Page 480 - The Veterinary Laboratory and Field Manual 3rd Edition

Common clinical problems 417

Table 10.9 Causes of weight loss and failure to gain weight.

Nutritional causes Comments
Inadequate food
Poor quality feed Diet low in energy or specific nutrients, in monogastric
species (pigs, poultry) protein may be the limiting factor
Imbalance of energy intake to energy May also see clinical signs of metabolic disease in some
output due to high production demands animals, i.e. hypoglycaemia
Malnutrition due to mineral, vitamin (B, D, Shortage of minerals such as magnesium or calcium can
E) and/or trace element (Fe, Mn, Co, Cu, K, cause serious metabolic disorders, other deficiencies
Se) deficiency (vitamin A, Cu, Zn) can result in chronic disease over a
period of time. Diagnosis is based on clinical history and
signs and supported by sampling
Inadequate food intake Check mouth for signs of trauma or lesions, check for any
obstructions in the throat, oesophagus or gut
Physiological factors Stress and cold weather will increase energy demand,
intake may decrease with ‘stress’, e.g. high stocking rates
Excessive loss of protein and carbohydrate
or faulty absorption
Loss of glucose in the urine Diabetes mellitus or renal disease
Metabolic disease, malabsorption Digestive upset or liver damage
Protein loss in the urine Renal disease
Protein loss in the faeces Helminths (Ostertagia sp., Nematodirus sp.
Paramphistomes) and protozoa
Increased protein and energy utilization Neoplastic disease
Internal and external parasites Malabsorption and competition
Chronic bacterial disease Tuberculosis (M. bovis), Johne’s disease
(M. paratuberculosis)
Systemic disease Fever and inappetence associated with infectious disease
may result in ill thrift
Inadequate utilization of nutrients Secondary to severe diarrhoea, hepatic disease and
metabolic disturbance

(in ruminants). Check the consistency of the fae- 10.6 Neurological signs
ces. If indicated, take smears from the ileocaecal
junction and intestinal mucosa for microbiologi- There are a number of causes of neurological
cal and parasitological examinations. Neoplasia disturbances, these can be the result of physi-
(tumorous growth) may be evident and may cal, physiological or pharmacological impacts
have an infectious cause in some species (for on the central or peripheral nervous system,
example, bovine leukosis). Examine the lymph for example, cystic lesions in the brain, toxic or
nodes of the abdominal viscera carefully. viral encephalitis, peripheral nerve damage. The
clinical signs observed depend on the location
of the lesions or the severity and nature of the

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