Effect of Energy Restriction on Feline Weight Loss

Villaverde, C., J. J. Ramsey, et al. (2008). "Energy restriction results in a mass-adjusted decrease in energy expenditure in cats that is maintained after weight regain." J Nutr 138(5): 856-60.

Treatment of obesity in cats can be frustrating, even if appropriate energy restriction (ER) is employed. The purpose of this study was to determine whether ER causes a long-term decrease in mass-adjusted energy expenditure (EE). Such a decrease in EE would impair weight loss and even promote regaining lost weight. EE and body composition were measured in 10 obese neutered adult cats (average body weight 6.1 kg, body condition score 7.6/9.0, fat mass 38%) at 3 time points: at baseline, during weight loss (40% ER), and after regaining weight. After weight loss, the average body weight was 5.0 kg, body condition score was 5.5/9.0, and fat mass was 31%. After a period of regaining weight, the average body weight was 6.2 kg, body condition score was 7.7/9.0, and fat mass was 42%. The total EE was significantly lower than baseline during weight loss, and remained lower than baseline even after weight regain. The results support the suggestion that ER results in a sustained mass-adjusted decrease in EE in cats.
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Related articles:
Weinsier, R. L., T. R. Nagy, et al. (2000). "Do adaptive changes in metabolic rate favor weight regain in weight-reduced individuals? An examination of the set-point theory." Am J Clin Nutr 72(5): 1088-94.
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Feline Patellar Luxation

Guillaumot, P., S. Scotti, et al. (2008). "Two cases of surgically treated feline patellar fractures." Vet Comp Orthop Traumatol 21(2): 156-8.


Diseases of the patella, such as luxation and fractures, are reported less commonly in the cat than in the dog. This articles details the reports of two cases of patellar fracture: one in a 6-month old cat and one in a 2.5-year old cat. Two different methods of repair are detailed, along with information on etiology and diagnosis.
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Related articles:
McLaughlin, R. M. (2002). "Surgical diseases of the feline stifle joint." Vet Clin North Am Small Anim Pract 32(4): 963-82.
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Heartworm in Cats: Diagnosis, Treatment, Prevention

Hoch, H. and K. Strickland (2008). "Canine and feline dirofilariasis: prophylaxis, treatment, and complications of treatment." Comp Contin Edu Vet 30(3): 146-151.

While several agents have been available for treatment of heartworm infection in dogs, no safe and effective adulticides exist for treatment of heartworm in the cat. Cats infected with heartworm may benefit from corticosteroid therapy to reduce clinical signs of pulmonary disease. Fortunately, four products are available for prevention of heartworm infection in cats (ivermectin, selamectin, moxidectin, milbemycin). Two products are given orally, and two are administered topically. Even cats diagnosed with heartworm infection can safely be given preventive treatment.
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Related articles:
Bowman, D. D., C. J. Torre, et al. (2007). "Survey of 11 western states for heartworm (Dirofilaria immitis) infection, heartworm diagnostic and prevention protocols, and fecal examination protocols for gastrointestinal parasites." Vet Ther 8(4): 293-304.
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Feline Heartworm: Life Cycle, Pathophysiology, Diagnosis

Hoch, H. and K. Strickland (2008). "Canine and feline dirofilariasis: life cycle, pathophysiology, and diagnosis." Comp Contin Edu Vet 30(3): 133-141.

The heartworm, Dirofilaria immitis, infects many animal species, including dogs and cats. While cats are resistant to heartworm infection, they may suffer infection rates 5-20% of the local canine rate. The American Heartworm Society released new guidelines on feline heartworm in 2007. It is important to understand the pathophysiology of heartworm disease in cats, and to educate pet owners that cats are at risk, even if they live 100% indoors.
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American Heartworm Society

KNOW Heartworms Campaign

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Differentiating Spayed from Intact Queens

Axnner, E., T. Gustavsson, et al. (2008). "Estradiol measurement after GnRH-stimulation as a method to diagnose the presence of ovaries in the female domestic cat." Theriogenology 70(2): 186-191.

Spaying is routinely recommended for population control in cats, as well as for specific health benefits and to avoid unwanted behaviors. It can be difficult to determine if a queen with an unknown history and no estrous activity is spayed or intact. In addition, one of the most common feline reproductive problems encountered by practicing veterinarians is ovarian remnant syndrome. A test that differentiates intact from spayed queens would be valuable. A commercially available luteinizing hormone assay (Witness LH, Synbiotics) has been marketed for this purpose, but is not available world-wide. GnRH induces release of follicle-stimulating hormone (FSH) and LH from the pituitary gland. FSH stimulates estradiol production by granulosa cells in ovarian follicles. The aim of this study was to evaluate if it is possible to differentiate between spayed and sexually inactive intact queens by measurement of plasma estradiol before and/or after stimulation with a GnRH-analogue, buserelin (Receptal, Intervet). Two groups of female cats (11 spayed, 11 intact) were treated with buserelin after baseline measurement of plasma estradiol and progesterone. A second blood sample was collected two hours later. Median estradiol increased after stimulation with buserelin in intact but not in spayed females. There was no overlap between the two groups of cats. Measurement of plasma estradiol concentration 2 hours after stimulation with a GnRH-analogue seems to be a reliable method to diagnose the presence of ovarian tissue in the female cat.

