SAD Ch 17 Nutrition and Skin Disease Flashcards
SAD Ch 17 Nutrition and Skin Disease
What is the study of nutrigenetics?
Focuses on how genes and genetic differences (SNPs, copy-number polymorphisms, and epigenetic phenomena) affect responses to nutrients and nutritional requirements.
What is the study of nutrigenomics?
How nutrients influence gene transcription and protein metabolism to affect animal’s overall health and susceptibility to disease.
What percentage of hair is made of protein?
95%
What is the function of Vitamin A in health of dogs and cats?
- Epidermal hyperkeratosis and scaling
- Occlusion of sebaceous ducts
- Papules associated with follicular hyperkeratosis
- Poor hair coat and alopecia
- Reproductive failure
- Retinal degeneration and night blindness
- Susceptibility to infections
What are the signs of vitamin A deficiency?
- Epidermal hyperkeratosis and scaling
- Occlusion of sebaceous ducts
- Papules associated with follicular hyperkeratosis
- Poor hair coat and alopecia
- Reproductive failure
- Retinal degeneration and night blindness
- Susceptibility to infections
What are the signs of vitamin A toxicity?
- Epidermal scaling
- Unkempt hair coat
- Anorexia
- Weight loss
- Bone decalcification
- Liver damage
What are the functions of vitamin D in health of dogs and cats?
- Normal calcium absorption and metabolism
- Normal bone development
- Keratinocyte proliferation and differentiation
What are the signs of vitamin D deficiency?
- Rickets in young
- Osteomalacia in adults
- Chest deformity
- Poor eruption of teeth
What are the signs of vitamin D toxicity?
- Increased blood calcium levels
- Soft tissue calcification
- Diarrhea
- Kidney failure
- Death!
What are the functions of vitamin E in the health of dogs and cats?
- Antioxidant (protects against oxidative damage)
- Normal immune functioning
What are the signs of vitamin E deficiency?
- Pansteatitis - in cats fed diet high in polyunsaturated fat
- Seborrhea
- Muscular dystrophy
- Reproductive failure
- Intestinal lipofuscinosis
- Impaired immunity - bacterial dermatitis and demodicosis (dogs)
What are the signs of vitamin E toxicity?
Anorexia
What are the functions of vitamin K in health of dogs and cats?
- Formation of clotting factors and normal clotting
What are the signs of vitamin K deficiency?
- Hemorrhage
- Increased bleeding times
What are the signs of vitamin K toxicity?
- None reported
What are the functions of vitamin C in the health of dogs and cats?
- Antioxidant
- Formation and maintenance of matrix of bone, cartilage, and CT
What are the signs of vitamin C deficiency?
- Rikets
- Impaired wound healing
- Bleeding
- Anemia
- Increased susceptibility to infections
What are the signs of vitamin C toxicity?
None reported. Dogs and cats synthesize adequate vitamin C levels and do not require it in their diet.
What are the functions of Thiamine (B1) in the health of dogs and cats?
- Component of two coenzymes essential in carbohydrate metabolism and energy transfer
- Promotes normal health and digestion and normal nerve function
What are the signs of thiamine (B1) deficiency?
- Anorexia
- Weight loss
- Vomiting
- Dehydration
- Ventral flexion of neck
- Paralysis
- Incoordination
What are the signs of thiamine (B1) toxicity?
Nontoxic
What are the functions of riboflavin (B2) in the health of dogs and cats?
- Forms parts of two coenzymes with roles in energy transfer and protein metabolism
- Component of xanthine oxidase required for epithelial cell maturation
What are the signs of riboflavin (B2) deficiency?
- Retarded growth, posterior muscle weakness
- Dry scaly skin, erythema
- Anemia
- Ocular lesions (pannus)
- Glossitis
- Reduced fertility, testicular hypoplasia
- Fatty liver
What are the signs of riboflavin (B2) toxicity?
Nontoxic
What are the functions of niacin in the health of dogs and cats?
- Component of two coenzymes with roles in energy transfer
- Required for metabolism
What are the signs of niacin deficiency?
- Blacktongue (pellagra)
- Pruritic dermatitis
- Diarrhea
- Dementia
- Anorexia
- Anemia
- Emaciation
- Death!
What are the signs of niacin toxicity?
- Cutaneous flushing
- Itching
What are the functions of pyridoxine (B6) in the health of dogs and cats?
- Part of enzyme involved in protein metabolism
- Essential for normal metabolism of tryptophan
What are the 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 are the signs of pyridoxine (B6) toxicity?
Nontoxic
What are the functions of pantothenic acid in the health of dogs and cats?
