Abstract

A two-and-a-half-year-old, spayed female North American River otter, "Terra," developed an unusual pattern of alopecia in June 2002. The otter had been found as an orphan in March 2000, and past medical history included intestinal hookworms as a juvenile and sporadic episodes of regurgitation as an adolescent. Recent medical history included an episode of bilaterally raised nictitans membranes 10 weeks prior and infestation with intestinal roundworms three weeks prior to the development of the alopecia. Terra had also been on 30 days each of amitriptyline followed by megestrol acetate from January through April 2002.

An initial physical exam on June 30, 2002, revealed an otter in good general health with acute onset of a band-like pattern of non-pruritic alopecia that completely encircled both wrists and ankles. Atopy or self/companion-induced barbering was suspected. No diagnostics were performed; methyl-prednisolone acetate (Depo-Medrol 20 mg IM once q 30 days) was administered. A second episode of bilaterally raised nictitans was noted two weeks later; it resolved with neomycin/polymyxin B & dexamethasone (Aktrol 2 drops OU TID). Thirty days post-injection, facial rubbing and increased whole body grooming activity was noted with no change in the alopecia. Hydroxizine (Atarax 1mg/kg PO SID) was initiated; no response was seen in 30 days. On August 25, 2002, Terra was sedated for a complete physical exam and diagnostics. CBC and SMA values were within normal limits; skin scrape and DTM were negative. Immuno-serologic allergy screening (Heska and Spectrum Labs) supported a diagnosis of atopy. The exhibit was thoroughly cleaned and cleared of all natural plant materials. Hypoallergenic diet (Hills Science Diet Feline D/D) was initiated and corticosteroid (Depo-medrol same as above and trimeprazine tartrate/prednisolone 0.25 mg/kg PO SID) usage was continued for a period of one more month with minimal response seen.

On October 2, 2002, Terra's condition began to decline. The alopecic skin became red and swollen and circular areas of bruising developed at the haired edges. She began to aggressively groom her feet and the alopecia spread onto the dorsal and planter surfaces of both rear feet. Triamcinolone acetonide (Vetalog 0.2 mg/kg IM) was administered on October 9, 2002, when Terra became lethargic and inappetant. She was sedated on October 12, 2002, for diagnostics that included repeated bloodwork, urinalysis and skin biopsy. Enrofloxacin (Baytril 2.5 mg/kg IM), metoclopramide (Reglan 0.125 mg/kg IM) and SQ fluids were administered. Preliminary bloodwork supported diabetes or acute pancreatitis and supportive therapy was planned. Terra was found deceased the next morning. Gross necropsy revealed bilateral adrenomegaly, hepatic mottling and edema & hemorrhage in lungs. Histopathology confirmed diffuse adrenal atrophy, moderate hepatic lipidosis and mild interstitial pneumonia. Fungal hyphae were found disseminated throughout the skin, heart and kidneys. Alopecia and immunosuppression associated with adrenal endocrinopathy is well documented in a variety of other species (specifically the common ferret Mustela putorius). Disseminated fungal disease is commonly a result of, or accompanied by, immunosuppression. Parental corticosteroid usage can induce iatrogenic hyperadrenocorticism and can exacerbate the clinical signs of systemic fungal disease. Terra's progression of clinical signs and case history suggest an initial dermatopathy that escalated to systemic fungal disease due to either a pre-existing adrenalopathy (species related?) or immunosuppression (orphan related?). The skin, adrenal and immune diseases were all likely to have been exaggerated by the repeated doses of parental corticosteroids. The combination of these three conditions resulted in the Terra's ultimate demise.

Acknowledgements

Thanks to Drs. Jeffery Schaffer, Ilze Berzins and Deke Beusse for their input and consultation on this complex case. A note of appreciation to HESKA Corp. and Spectrum Labs, Inc. for their generous donations and cooperation in sample processing.