Veterinary Internal Medicine - General Systemic States

Veterinary Internal Medicine - General Systemic States

• Chapter 1: General Systemic States, covering disturbances of appetite, food intake, and nutritional status.
• Instructor: Prof. Hosam Ibrahim, Dr. Mahmoud Abdelnaeem (BVSc, MVSc, PhD).
• Level: 4 Students, General Program.

Disturbances of Appetite

• Hunger: A purely local sensation arising from gastric hypermotility, often due to lack of distension by food.
• Appetite: A conditioned reflex depending on past experiences with palatable food, expressing the degree of hunger. Measured by feed intake.
• Increased Appetite (Hyperorexia): Usually a result of increased hunger contractions, manifested by increased food intake (polyphagia).
• Partial Loss of Appetite (Inappetance): Manifested by varying degrees of reduced food intake, ranging from anorexia to aphagia.
• Complete Loss of Appetite (Anorexia): Complete lack of appetite for food.
• Abnormal Appetite (Pica/Allotriophagia): The animal engulfs strange substances instead of normal food. This can be a symptom of various conditions.
• Polyphagia (Hyperorexia): The desire to overeat, often associated with specific diseases.

Causes of Appetite Disturbances

• Starvation: A common cause of appetite and nutritional disturbances.
• Functional Diarrhea: Associated with appetite changes.
• Pancreatic Insufficiency: In pet animals, this condition can cause appetite issues.
• Metabolic Diseases: Examples include diabetes mellitus (in pets) and hyperthyroidism.
• Internal Parasitism: Gastrointestinal parasites are a significant cause affecting appetite.

Anorexia (Aphagia) Causes

• Physical Factors: Mouth or pharynx pain (stomatitis, pharyngitis)..
• Lack of Desire to Eat: Appetite loss, including related conditions.
• Hyperthermia/Toxemia/Fever: These factors decrease hunger contractions.
• Nutrient Deficiencies: Like zinc, cobalt, and thiamine insufficiency.
• Alimentary Tract Stasis: Severe pain, excitement, and fear.
• Anxiety: Stress responses and other emotional factors.
• Excitement of Estrus: Hormonal influence affecting appetite.
• New Surroundings Stress and environment.
• Loss of Newborn: Stress and environment
• Bad Weather: Stress and environment.
• Tick or Other Insect Worry: Stress and environment.

Pica (Allotriophagia)

• Causes: Salt deficiency (e.g., cobalt and phosphorus), chronic abdominal pain (peritonitis or gastritis), central nervous system (CNS) disturbances (e.g., rabies, ketosis).
• Forms of Pica: Osteophagia (Chewing Bones), Coprophagia (Eating Feces), Infantophagia (eating of young fetus).

Complications of Appetite Disturbances

• Allotriophagia: Can lead to serious health problems like obstruction, perforation, death due to cannibalism, poisoning (e.g., lead poisoning, botulism).

Starvation and Inanition (Malnutrition)

• Starvation: Prolonged deprivation of food leading to rapid depletion of glycogen stores, fat, and protein; ketosis, acidosis.
• Inanition: Incomplete starvation, where insufficient amounts of essential nutrients are offered to the animal. This is more common than complete starvation clinically.

Weight Loss (Ill-Thrift)

• Causes: Nutritional deficiencies (energy, essential minerals), excessive protein and carbohydrate loss, chronic conditions.
• Protein Loss in Digestion: Include conditions like ulcerative lesions in the gastrointestinal tract, exudation through intestinal mucosa, lymphatic disorders, bleeding in the intestines due to neoplasms.
• Protein Loss in Urine: Conditions such as chronic renal disease, diabetes mellitus cause glucosuria, leading to weight loss.

Assessing Weight Loss

• Diagnosis: Identifying the cause of weight loss involves assessing total food intake, clinicopathological tests, and digestion absorption tests.

Shortfalls in Performance (Animals)

• Assessment: Comparing performance to peers, considering similar environmental and management conditions.
• Causes: Factors like nutrition, inherited traits, environmental factors, and general management.
• Examples of Causes: Inadequate energy, protein, etc., genetic background, shelter, and housing issues, population density impacting resource availability. Disease wastages (both clinical and subclinical) such as mastitis, metabolic profiles, fecal egg counts.