- Constituent of coenzyme A required for normal metabolism of carbohydrates, fats, and proteins
What are the signs of pantothenic acid deficiency?
- Anorexia
- Stunted growth
- Hypoglycemia
- Uremia
- Gastroenteritis
- Seizures
- Fatty liver
- Coma, death!
What are the signs of pantothenic acid toxicity?
Nontoxic
What are the functions of folic acid in the health of dogs and cats?
- Normal RBC development and DNA synthesis
What are the signs of folic acid deficiency?
- Anemia
- Leukopenia
- Stunted growth
- Glossitis
What are the signs of folic acid toxicity?
Nontoxic
What are the functions of biotin in the health of dogs and cats?
- Required for metabolism of fats and amino acids
- Essential for skin and hair health
- Functions in enzyme systems
What are the signs of biotin deficiency?
- Scaly dermatitis
- Alopecia
- Anorexia and weakness
- Diarrhea
- Progressive spasticity
- Posterior paralysis
What are the signs of biotin toxicity?
Nontoxic
What are the functions of cobalamin (B12) in the health of dogs and cats?
- Synthesis of nucleic acids
- Involved in purine synthesis and carbohydrate and fat metabolism
What are the signs of cobalamin (B12) deficiency?
- Anemia
- Impaired growth
- Posterior coordination
What are the signs of cobalamin (B12) toxicity?
Nontoxic
What are some signs of protein deficiency?
- Hyperkeratosis
- Epidermal hyperpigmentation
- Loss of hair pigment
- Patchy alopecia with thin, rough, dry, dull, and brittle hairs
- Wound dehiscence
In which syndrome is epidermal degeneration seen in conjunction with hypoaminoacidemia?
Superficial necrolytic dermatitis (necrolytic migratory erythema, metabolic epidermal necrosis, hepatocutaneous syndrome).
In patients with superficial necrolytic dermatitis, how do their serum amino acid levels compare to normal patients?
About a third of normal patients.
Which amino acids are most affected in dogs with superficial necrolytic dermatitis?
Arginine, leucine, lysine, methionine, proline, threonine, and valine.
Name three aromatic amino acids.
Phenylalanine, tryptophan, tyrosine.
What are the essential polyunsaturated fatty acids for dogs? Cats?
Linoleic acid and α-linoleic acid. Cats also require arachidonic acid.
How are fatty acids classified?
- Size (number of carbon atoms)
- Number of double bonds
Where are the double bonds located in omega-3 and omega-6 fatty acids?
Omega-3s have double bond at 3-carbon position from carboxyl end, Omega-6 has double bone at 6-carbon position from carboxyl end.
n-3 and n6 fatty acids are essential components of which cell structure?
Plasma membrane. Maintains integrity, fluidity, and permeability.
Which essential fatty acid is an important component of epidermal ceramides and involved in maintaining the epidermal water permeability barrier?
Linoleic acid
In cats, which enzyme is low, precluding them from synthesizing enough arachidonic acid to meet their physiologic requirement?
Δ-6 desaturase
What are the functions of calcium in the health of dogs and cats?
- Bone and tooth formation
- Blood clotting
- Enzyme activation
- Muscle contraction
- Nerve impulse transmission
What are the signs of calcium deficiency?
- Rickets in young, osteomalacia in adults
- Lameness, stiffness
- Constipation, anorexia
- Loss of teeth
- Tetany with acute deficiency
What are the signs of calcium toxicity?
- Impaired skeletal development
- Secondary deficiencies of other minerals (zinc, phosphorus, copper d/t interference with absorption)
- Bloat
What are the functions of phosphorus in the health of dogs and cats?
- Bone and tooth formation
- Enzyme systems
- Energy transfer (component of high-energy bonds)
- Part of RNA and DNA
What are the signs of phosphorus deficiency?
- Rough hair coat
- Pica
- Anorexia
- Slow growth
- Rickets in young, osteomalacia in adults
What are the signs of phosphorus toxicity?
- Impaired skeletal development
- Secondary deficiency of calcium
- Kidney damage
What are the functions of sodium in the health of dogs and cats?
- Muscle contraction
- Maintenance of body fluid volumes
- Component of bile, muscle, and nerve function
What are the signs of sodium deficiency?
Salt hunger, pica, weight loss, fatigue, impaired milk secretion, polyuria, circulatory failure.
What are the signs of sodium toxicity?
Thirst, pruritus, constipation, anorexia, seizures, hypertension
What are the signs of sodium toxicity?
Thirst, pruritus, constipation, anorexia, seizures, hypertension (all unlikely if water is freely available).
