Showing papers in "Journal of Feline Medicine and Surgery in 2001"

Insulin Sensitivity Decreases with Obesity, and Lean Cats with Low Insulin Sensitivity are at Greatest Risk of Glucose Intolerance with Weight Gain

Abstract: This study quantifies the effects of marked weight gain on glucose and insulin metabolism in 16 cats which increased their weight by an average of 442% over 10 months Significantly, the development of feline obesity was accompanied by a 52% decrease in tissue sensitivity to insulin and diminished glucose effectiveness In addition, glucose intolerance and abnormal insulin response occurred in some cats An important finding was that normal weight cats with low insulin sensitivity and glucose effectiveness were at increased risk of developing impaired glucose tolerance with obesity High basal insulin concentrations or low acute insulin response to glucose also independently increased the risk for developing impaired glucose tolerance Male cats gained more weight relative to females and this, combined with their tendency to lower insulin sensitivity and higher insulin concentrations, may explain why male cats are at greater risk for diabetes Results suggest an underlying predisposition for glucose intolerance in some cats, which is exacerbated by obesity These cats may be more at risk of progressing to overt type 2 diabetes mellitus

Feline nasal and paranasal sinus tumours: clinicopathological study, histomorphological description and diagnostic immunohistochemistry of 123 cases.

Abstract: Histological examination was performed in 123 cats with primary nasal and paranasal sinus tumours; 117 had undergone surgical biopsy and six necropsy. Special stains and immunohistochemistry were performed on poorly differentiated cases. Ninety-two percent (113/123) of the tumours were malignant. There was an increased risk for old cats (mean age of 10.9 years), and a male predilection (59% males). Clinical signs and breeds varied with the histological type of tumour. Thirty-nine percent (48/123) of the cases presented with nasal discharge, 21% (26/123) with dyspnea, 20% (24/123) with facial swelling, and 15% (19/123) with epistaxis. Forty-three percent (53/123) of the tumours were of epithelial origin. Adenocarcinomas (18/53) and squamous cell carcinomas (17/53) were the most common epithelial tumours. Fifty percent (26/53) of the epithelial tumours originated from the pseudo-stratified respiratory epithelium of the nasal cavity, 28% (15/53) from the stratified squamous epithelium of the vestibule, 9% (5/53) from olfactory epithelium, 9% (5/53) from submucosal glands and 4% (2/53) from minor salivary glands. Malignant lymphoma (35/123) was the most common tumour. Seventy-one percent (25/35) of the malignant lymphomas were B-cell tumours and 29% (10/35) were T-cell tumours. Six cases of malignant lymphomas were proved to be epitheliotropic T-cell lymphomas. This is the first report of a primary nasal epitheliotropic T-cell lymphoma in cats.

Ocular manifestations of feline herpesvirus.

Abstract: Feline herpesvirus-1 (FHV-1) infection is ubiquitous in the domestic cat population worldwide. The most common clinical ocular manifestations of infection with FHV-1 are conjunctivitis and keratitis. This paper reviews the pathogenesis of feline herpesvirus-1 and discusses the various clinical ocular manifestations, diagnostic techniques and treatment of FHV-1-induced diseases. Ocular manifestations include: conjunctivitis, keratitis, stromal keratitis, keratoconjunctivitis sicca, ophthalmia neonatorium, symblepharon, corneal sequestrum, eosinophilic keratitis and anterior uveitis. Diagnostic techniques discussed include: virus isolation, fluorescent antibody testing, serum neutralising titers, ELISA and polymerase chain reaction. Various therapies are also discussed.

