by Toni Bunnell PhD
When presenting an ailing hedgehog for examination by a veterinarian it is advisable to, whenever possible, provide a faecal sample for scrutiny. This article presents a simple technique that allows assessment of aspects of hedgehog health from the overt appearance of the faeces. Analysis, using this technique, will allow more appropriate treatment to be administered in the majority of cases where overburdening by gastrointestinal parasites and/or pathogens is producing ill health. The technique has widespread applications in veterinary work, wildlife rehabilitation, and field zoology.
TONI BUNNELL began rehabilitating hedgehogs in 1990. Since then she has taken in an ever-increasing number of sick or injured animals, the number over the past three years (1998-2000) being 168. She takes most (90%) of the hedgehogs received by the York (England) RSPCA, releasing the survivors back to the wild with an 80% success rate. Bunnell received a BSc with honours in zoology from Cardiff University, South Wales; an MSc based on two years research into human gastrointestinal hormones from the Faculty of Medicine, University of Manchester; and a PhD from the Open University (Milton Keynes, England) on playful behaviour in the polecat (Mustela putorius) in relation to family group activity. She lectures full-time in biological sciences at the University of Hull, England.
It is widely known that faecal characteristics can provide broad information on the condition of the animal of origin (Sykes and Durrant 1995). The European hedgehog (Erinaceus europaeus) is host to a wide variety of gut pathogens and parasites (Stocker 1987, Boag et al. 1988, Majeed et al. 1989, Reeve 1994, Robinson et al. 1999), the overburdening with which can significantly alter the fitness of the animal and also its suitability for release from wildlife rehabilitation centre.
As part of a hedgehog rehabilitation programme based in York, England, and run solely by the author, routine screening of faeces has been undertaken of displaced hedgehogs presented by the public. "Displaced", in this instance, refers to any animal found in an exposed position in daylight hours, such behaviour often bringing it to the attention of the public. It should be noted that hedgehogs are nocturnal animals that remain hidden in nests during daylight hours. They tend only to be visible during the daytime when they are unable to retreat to their nest due to illness or injury. Hyperactive behaviour, caused by a heavy parasite burden, also means that they tend to wander about during the daytime, forgoing their normal nocturnal habit.
Data obtained from 168 hedgehogs suggests that overburdening by helminths, nematodes, flukes, protozoans, and specific bacteria produces characteristic changes in the gross morphology and texture of the faeces. This can be of value in determining the suitability of particular regimens for the animals concerned. It is of particular value in the case of the hedgehog, which normally presents for examination as a ball of impenetrable spines.
Displaced animals were presented at the York Animal Home, a branch of the Royal Society for the Prevention of Cruelty to Animals (RSPCA), by members of the public, between April 1998 and December 2000 and were subsequently taken to a sanctuary run by the author. The hedgehogs were either immobile due to injury or hypothermia, or found roaming about restlessly. Hedgehogs found foraging during the day tend, in the author's experience, to have a high gastrointestinal parasite load.
Routine screening of faecal samples was undertaken. Fresh faeces were placed in suspension in distilled water, and the preparations examined using a light microscope (Gardner 1996). (A simple faecal smear obtained from a suspension is commonly used for hedgehogs and was recommended by the veterinarian consulted with regard to this study.) Slides were examined qualitatively and the presence of gut parasites recorded. The author assessed for adults, larvae, and eggs, all of which are generally detected using this method, with the exception of Crenosoma striatum adults, which are only seen in samples after a hedgehog has been treated with a wormer (Sykes and Durrant 1995). Parasite species were identified from photographs and descriptions supplied by Sykes and Durrant (1995), and with the assistance of the Minster Veterinary practice in York. During 1998 the faeces of most animals arriving at the sanctuary were examined and monitored over a sequence of days, and any subsequent change indicating a response to treatment were recorded. A reduction in number of gut parasites was taken to indicate a positive response to a particular treatment.