What are the function of magnesium in the health of dogs and cats?
- Enzyme activator
- Constituent of skeletal tissue, required for muscle and nerve function
- Role in energy metabolism and protein synthesis
What are the signs of magnesium deficiency?
- Calcification of soft tissues
- Retarded growth
- Spreading of toes
- Hyperirritability
- Seizures
- Excess salivation
What are the signs of magnesium toxicity?
- Acute excesses may cause diarrhea
- Chronic excesses may cause urolithiasis, cystitis, and urinary tract disease in cats
What are the functions of zinc in the health of dogs and cats?
- Essential component of many enzyme systems, including protein and carbohydrate metabolism
- Required for maturation of skin cells and healthy hair coat
- Required for normal immune function
What are the signs of zinc deficiency?
- Impaired growth
- Scaly skin with parakeratosis
- Depigmentation of hair
- Infertility, testicular hypoplasia
- Impaired wound healing
- Increase susceptibility to infections
What are the signs of zinc toxicity?
- Interference with absorption of calcium and/or copper
- Acute toxicity causes hemolytic anemia
What are the functions of copper in the health of dogs and cats?
- Roles in erythropoiesis, coenzymes, hair pigmentation, reproduction, collagen and elastin synthesis, iron utilization.
What are the signs of copper deficiency?
- Pica
- Stunted growth
- Diarrhea
- Dipigmentation of hair
- Anemia
- Impaired bone growth
What are the signs of copper toxicity?
- Inherited disorder of metabolism in some breeds leads to liver damage
What are the functions of manganese in health of dogs and cats?
- Carbohydrate and lipid metabolism
- Formation of cartilage
What are the signs of manganese deficiency?
- Infertility
- Enlarged stiff joints
- Short brittle bones
What are the signs of manganese toxicity?
- Infertility
- Partial albinism (rare)
What are the functions of iodine in the health of dogs and cats?
- Thyroid hormone synthesis (involved in regulation of metabolism)
What are the signs of iodine deficiency?
- Hypothyroidism
- Goiter
- Alopecia
- Infertility
- Lethargy
- Myxedema
What are the signs of iodine toxicity?
- Decreased thyroid function and signs similar to deficiency
Which species is unable to synthesize vitamin A and require a dietary source?
Cats. They cannot synthesize it from its precursor, β-carotene
Cats occasionally develop hypervitaminosis A if being fed large amounts of this.
Liver
Which vitamin is being investigated in the topical or systemic treatment of psoriasis?
1,25-dihydroxy vitamin D3
Selenium, together with which vitamin, function to scavenge free radicals produced during metabolism of what?
Vitamin E, lipid metabolism.
Cats fed diets high in red tuna or other PUFA-rich foods without receiving Vit E supplements may develop what?
Pansteatitis
Biopsies of cats with pansteatitis demonstrate presence of lobular panniculitis with ______ within lipocytes, macrophages, and giant cells.
Ceroid - product of lipid peroxidation.
What is the treatment for pansteatitis?
Vitamin E supplementation at 13.5 IU/kg/day. In severe cases, systemic corticosteroids may be used to decrease inflammation and pain.
What is the prognosis for pansteatitis?
Poor.
Vitamin E has synergistic effects with which other vitamin?
Vitamin A
Supraphysiologic doses of Vitamin E have been used to treat which diseases?
- Dystrophic epidermolysis bullosa
- Discoid lupus erythematosis
- Granuloma annulare
- Benign familial pemphigus
- DLE, dermatomyositis, and acanthosis nigricans may respond to treatment
- Adjuvant to treatment of canine demodicosis
What are some functions of zinc in the body?
- Component of metalloenzymes involved in regulating metabolism
- Cofactor for RNA and DNA polymerases
- Important in rapidly dividing cells (epidermis)
- Biosynthesis of fatty acids
- Vitamin A metabolism
- Immune function and inflammatory reactions
What are some clinical signs of zinc deficiency?
- Depressed appetite d/t decreased sense of taste and smell
- Weight loss, impaired wound healing, conjunctivitis, and keratitis
- Focal areas of erythema, alopecia, crust, and scale, appearing first at areas of friction (MC junctions, distal extremities, and footpads)
- Secondary infections, lymphadenopathy
Bull terriers with this disease have a genetic defect that inhibits zinc absorption and utilization.
Lethal acrodermatitis
What type of zinc dermatosis occurs in Alaskan malamutes and Siberian huskies?
Syndrome I zinc-responsive dermatosis. May also affect Bull terriers.
During what time of year are patients with syndrome 1 zinc-responsive dermatosis most affected?
