ANS 42 Midterm 2

Pet species

• mammals - mammary glands, milk

• avian - feathers

• reptiles - scales + breathe air

• fish - scales, no limbs, gills, water living

• amphibians - gill in larvae stage, land in adult stage

Birds

• Archaeopteryx - earliest known bird ancestor

• furcula - fused clavicle

• weight needs to be minimized for flight

• drag needs to be minimized

• lift needs to be maximized - keeps in air

• thrust needs to be maximized - maintains lift, counteracts drag

• wing loading = body mass/wing area

• body weight is relative to wing area

• lift is generated by flow of air over wing, larger area = more flow = more lift

• flapping wings requires muscle and muscle has weight, more energy needed

• requires 50-75% more energy than a same sized mammal

• and requires 1.5-3x more oxygen

• birds are homogenous in essential structure, streamlined, aerodynamic 

• flightless birds are descended from flight birds, wings are vestigial

requirements for flight: 

• reduction of body weight- thin skin, fewer and fused bones, thinner bones, hollow bones, some are pneumatic (used in respiration), no bladder (paste excrement, uric acid), reproductive tract only active and developed during reproductive season, lay eggs, no teeth

• commitment of forelimb to flight- arm bones fused to create wing, specialized chest pectorals for flight (up to 50% body weight), modified sternum (keel), accentuated vision and balance (eyes up to ⅓ of head, more photoreceptors, 4 types of cones, more developed vestibular apparatus) enhanced respiratory and circulatory systems (better are extracting oxygen from air, rigid lungs, air sacs expand throughout body, makes them susceptible to airborne toxins [canary in coal mine])

• trimming of primary feathers reduces thrust 

• evolutionary adaptation - birds will not show illness, as other birds will ostracize a sick bird

Fish

• 3rd most popular pet

• fish industry sells aesthetics

• originated in china for both food and aesthetics

• fish in rice paddies resulted in better rice yield and fish available for consumption

• common carp - koi

• prussian carp - goldfish

Goldfish

• Tang Dynasty - genetic mutation in Prussian carp caused gold scales, considered sacred

• Song Dynasty - only imperial family were allowed goldfish 

• Ming Dynasty - ceramic goldfish containers, begin to be raised indoors, led to selection of traits that would not survive outdoors

• Europe acquired in 1600s - thought to bring good fortune

  • permissible characteristics

    • freshwater

    • cold water ~68 degrees F

    • omnivores

    • nonagressive

    • hardy (change 25% of water every 1-2 weeks

• US in 1874

• Shifted from China to Japan

Koi

• Ornamental pond species

• began ~200 years ago from golden carp

Modern Home Aquaria

• Biological  filtration for balanced aquarium 1850s

• electricity in 1920’s

• Air transportation and compressed air WWII

• Aeration - airstones, sub gravel filters

• immersion heaters

• community tanks - many types of fish in one tank

Saltwater Aquariums

• Silicone glue allowed for saltwater tanks as before, tanks were secured with metal edges that would rust if exposed to salt water

• ~10% volume of sales 25% value of total sales ($400-600/lb)

• most saltwater fish are imported and exported from the wild

  • issues: degradation of reefs due to physical damage by collectors and gear, sometimes dynamite

Freshwater

• 90% volume, 75% value

• imported from Southeast Asia, india, and South America 

• florida and Hawaii are domestic culture locations (warm)

Advantages to captive bred

• Accustomed to people

• acclimated to aquarium life

• offspring easier to rear

• always young fish

• less shipping stress

• fewer parasites

• better for environment 

• only about 100 saltwater fish are captive bred worldwide and 30 in US

Reptiles (Dr. DeNardo)

• Squamates - snakes and lizards

• chelonians - turtles and tortoises

• crocodilians - crocodiles and alligators 

• ancestrally, closest living reptiles to birds are crocodiles

• feathers are modified scales

• Can live in deserts and jungles

• not domesticated

• homeotherm - same temperature over time

• poikilotherm - varied temperature over time

• endotherm - heat is generated by animal

• ectotherm - heat is gained from environment

• Reptiles are warm blooded homeothermic ectotherms

• reptiles should stay in between thermal maximum and minimum for optimal performance

• Cool morning - lizard presses itself on dark rock perpendicular to the sun, it has a dark color, increased heart rate, and increased blood flow to its backside

• Warm midday - lizard standing with body off of rock, facing sun, open mouth, light color, reduced blood flow

• hot afternoon - escapes to burrow

Zoonotics

• Definition: diseases transmitted from animals to humans that pose a threat to human health

• Methods of transmission include

  • bites

  • scratches

  • direct contact

  • ingestion

  • inhalation

• Infectious agents on an inanimate object is called a fomite

• Zooanthroponosis - when humans give an animal a disease

• Zoonoses are categorized by their causative agents

  • viral - reproduce in living cells

  • bacterial - single celled organisms

  • fungal

  • parasitic 

• Zoonotics have the most significant impact on the young, old, and immunocompromised 

