animal health - non infectious diseases

types of non infectious diseases

• metabolic

• nutritional

• neoplastic

• degenerative

• developmental

• genetic

• toxicities

acute conditions

• rapid onset

• short duration

chronic conditions

• slow onset

• long term

welfare implicates acute vs chronic

• pain + discomfort

• reduced productivity or performance

• long term quality of life issues

metabolic + nutritional disorders

• can be inherited or acquired

• often linked w higher requirements for energy and/or nutrients that are not met thru nutrition

• esp common during critical stages in life or high stress situations

• associated w too much of a specific nutrient - mins + vits

• affect energy production or damage tissues critical for survival

key examples

• hypocalcemia (milk fever)

• pregnancy toxaemia

• equine metabolic syndrome

• diabetes mellitus

common nutritional disorders

• calcium + phosphate imbalance

• copper deficiency

• vitamin A deficiency

• iodine deficiency

• obesity as malnutrition

acidosis

• microflora digest fibre successfully

• microflora starts to ‘choke’ - sub acute ruminal acidosis red milk fat

• microflora cannot digest fibre - acute acidosis - animal death

ketosis - acetonemia - twin lamb disease

storage diseases

• accumulation or storage of lysosomal enzyme substrates or byproducts within cells

storage diseases - happen why

• genetic - animals appear normal at birth, signs show win first few weeks of life, progress quick + end w death

• no known treatment

• acquired - linked w ingestion of plants containing inhibitors of specific lysosomal catabolic enzymes

obesity

• excessive accumulation of adipose tissue

• obesity - over 20% above ideal body weight

• most common in companion animals

• 50% dogs

• 43% cats

• 31% small mammals

• 9% birds

body condition scales

1. healthy

2. overweight

3. obese

4. very obese

1. very thin

2. thin

3. ideal

4. overweight

5. obese

causes + risk factors of obesity

• poor diet formulation - nutrient deficiencies or excesses

• rapid production demand - esp in production animals

• obesity + exercise

• life stage

management + prevention

• diet management

• body condition scoring

• monitoring + early intervention - esp during transition stages

• supplements (?)

adverse reaction to food

• clinically abnormal response to any food

food intolerance

• does not involve the immune system e.g. food poisoning

food allergy

• involves the immune system e.g. colitis or atopic dermatitis

intolerance vs allergy

• food allergies hard to differentiate from intolerance so need to do a food trial

• symptoms from GI tract should be tested for 2-4 weeks

• skin reactions should be tested over 8-12 weeks

neoplastic diseases

• neoplasia = new growth

• uncontrolled cell growth

• forms a tumour or mass

• can affect any tissue

• all cancers are tumours - not all tumours are cancerous

benign tumour

• slow growing

• dont spread

• often surgically curable

malignant tumour

• invasive growth

• can metastasise - spread

• often life limiting

cell activity in nonneoplastic tissue

• continuously dividing (labile tissues - e.g. surface epithelium)

• quiescent - stable - tissues e.g. parenchymal cells of liver

• nondividing - permanent tissue - e.g. neurons

normal tissue growth

• size of a cell pop is controlled by the relative rates of cell

• proliferation

• differentiation

• death - apoptosis

basic cell changes

• pre-neoplastic changes - usually reversible

hyperplasia

• inc cell number in a tissue

metaplasia

• transformation of one differentiated cell type into another

dysplasia

• abnormal pattern of tissue growth

tumour growth - mutation

• damage to the nuclear DNA which will be passed on to the next gen of cells

tumour growth - promotion

• factors promoting replication of mutated cells

• mutated cell number are small + can be eliminated by immune system

tumour growth

• irreversible tumour growth

latent period

• time before tumour becomes clinically detectable

• 1cm or 1g with 10 squared 9 cells

tumour characteristics

• unlimited proliferation

• much less differentiation than normal

• can be forced to differentiate into more mature near normal cells

• resistant to apoptotic cells

• genomic instability

common examples by species

• dogs: mast cell tumours, lymphoma, osteosarcoma

• cats: mammary tumours, squamous cell carcinoma, lymphoma

• horses: sarcoids, melanomas, squamous cell carcinoma

• livestock: ocular squamous cell carcinoma, papillomavirus - induced lesions

causes of neoplasia

• complex - often more than one event involved

• exposure to carcinogen (e.g. UV light, chems)

