NUTRITION FOR BUSHFIRE-AFFECTED WILDLIFE
5.1 Nutrition
Replenishing depleted fluid, energy and nutrient reserves through appropriate caloric and fluid support early in the treatment phase will optimise patient recovery.
Commencing enteral feeding within 24-48 h post-burn injury is recommended (Vaughn et al. 2012). Severe burns cause the body to go into a hypermetabolic state. Losses of fluids and protein in burn patients are high. Failure to meet increased caloric demand can result in substantial muscle loss, impaired wound healing and immune compromise. Some patients may have been unable to eat or drink for several days before rescue due to their injuries or because of the lack of food or water in the fireground. Providing an appropriate diet is critical to the success of treatment and rehabilitation of wildlife. It is important that veterinarians consult with a wildlife hospital, experienced wildlife volunteer or rescue organisation if they are unfamiliar with what to feed a patient under treatment for burns. A range of general or species-specific products are available (e.g. Wombaroo (Glen Osmond, SA), Veta- farm (Wagga Wagga, NSW), Oxbow (Oxbow Animal Health, Omaha, NB, USA; distributed in Australia by Specialised Animal Nutrition, QLD), EmerAid (EmerAid LLC, Cornell, IL, USA; distributed in Australia by Veterinary Nutrition Solutions, NSW)). When feeding malnourished or starving wildlife, the risk of refeeding syndrome must be considered. Refeeding syndrome is a metabolic disturbance that occurs because of re-institution of nutrition to animals that are starved, severely malnourished or metabolically stressed due to severe injury or disease. Any patient with negligible food intake for >5 d is at risk of refeeding problems. When excessive nutritional supplementation is provided during the initial 4-7 d, it triggers the production of glycogen, fat and protein in cells, to the detriment of serum concentrations of potassium, magnesium and phosphorus. Cardiac, pulmonary and neurological signs may occur with refeeding syndrome. Low serum levels of minerals, if severe enough, can be fatal. Refeeding syndrome can be prevented by commencing refeeding at no more than 50% of energy requirements. The rate can then be increased if no refeeding problems are detected on clinical and biochemical monitoring and should be tailored to the needs of each patient. Feeding can then be increased to meet or exceed full needs over 4-7 d. Multivitamin and trace element supplementation is important (Mehanna et al. 2008).Some animals will not feed voluntarily during the initial phases of treatment and may need to be tube-, force- or assist-fed. Liquid diets must be made up fresh daily and refrigerated and warmed to near body temperature before feeding. Gavage (tubing) or force-feeding burned wildlife patients allows administration of constant calories and improves their care and survival. Great care must be taken when tube- or force-feeding any debilitated animal because aspiration and subsequent pneumonia are common. If tube- or force-feeding are required, the stress of doing this must be balanced against the potential benefits. In some cases, it is preferable to minimise handling and allow the animal to discover and develop a taste for the food items provided on its own. If a variety of food items appropriate for the species are provided, especially if fresh or alive (e.g. insects, freshly killed mice) it generally does not take long for the animal to start eating. The feeding of koalas is specialised and it is important they are treated and cared for by wildlife hospitals and wildlife volunteers with relevant experience (Blanshard and Bodley 2008; see Chapter 33). Normal gastrointestinal function in koalas relies on a steady intake of energy and fibre. Faecal output and consistency are important indicators of gastrointestinal function and should be monitored daily. Inappetent koalas can be syringe-fed with blended leaf formula or Koala Crittac- are (Vetafarm, Wagga Wagga, NSW).
All burnt wildlife must be provided with water. Oral rehydration solutions such as Spark Electrovet (Veta- farm), Lectade (Jurox Animal Health, Rutherford, NSW) or Vy-trate (Jurox Animal Health) can be used. All wildlife under treatment should be weighed frequently (at least every 3 d during initial treatment and then weekly). This provides a guide as to the effectiveness of supportive care and treatment.
5.2 Feeding free-ranging wildlife during or after bushfires
During and after a bushfire or other natural disaster that impacts wildlife, veterinarians may be asked for advice on feeding free-ranging wildlife that may not have ready access to water, food or shelter. The Wildlife Health Australia fact sheet, ‘Supplying water and food for free-living wildlife after natural disasters’ (https://wildlifehealthaus- tralia.com.au/FactSheets.aspx), provides useful information and additional resources.
Careful consideration must be given to the provision of supplementary feed to free-ranging wildlife and should ideally be carried out under the direction and supervision of the relevant jurisdiction’s wildlife agency. Food type and method of presentation must be appropriate to the species in the area. Risks include introduction of disease, gastrointestinal illness, aggression, predation, introduction and spread of weeds and displacement of species by more dominant or feral species (Albery et al. 2021; Webb et al. 2022; Legge et al. 2023; Sherwen et al. 2023).
ACKNOWLEDGEMENTS
I thank Drs Leanne Wicker, Michelle Campbell, David McLelland, Jenny McLelland, Megan Curnick, Kate Bodley, Chloe Steventon and Jasmine Hunter for their insights based on experience with the treatment and care of wildlife burn patients during and after the 2019-20 Black Summer fires in Australia.