Nutritional Diseases Flashcards
How does malnutrition develop?
interference with intake, absorption, or use of nutrients
increased requirements or excretion of nutrients
inhibition
What are the clinical signs of general malnutrition in horses?
causes the skin to become dry, scaly, thin, and inelastic
skin may become more susceptible to infections
hemorrhagic tendencies
pigmentary disturbances
hair coat becomes dry, dull, brittle, thinned, and perhaps faded in color
Normal hair shedding and regrowth can be impaired
What percentage protein is hair?
95%
What percentage of an animal’s daily protein requirement does normal growth of hair and the keratinization of skin require?
25-30%
What are the cutaneous manifestations of protein deficiency?
hyperkeratosis
cutaneous atrophy
pigmentary disturbances
- epidermal hyperpigmentation
- loss of hair pigment
dry, dull, brittle, thin, faded, and easily epilated hair
- patchy alopecia
Poor hair growth/prolonged shedding
Poor wound healing
Severe hypoproteinemia
results in cutaneous edema
Which enzymes are copper an essential component of?
many oxidative enzymes ex.:
- tyrosinase
- ascorbic acid oxidase
- lysyl oxidase
- cytochrome oxidase
Also has roles in erythropoiesis, reproduction, and iron utilization
What causes copper deficiency (hypocuprosis)?
dietary deficiency
interference with absorption by zinc or cadmium
What are the typical clinical signs of copper deficiency?
hair coat fading or leukotrichia (tyrosinase)
- “spectacled” horses
Pica
Impaired bone growth
What dogs have a genetic predisposition for copper-associated hepatopathy (CAH)?
Belington terrier and Labrador retriever are two breeds where the mutation has been identified
- other breeds but mutation not identified
What are the causes of iodine deficiency?
Decreased intake
- certain soils ex. Great Lakes, Northern plains, PNW
goitrogens that interfere with thyroidal iodine uptake
- thiocyanates
- perchlorates
- rubidium salts
- arsenic
What are the clinical signs of iodine deficiency in horses?
weak foals with variable hair loss and thickened, puffy (myxedematous) skin
goiter may or may not be visible externally.
What is zinc used for in body metabolism
muscle and bone growth
feed use
normal reproductive function
taste and smell acuity
normal leukocyte function normal keratogenesis
wound healing
component of over 70 metalloenzymes
What supplementation needs to occur with hepatocutaneous syndrome?
Amino acids
arginine, leucine, lysine, methionine, proline, threonine, valine
What does linoleic acid do?
Omega-6 fatty acid
Component of epidermal ceramides
Involved in maintaining epidermal water permeability barrier
What does arachidonic acid do?
Omega-6 fatty acid
Essential in cats only
Regulates epidermal proliferation via metabolism into prostaglandin E2
- without PGE2 –> too much proliferation
What does a-linolenic acid do?
Omega-3 fatty acid
The eicosanoids produced from omega-3 fatty acids are less inflammatory than those produced from arachidonic acid
“Anti-inflammatory” fatty acid
How can food storage affect fatty acid quantity/quality in commercial pet foods?
Oxidation may occur in canned food after 1 year and dry food after 6 months, especially if food is stored at a higher temperature
What are the clinical signs of fatty acid deficiency?
develop in patients eating a diet containing <1% EFAs
initial “dry phase”: fine scaling, loss of hair luster and sheen
Followed by alopecia, secondary bacterial infection, greasy & lichenified skin, pruritus
if arachidonic, epidermal hyperplasia, hypergranulosis, orthokeratotic to parakeratotic hyperkeratosis
What are the clinical signs of deficiency and excessive iodine?
Signs of deficiency:
- Hypothyroidism
- goiter
- alopecia
- infertility
- lethargy
- myxedema
Signs of toxicity
- Decreased thyroid function
What are the primary functions of manganese in the body?
Carbohydrate and lipid metabolism
What is the typical dermatological sign associated with manganese deficiency?
partial albinism
What bodily functions is zinc required for?
Component of enzyme systems (protein & carbohydrate metabolism):
- fatty acid synthesis
- Vitamin A metabolism
- maturation of skin cells
- healthy hair coat
- normal immune function
What are signs of zinc deficiency?
Impaired growth
scale + parakeratosis
depigmentation of hair
infertility
- testicular hypoplasia
impaired wound healing
increased susceptibility to infections
- needed for T cell development in the thymus
What are signs of zinc toxicity?
May interfere with absorption of calcium and/or copper
acute toxicity can lead to hemolytic anemia
What are the histopathologic findings associated with zinc deficiency/zinc responsive dermatoses?