September through January
What are the clinical signs of Syndrome I zinc-responsive dermatosis?
- Lesional pruritus
- Early erythema followed by alopecia, crusting, scaling and underlying suppuration near mouth, chin, eyes, & ears
- Scrotum, prepuce, or vulva may be affected
- Thick crusts at elbows and other pressure points
- Secondary infections common
- Hyperkeratotic footpads and onychomalacia
What is the term for decreased sense of smell? Taste?
Hyposmia - decreased smell
Hypogeusia - decreased taste
What is the treatment of syndrome I zinc-responsive dermatosis?
- Correction of diet if needed
- 2-3mg/kg/day elemental zinc
- Zinc sulfate 10mg/kg/day (zinc comprises 23% of weight in zinc sulfate)
How should zinc sulfate tablets be administered?
Crushed and mixed with food to enhance absorption and decrease gastric irritation.
What are two alternatives to zinc sulfate for use in supplementation? Why would you use these?
Zinc methionine and zinc gluconate. Have higher bioavailability of zinc and less likely to cause gastric irritation.
Which breeds are less likely to respond to oral zinc supplementation?
Siberian huskies, Pharaoh hounds.
For patients that do not respond to oral zinc supplementation, what treatment is recommended?
IV zinc sulfate (10-15mg/kg) weekly for 4 weeks, then maintenance every 1-6 months to prevent relapse.
What are the drawbacks to IV zinc sulfate administration?
- Expensive
- Cardiac arrhythmias may occur if administered too quickly
- No one wants to give a loud, annoying husky a slowly administered IV medication in the clinic once a week.
What can be added to the diet to potentially enhance the bioavailability of zinc?
Phytase, by hydrolyzing phytates present in food.
T/F Corticosteroids can be used in syndrome I zinc-responsive dermatosis.
True. Low-dose steroids can benefit patients not responding to zinc alone.
How do steroids help patients with syndrome I zinc-responsive dermatosis?
Increase zinc absorption from the GI tract by induction of metallothionein and may have some direct effect on skin.
What surgical procedure may help certain patients with syndrome I zinc-responsive dermatosis.
OVH may help affected female dogs.
In what population is syndrome II zinc-responsive dermatosis seen?
Rapidly growing puppies or young adult dogs fed zinc-deficient diets, diets high in phytates or minerals (ex calcium or iron which interfere with zinc absorption) or diets over supplemented with other minerals and vitamins.
What are some clinical signs associated with syndrome II zinc-responsive dermatoses?
- Vary widely
- Hyperkeratotic plaques in areas of repeated trauma, leading to deep fissures
- Footpads and nasal planum affected
- Secondary skin infections and lymphadenopathy
- May appear similar to distemper
How is syndrome II zinc-responsive dermatosis diagnosed?
- Hx and PE
- Biopsy - hyperplastic superficial perivascular dermatitis with marked diffuse and follicular parakeratotic hyperkeratosis. Papillomatosis and mild diffuse spongiosis. Evidence of secondary bacterial or Malassezia infection
How is syndrome II zinc-responsive dermatosis treated?
- Fix the diet
- Treat secondary infection
- Hydrate crusts with wet dressings or whole-body warm water soaks for 5-10 min.
- Bathing with antiseborrheic shampoo.
- Topical petrolatum or ointment-based topical on facial lesions.
How quickly can skin lesions resolve after initiating treatment for syndrome II zinc-responsive dermatosis?
2-6 weeks
What are some functions of probiotics?
- Promote beneficial intestinal microbiota
- Improve gut barrier function
- Avert abnormal immune responsiveness and inflammatory diseases in the GI tract
What species are included in probiotics?
Lactobacillus, Bifidobacterium, and Enterococcus
A genetically modified Lactococcus lactis has been engineered to produce which cytokine?
IL-10, a cytokine that promotes immunologic tolerance.
What is the function of Lactobacillus paracasei in probiotics?
- Reduces T H 1 and T H 2 secretion of inflammatory cytokines
- Increases production of anti-inflammatory cytokines TGF-β and IL-10
What is the function of Lactobacillus casei in probiotics?
Suppresses allergic responses in murine model of food allergies
What is the function of Lactobacillus GG in probiotics?
Administering to mothers of high-risk infants during pregnancy and lactation results in significant reduction in prevalence of atopic eczema in children.
What effect does Lactobacillus rhamnosus have on puppies?
Administering to a severely atopic bitch starting at the third week of gestation, continuing during lactation, and administering to puppies through 6 months old resulted in significantly lower titers of allergen-specific IgE and milder reactions to intradermal testing compared to full siblings from litter that did not receive probiotics.