• environmental causes

• predisposing risk factors

some cases - known aetiological agent (e.g. feline leukaemia virus)- but most are unknown or partially understood

extrinsic causes

• physical agents

• tumour viruses

• chemical carcinogens

physical agents - neoplasia

• UV light

• ionising radiation

tumour viruses

• DNA viruses

• RNA viruses

chemical carcinogens

• aromatic hydrocarbons

• nitrosamines

• benzidines

• mycotoxins

intrinsic causes - neoplasia

• diet

• hormones

• genetic

• age

diet causes neoplasia

• indirect

• food components may act to initiate cell changes or modulate organ susceptibility

hormones causes neoplasia

• neoplasia can result from prolonged stimulation of a tissue - e.g. mammary gland, uterus, testes - rep status of animals makes a diff

genetic cause neoplasia

• genetic susceptibility + hereditary predisposition is recognised for certain types of tumour

age causes neoplasia

• most neoplasia occurs in older animals - with exceptions

other factors for causing neoplasia

• host dependent factors - species, breed, sex

• environ factors - climate, regional diet, toxins

• lifestyle - obesity, lack of activity

• management systems - stress

management, treatment + prevention of neoplasia

• surgery, chemo, palliative care

• welfare-based decision making

• early detection + monitoring

• preventative strats - neutering, UV protection

degenerative diseases

• progressive deterioration of function + structure of tissues + organs

• can affect any tissue + any animals - max common in pets

• most common in older animals

• usually start slowly w/ symptoms but progresses causing pain + discomfort

• can cause permanent disability + even death

arthritis

• degenerative joint disease

• can affect any breed at any age

symptoms of arthritis

• pain

• inflammation

• bone damage

• restricted mobility

• reluctancy to play, run, jump

treatment of arthritis

• medication

• laser

• weight control

• supplements

• stem cell therapy

arthritis risk factors

• breed - can be hereditary: cats: persian + siamese, dogs: german sheperd, golden retriever, great dane, lab, mastiff, rott, saint B

• obesity

• joint abnormalities - e.g. hip dysplasia

• stress or trauma to the joints e.g. prev accidents, rep motions

• infections

• immune disorders - lead to inflammation + degeneration

hip dysplasia

• ball of the hip joint is malformed + doesnt fit properly together w the socket

• earliest signs 4-8months can appear later in life

• symptoms sim to arthritis bunny hopping, lameness

• common in larger breeds

hip dysplasia treatment

• med

• surgery

• stem cells

developmental orders

• inherited disorders present at birth

• congenital - present or apparent at birth

• other defects that might appear later in life but are result of developmental defect

teratogens

• agents or factors that cause the development of physical defects in the embryo or foetus

• timing is important

inherited defects

• can be recessive or dominant

• het z might appear normal - need to be tested

• sometimes selected for:

• het z cattle - short tibia sometimes desired

• overo colour in horses lethal in homoz - hetz desired

• polled gene in goats is linked w masculinisation of females in homoz

nutritional factors in congenital + inherited anomalies

• deficiency of nutrients can result in congenital defects in the neonate

• iron deficiency - congenital goitre or cretinism

• copper deficiency - enzootic ataxia in lambs

• maganese deficiency - congenital limb deformities in calves

• vit D deficiency - neonatal rickets

• vit A deficiency - eye defects or cleft lip

• nutrient excesses can also be teratogenic

physical factors in congenital + inherited anomalies

• restricted space in uterus can lead to joint contracture

• transverse or caudal foetal presentation can result in spinal or limb abnormalities

• pervious urachus caused by twisting of umbilical cord

• atresia coli in calves due to rectal exam during preg

toxicities +poisoning

• natural or synthetic substances - gas, liquid, solid

• poisoning occur when large enough dose enters body - can be a minute amount but enough to cause damage, dont need to be ingested to cause harm

what is toxic + poisonous

• damage caused

• attacking blood cells, can cause internal bleeding

• limiting cellular func - processing protein

• attacking the CNA - affect brain + heart

• slowly shit down organs

chocolate toxicity

• mostly methylxanthines theobromine 3,7 dimethylxanthine

• also caffeine 1,3,7 trimethylxanthine

• causing potentially life threatening cardiac arrythmias and CNS dysfunction

signs of poisoning/ toxicity

• vomiting

• diarrhoea

• coughing + sneezing

• drooling

• lack of appetite

• drinking more than usual

• skin irritation, swelling, inflammation

• inc or unable to urinate

• pale gums

• lethargy

• abdominal pain

• inc heartbeat

• shaking + muscle treamors

• lack of coordination

• trouble breathing

• seizures
  extreme excitability or agitation