Glucocorticoids and Cats

Lowe, A. D., K. L. Campbell, et al. (2008). "Clinical, clinicopathological and histological changes observed in 14 cats treated with glucocorticoids." Vet Rec 162(24): 777-83.

Glucocorticoids such as prednisone and prednisolone are commonly used to treat a variety of conditions in feline medicine. Adverse effects from this class of drugs in cats are well known, and may be dose-dependent. In this study, 14 cats were given immunosuppressive doses of prednisolone (4.4 mg/kg/day) or dexamethasone (0.55 mg/kg/day) for 8 weeks. Complete blood counts, serum biochemistry profiles and urinalyses were performed on days 0 and 56, and liver biopsies were taken on day 56. Significant increases were noted in mean white blood cell counts, neutrophil counts, and monocyte counts. Significant decreases were noted in mean lymphocyte counts and eosinophil counts. Consistent increases in serum albumin, glucose, triglycerides and cholesterol were observed. A steroid hepatopathy was present in varying degrees in all liver biopsies. One cat developed clinical signs believed to be related to the therapy, such as icterus and curling of the pinnae.
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Related articles:
Sharkey, L. C., T. Ployngam, et al. (2007). "Effects of a single injection of methylprednisolone acetate on serum biochemical parameters in 11 cats." Vet Clin Pathol 36(2): 184-7.
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Insulins for Cats: Glargine, PZI, Lente

Marshall, R. D., J. S. Rand, et al. (2008). "Glargine and protamine zinc insulin have a longer duration of action and result in lower mean daily glucose concentrations than lente insulin in healthy cats." Journal of Veterinary Pharmacology and Therapeutics 31(3): 205-212.

This 3-way crossover study was designed to evaluate the effects of glargine (Lantus®), protamine zinc (PZI), and lente insulins in 9 healthy cats. Plasma concentrations of insulin and glucose were determined for 24 hours after a single subcutaneous injection of each insulin at 3-day intervals. Time to onset of action did not differ among insulins. The mean time to the glucose nadir was longer for glargine (14 hours), than for PZI (4 hours) or lente (5 hours). PZI was biphasic, with nadirs at 4 and 14 hours. The nadir glucose value did not differ among insulin types. The duration of action was similar for glargine and PZI, and was longer than for lente. A larger study is required to further compare glargine and PZI insulins in cats.
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Related articles:
Weaver, K. E., E. A. Rozanski, et al. (2006). "Use of glargine and lente insulins in cats with diabetes mellitus." J Vet Intern Med 20(2): 234-8.
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Rand, J. (2006). "Editorial: glargine, a new long-acting insulin analog for diabetic cats." J Vet Intern Med 20(2): 219-20.
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Fecal Parvovirus Testing in Cats

Neuerer, F. F., K. Horlacher, et al. (2008). "Comparison of different in-house test systems to detect parvovirus in faeces of cats." Journal of Feline Medicine & Surgery 10(3): 247-251.

Feline panleukopenia virus (FPV) is a common infection of domestic cats. The disease is highly contagious and associated with significant morbidity and mortality, especially in kittens. The virus is highly resistant and can survive up to 1 year in infected organic material. Clinical signs in cats are variable and leukopenia is not always present at the time of presentation. In-house tests for the detection of fecal canine parvovirus and/or FPV antigen for use in veterinary practice have become available. The close structural and antigenic relation of FPV and canine parvoviruses offers the possibility to test cats for FPV with the same test kit used for dogs. This study was designed to evaluate the strength and weaknesses of 5 commercial tests and to assess their sensitivity, specificity, and predictive values. In total, 200 fecal samples from randomly selected healthy cats (148) and cats with diarrhea (52) were tested and compared with the results of examination by electron microscopy. Ten cats were positive for FPV and all of these had diarrhea. All tests were suitable to screen cats for fecal parvovirus excretion. In-house parvovirus tests may be positive up to 2 weeks after vaccination, and therefore, in recently vaccinated cats positive results do not necessarily mean infection.
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Related articles:
Patterson, E. V., M. J. Reese, et al. (2007). "Effect of vaccination on parvovirus antigen testing in kittens." J Am Vet Med Assoc 230(3): 359-63.
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Blood Transfusions in Cats

Roux, F. A., J.-Y. Deschamps, et al. (2008). "Multiple red cell transfusions in 27 cats (2003-2006): indications, complications and outcomes." Journal of Feline Medicine & Surgery 10(3): 213-218.