- marked epidermal and follicular parakeratosis
Papillomatosis, spongiosis, and eosinophilic/lymphocytic superficial perivascular dermatitis are also common findings
Why does zinc deficiency cause parakeratosis?
due to the insufficient function of zinc-related lytic enzymes and/or an increase in epidermal cell turnover time (and thus a lack of time for hydrolysis of the nuclei)
What is Zinc-Responsive Dermatosis Syndrome I?
Huskies, Malamutes > Dobermans, Great Danes
Potentially poor intestinal absorption versus increase need
- have normal circulating levels
Usually onset is early adulthood
- can worsen with stress and estrus
What are the clinical signs associated with Zinc Responsive Dermatosis Syndrome I?
Erythema, alopecia, scaling, crusting around mouth, eyes, ears, and paws
Pruritus in “normal” skin can be the hallmark of a pending relapse
Other body orifices can be affected
Claws can develop onychomalacia
What is the treatment of Zinc-Responsive Dermatosis Syndrome I?
2-3 mg/kg/day elemental zinc
low dose steroids
- increases metallothionein
+/- omega 3/6 fatty acids
+/- phytase to the diet to hydrolyze phytates in food
What is Zinc-Responsive Dermatosis Syndrome II?
Seen in rapidly growing puppies or young adults fed zinc-deficient diets or diets high in calcium/iron/phytate
hyperkeratotic plaques over areas of repeated trauma, foot pads, nasal planum, secondary pyoderma, fissuring
What are the signs of zinc‐responsive dermatoses in farm animals?
More or less symmetrical erythema and scaling
progress to crusting and alopecia
face, pinnae,
mucocutaneous junctions, pressure points, distal legs,
flanks, and tail head are typically affected
dull, rough, brittle hair coat
variable pruritus
usually have systemic signs
What is magnesium needed for in bodily functions?
Enzyme activator
constituent of skeletal tissue
required for muscle and nerve function
energy metabolism
protein synthesis
What are some signs of magnesium deficiency?
Calcification of soft tissues
stunted growth
spreading of toes
seizures
hypersalivation
What are some signs of magnesium toxicosis?
Diarrhea, urolithiasis, cystitis
What are the role of sodium in bodily functions?
Muscle contractions
maintenance of body fluids
component of bile/muscle/nerve function
What are clinical signs of sodium deficiency?
Salt hunger
pica
weight loss
fatigue
polyuria
impaired milk secretion
What are clinical signs of sodium toxicity?
Pruritus
thirst
constipation
anorexia
What are the primary roles of phosphorous in bodily functions?
Part of DNA and RNA
bone and tooth formation
component of enzyme systems
What are the clinical signs of phosphorous deficiency?
Rough hair coat
pica
anorexia
slow growth
rickets
osteomalacia
What are clinical signs of phosphorous toxicity?
Impaired skeletal development
secondary calcium deficiency
kidney damage
What are primary roles of calcium in bodily functions?
Bone & tooth formation
blood clotting
enzyme activation
- many in skin development
muscle contraction
nerve impulse transmission
What are the clinical signs of calcium deficiency?
Rickets in young
osteomalacia in old
lameness
stiffness
constipation
anorexia
loss of teeth
tetany with acute deficiency
What causes parakeratosis in swine?
Dietary zinc
essential fatty acids
calcium and other chelating agents
other disease conditions
typically occurs in housed feeder pigs between the ages of 7 and 20
weeks
What are the clinical signs of parakeratosis in swine?
symmetrical erythematous macules and papules appear on the ventral abdomen and medial thighs
dermatitis then becomes widespread and brownish‐to blackish crusts develop
No pruritus or greasiness
What are the clinical signs of calcium toxicosis?
Impaired skeletal development
secondary deficiencies of other minerals like zinc, phosphorus, and copper
What are some clinical signs of selenium toxicity?
nausea
vomiting
nail discoloration, brittleness, and loss
- onychomadesis
- Erythema and swelling of the coronary band with separation of the hoof wall
bilateral hair fragility/loss
fatigue
cardiac lesions
peracute death if acute
garlic odor to the breath
What is the role of selenium in bodily functions?
integral to numerous enzymes and proteins, including glutathione peroxidase, which prevents oxidative injury, as well as several enzymes involved in thyroid hormone homeostasis
What are the typical clinical signs of selenium deficiency?
nutritional myopathy
hepatosis dietetica in swine
exudative diathesis in growing chickens
cardiomyopathy in humans
abortion/stillbirth
What is the function of selenium linked to?
Vitamin E
A selenium deficiency can therefore partially be compensated if there is enough vitamin E and visa-versa
What is the role of Vitamin A in bodily functions?
Important in cellular metabolism and regeneration in eyes
Required for normal maturation of skin and hair follicles
Essential for normal epithelial tissue lining in digestive, respiratory, and reproductive tracts
Required for proper immune system functioning
What are clinical signs of Vitamin A deficiency?