Arthropod-transmitted infectious diseases of cats

Abstract: The emergence of new, and the reemergence of previously controlled, arthropod-transmitted microparasitic diseases are challenges for human and veterinary medicine. Both arthropods and arthropodtransmitted infections are expanding their zoogeographic range due to climate change and increased accessibility to niche environments. In addition, the relatively unimpeded movement of companion animals to and from countries with a high prevalence of arthropod-transmitted diseases has introduced both the arthropods and the diseases they carry to previously non-endemic areas. For example, in 2000–2001, the compulsory requirement for a 6 month quarantine period for dogs and cats travelling from specified European countries and rabies-free islands to the United Kingdom (UK) was eliminated under the conditions of the Pet Travel Scheme (PETS). The scheme has encouraged considerable movement of domestic pets and in the first 14 months of its operation 17 465 dogs and cats entered the UK, many from areas with arthropods and arthropod-transmitted diseases that are not currently found in the UK. Changes in land and water management are also encouraging increases in arthropod populations and their more widespread distribution.

Intervertebral Disc Extrusion in Six Cats

Abstract: Existing reports concerning intervertebral disc disease (IVDD) have focused almost exclusively on dogs, although a small number of individual case reports of IVDD of cats has been published. The medical records of six cats with IVDD were reviewed. Radiographic studies confirmed narrowed intervertebral disc spaces, mineralised intervertebral discs, and one or more extradural compressive lesions of the spinal cord in each cat. All disc extrusions were located in the thoracolumbar region. Surgical decompression of the spinal cord was achieved in all cats by means of hemilaminectomy and removal of compressive extradural material confirmed to be degenerative disc material. Good to excellent neurological recovery was noted in five of the six cats included in this report. Based on this review, it appears that IVDD of cats has many similarities to IVDD of dogs, and that healthy cats with acute intervertebral disc extrusion(s) respond favourably to surgical decompression of the spinal cord.

A field trial to assess the effect of vaccination against feline herpesvirus, feline calicivirus and feline panleucopenia virus in 6-week-old kittens.

Abstract: A trivalent (feline panleucopenia, feline herpesvirus, feline calicivirus), modified live, commercially available cat vaccine was used at either 6, 9 and 12 weeks of age (early schedule) or 9 and 12 weeks of age (conventional schedule), and the serological response to vaccination was assessed. The level of maternally derived antibody present at 6 weeks of age was also established. The use of early vaccination at 6 weeks of age induced an antibody response to each virus by 9 weeks of age in a significant proportion of kittens compared with unvaccinated littermates. There was no difference between the conventionally and early-vaccinated groups in terms of antibody response to any antigen by 12 and 15 weeks of age.

Clinical application of plasma clearance of iohexol on feline patients

Abstract: Glomerular filtration rate (GFR) was estimated by plasma clearance of iohexol (PCio) in 52 conscious cats presented for a variety of reasons to Angel Animal Hospital over a 2-year period. Cats were divided into four groups according to their clinical conditions and reasons for measuring PCio. The median PCio (ml/min/kg) was 3.68 in normal cats (NM), 2.39 in cats with suspected renal disease (SP), 1.35 in cats referred to confirm renal dysfunction (RD), and 0.84 in cats with apparent clinical signs of renal failure (RF). There was a significant difference between the results for each group. The respective medians of blood urea nitrogen (BUN) and plasma creatinine concentration (Pcr) (mg/dl) were 15 and 1.40 in NM cats, 21 and 1.71 in SP cats, 30 and 2.20 in RD cats, and 48 and 3.30 in RF cats. The reference values of BUN and Pcr were 21±7 mg/dl and 1.5±0.4 mg/dl (mean±SD). Diminished renal function could not be detected in SP cats by either BUN or Pcr, while a marked decrease of GFR was demonstrated before BUN and Pcr increased, indicating the insensitivity of BUN and Pcr in detecting renal dysfunction in cats. PCio can be performed non-invasively in conscious cats, which improves the veterinarian's ability to detect early stages of chronic renal disease.

Pharmacology of a 40 IU/ml porcine lente insulin preparation in diabetic cats: findings during the first week and after 5 or 9 weeks of therapy.