Feline critical care, and in particular transfusion medicine, has been advancing in recent years. It is generally accepted that blood transfusions are more difficult in cats than in dogs. A particular challenge is the cat that has suffered catastrophic blood loss or hemolysis, requiring multiple transfusions (massive transfusion). The goals of this study were to evaluate the indications, complications and outcome of multiple red cell transfusions (MrcTs) in cats; to describe those that received massive transfusion; and to compare them with those who received MrcTs over a longer time course. Twenty-seven cats were identified which received a total of 110 transfusions. The median age of cats was 6 years and cats were hospitalized for a median of 6 days. No acute transfusion reactions were documented. Sixteen cats survived to discharge and 11 died or were euthanized. Indications for transfusions included bone marrow failure, surgical loss, sepsis, neoplasia, and trauma. The researchers conclude that MrcTs are well-tolerated in cats and may be associated with a favorable outcome.
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Related articles:
Iazbik, M. C., P. Gomez Ochoa, et al. (2007). "Effects of blood collection for transfusion on arterial blood pressure, heart rate, and PCV in cats." J Vet Intern Med 21(6): 1181-4.
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Meloxicam for Feline Arthritis

Gunew, M. N., V. H. Menrath, et al. (2008). "Long-term safety, efficacy and palatability of oral meloxicam at 0.01-0.03 mg/kg for treatment of osteoarthritic pain in cats." Journal of Feline Medicine & Surgery 10(3): 235-241.

Osteoarthritis is a painful condition that typically affects the elbow, hip, and shoulder joints of as many as 1 in 5 senior cats. Affected cats may have a variety of clinical signs, such as difficulty in jumping, lameness, resentment of handling and stiff gait. However, many owners do not recognize the significance of these clinical signs and may attribute them to aging changes. Although this is a common disease, reports of long-term osteoarthritis therapy in cats are rare. Non-steroidal anti-inflammatory drugs (NSAIDs) have proven efficacy in dogs and humans but there are limited published data on the use of NSAIDs in the long-term management of this condition in cats. This prospective study aimed to assess the long-term safety and palatability of oral meloxicam (Metacam, Boehringer Ingelheim Vetmedica, Inc.) and its efficacy in treating osteoarthritic pain in cats when given at a dose of 0.01 to 0.03 mg/kg once daily. Forty cats diagnosed with osteoarthritis completed the trial with a mean treatment duration of 5.8 months. Gastrointestinal upset in 2/46 (4%) cats was the only adverse effect noted. Three of the cats had stable chronic renal insufficiency (IRIS stage 3). No deleterious effect on renal function was detected in cats studied. Owners subjectively assessed treatment efficacy as good or excellent in 34/40 (85%) of cases. The results of this study showed oral meloxicam to be safe and palatable long-term treatment for osteoarthritis in cats when given with food at a dose of 0.01 to 0.03 mg/kg.
>> PubMed abstract

Related articles:
Clarke, S. P., D. Mellor, et al. (2005). "Prevalence of radiographic signs of degenerative joint disease in a hospital population of cats." Vet Rec 157(25): 793-9.
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Godfrey, D. R. (2005). "Osteoarthritis in cats: a retrospective radiological study." J Small Anim Pract 46(9): 425-9.
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New FeLV/FIV Management Guidelines

Levy, J., C. Crawford, et al. (2008). "2008 American Association of Feline Practitioners' feline retrovirus management guidelines." Journal of Feline Medicine & Surgery 10(3): 300-316.

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are among the most common infectious diseases of cats. Although vaccines are available for both viruses, identification and segregation of infected cats form the cornerstone for preventing new infections. Guidelines in this report have been developed for diagnosis, prevention, treatment, and management of FeLV and FIV infections. All cats should be tested for FeLV and FIV infections at appropriate intervals based on individual risk assessments. No test is 100% accurate at all times under all conditions; results should be interpreted along with the patient's health and risk factors. Retroviral tests can diagnose only infection, not clinical disease, and cats infected with FeLV or FIV may live for many years. A decision for euthanasia should never be based solely on whether or not the cat is infected. Vaccination against FeLV is highly recommended in kittens. In adult cats, antiretroviral vaccines are considered non-core and should be administered only if a risk assessment indicates they are appropriate.
>> PubMed abstract

Related articles:
Levy, J., H. Scott, et al. (2006). "Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in North America and risk factors for seropositivity." J Amer Vet Med Assoc 228(3): 371-376.
>> PubMed abstract

Goldkamp, C. E., J. K. Levy, et al. (2008). "Seroprevalences of feline leukemia virus and feline immunodeficiency virus in cats with abscesses or bite wounds and rate of veterinarian compliance with current guidelines for retrovirus testing." J Am Vet Med Assoc 232(8): 1152-8.
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Diagnosis of Hyperthyroidism in Cats with Kidney Disease

Wakeling, J., K. Moore, et al. (2008). "Diagnosis of hyperthyroidism in cats with mild chronic kidney disease." Journal of Small Animal Practice 49(6): 287-294.


