CLINICAL SIGNS

Clinical signs of cryptococcosis are reflective of the tissue involved and taxonomic group. In all species, clinical signs reflecting respiratory tract and neurological disease are most important (Table 25.3).

Fig. 25.2. Koala (Phascolarctos cinereus) with extensive nasal cryptococcosis. Note the marked swelling over the nasal plane and epistaxis. The koala was successfully treated with a combination therapy of amphotericin B and fluconazole and then fluconazole as monotherapy over a 2-yr period. The animal died of unrelated disease 10 yr later.

Fig. 25.3. Lateral radiograph of the skull of a free-ranging male koala (Phascolarctos cinereus). Note the mass and osteolysis of the frontal bone from nasal cryptococcosis. The animal was in poor body condition at presentation and subsequently euthanased. Image: Meaghan Barrow

Fig. 25.4. Necropsy images of a koala (Phascolarctos cinereus) with a nasopharyngeal cryptococcoma (arrow). The mandibles have been removed and the soft palate incised. The mass caused significant stertor and aerophagia in this case. Cryptococcal mass lesions, in all host species, often have a gelatinous consistency.

dilatation. Involvement of the lower respiratory tract, including trachea, lungs or pleural space, is usually clini­cally silent, but has the potential to lead to dissemination to the CNS, which can result in signs reflecting menin­goencephalitis, including seizures, vestibular signs and cranial nerve dysfunction. As well, and indeed initially, most animals (koalas and other Australian mammals) with clinical cryptococcosis appear to be systemically unwell, with changes in behaviour, reduction in appetite and loss of body condition and weight. Unexpected death may be the only presenting sign in some cases. A wide range of other non-specific clinical signs may be seen in species other than koalas, but loss of body condition and weight and sudden death are the most common.

5.