Nutritional secondary hyperparathyroidism (NSH) was diagnosed in six cats during a three-year period, based on clinical, radiographic and laboratory findings. Clinical signs were attributable to severe osteopenia (n = 5) and hypocalcaemia (n = 4), which had resulted in spontaneous fractures of long bones, scapulae, pelvis, nasal bones, or spine, and in excitation, muscle twitching or seizures, respectively. Serum parathormone levels were markedly elevated, and 1,25(OH)2-vitamin D3 mildly elevated, whereas 25(OH)-vitamin D3 was mildly decreased compared to age-matched healthy cats. Treatment was limited to short-term parenteral calcium gluconate injections, as clinically indicated, a balanced diet and cage rest, which resulted in quick clinical recovery in four cases. The remaining two cats had to be euthanased because of progressive neurological deficits secondary to spinal fractures. At the time of writing, a multitude of commercial balanced diets is widely available and diseases secondary to dietary deficiencies have become rare. Nevertheless, NSH is still an important clinical entity, and should be considered in growing cats presenting with spontaneous fractures or seizures.

Localized infection of the nasal or paranasal cavities caused by Aspergillus spp or Penicillium spp was diagnosed in 3 cats. Clinical signs included chronic mucopurulent nasal discharge, epistaxis, and mandibular lymphadenopathy. Rhinoscopic and diagnostic imaging findings were compatible with severe inflammation of the nasal mucosa and destruction of the turbinates. Fungal plaques were observed rhinoscopically in 2 cats, and histologic examination of biopsy specimens revealed fungal colonies with surrounding inflammatory infiltrates in all 3. Results of fungal culture were negative for all 3 cats. Results of serum immunoelectrophoresis for antibodies against Aspergillus spp were positive in 2 cats. Treatment with itraconazole was effective in controlling clinical signs in 1 cat, but hepatotoxicosis developed. A single intranasal infusion of clotrimazole subsequently led to long-term resolution of clinical signs in this cat. Localized aspergillosis-penicilliosis is clinically indistinguishable from other pathologic conditions of the nasal and paranasal cavities in cats and should be considered when examining cats with chronic nasal discharge.

To elucidate the impact of dietary influence on carbohydrate and lipid metabolism and on the development of diabetes mellitus in the carnivorous cat, a 3 weeks feeding trial was carried out on six sexually intact and six neutered adult male cats. The effects of two isonitrogenic diets, differing in carbohydrate and fat content, were investigated on plasma metabolite levels in a 24-h blood sampling trial. Plasma leptin concentrations were also determined at the beginning and at the end of the 24-h trial. Glucose and insulin response was measured in an i.v. glucose tolerance test. A 5 days long digestion trial was also performed, which revealed a high digestion capacity of both fat and carbohydrates in cats. The high fat diet induced a significant rise in the plasma triglyceride, FFA, beta-hydroxybutyrate and cholesterol concentration, while the elevation in the glucose level did not reach significance. In the glucose tolerance test no significant difference was found between the neutered and intact cats. However, independently of the sexual state, the cats on the high fat diet showed a slightly elongated glucose clearance and reduced acute insulin response to glucose administration. This is indicative of diminished pancreatic insulin secretion and/or beta-cell responsiveness to glucose. The results of this preliminary study may be the impetus for a long-term study to find out whether it is rather the fat rich ration than carbohydrate rich diet that is expected to impair glucose tolerance and thus might contribute to the development of diabetes mellitus in cats. Whether the alteration in glucose metabolism is due to altered leptin levels remains to be determined.

The clinical, neuropathologic, and magnetic resonance (MR) imaging features in four cats with necrosis of the hippocampus and piriform lobe are described. All cats had acute generalized seizures and behavioral changes including aggression, salivation, polyphagia, and disorientation. Routine hematologic, serum chemistry, and cerebrospinal fluid analyses were normal. MR imaging abnormalities were restricted to the area of the hippocampus and piriform lobe. The lesions were T2-hyperintense, T1-hypointense, and were characterized by various degrees of contrast enhancement. Lesions were consistent with necrotizing encephalitis. Two cats were euthanized and underwent postmortem examination within a week after MR imaging due to the lack of response to antiepileptic drug therapy and progressive neuropathy. The remaining two cats lived for about four months and were then euthanized because of persistent behavioral and neurologic signs; only one of these cats underwent postmortem examination with histopathologic examination. Histopathological findings were typical of severe, diffuse, bilateral symmetric necrosis, and degeneration of neurons in the hippocampus and piriform lobe, but an etiologic agent was not apparent. This apparently unique feline syndrome, now reported in Switzerland and Italy, has no known cause at this time.

Hypobaric (high-altitude) hypoxia is a physiologic cause of pulmonary hypertension, and alters left ventricular (LV) systolic and diastolic function. In the presence of tricuspid regurgitation, systolic pulmonary artery pressure can be measured noninvasively using the peak tricuspid regurgitation velocity and the Bernoulli equation. In the absence of measurable tricuspid regurgitation, severity of pulmonary hypertension may be estimated using two-dimensional, M-mode, and Doppler-derived parameters. To evaluate the usefulness of echocardiographic parameters for detecting mild-to-moderate pulmonary hypertension caused by moderate-to-marked hypoxia and to study the effect of high-altitude hypoxia on systolic and diastolic LV function in dogs, 19 Greenland dogs were examined at moderate altitude (2300 m) and high altitude (3500 m), and 10 Greenland control dogs were examined at 700-900 m. Evaluated parameters were pulmonary flow profile (shape, right ventricular acceleration time (RVAT), ejection time (RVET), RVAT/ET), peak mitral inflow velocities (LVE, LVA, LVE/A-ratio), LV % fractional shortening (FS), systolic time intervals (LVPEP, LVPEP/ET), and stroke volume index (SVI). Notching during deceleration was common in dogs at high altitude and in the control dogs, but not in dogs at moderate altitude. RVAT was shorter in dogs at high altitude compared with moderate altitude, but not compared with control dogs. Peak A-velocity was higher and E/A-ratio was lower in dogs at high altitude compared with moderate altitude and control dogs. FS was increased in dogs at high altitude compared with moderate altitude, and LVPEP and LVPEP/ET were shorter in the dogs at high altitude compared with moderate altitude and control dogs. In conclusion, significant differences in pulmonary flow profiles and systolic and diastolic parameters can be observed echocardiographically in dogs at different degrees of hypobaric hypoxia. However, overlap between the groups compromises their usefulness for diagnosing and estimating the degree of mild-to-moderate pulmonary hypertension in individual dogs.