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154 Hand-Rearing Birds

Figure 9.2 Loons are prone to development of hock lesions when housed out of water for any reason.

aspergillosis on necropsy; no prophylactic medications were administered to these chicks. The
authors of this chapter give all loon chicks in captivity 10–12.5 mg/kg voriconazole orally twice
daily for the duration of their rehabilitation. Sporanox or Itrafungol may be acceptable alterna-
tives; however, the authors have not used these products. Compounded itraconazole from the
chemical powder should be avoided due to lack of bioavailability in cats (Mawby et al. 2018). Other
rehabilitators (Diane Winn, pers. comm.) do not give antifungal prophylactic medications to loon
chicks and anecdotally have not seen an increase in aspergillosis infections. It is unclear whether
the side effects of voriconazole outweigh the benefits of perceived aspergillosis prevention.

Lead­and Mercury­Toxicosis
Because of their high percentage fish diet and the propensity for accidentally picking up fishing
sinkers instead of stones for digestion, loons can develop methylmercury and lead toxicosis. Lead
toxicosis is a very common problem for loons and has been shown to decrease overall populations
(Grade et al. 2018). Lead toxicosis and fishing tackle ingestion are common in adults, but less so in
chicks. Nevertheless, an initial radiograph should be taken to look for metal opacities in the body
and a blood lead level evaluated for previous exposure, especially in any ill chicks without obvious
injury. Mercury toxicity is less likely in a loon chick than an adult. Loons are used as environmen-
tal indicators for exposure to methylmercury in aquatic systems (Depew et al. 2012).

Traumatic­Injuries

Traumatic injuries may result from entanglement in fishing line, an altercation with a boat, attack
from a nonparent adult loon, or, rarely, siblicide attempts. Injuries should be treated as other sea-
bird species, with particular care being taken to preserve waterproofing and prevent pressure sores.

­ Reuniting­with Parents

Reuniting a healthy chick with its parents is ideal, and the best chance of survival for the chick. It
is very difficult to “kidnap” a healthy chick and often there is underlying illness or trauma;
consequently, an obligatory medical work up should be conducted prior to considering family