Abstract: The aim of this study was to measure the pharmacokinetics and pharmacodynamics of subcutaneously injected 40 IU/ml porcine lente insulin preparation (Caninsulin, Intervet BV, The Netherlands) in diabetic cats. The pharmacological properties of the insulin in poorly controlled or untreated cats were compared with those after several weeks of treatment, to determine if improved diabetic stability altered the pharmacology of this insulin. In addition, the pharmacological properties of intravenously injected 100 IU/ml regular porcine insulin (Actrapid MC, NovoNordisk, Denmark) were measured. Serial plasma samples were collected after subcutaneous injection of porcine lente insulin from 25 diabetic cats in the first week of admission to a 12-month diabetic treatment trial. Samples were also collected after 4 or 8 weeks of treatment, in those cats which had not achieved diabetic remission by this time. At this time, serial plasma samples were also collected from these cats after intravenous injection of porcine regular insulin. Plasma samples were assayed for glucose, anti-insulin antibodies were extracted using a PEG technique, and samples were assayed for insulin using an RIA kit with low sensitivity for endogenous feline insulin, but high sensitivity for exogenous porcine insulin in feline plasma. Caninsulin injected subcutaneously in diabetic cats led to a peak insulin concentration in plasma after 1.7+/-0.1 h, and a nadir of blood glucose after 4.1+/-0.3 h. Insulin and glucose concentrations returned to baseline within 12 h. There was no significant change in the onset or duration of Caninsulin action between the first week of treatment and 5 or 9 weeks of treatment. Actrapid MC injected intravenously had a peak insulin at 0.36+/-0.03 h, and a nadir of blood glucose at 1.9+/-0.3 h. Insulin and glucose returned to baseline within 6 h. It was concluded that Caninsulin injected subcutaneously has suitable pharmacological properties for the twice-daily treatment of diabetes mellitus in cats. In addition, Actrapid MC insulin injected intravenously has suitable pharmacological properties for injection every 4-6 h in diabetic cats.

Laboratory profiles in cats with different pathological and immunohistochemical findings due to feline infectious peritonitis (FIP).

Abstract: Blood was collected from 55 cats with feline infectious peritonitis (FIP) and from 50 control cats in order to define whether differences in pathological findings and in distribution of feline coronaviruses (FCoV) can be associated with changes in haemograms, serum protein electrophoresis, and antibody titres. Compared to controls, the whole group of FIP-affected cats had blood changes consistent with FIP. Based on the pathological findings or on the immunohistochemical distribution of viral antigen, FIP-affected cats were divided in the following groups: subacute against acute lesions; low against strong intensity of positivity; intracellular against extracellular positivities; positive against negative lymph nodes. Lymphopenia was more evident in cats with acute forms, strong intensity of positivity, extracellular antigen and negative lymph nodes. Cats with positive lymph nodes had the most evident changes in the protein estimations. These results suggest that differences in pathological findings might depend on different reactive patterns to the FCoVs.

Review of feline pancreatitis part two: clinical signs, diagnosis and treatment.

Abstract: In the past decade pancreatitis has become recognised as a significant disease in the cat. Chronic, mild pancreatitis is often associated with more commonly diagnosed diseases such as inflammatory bowel disease or cholangitis/cholangiohepatitis. Furthermore, acute pancreatitis with similar complications to those seen in dogs is now diagnosed more frequently in cats. Unfortunately, the clinical signs and clinicopathological findings in cats with pancreatitis are often non-specific and vague. The lack of specific signs often results in a diagnosis being made only when the veterinary surgeon has a strong index of suspicion for pancreatitis and vigorously pursues that diagnosis. Pancreatitis is an important disease in cats, has been implicated as a potential cause of diabetes mellitus, and when present complicates the treatment of diabetes and other intra-abdominal diseases in cats.

An investigation into the effects of storage on the diagnosis of crystalluria in cats

Abstract: Urinalysis was performed on 41 cats with no history of urinary tract disease. Samples were divided into aliquots, stored under differing condition and then examined for the presence of crystalluria. Crystalluria was detected in at least one stored sample in 92% of cats fed a mixed wet/dry food diet compared to 24% in the fresh sample. Crystalluria was not detected in any sample or aliquot from cats fed all wet food diets.

