdysis in captive reptiles
How is the epidermis of an amphibian different to that of reptiles/mammals?
Epidermis is considerably thinner compared to reptiles and mammals and is easily damaged
Stratum corneum may only be 1 cell layer thick or may even be absent
Do amphibians shed?
Many amphibians shed and eat their skin on a regularly basis
What does an amphibian dermis consist of?
Dermis consists of an outer stratum spongiosum and an inner stratum compactum.
Dermis contains nerves, vessels, smooth muscle, chromatophores and specialised glands
In salamanders the stratum compactum is….
tightly adhered to underlying connective tissue
In anurans (frogs & toads) the stratum compactum is…
loosely adhered to the underlying connective tissue = useful site for injection of fluids and medications
What is the pelvic patch/drinking patch in amphibians?
Many anurans have marked increased vascularity over an area on the ventral pelvis known as the ‘drinking patch’ or ‘pelvic patch’ to enable water absorption (most amphibians do not drink)
Amphibians may have glands that produce a thick mucus/waxy substance, what is its function?
Which may serve to enhance cutaneous respiration and reduce evaporative water loss respectively
Why will toxic frogs be less toxic in captivity?
Toxins are concentrated or metabolised from wild prey items and thus captive bred and long-term captives contain little if any toxin
How do cane toads produce toxins?
Cane toads possess large parotid glands which release skin toxins
What are some clinical implications of amphibians thin skin?
May be utilised to administer topical medications
Soaking in shallow water aids rehydration via the pelvic patch
Even trace amounts of environmental toxins and pollutants can cause illness and/or death
What is Chytridiomycosis?
Chytridiomycosis a fungal disease caused by Batrichochytrium dendrobatidis has caused mass mortality and extinction in many amphibian species climate change and/or pollution are probable underlying causes
Freshwater fish have tendency to ………….. and gain water
Marine fish have tendency …………. and lose water.
lose salt
gain salt
In fish the skin functions to…
Provide a semi-waterproof barrier which helps maintain fluid and salt balance (in addition to the kidney & gills)
The skin of fish consists of….
Skin consists of epidermal cells and scales (most species) which is covered by a protective outer mucus cuticle.
What does the fish epithelium consist of?
Stratum basale & stratum germinatum. There is no stratum corneum or stratum spinosum though in some species e.g. Goldfish
What are breeding tubercles in fish?
accumulations of localised cornified cells that occur during the breeding season
What does the cuticle in fish consist of?
Cuticle consists of mucus and contains antibodies and lysozymes
What is different about the division of the epithelium in fish?
Unlike mammals fish epidermal cells at all levels are capable of cell division
What does the fish dermis consist of?
Superficial stratum spongiosum & deeper stratum compactum
Contains chromatophores, mechanoreceptors, chemoreceptors and electroreceptors
Fish scales are embedded in the….
Scales are embedded in the dermis and covered by a layer of the epidermis; thus loss of scales will almost always damage the skin leading to osmotic balance problems