Epidermal hyperkeratosis, scaling, and seborrhea
Occlusion of sebaceous ducts
- Follicular casting in cocker spaniels with true Vitamin A deficiency
Papules associated with follicular hyperkeratosis
Poor hair coat & alopecia
Reproductive failure
Retinal degeneration and night blindness
Excessive lacrimation
Neurologic disorders
Decreased serum concentrations of iron, albumin, and cholesterol
Increased susceptibility to infections
What are clinical signs of Vitamin A toxicosis?
Epidermal scaling, unkempt hair coat, anorexia, weight loss, bone decalcification, liver damage
Hypervitaminosis A can occur as a result of large amounts of liver ingestion
Reproductive abnormalities
Decreased tear production
Hepatopathy
What are the fat soluble vitamins?
vitamins A, D, E, and K
What are the primary roles of Vitamin D in bodily functions?
Required for normal calcium absorption and metabolism
Essential for normal bone development
1,25-dihydroxy vitamin D3 also has role in regulation of keratinocyte proliferation and differentiation
What are the clinical signs of Vitamin D deficiency?
Rickets in young patients
Osteomalacia in adults
Chest deformity
Poor eruption of teeth
Risk of cardiovascular disease
Increased cancer risk
What are the typical clinical signs of Vitamin D toxicity?
Increased blood calcium levels
Soft tissue calcification
Diarrhea
Kidney failure
Death
What form of Vitamin D is made in the skin?
cholecalciferol (D3)
What form of Vitamin D is made by plants?
ergocalciferol (D2)
How do cats and dogs get most of their Vitamin D?
acquire most of their vitamin D through diet
- UV-mediated production in the skin serving an insignificant role
- cats need Vitamin D3
What converts Vitamin D to stable, long-lived metabolites?
cytochrome P450 enzymes in the liver
What anticancer activities does Vitamin D have?
1,25(OH)2D induces apoptosis and reduces cancer cell growth
How do humans get most of their Vitamin D?
UVB photons entering the skin
What are the primary roles of Vitamin E in bodily functions?
Antioxidant
Protects cells from oxidative damage
May have role in normal immune function
Scavenges free radicals produced during lipid metabolism
Reduces prostaglandin E2 synthesis, which at high levels can yield free radical production and cause oxidative stress
- helps prevent against this PUFA-induced oxidative stress
increases IL-2
- can be used at supraphysiologic doses to modulate inflammation
- work synergistically with Vitamin A
What are clinical signs of Vitamin E deficiency?
Pansteatitis
- Classic example: cat fed high red tuna diet (high in PUFA) without vitamin E supplementation
- see panniculitis and ceroid (product of lipid peroxidation) on histopathology)
Seborrhea
Muscle dystrophy
Reproductive failure
Intestinal lipofuscinosis
Impaired immunity with predisposition to bacterial skin infections & demodicosis (dogs)
What are the primary role of Vitamin K in bodily functions?
Required for formation of clotting factors and normal blood clotting
What are the typical clinical signs of Vitamin K deficiency?
Hemorrhage & increased bleeding times
Elevated Prothrombin Time (PT)
What are the primary roles of Vitamin C in bodily functions?
Antioxidants
Formation and maintenance of matrix of bone, cartilage, and connective tissue
What are reasons for Vitamin A deficiency?
Deficient diets
- poor-quality forage
- horse fed grains such
as barley or oats (low Vit A)
Foods stored for prolonged periods of time
- rapidly destroyed by oxygen and light
What is Vitamin
C–Responsive Dermatosis in cattle?
may represent a temporary vitamin C deficiency in growing calves
most often seen in the fall and winter in temperate climates
Moderate to severe scaling, alopecia, occasional crusts, and easy epilation of hairs begin on the head and/or limbs
Extremities are erythematous, petechiae and ecchymoses are seen
May be depressed and grow slowly
Which animals have an absolute need for Vitamin C?
do not all have a phylogenetic relationship with each other
- humans
- non-human primates
- guinea pigs (10 mg/kg/day)
- capybara
- some birds and fish
- maybe some snakes
Need can increase with pregnancy or stress
What are clinical signs of hypovitaminosis C?
early cutaneous signs are roughened hair coat, and scaling of the pinnae
- progress to generalized scaling with petechiae, ecchymoses/hematomas
defects in connective tissue
- wound dehiscence
- poor wound healing
- loosening of teeth
corkscrew hairs
perifollicular hemorrhages
Bleeding and anemia
- gingival bleeding
rickets
increased susceptibility to infections
When does hypovitaminosis C typically occur in guinea pigs?
fed commercial rabbit food or an outdated guinea pig ration as the sole source of nutrition
can play a role in bumblefoot
What is the primary roles of thiamine (B1) in bodily functions?