Review of Feline Pancreatitis Part One: The Normal Feline Pancreas, the Pathophysiology, Classification, Prevalence and Aetiologies of Pancreatitis

Abstract: The cellular mechanisms involved once pancreatitis has been initiated are reasonably well understood. The events leading up to this process are less well established. Much of our current understanding of pancreatitis in cats has been determined from experiments in cats or extrapolated from other species. The normal anatomy and function of the pancreas and a review of the current state of knowledge about the pathophysiology of pancreatitis is discussed. The current prevalence of feline pancreatitis is unknown, but the disease is being reported with increasing frequency. The aetiology of pancreatitis and the types of pancreatic inflammation present in cats is different from other species, such as the dog, a species where the disease is considered more common. Concurrent diseases are often present that may be more serious than the pancreatic inflammation and the treatment of these diseases is often complicated by pancreatitis.

Iatrogenic hyperadrenocorticism in a cat following a short therapeutic course of methylprednisolone acetate

Abstract: Iatrogenic hyperadrenocorticism (or iatrogenic Cushing's syndrome) is an adrenal disorder that may result from long-term administration of glucocorticoids for therapeutic purposes, most often given to treat allergic or immune-mediated disorders. Prolonged treatment with synthetic glucocorticoids can suppress hypothalamic corticotrophin releasing hormone and plasma adrenocorticotrophic hormone (ACTH), thus causing a functional inactivity of the adrenal cortex. The result is a clinical syndrome of hyperadrenocorticism but with basal and ACTH-stimulated plasma cortisol concentrations that are consistent with spontaneous hypoadrenocorticism (Addison's disease). Whilst iatrogenic hyperadrenocorticism is relatively frequent in dogs, the diagnosis of iatrogenic hyperadrenocorticism in cats is very uncommon because this species has been found to be remarkably resistant to prolonged administration of glucocorticoids. To the author's knowledge, there are only two published clinical cases of feline iatrogenic Cushing's syndrome. This report describes a case of iatrogenic hyperadrenocorticism in a cat, and shows how normalisation of the adrenal function was achieved with supportive treatment and withdrawal of glucocorticoid administration.

Detection of Feline Leukaemia Virus in Blood and Bone Marrow of Cats with Varying Suspicion of Latent Infection

Abstract: The purpose of this study was to determine if polymerase chain reaction (PCR) could be used to detect FeLV proviral DNA in bone marrow samples of cats with varying suspicion of latent infection. Blood and bone marrow samples from 50 cats and bone marrow from one fetus were collected, including 16 cats with diseases suspected to be FeLV-associated. Serum enzyme-linked immunosorbent assay (ELISA), blood and bone marrow immunofluorescent antibody test (IFA), and blood and bone marrow PCR were performed on each cat, and IFA and PCR on bone marrow of the fetus. Forty-one cats were FeLV negative. Five cats and one fetus were persistently infected with FeLV. Four cats had discordant test results. No cats were positive on bone marrow PCR only. It appears persistent or latent FeLV infection is not always present in conditions classically associated with FeLV.

Management of Anorexia in the Cat

Abstract: One of the most frequent motivations for seeking veterinary attention for a cat is when the owner recognises a loss of normal appetite in his pet. The medical term for a lack of appetite for food is 'anorexia', and it may be partial or complete. While anorexia is a common manifestation of disease, the mechanisms underlying decreased food intake are complex and not completely understood. The regulation of appetite involves interaction of external stimuli with signals from the gastrointestinal tract and central nervous system. Aberrations in any of the internal control systems for hunger and satiety, or changes in external factors such as diet or feeding environment, can result in partial or total anorexia. The challenge for the practitioner is not only to diagnose and treat the underlying condition, but to recognise at what point inadequate food intake has or will impinge on the patient's nutritional status to the extent that it might deleteriously affect clinical outcome. It is also important to bear in mind the significance that the patient's appetite and food intake has for the cat owner in his overall perception of his pet's condition and quality of life.

Chylothorax in cats: is there a role for surgery?