Viral Zoonotics

• Rabies

  • on every continent except Antarctica

  • Enzootic - a geographical region having a reservoir of the zoonotic agent in the animal population

    • considered enzootic because the wild animals in US have the disease and can spread it to humans

  • all mammals are susceptible but more common in carnivores

  • transmitted by bite, inhalation, ingestion, and exposure to open wounds

  • travels up nerves to brain and salivary glands

    • replicates in brain causing damage and increased salivation

  • the deeper and closer to the brain the wound is, the faster the progression

  • in dogs and cats it lasts 2-8 weeks but up to 6 months, up to 1 year in humans 

  • Symptomology - reflects replication in brain and brain damage 

    • prodromal - anxiety, nervousness

    • excitatory - excitement, aggression, hydrophobia (furious rabies) lasts up to two days

    • paralytic - limbs and body becomes paralyzed including lungs

  • once symptoms are expressed 99% certain death

  • a definitive diagnosis comes from an autopsy (necropsy) of the animal’s brain

  • prophylaxis- vaccination for pets and humans at high risk, also a post exposure vaccine

• Newcastle Disease

  • transmission - aerosols

  • affects primarily domestic fowl (ducks and geese are more resistant)

  • symptoms - depressed growth, tremors, respiratory impairment

  • human threat - conjunctivitis, flu symptoms 

  • no treatment

  • prevention - vaccination

• Western Equine Encephalomyelitis 

  • transmission - mosquito bite

  • affects - many animals, including reptiles and amphibians, though only horses and humans show symptoms

  • Symptoms - horses: inflammation of brain, lack of coordination, up to 50% mortality humans: children could get permanent brain damage from inflammation

  • prevention - vaccinations

Bacterial Zoonotics

• Psittacosis (parrot fever) chlamydia

  • transmission - aerosol 

  • affects birds

  • symptoms - diarrhea, respiratory infection, stress causes progression of disease

  • human threat - generally asymptomatic but some flue like

  • treatment - tetracyclines from diet

  • prevention - cleanliness

• Salmonella

  • Transmission - ingestion

  • affects all animals

    • 1-3% of all domestic animals, 37% of reptiles in Washington zoo

  • symptoms - asymptomatic to gastroenteritis, can cause mortality, dehydration is dangerous

  • treatment - antibiotics, in humans it is self limiting

  • prevention - “treat and delete”

  • typhoid fever is a subcategory 

  • CDC estimates 1.35 million cases 

    • 26,500 hospitalizations

    • 420 deaths / year in US

  • found on food and reptiles have the most severe strain

  • reptiles also carry botulism toxin

  • Bartonella Henselae (cat scratch fever)

  • Transmission - scratch or bite 

  • cats are usually asymptomatic

  • human threat - swollen lymph nodes, fever, rash but is self limiting in 2-6 months

  • prevention - keep cats indoors, clean all wounds from cat

Fungal Zoonotics

• Ringworm (Dermatophytosis)

  • transmission - direct contact or fomites

  • not a worm - a fungus

  • affects dogs, cats, rodents, livestock, and people

  • thrives in moist environments

  • symptoms - raised circular ring on skin, scaly, itchy

    • cats - head

    • dogs - trunk

    • mice - head and body

    • human - anywhere

  • treatment - topical fungicide, self limiting in humans in about 4 months but reinfection is prevalent

  • spores can live up to 18 months

  • prevention - dilute bleach 1:10 clean surfaces

  • fluoresces green under black light 

Parasitic Zoonotics

• Toxoplasmosis

  • protozoa is called toxoplasma gondii

  • transmission - ingestion

  • complex life cycle that includes infective form and oocysts that form cysts in tissue

  • affects mammals and birds 

  • cats are a complete host as it can complete a full life cycle in a cat and can shed its infective form through a cats feces

  • cats get it by eating a rodent with a cyst, it will begin to shed the infective form in about 2 weeks, the fecal matter a human may ingest leads to human infection

  • a woman who is pregnant in the first trimester who gets infected for the first time will develop birth defects

  • in US 11% of people have already been infected

    • up to 60% in other parts of the world

  • cat feces in natural water sources can infect rodents, birds and sea otters

  • symptoms - cats and dogs get diarrhea, humans have flu like symptoms, and sea otters can get lethal neurological damage

  • prevention - cook meat, boil camping water, blood test for pregnant woman

• Worms

  • tapeworms, hookworms, pentastomida

  • transmission - ingestion 

Nutrition

• Nutrient - substance that is consumed, provides nourishment, used for growth and maintenance of life

