lecture 10 - diseases 2 Flashcards
1 cause of death in domestic horses
colic
symptoms of colic
- abnormal behavior: pawing or kicking at abdomin
- abnormal posture: stretching for minutes at a time
- abnormal appearance: bloating or distention of abdomin
- abnormal body functions: constipation
- all shown even in minor cases
cause of colic - concentrate feeding
concentrate feeding
- large meals high starch reduce ingesta flow rates
- excess carbs reach colon for fermentation
- microbial population shift, lowering pH
- bacteria synthesize high amounts of lactic and propionic acid
- microbial shift causes inability to ferment fibre from hay
- consumption of hay causes blockage with non-fermented fibers
reduction of colic in performance horses
small meals and access to hay
cause of colic - hay quality
- lignin is not fermented
- can block ingesta through large intestine
- mature plants higher lignin content
- mold groth destroys other fibres, increase relative lignin concentration
cause of colic - parasites
parasites ex. strongyles - infect lining of cecum and colon - cause inflammation and changes in intestinal motility which lead to colic tapeworms (anoplocephala perfoliata) - attach to mucosa of ileum and cecum - large can block narrow illeum - reduce motility in colon
colic dietary prevention
- 2 large meals per day can exceed stomach capacity
- inability for horse to vomit can result in gastric blockage
- frequent small meals reduces risk of blockage
- pasture time and adequate hay reduces colic risk
- changes in feed introduced slowly allowing time for microflora to adjust
- exercise increase motility while minimizing gas
heaves
pulmonary edema
- loss of lung elasticity
- accumulation of air in lung tissue
heaves common cause
dust in lung tissue
- inhalation of dust from moldy feeds and dusty beding
heaves signs
coughing
difficulty breathing
nasal discharge
heaves treatment
turning horses out to pasture
- feeding of pellets and sprinkling hay in water shown to help
- includes fibre sources into pellets (beet pulp, citrus pulp) can also help
ulcer can be caused by
physical charateristics of feed
- too fine a grind of grain
problem with existance of ulcers
destroys epithelial tissues of esophagus stomach and intestines
- malabsorption and death
key contributor to ulcer development
- HCl constantly secreted, only grazing animals continuously eat
- Parasites
- fermentation in stomach causes VFAs, that trigger ulceration
hyperlipemia
excessive concentrations of lipid, mostly TIGs, in blood
- strong genetic component
- lipids in blood typically 100-500mg/ld
- disease 1700mg/dl
- seen when capacity to metabolize lipids is exceeded
- excess mobalization of adipose tissue during weight loss from reduced food intake
wood chewing characteristics and cause
condition were horses eat stalls, fences and gates - lack of roughage in diet causes - inadequate mineral nutrition - completely pelleted diet
wood chewing prevention
increasing fibre length of hang ground for inclusion in pellets decreases problem
equines cushing disease (ECD)
disease of the pituitary gland
- is a chronic progressive neuroendocrine disease
- mostly older horses
- insulin resistance and laminitis
- pituitary pars intermedia dysfunction - regulation by dopamine is lost
- polyuria and polydipsia from excess sweating
- hirsutism, long curly coat that doesnt shed in spring
cushing disease - loss of control of pituitary gland
by dopamine
- increase peptide hormone secretion
- hyperplasia of pars intermedia and adrenal cortex
- adrenal cortex increase corticosteroid production
- chronic excessive production of adrenocorticotropin stress hormone, increases blood cortisol
- high endorphins, relieves pain and biomarker for diagnosis
cushing disease - hormone change effect on health
high adrenocorticotropin, raises cortisol
- catabolic state typical of stress
- immunodeficiency
- catabolism of protein reserves (muscle)
- insulin resistance
elevated endorphin levels
- more docile
- pain tolerant
hirsutism
symptom of cushing disease
- long curely haired coat that fails to shed in the spring
cushing disease prevention
increase dietary fat will minimize complications due to insulin resistance
sufficient exercise prevents obesity and increases blood flow to minimize laminitis
Insulin resistance - risk factor for what diseases
laminitis
hyperlipedia
equine cushing’s disease
insulin resistance
normal metabolic response to circulating insulin is not seen in adipose tissue, liver and muscle
insulin resistance cause
consumption of high-glycemic sweet feeds which alter sensitivity
- resistance effected by fat/muscle ratio, physical activity and diet
- seen in obese, fasting and inactive horses
- breed differences
- impaired cell signalling - before, at, or distal to cell receptor
insulin resistance effects
hyperinsulinemia
hyperglycemia
glucose intollerance
hyperlipidemia
