Spontaneous primary hypothyroidism in 7 adult cats.

BACKGROUND: Naturally occurring hypothyroidism in adult cats is rare, with only 4 cases reported. OBJECTIVES: To describe the historical, clinical, laboratory, and scintigraphic features of adult cats with spontaneous hypothyroidism. ANIMALS: Seven adult cats referred for suspected hypothyroidism. METHODS: Prospective case series. We collected data on cats' signalment, clinical signs, results of physical examination, routine laboratory and thyroid hormone testing, and thyroid imaging (thyroid scintigraphy or ultrasound). We subsequently treated cats with levothyroxine and evaluated their response to treatment. RESULTS: Cats ranged from 3.5 to 11 years, with no apparent breed predilection; 6/7 cats were male. Only 2/7 cats were initially tested because of signs of hypothyroidism (hair-coat changes, lethargy, obesity); others were tested for routine thyroid monitoring or palpable thyroid nodules. Four were azotemic (serum creatinine, 2.2-3.4 mg/dL). Six of the cats had low serum thyroxine (T4 ) and free T4 (fT4 ) concentrations, whereas all 7 cats had high thyroid-stimulating hormone (TSH) concentrations. In 6/7 cats, thyroid scintigraphy revealed bilateral goiter with intense radionuclide uptake; imaging showed no visible thyroid tissue in the other. After levothyroxine treatment, serum concentrations of T4 and fT4 increased and TSH fell; high serum creatinine normalized in azotemic cats; and repeat imaging showed reduction in goiter size. CONCLUSIONS AND CLINICAL IMPORTANCE: Primary hypothyroidism develops in adult cats, with a higher prevalence than previously thought. Most cats appear to develop a goitrous form of hypothyroidism associated with thyroid hyperplasia, whereas thyroid atrophy appears to be less common. With levothyroxine replacement, clinical and laboratory abnormalities improve or resolve.

Management and closure of multiple large cutaneous lesions in a juvenile cat with severe acquired skin fragility syndrome secondary to iatrogenic hyperadrenocorticism.

CASE DESCRIPTION A 13-month-old castrated male cat was evaluated for a large, spontaneously developed cutaneous laceration over the left scapular region. The cat had a history of severe gingivostomatitis, conjunctivitis, giardiasis, and feline herpesvirus infection and had received systemic glucocorticoid treatment for 7 weeks prior to evaluation. CLINICAL FINDINGS Physical examination revealed a 10 × 7-cm full-thickness cutaneous laceration over the left scapular region, extremely thin skin, crusts over the dorsal aspect of the neck and base of the skull, medially curling pinnae, and moderate gingivostomatitis. TREATMENT AND OUTCOME Staged wound closure was performed with a combination of daily wound cleaning and debridement, tension and appositional sutures, and wet-to-dry and nonadherent dressings initially with a bacitracin, neomycin, and polymyxin B ointment and then with a 30:1 mixture of silver sulfadiazine and insulin. Multiple additional lesions developed and were treated in the same manner. Complete closure and resolution of all cutaneous lesions was achieved in 9 weeks. CLINICAL RELEVANCE Cats are fairly resistant to the adverse effects of glucocorticoid treatment, and iatrogenic hyperadrenocorticism is rarely reported. This case demonstrated that acquired skin fragility syndrome secondary to iatrogenic hyperadrenocorticism can develop following short-term systemic glucocorticoid administration and that large cutaneous wounds associated with this condition can be successfully managed and closed by means of the reported methods. The prognosis for skin recovery in cats with acquired skin fragility syndrome may be more favorable than previously reported.

Multifocal odontoblastic dysplasia in a dog.

A two-year-old Boerboel dog presented for a discolored left maxillary canine tooth. Dental radiographs revealed abnormally mineralized pulp within the discolored tooth. Similar radiographic findings were also seen in both maxillary third incisor teeth and in the remaining canine teeth to varying degrees. The discolored tooth was treated by surgical extraction and histopathology revealed abnormal dentin deposition within the canal indicative of dentin dysplasia. Although not previously documented in the dog, the pulpal changes in multiple teeth of the dog reported here were similar to those described for odontoblastic dysplasia in humans. This case report includes a review of developmental abnormalities of dentin in humans and pulpal response to inflammation and injury.