• herbivore - an animal that does best when consuming plant derived foods

  • unguligrades, elephants, tortoises, rabbits

• carnivore - an animal that does best when consuming animal derived foods

  • cats, snakes, most fish

• omnivore - consumes both plant and animal foods

  • humans, dogs, mice, rats

• obligate - must consume a particular type of food to thrive and meet all growth and maintenance needs

  • rabbit - obligate herbivore

  • cat - obligate carnivore

  • you cannot have an obligate omnivore 

• essential - refers to elements that must be consumed from the diet because the animal cannot synthesize them in their body

  • vitamin C in humans and guinea pigs

• 6 categories of nutrients

  • water

    • most important

    • average mammal is 60% water

  • vitamins

    • organic molecules that assist in bodily functions (blood clotting)

    • some are fat soluble (A,D,E,K)

    • some are water soluble (B,C)

    • there are about 14 essential ones

  • minerals

    • inorganic molecules that assist in bodily functions (enzymes, hormones)

    • provide strength and structure (calcium in bones)

    • about 20 essential ones 

  • Lipids

    • provide energy, a storage form of energy

    • basis of the cell membrane

    • important for metabolic processes and signaling

    • hormone precursors

    • provides insulation

    • aids in the absorption of fat soluble vitamins

    • role in cellular function is critical 

    • carbon and hydrogen chains connected through bonds

      • end of chain is carboxylic acid group

    • carbon has four binding sites, if all are bound it si a saturated fat, if 2 binding sites are bound to the same molecule (Double bond) it is an unsaturated fat

      • saturated - solid at room temperature

      • unsaturated - liquid at room temperature

        • double bonds created bends and angles in the molecule

    • saturated and unsaturated fats influence fluidity of cell membranes

    • cellular signaling requires molecules in membrane to move about

    • Omega 6 and Omega 3 fatty acids

      • carbons are numbered sequentially from carboxylic acid end 

      • the end of a fatty acid without carboxylic acid is called the omega end

    • essential fatty acid - unsaturated

    • most animals can add carbon atom as and double bonds once they have the starting essential unsaturated fatty acid

    • cats needs more fatty acid types because they don’t have the enzyme to synthesize one unsaturated fat into another - cause for obligate carnivore

    • Linoleic acid -> enzyme in body adds double bond - gamma linoleic acid -> enzymes in body add double bond and more carbons - arachidonic acid

    • free radicals are formed in normal body processes but also from toxicants such as cigarette smoke

    • they attack double bonds (rancidification / oxidation)

    • break down the molecule, no longer the essential volatile fatty acid (VFA)

    • antioxidants protect the essential fatty acids from rancidification

    • chemical forms: BHT, BHA, Ethoxyquin

    • natural forms: vitamin C, vitamin E

    • these are also needed for bodily functions, so you need an excess amount for them to also act as antioxidants 

    • antioxidants can also protect against cancer and improve cognitive functions

    • fatty acids improve the palatability of foods

    • dogs are highly sensitive

    • Deficiencies result in dry skin and coats and impact cell membrane function, reproduction is also reduced, there are vision and neurological problems, and reduced immune function

  • Proteins

    • building blocks for muscle and tissue

    • enzymes, hormones and cell signaling

    • amino acids come from broken down proteins

      • 8 essentials

    • in excess it is an energy source, but you must remove the amino group first

    • amino groups have nitrogen

      • becomes toxic ammonia if accumulated

      • expelled through urine

  • Carbohydrates

    • provide energy

    • large molecules are made of sugar 

    • complex carbohydrates are broken down more slowly vs simple sugar

Teeth

• Humans and plant eaters have teeth designed for chewing

• dogs and cats have teeth designed for ripping and shredding

  • their stomach acid is stronger to cope with larger chunks of tissue

Digestion

• GI tract reflects your diet

  • a simpler tract is related to a nutrient dense diet

  • complex tract is related to a dilute nutrient diet

• the more complex the tract, the more time food stays in the tract, therefore, more time to utilize the nutrients

  • usually plant based diets

• Energy Storage forms: lipid, protein, carbohydrates

  • protein and carbs have the same amount of energy

Diets

• Adults

  • need nutrients for maintenance

  • primary need is energy

  • activity level of animal influences need

• young / growing

  • need maintenance and more for growth

  • food usually more expensive because it has more nutrients and higher quality ingredients

• quality - the bioavailability of nutrients in the food

• high quality protein is usually from animals

• low quality protein is usually from plants, harder to digest

• cat food is expensive because they require more protein as they are obligate carnivores

• AAFCO - association of American feed control officials

  • set pet food standards of nutrition

  • clear and consistent labeling

  • only regulate dog and cat food

  • requires a statement saying either:

    • the food was tested and the animals did well, meets nutrition standards

    • food was formulated to meet the nutritional standards of

• If an animal does not have all of its essential nutrients, it can develop health disorders