Component of two coenzymes essential in carbohydrate metabolism and energy transfer
Promotes normal health and digestion and normal nerve function
What is the primary roles of riboflavin (B2) in bodily functions?
Forms part of two coenzymes with roles in energy transfer and protein metabolism
Component of xanthine oxidase required for epithelial cell maturation
What are the clinical signs of thiamine (B1) deficiency?
Anorexia
weight loss
vomiting
dehydration
ventral flexion of the neck
paralysis
incoordination
What are the clinical signs of riboflavin (B2) deficiency?
Stunted growth
dry scaly skin, erythema
posterior muscle weakness
anemia
ocular lesions (pannus)
glossitis
reduced fertility
testicular hypoplasia
fatty liver
What are the clinical signs of pyridoxine (B6) deficiency?
Dermatitis with dull, waxy, unkempt hair coat, alopecia and scaling
Seizures
anemia
high serum iron
anorexia
weight loss
impaired growth
What is the primary roles of pyridoxine (B6) in bodily functions?
Part of enzyme involved in protein metabolism
Essential for normal metabolism of tryptophan
What is the primary roles of cobalamin (B12) in bodily functions?
Required for synthesis of nucleic acids
Involved in purine synthesis and carbohydrate and fat metabolism
What are the clinical signs of cobalamin (B12) deficiency?
Anemia
impaired growth
posterior incoordination
What is the primary roles of niacin (B3) in bodily functions?
Component of two coenzymes with roles in energy transfer
Required for metabolism
What are the clinical signs of niacin (B3) deficiency?
Black tongue
Pruritic dermatitis
Diarrhea
dementia
anorexia
anemia
emaciation
death
Deficiency of which vitamin can cause a black tongue?
Niacin (B3)
What are the clinical signs of niacin toxicosis?
Cutaneous flushing
Pruritus
What is the primary roles of pantothenic acid (B5) in bodily functions?
Constituent of coenzyme A required for normal metabolism of carbohydrates, fats, and proteins
What are the clinical signs of pantothenic acid (B5) deficiency?
Anorexia
stunted growth
hypoglycemia
uremia
gastroenteritis
seizures
fatty liver
coma
death
What is the primary roles of folic acid (B9) in bodily functions?
Required for normal red blood cell development and DNA synthesis
What are the clinical signs of folic acid (B9) deficiency?
Anemia
leukopenia
stunted growth
glossitis
What is the primary roles of biotin (B7) in bodily functions?
Required for metabolism of fats & amino acids
Essential for skin and hair health
Functions in enzyme systems
What are the clinical signs of biotin (B7) deficiency?
Scaly dermatitis, alopecia
Anorexia
weakness
diarrhea
progressive spasticity
posterior paralysis
Deficiency of which vitamins/minerals can cause pruritus?
Zinc
EFAs
Niacin
Toxicity of which vitamins/minerals can cause pruritus?
Sodium
Niacin
What causes hypovitaminosis A in birds?
an all-seed diet
- Amazon parrots are predisposed
What are the clinical signs of hypovitaminosis A in birds?
Hyperkeratosis of the skin is evident
white plaques in the oral mucosa
Rhinitis and blepharitis
Can contribute to bumblefoot
Overgrown beak and claws
Palor in Factor Canary
Susceptibility to Cnemidocoptidae
What causes Angel-Wing in waterfowl?
overfeeding due to a diet too high in protein and energy
a relative vitamin E deficiency
What can vitamin A deficiency do to lizards and chelonians?
impaction/swelling of temporal/femoral/precloacal pores glands, stomatitis, closed eyes
- squamous metaplasia of glands
What causes hypovitaminosis E in lizards and what problems can arise?
High-fat diets
secondary steatites
What causes hypovitaminosis A in turtles and terrapins?
all-meat diet
What causes “yellow ears/yellow fat” in chinchillas?
diet deficient in choline, methionine or Vitamin E
What causes cotton fur syndrome in chincillas?
high protein diet (crude protein >28%)
- weak textured hair
What are omega-3 fatty acids?
fatty acids that have the first double bond three carbon molecules away from the methyl group
What are omega-6 fatty acids?
fatty acids that have the first double bond six carbons from the methyl group
Which desaturase enzyme is deficient in atopic humans and dogs?
D-6-desaturase deficiency
Why are omega-3 fatty acids anti-inflammatory in the skin?
skin is deficient in desaturase enzymes
competes with arachidonic acid for cyclooxygenase and lipoxygenase enzymes
What are signs of hypovitaminosis A in young chelonians?
palpebral edema, aural abscesses, sometimes dyskeratosis
What are the clinical signs of hypovitaminosis C in chelonians and snakes?
stomatitis
What causes steatitis in snakes?
diet too high in fats (fish, obese rats) which leads to unsaturated fatty acid oxidation and a secondary vitamin E deficiency
