Prevalence of spondylosis deformans in the feline spine and correlation with owner-perceived behavioural changes.

OBJECTIVES: The primary objective was to determine the prevalence, spinal distribution, and association with the signalment of cats suffering from different grades of feline spondylosis deformans (spondylosis). The secondary objective was to document behavioural changes associated with spondylosis by owner observation. METHODS: A cross-sectional study was performed to determine the prevalence of feline spondylosis (group 1). A prospective study was performed to determine the association between radiographic abnormalities of the lumbosacral region (L3-S1) and owner perceived behavioural changes based on a completed questionnaire (group 2). The radiographs were reviewed using a grading system (0-3) for spondylosis. RESULTS: The prevalence of spondylosis in group 1 was 39.4% (158/402). Cats with spondylosis were significantly older than cats without spondylosis (p <0.001). The thoracic (T) vertebrae T4-T10 were most often affected by spondylosis, but spondylosis was most severe in the T10-S1 vertebrae. In group 2, spondylosis of the lumbosacral region was significantly correlated with owner-reported behavioural changes, such as a decreased willingness to greet people and to being petted, increased aggressiveness, and a poor perceived quality of life (p = 0.037). CLINICAL SIGNIFICANCE: This study found that feline spondylosis is common and that spondylosis of the lumbosacral region may be accompanied by behavioural changes.

Cross-sectional study of the prevalence and clinical features of osteoarthritis in 100 cats.

To assess clinical signs and relevance of osteoarthritis (OA) in cats, the radiographic prevalence of OA in the appendicular skeleton of 100 client-owned cats (≥ 6 years old) was assessed. Possible associations between radiographic OA, clinical locomotor system examination, and owner-perceived behavioural changes were evaluated. OA was most prevalent in the shoulders, elbows, hips and tarsal joints with 61% of cats having OA in at least one joint and 48% in more than one joint. Overall, clinical examination of the larger peripheral joints had the highest sensitivity and specificity for radiographic OA. Regression analysis showed age to be related to OA (P = 0.002), as were decreased mobility and grooming (P = 0.008), although there was a correlation with age. Finally, increased inappropriate elimination was associated with OA (P = 0.046). It was concluded that the prevalence of OA in cats is strikingly high and increases with age. OA in cats seems to be associated with behavioural changes.

Indoor confinement and physical inactivity rather than the proportion of dry food are risk factors in the development of feline type 2 diabetes mellitus.

With domestication and urbanisation, cats have transformed from being hunting animals that eat protein-rich prey into more sedentary animals that eat a carbohydrate-rich diet. It was hypothesised that a high intake of dry cat food and a lack of physical activity may play a role in the development of feline type 2 diabetes mellitus. Information on dietary history and physical activity of 96 cats with diabetes mellitus and 192 matched controls was collected retrospectively, using a telephone questionnaire. Conditional logistic regression analysis was used to investigate the association between questionnaire-derived variables and the development of diabetes mellitus. The energy percentage of dry food in the diet was not significantly correlated with the development of diabetes mellitus (P=0.29), whereas both indoor confinement (P=0.002) and low physical activity (P=0.004) were. The results indicated that the proportion of dry food in a cat's diet may not be an independent risk factor for the development of type 2 diabetes mellitus, whereas physical inactivity and indoor confinement are.

Growth hormone excess and the effect of octreotide in cats with diabetes mellitus.

In this prospective study 16 cats with diabetes mellitus were examined for concurrent acromegaly by measuring plasma growth hormone (GH) and insulin-like growth factor-I concentrations, and magnetic resonance imaging (MRI) of the pituitary fossa. Additionally, the effects of octreotide administration on the plasma concentrations of glucose, GH, alpha-melanocyte-stimulating hormone (alpha-MSH), adrenocorticotrophic hormone (ACTH), and cortisol were measured. Five cats were diagnosed with hypersomatotropism. The pituitary was enlarged in these 5 cats and in 2 other cats. Six cats that required a maximum lente insulin dosage >or=1.5 IU/kg body weight per injection had pituitary enlargement and 5 of these cats had acromegaly. Plasma concentrations of GH, ACTH, and cortisol decreased significantly after single intravenous administration of the somatostatin analogue octreotide in the acromegalic cats. The effect on GH concentrations was more pronounced in some of the acromegalic cats than in others. In the non-acromegalic cats only ACTH concentrations decreased significantly. In both groups plasma glucose concentrations increased slightly but significantly, whereas alpha-MSH concentrations were not significantly affected. In conclusion, the incidence of hypersomatotropism with concomitant pituitary enlargement appears to be high among diabetic cats with severe insulin resistance. Some of these cats responded to octreotide administration with a pronounced decrease in the plasma GH concentration, which suggests that octreotide administration could be used as a pre-entry test for treatment with somatostatin analogues.