It is a well known phenomenon that hyperthyroid cats with concurrent non-thyroidal illness, such as chronic kidney disease (CKD), may have total thyroxine concentrations within the normal reference range. This causes a diagnostic dilemma. The objective of this study was to determine total thyroxine, free thyroxine and/or thyroid-stimulating hormone concentrations in cats with mild CKD. Three groups of cats were included: 16 cats with CKD and clinical signs compatible with hyperthyroidism but total thyroxine within the reference range (these cats were confirmed with hyperthyroidism at a later date); 20 cats with CKD and no signs of hyperthyroidism; 20 clinically healthy senior cats (over 8 years of age). Four of the 20 cats with CKD had free thyroxine concentrations that were borderline or high. Of the 16 cats with hyperthyroidism and CKD, free thyroxine was high in 15/16 cats and thyroid-stimulating hormone was low in all cats. The researchers conclude that the combined measurement of free thyroxine with total thyroxine or thyroid-stimulating hormone may be of merit in the diagnosis of hyperthyroidism in cats with chronic kidney disease.
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Related articles:
Langston, C. E. and N. J. Reine (2006). "Hyperthyroidism and the kidney." Clin Tech Small Anim Pract 21(1): 17-21.
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Feline Large Granular Lymphocyte Lymphoma

Krick, E. L., L. Little, et al. (2008). "Description of clinical and pathological findings, treatment and outcome of feline large granular lymphocyte lymphoma (1996-2004)." Veterinary and Comparative Oncology 6(2): 102-110.

Large granular lymphocytes (LGL) can be found in the blood of healthy animals and usually constitute 10% or less of total circulating lymphocytes. Large granular lymphosarcoma/leukemia is a neoplastic disease of lymphocytes rarely seen in cats and dogs and is a distinct variation of lymphoma. Limited information exists regarding pathological and immunohistochemical descriptions, clinical findings, treatment and survival times in cats. Medical records of 45 cats with LGL lymphoma were retrospectively evaluated. The most common clinical signs were decreased appetite, anorexia, weight loss, lethargy, and vomiting. The mesenteric lymph nodes and small intestine were the most commonly affected organs. One complete response and six partial responses were noted in the 23 cats that received chemotherapy as their initial treatment. Median survival time for cats that were treated was 57 days. Based on these results, feline LGL lymphoma appears to be minimally responsive to chemotherapy and is associated with a grave prognosis.
>> Journal abstract

Related articles:
Roccabianca, P., W. Vernau, et al. (2006). "Feline large granular lymphocyte (LGL) lymphoma with secondary leukemia: primary intestinal origin with predominance of a CD3/CD8(alpha)(alpha) phenotype." Vet Pathol 43(1): 15-28.
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Carbimazole for Feline Hyperthyroidism

Frenais, R., S. Burgaud, et al. (2008). "Pharmacokinetics of controlled-release carbimazole tablets support once daily dosing in cats." Journal of Veterinary Pharmacology and Therapeutics 31(3): 213-219.


Carbimazole is a common oral treatment for feline hyperthyroidism, although not in North America. Carbimazole is a prodrug, as it is converted to methimazole after metabolism. Methimazole reduces production of the thyroid hormones, T3 and T4. The pharmacokinetics of methimazole was investigated in healthy cats following oral administration of 15 mg of carbimazole as a newly available controlled-release tablet (Vidalta®, Intervet). Methimazole levels were sustained and without a peak when compared to dosing with conventional carbimazole tablets. Repeated oral dosing for 13 days did not lead to accumulation of methimazole in plasma. Absorption of carbimazole was improved when administered with food. The relative oral bioavailability of methimazole following administration of the controlled-release tablets was similar to that of a conventional release formulation (83 ± 21%). The pharmacokinetics of this controlled-release formulation of carbimazole supports its use as a once daily treatment (both as a starting dose and for maintenance therapy) for cats with hyperthyroidism.
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Related articles:
Bucknell, D. G. (2000). "Feline hyperthyroidism: spectrum of clinical presentions and response to carbimazole therapy." Aust Vet J 78(7): 462-5.
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