  • deficiency in arginine: leads to ammonia build up

  • deficiency in taurine: leads to decreased reproduction, blindness, cardiac problems

  • most health problems in lizards and turtles are from dietary deficiencies

• high quality food reduces anxiety behavior in shelter dogs

  • reduced yawning, nose licking, sweaty paws

• excessive fish food allows nutrients to leach into water, feeding the bacteria, increasing pH, this is detrimental to fish

  • feed fish 1-5% of body weight, or what they can eat in about 3 minutes 

• Overfeeding leads to obesity

  • should be able to feel ribs

  • reduces lifespan

  • increases joint loading (increased chance of arthritis)

  • exacerbates complex genetic traits

    • skeletal abnormalities

    • osteochondritis dissecans - cartilage flakes off of joints

    • hip dysplasia - ball joint of femurs doesn’t fit in socket

  • an overweight puppy will have joint issues as the extra body weight is pressing on growing joints

• chocolate contains Theobromine

  • diuretic

  • related to caffeine

  • a neurotoxin that affects heart rate and the CNS

  • dangerous because it metabolizes slowly, causing a longer acting reaction

  • dark chocolate has more theobromine

• Onion contains and alkaloid (n-propyl disulfide)

  • yummy flavor 

  • can cause hemolytic anemia

    • dark urine

    • fever

    • lack of oxygen

  • cooked onion is still dangerous

• egg is ideal food

  • contains all materials needed to develop a neonate

  • also contains compounds to protect developing embryo such as:

    • Avidin

      • antibacterial agent that is secreted into egg white

      • tightly binds with essential B vitamin Biotin

        • B vitamin involved in metabolic pathways such as fatty acid synthesis 

      • when bonded with biotin, the biotin becomes no longer available 

      • excess avidin can cause a biotin deficiency 

        • cooking destroys avidin and reduces salmonella risk

        • although biotin is in the shell of an egg, it might not be enough to compensate for the amounts of avidin in the egg white

• Cats lack the ability to taste sweet, they don’t eat carbs

Pocket Pets

• Ferret - carnivore and illegal in CA

  • simple GI tract, 3-4 transit time

• hamster - omnivore 

  • has fore-stomach like a cow

  • has cecum

• mini pig - omnivore

  • can grow too fast with normal hog food

• mouse - omnivore and opportunistic

• gerbil - granivore and illegal in CA

• chinchilla - herbivore

• Rabbit - obligate herbivore

  • complex GI tract

  • hind gut fermenter

  • need hard pellets to wear down teeth

  • intakes food, arrives at glandular stomach to digest food, enters small intestine that absorbs water soluble nutrients, fiber is passed to large intestine and is sorted by size, small fiber goes to cecum, large fiber is excreted

  • the cecum ferments the fiber that is indigestible and produces vitamins, VFAs, and essential amino acids

  • excreted cecal pellets contain important nutrients and are reconsumed (coprophagy)

  • diets that are too high in protein, energy, or too low in fiber can result in excess pellets

• pygmy hedgehog - insectivore and illegal in CA

  • also likes to eat snails, snakes, and worms

• Rodents have continuously growing teeth (open-rooted)

  • grows ¼ to ½ inches per month

  • risk of malocclusion

Feeding Methods

• Ad libitum - free choice

• limit feeding - best for rabbits, ferrets, and mini pigs that wont limit themselves

• limit treats as they could lead to obesity and tooth decay

• certain species will spit food into their water, careful with sipper tubes, breeding ground for bacteria

Bird Nutrition

• Digest quickly to keep body weight down

• Food moves from mouth to crop

  • crop stores food

  • expands and if contracted, sends hunger signals

• then moves from crop to proventriculus (glandular stomach)

• then moves from proventriculus to gizzard which grinds food with sand and small rocks

• birds also have a ceca that produces VFAs

• birds regurgitate food for babies from crop

• Tom Roudybush - cockatiel experiment UCD alum

  • baby birds need more dilute food when younger and more solid food as they get older

  • baby cockatiels had to be separated from each other during the study or else they would feed each other

  • found that they need 20% protein for best health

• changing a bird’s diet is not easy, they may not recognize they new food as a food

Feather Color

• Pigment can come directly from food

  • canary should eat foods rich in beta-carotene and canthaxanthin

  • flamingos eat canthaxanthin

  • canthaxanthin comes from crustaceans

    • reason shrimps change color when cooked

• pigment can also come from the metabolism of food

  • most parrots (psittacine) colors

  • change of feather color indicates nutritional completeness of diet

• achromatosis - lacking pigment

  • lysine deficiency - an essential amino acid that causes achromatosis in turkeys, quail, rats

    • Not the cause for achromatosis in cockatiels - that is a B vitamin deficiency

    • instead, lysine deficiency causes decreased growth and body fat