Abstract: Chylothorax is a complex disease with many identified underlying causes including cardiac disease, mediastinal masses, heartworm disease and trauma. Management of this disease should be directed at identifying the cause, if possible, and treating the underlying disorder. In cats with idiopathic chylothorax, medical management is recommended initially because the condition may resolve spontaneously. Owners should be made aware of the potential development of fibrosing pleuritis in affected cats. When medical management is impractical or unsuccessful, surgical intervention should be considered. Surgical options include mesenteric lymphangiography and thoracic duct ligation, pericardiectomy, omentalisation, passive pleuroperitoneal shunting, active pleuroperitoneal or pleurovenous shunting, and pleurodesis. Of these, only thoracic duct ligation and pericardiectomy are preferred by the author because, if successful, the result is complete resolution of the chylothorax, thereby reducing the risk of developing fibrosing pleuritis. Omentalisation may be beneficial in some animals as adjuvant therapy, but this procedure may still allow fibrosing pleuritis to occur. Until the aetiology of the effusion in cats with idiopathic chylothorax is understood, the treatment success rate will be less than ideal. Future research needs to be directed at determining the pathophysiologic mechanisms underlying this disease in cats.

Feline Acute Pancreatitis—Important Species Differences:

Abstract: Peri-pancreatic fat necrosis and acinar cell necrosis are now recognised as an important cause of morbidity and mortality in the domestic cat. Reports of this condition were uncommon prior to the early 1990s, probably related to difficulties in diagnosis as well as low incidence of disease. Some of the difficulties in the diagnosis and treatment of this disorder may have, in fact, related to preconceived notions about the same disorder in the dog. Like many other companion animal disorders, there are important differences in the natural history of the disease between cats and dogs. This manuscript will attempt to provide an overview of those differences.

Genetic diseases of cats

Abstract: In small animal practice, veterinarians are confronted by a bewildering number of disease conditions. As a generalisation, however, many disease conditions we see in dogs are ultimately genetic in aetiology, whereas most disease conditions in cats have a traumatic or infectious aetiology. This situation has arisen because a substantial proportion of dogs are purebreds or purebred-cross dogs. Breeding practices which have fixed a number of ‘desirable’ physical and behavioural traits have also established a number of genetic defects that ultimately give rise to disease. Some of these are obvious. Others, on the other hand, do not obviously make a veterinarian think of the underlying genetic predisposition. By their very nature, some canine breeds are genetic mutants. Dachshunds and Bassets, for example, are obviously chondrodystrophic dwarfs. Toy poodles and Italian Greyhounds are midgets. Bulldogs have malformed heads which result in brachycephalic upper airway obstruction syndrome and fetal dystocia. Other breeds have become very strongly associated with certain genetically inherited defects. For example, almost all Bedlington terriers (at least in Australia) have copper storage disease that ultimately gives rise to liver failure. There are other genetic diseases which are very common in certain breeds, such as the association between German Shepherds and hip dysplasia and Rottweilers and elbow dysplasia. Still other genetic diseases are not seen especially commonly, but have very strong breed associations, such as Yorkshire terriers and Maltese

Management of hypokalaemia and hyperkalaemia.

Abstract: Decreased intake of potassium alone is unlikely to cause hypokalaemia but, in chronically ill animals, prolonged anorexia, loss of muscle mass, and ongoing urinary potassium losses may combine to cause hypokalaemia. Alkalemia contributes to hypokalaemia as potassium ions enter cells in exchange for hydrogen ions. Insulin promotes uptake of glucose and potassium by hepatic and skeletal muscle cells. A syndrome characterised by recurrent episodes of limb muscle weakness and neck ventroflexion, increased creatine kinase concentrations, and hypokalaemia has been reported in related young Burmese cats. Gastrointestinal loss of potassium (especially vomiting of stomach contents) is an important cause of hypokalaemia in small animals. Chloride depletion and sodium avidity due to volume depletion contribute to perpetuation of potassium depletion and metabolic alkalosis by enhancing urinary losses of potassium and

Cholelithiasis and hyperthyroidism in a cat.

Abstract: A 14-year-old domestic short-hair cat presented with a history of intermittent malaise and increased drinking. A diagnosis of hyperthyroidism and cholelithiasis was made by a combination of blood testing, radiography and ultrasonography. After medical management of hyperthyroidism, thyroidectomy and cholecystectomy were successfully performed. Removed choleliths were comprised of calcium carbonate and bilirubinate. Histopathological analysis of tissue suggested low grade pancreatic and hepatobiliary disease, as well as hyperthyroidism, might have contributed to stone formation.