The usual appearance of hedgehog faeces is shown by Sykes and Durrant (1995) and Reeve (1994). Characteristically hedgehogs with severe helminth, nematode, fluke, or protozoan burden, or greater than normal bacterial numbers, produce faeces that differ markedly from the norm (Table 1) and Sykes and Durrant (1995). Most hedgehogs carry a parasite load that is asymptomatic in a healthy animal. To determine whether the parasite load for displaced hedgehogs was "higher than normal," comparisons were made between parasite (adults/larvae/eggs) numbers present in healthy animals with normal droppings and that demonstrated consistent weight gain, and those of ailing animals with abnormal droppings that showed either poor weight gain or a loss in weight. In addition, reference was made to the data on the "normal" parasite load for wild hedgehogs summarized in Reeves (1994).
Most of the hedgehogs in the present study responded well to propriety brand antihelminthics and antiprotozoan drugs (Table 2). Reduction of parasite burden is thus readily achieved and results in immediate weight gain, which hastens the release of the animals to the wild state (Bunnell, unpubl.).
In the majority of displaced hedgehogs presented at wildlife sanctuaries, the nematodes Crenosoma striatum, Capillaria erinacei, and Capillaria areophila tend to be present (Reeve et al. 1999), the former two being the most prevalent (Boag et al.1988). Infestation with these nematodes is age-related, with very few juveniles and even fewer nestlings showing signs of harbouring Crenosoma spp. or Capillaria spp. (Majeed et al. 1989). The findings of Majeed et al. (1989) also suggest that hedgehogs acquire Crenosoma spp. infestation more rapidly than they do Capillaria spp. They noted that this was an unexpected finding, since Crenosoma spp. is believed to require an intermediate host, while Capillaria spp. can he obtained by direct transmission.
In animals with digestive problems of any kind and/or appetite loss, it is essential to maintain fluid balance. This can he done by administration of Lectade, an oral rehydration electrolyte preparation for dogs and cats. The mixture must he prepared according to the manufacturer's specifications and then diluted 1 in 10 in warm water. The further dilution is necessary for hedgehogs, as the original dilution is too concentrated and will precipitate further dehydration of the animal (Sykes and Durrant 1995).
Following a period of appetite loss/digestive disturbance, an animal can be encouraged to cat again by oral administration of Esbilacā, a milk substitute for puppies. Esbilacā, is easily digestible and prevents further weight loss while the animal is recovering its appetite. As always, care must be taken to hold the animal in as upright a position as possible while giving fluids orally. Oral administration of fluids involved releasing one drop of fluid at a time into the mouth, using a 1 mi syringe. This helps to prevent fluid from entering the airway and either choking the animal or precipitating inhalation pneumonia.
Following treatment of parasite/pathogen infestation with propriety brand drugs, successfully rehabilitated animals were released to the wild. Studies carried out by Morris et al. (1 993) and Morris and Warwick (1994) concluded that rehabilitated adult hedgehogs probably cope well with release.
In all of the 168 hedgehogs observed (with the exception of orphaned babies brought immediately to the sanctuary after being found displaced from their nest), the following examples of gastrointestinal parasites and pathogens were recorded:
The widespread prevalence of the parasites/pathogens listed in Table 1 indicates the importance of dealing with any infestation and/or infection affecting the alimentary canal of hedgehogs as soon as possible. Even in circumstances when such organisms are not the main reason for the animal being found out during daylight hours, an immediate reduction in numbers of nematodes and other parasites/pathogens will enable the hedgehog to use its resources to combat the presenting ailment or injury.
It is obviously vital to provide any displaced hedgehog with the best chances of recovery. Early recognition of overburdening and subsequent treatment of intestinal parasites/ pathogens will hasten this process.
Many displaced hedgehogs presented to veterinarians are assessed and treated immediately upon arrival at wildlife rehabilitation centres and, in the United Kingdom, RSPCA animal homes. It is suggested that any faeces produced by the animal be made available to the veterinarian to enable a more thorough assessment to be made. The technique described in this article is both time- and cost-effective, is reliable, can markedly improve the chance of hedgehog survival.
1 would like to thank Keith Warner, MRCVS (Veterinarian, Minster Veterinary Practice, York), and Dr Huw Griffiths (Department of Geography, University of Hull, England) for invaluable help and discussion.
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Copyright © Toni Bunnell 1998-2010