VN May 2023

Vetnuus | May 2023 34  If the patient is not eating but not vomiting or moribund, crop gavage with hand-rearing formula or other appropriate foods can be instituted.  Oesophagostomy feeding tubes, placed into the proventriculus, can be used to bypass the patient’s head and in cases such as head trauma where eating or passing a crop tube is not feasible.  Duodenal catheters have been used with a degree of success by some clinicians. This is a reasonably complex surgical procedure.  Total Parenteral Nutrition via an intravenous catheter is not routinely practised in avian medicine at this time. Respiratory Compromise Clinical signs  Open mouth breathing  Increased respiratory effort, seen as tail bobbing and inspiratory sternal lift  Audible respiratory noise  Collapse Treatment  If the dyspnoea is of an acute nature the clinician must consider the possibility of tracheal obstruction. If this is the case an air sac catheter placed in the left caudal thoracic air sac can be life-saving  Oxygen therapy supplied either through a face mask or in an oxygen chamber can help patients with respiratory compromise. Clinicians must be aware that prolonged exposure to 100% oxygen can cause perivascular oedema and increase the degree of respiratory compromise. Analgesia Clinical signs Birds, unlike domestic mammals, indicate pain less clearly than many clinicians are accustomed to. They will respond to painful stimuli in one of two ways:  ‘fight-or-flight’ responses o excessive vocalisation o wing-flapping o decreased head movement  conservation-withdrawal responses o immobility o closure of eyes o inappetence o fluffing of feathers The ‘fight-or-flight’ response is thought to be more common with acute pain from which the bird attempts to escape. In contrast, with chronic or overwhelming pain – perhaps from which the bird feels it cannot escape - the bird may adopt the ‘conservation-withdrawal’ responses, perhaps to minimise further pain that struggling would induce. Care must therefore be taken not to misinterpret lack of movement or vocalisation as an indication that the bird is not in pain. Therefore, it is wise to assume that what would be painful to another species would be painful to humans, and adequate analgesia should therefore be provided. Treatment  Butorphanol appears to be more effective in many birds than buprenorphine. Dose: 1-4 mg/kg q6hrly IM, PO  Meloxicam 0.2 -0.5 mg/kg q12hrly IM, PO  Carprofen 2-4 mg/kg q24hrly IM, PO  Combining an opioid (e.g. butorphanol) and an NSAID (e.g. meloxicam) may achieve better analgesia than either alone. Blood Loss Birds can withstand comparatively greater blood loss than mammals. This is thought to be the result of:  an increased capillary surface area within the skeletal muscle for rapid extravascular fluid resorption tomaintain vascular volume  the ability to mobilise large numbers of immature erythrocytes; and  the absence of the autonomic response to haemorrhage that contributes to haemorrhagic shock. Clinical signs  history or physical evidence of recent blood loss  the pallor of mucus membranes  increased respiratory rate and effort  weakness, lethargy  PCV < 20% Treatment  Many cases of blood loss do not require a transfusion. In mild cases, or when a blood donor is unavailable, intravenous or intra-osseous colloids or crystalloids, alone or in combination, may be sufficient. When given together, crystalloids are administered at 30 – 40mls/kg doses while the colloid is administered at 5mls/kg. With the bird’s ability to mobilise immature erythrocytes, it is not uncommon for the PCV to return to normal within seven days with this therapy alone. Technical I Article