Cerebral cryptococcal granuloma in a cat: pp. 201-206

Abstract: A 7-year-old cat was presented for seizures. Cerebrospinal fluid cytology and serology were consistent with a diagnosis of toxoplasmosis. The cat was treated with clindamycin but seizures continued and additional neurological signs developed over 6 months. A mass lesion was identified in the left cerebral hemisphere using magnetic resonance imaging (MRI). The lesion enhanced after gadolidium and a tumour was considered likely. Histologically, the lesion proved to be a cryptococcal granuloma and retrospective serology confirmed that the cat had cryptococcosis at its initial presentation. This report provides the first description in the veterinary literature of the MRI appearance of a cerebral cryptococcoma and emphasises the importance of performing cryptococcal antigen determination in cats with signs of intracranial disease.

What is new on feline lymphoma

Abstract: Previous reports document that approximately 70% of cats with lymphoma are feline leukaemia virus (FeLV)-positive. The prevalence of viremia in cats with lymphoma varies with the anatomic form of presentation, but, in general, young cats with lymphoma are FeLV-positive, whereas older cats are negative. Over the past few years, the prevalence of FeLV infection in cats with lymphoma in our clinic is decreasing. Feline immunodeficiency virus (FIV) infection significantly increases the risk of developing lymphoma. The age of presentation in cats with lymphoma is bimodal; the first peak occurs at approximately 2 years of age and the second one at approximately 10 to 12 years of age. The first peak is composed mainly of FeLV-positive cats, whereas the second one includes predominantly FeLVnegative cats. The mean age of presentation of lymphoma in FeLV-positive cats is 3 years, whereas in FeLV-negative cats it is 7 to 8 years.

Anatomy of the patent ductus venosus in the cat

Abstract: The biplanar mesenteric vein portovenograms of 10 cats with left divisional intrahepatic portosystemic shunts consistent with a patent ductus venosus (PDV) were reviewed. A corrosion cast of the hepatic portal vasculature was made post mortem from one individual that died post operatively following surgical attenuation of the shunting vessel. On the basis of the combined surgical, post mortem and imaging data, these left divisional shunts were found to have consistent anatomy, each having a straight vessel which drained into a venous ampulla before draining into the caudal vena cava at the level of the diaphragm. The left phrenic vein and left hepatic vein both entered the ampulla independently of the shunting vessel. The anatomical similarity between these findings in the cat and the PDV in the dog suggest that it is appropriate to describe this particular portosystemic shunt as a PDV.

Prevention and treatment of injection-site sarcomas.

Abstract: There is epidemiologic evidence showing a strong association between the administration of inactivated feline vaccines (or other injectables) and subsequent development of soft tissue sarcomas at vaccine sites in cats. The prevalence of soft tissue sarcomas after vaccination varies between 1/1000 and 1/10 000. If these prevalence rates are to be applied to the 1991 United States cat population, a total of 22 000 vaccine-associated tumours occurred in 1991. Recommendations for preventing or decreasing the prevalence of injection-site sarcomas in cats are controversial, and include a change in vaccination site location, decreased use of polyvalent vaccines, use of non-adjuvanted vaccines, avoiding the use of aluminum-based adjuvants, and not overvaccinating, among others. The most important recommendation for prevention of injection-site tumours would appear to be not to overvaccinate. Kas, et al. (1993) has clearly shown that the risk of injection-site tumours increases with the number of vaccines administered. It is also clear from recently published articles by Scott et al. (1997) that the duration of immunity of many of the commercially available vaccines for cats is longer than 1 year, and an every 3 year programme should be instituted for many vaccines for infectious agents of cats. With respect to rabies vaccination, annual vaccination for rabies with a 3-year rabies product should be discouraged (malpractice?). The indiscriminate use of feline leukaemia virus vaccine should be stopped since epidemiologic

Aspergillus species cystitis in a cat.