Response of cats to familiar and unfamiliar human contact using continuous direct arterial blood pressure measurement.

Continuous direct measurement of feline arterial blood pressure (ABP) was carried out via a modified method with percutaneous, ultrasound guided catheterization of the common carotid artery. In 21 healthy, conscious cats the ABP was measured during rest, alertness and activity. Furthermore, the ABP response to being petted by familiar and unfamiliar persons was assessed. Linear mixed modelling revealed that the mean blood pressure (MBP) in resting cats (114.6mmHg) was lower (P<0.001) than in alert cats (122.7mmHg), which was lower (P<0.001) than that of active cats (136.8mmHg). The MBP during petting by a familiar person (144.7mmHg) tended to be higher (P=0.065) than that during petting by an unfamiliar person (139.4mmHg). The MBP of active cats was lower (P=0.003) than MBP of cats petted by a familiar person, but not different from MBP of cats petted by an unfamiliar person. The MBP returned to resting values between 16 and 20min after the familiar person had left, whereas resting values were reached between 11 and 15min after the unfamiliar person had left. The complications of the described method were limited considering the potential risks of continuous direct ABP measurement. In conclusion, the described technique enables accurate measurement of feline ABP, which is influenced by the cat's activity level and the familiarity of persons.

Calcium-stimulation test for the assessment of beta-cell function in cats.

To assess the potential of an intravenous calcium-stimulation test (CST) as an indicator of insulin secretion in cats, indices calculated from CST results were compared with indices of insulin secretion derived from an intravenous glucose tolerance test (ivGTT) and hyperglycaemic glucose clamp (HGC) in 11 healthy, normal glucose tolerant, conscious cats. Intravenous administration of 2.5mg/kg Ca(2+) resulted in a significant increase in plasma free Ca(2+) (P<0.001) and plasma insulin (P=0.047) concentrations but did not affect the plasma glucose concentration. The indices of insulin secretion based on the CST did not correlate significantly with corresponding indices based on the ivGTT and HGC. In conclusion, the CST is not a useful test for assessing insulin secretion in cats. Other indices of insulin secretion, such as fasting insulin concentrations and the homeostasis model assessment of beta-cell function (HOMA-B), are easier to obtain and correlate better with indices of insulin secretion derived from the HGC, the gold standard technique for assessing insulin secretion.

Insulin sensitivity and beta-cell function in healthy cats: assessment with the use of the hyperglycemic glucose clamp.

A hyperglycemic clamp (HGC) was developed for use in conscious cats. In 21 healthy, normal glucose tolerant cats glucose disposal rate (M), insulin sensitivity (ISI (HGC)), and beta-cell response (I) at arterial plasma glucose of 9 mmol.l (-1) were measured. The HGC was tolerated well and steady state glucose infusion was achieved. Compared to values reported for humans, M values for the cats were low, which appeared to relate to both a low ISI (HGC) and a low I. HGC measures correlated with fasting plasma glucose and insulin concentrations as well as with their HOMA (homeostasis model assessment) and QUICKI (quantitative insulin sensitivity check index) counterparts. Also, I and ISI (HGC) correlated with their counterparts derived from intravenous glucose tolerance tests. In conclusion, this is the first report of hyperglycemic glucose clamping in cats. The procedure (HGC) allows for measurements of glucose disposal, beta-cell response and insulin sensitivity. Compared to human data, both insulin sensitivity and insulin secretion appeared to be low in cats. This is compatible with the carnivorous nature of this species, for which insulin resistance would be advantageous during periods of restricted food availability.