Abstract: A Persian male cat with a history of lower urinary tract disease was presented because of polydipsia, polyuria, constipation and nasal discharge. Ten weeks before admission, the cat had been treated for lower urinary tract disease by catheterisation and flushing of the bladder. The animal was thin, dehydrated, anaemic and azotaemic. Urine culture revealed Aspergillus species cystitis. Antibodies against Aspergillus nidulans were identified in serum. Fluconazole was administered orally (7.5 mg/kg, q 12 h) for 10 consecutive weeks. The azotaemia was resolved, the kidney concentrating ability was recovered and the cat has remained healthy without similar problems.

What is so special about feline diabetes mellitus

Abstract: The two major classifications of DM are type 1, also known as IDDM (insulin dependent DM), juvenile onset DM, or non-ketosis prone DM, and type 2 or NIDDM (non-insulin dependent DM), adult onset DM, or ketosis prone DM. Type 1 DM refers to a diabetic state brought about because of a loss of insulin production and secretion by the -islet cells. Because these patients are insulinopenic they require insulin injections as part of their treatment. Type 2 DM refers to a diabetic state brought about because of insulin resistance, generally through a loss of insulin receptor numbers or affinity. This renders the insulin that diabetics do have less effective and, at least initially, these patients have hyperinsulinemia as well as hyperglycaemia. Treatment for these patients focuses on increasing the efficiency of insulin utilisation and production. Additionally, type 2 DM can progress to type 1 DM. In people type 2 is the most common cause of DM, whereas our small animal patients usually have type 1 DM. In dogs DM is almost exclusively type 1, with rare cases of type 2. In contrast, the cat has a much higher (at least 20%) incidence of type 2 DM. The actual incidence of

Disorders of sodium: hypernatraemia and hyponatraemia.

Abstract: The volume and tonicity of body fluids are maintained within a narrow normal range by regulation of sodium and water balance. The volume of extracellular fluid is determined by total body sodium content whereas the osmolality and sodium concentration of extracellular fluid are determined by water balance. The kidney balances excretion of sodium and water with their intake and avidly conserves them when intake is restricted. Serum sodium concentration is an indication of the amount of sodium relative to the amount of water in extracellular fluid and provides no direct information about total body sodium content. Patients with hyponatraemia or hypernatraemia may have decreased, normal, or increased total body sodium content. An increased serum sodium concentration implies hyperosmolality whereas a decreased serum sodium concentration usually, but not always, implies hypoosmolality.

Interpretation of Metabolic Acid Base Disturbances Using the Routine Serum Biochemical Profile

Abstract: The routine serum biochemical profile contains several pieces of information useful in the interpretation of metabolic acid base disturbances. The most important of these are the total CO2, serum sodium, serum potassium, and serum chloride concentrations. The total CO2 content is a measure of all potential sources of CO2 in plasma or serum. When a sample is handled anaerobically, this includes HCO3 − ions, dissolved CO2, carbamino CO2 bound to amino groups in haemoglobin, H2CO3, and CO3 −2 ions. The total amount of carbamino CO2, H2CO3, and CO3 −2 present is negligible, and total CO2 usually is defined as HCO3 − +dissolved CO2 or HCO3 − +0.03×pCO2, where 0.03 is the solubility coefficient for CO2 in plasma. In a normal dog with a [HCO3 ] of 21 mEq/l and pCO2 of 37 mmHg, total CO2 would be 22.1 mEq/l with HCO3 − representing 95% of the total CO2 content. Invariably, samples sent to laboratories for routine biochemical profiles are not handled anaerobically. When the sample is handled aerobically, dissolved CO2 is released to the atmosphere and the total CO2 measurement is essentially equal to the concentration of HCO3 − in the sample. Thus, in routine clinical practice the total CO2 determination often is considered synonymous with [HCO3 ]. Determination of total CO2 does not allow differentiation of metabolic and respiratory acid base disorders. Occurrence of a high total CO2 indicates either a primary metabolic alkalosis or an increased HCO3 − concentration as an