Measurement of Heart Size in Cats

Ghadiri, A., R. Avizeh, et al. (2008). "Radiographic measurement of vertebral heart size in healthy stray cats." J Feline Med Surg 10(1): 61-5.

Determination of heart size on chest radiographs is important when evaluating cats for cardiac disease. An enlarged cardiac silhouette is an indicator of cardiac disease. However, determination of cardiac size is usually subjective. In recent years, a cardiac measurement technique called the vertebral heart size or score (VHS) has been investigated as a less biased assessment of cardiac size. VHS compares cardiac dimensions with the length of mid-thoracic vertebrae. It has previously been evaluated in mixed groups of obese and non-obese cats of various ages, breeds, and sizes. Different breeds of dogs may have different normal reference values for VHS but it is not known if there is variability in normal reference values for different populations of cats. The objective of this study was to determine VHS in clinically normal, domestic shorthair, non-obese stray cats. The study was performed in Ahvaz, Iran. Left and right lateral, dorsoventral and ventrodorsal radiographs were taken and evaluated. Absolute measurements and vertebral heart scale values were slightly smaller than those previously reported in the literature, indicating that normal reference values may vary by breed or population in cats.
>> PubMed abstract

Related articles:
Litster, A. and J. Buchanan (2000). "Vertebral scale system to measure heart size in radiographs of cats." J Amer Vet Med Assoc 216(2): 210-214.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

Ghadiri, A., R. Avizeh, et al. (2008). "Radiographic measurement of vertebral heart size in healthy stray cats." J Feline Med Surg 10(1): 61-5.

Determination of heart size on chest radiographs is important when evaluating cats for cardiac disease. An enlarged cardiac silhouette is an indicator of cardiac disease. However, determination of cardiac size is usually subjective. In recent years, a cardiac measurement technique called the vertebral heart size or score (VHS) has been investigated as a less biased assessment of cardiac size. VHS compares cardiac dimensions with the length of mid-thoracic vertebrae. It has previously been evaluated in mixed groups of obese and non-obese cats of various ages, breeds, and sizes. Different breeds of dogs may have different normal reference values for VHS but it is not known if there is variability in normal reference values for different populations of cats. The objective of this study was to determine VHS in clinically normal, domestic shorthair, non-obese stray cats. The study was performed in Ahvaz, Iran. Left and right lateral, dorsoventral and ventrodorsal radiographs were taken and evaluated. Absolute measurements and vertebral heart scale values were slightly smaller than those previously reported in the literature, indicating that normal reference values may vary by breed or population in cats.
>> PubMed abstract

Related articles:
Litster, A. and J. Buchanan (2000). "Vertebral scale system to measure heart size in radiographs of cats." J Amer Vet Med Assoc 216(2): 210-214.
>> PubMed abstract

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Blood Pressure and Survival in Sick Cats

Silverstein, D. C., F. A. Wininger, et al. (2008). "Relationship between Doppler blood pressure and survival or response to treatment in critically ill cats: 83 cases (2003-2004)." J Am Vet Med Assoc 232(6): 893-7.

Critically ill cats pose special challenges in veterinary medicine. Standard means of monitoring cardiovascular status include temperature, respiratory rate, pulse rate (TPR) and blood pressure (BP). Both Doppler and oscillometric methods are routinely used to monitor BP in cats. Hypotension in cats is defined as a BP of under 80-90 mm Hg. Intermittent or prolonged hypotension can lead to serious consequences, such as impaired perfusion and decreased oxygen delivery, causing organ damage or failure. The purpose of this study was to evaluate the relationship between Doppler BP and survival or response to treatment in critically ill cats. The study is a retrospective case series involving the records of 83 cats. In addition to BP, other factors evaluated included survival to discharge, heart rate, rectal temperature, packed cell volume (PCV), plasma pH, serum ionized calcium, disease process, body weight, age, duration of hospitalization, and catecholamine treatment. Of the 83 cats, 39 were considered hypotensive and 44 were normotensive. Overall survival rate was 53%, with a significantly higher mortality rate amongst hypotensive patients. Of the other variables, only low rectal temperature and low PCV were significantly associated with hypotension. Monitoring for and correcting hypotension should be addressed in hospitalized, critically ill cats.
>> PubMed abstract

Related articles:
Lin, C. H., C. J. Yan, et al. (2006). "Systolic blood pressure of clinically normal and conscious cats determined by an indirect Doppler method in a clinical setting." J Vet Med Sci 68(8): 827-32.
>> Free, full text article

More on cat health: Winn Feline Foundation Library

Silverstein, D. C., F. A. Wininger, et al. (2008). "Relationship between Doppler blood pressure and survival or response to treatment in critically ill cats: 83 cases (2003-2004)." J Am Vet Med Assoc 232(6): 893-7.

Critically ill cats pose special challenges in veterinary medicine. Standard means of monitoring cardiovascular status include temperature, respiratory rate, pulse rate (TPR) and blood pressure (BP). Both Doppler and oscillometric methods are routinely used to monitor BP in cats. Hypotension in cats is defined as a BP of under 80-90 mm Hg. Intermittent or prolonged hypotension can lead to serious consequences, such as impaired perfusion and decreased oxygen delivery, causing organ damage or failure. The purpose of this study was to evaluate the relationship between Doppler BP and survival or response to treatment in critically ill cats. The study is a retrospective case series involving the records of 83 cats. In addition to BP, other factors evaluated included survival to discharge, heart rate, rectal temperature, packed cell volume (PCV), plasma pH, serum ionized calcium, disease process, body weight, age, duration of hospitalization, and catecholamine treatment. Of the 83 cats, 39 were considered hypotensive and 44 were normotensive. Overall survival rate was 53%, with a significantly higher mortality rate amongst hypotensive patients. Of the other variables, only low rectal temperature and low PCV were significantly associated with hypotension. Monitoring for and correcting hypotension should be addressed in hospitalized, critically ill cats.
>> PubMed abstract

Related articles:
Lin, C. H., C. J. Yan, et al. (2006). "Systolic blood pressure of clinically normal and conscious cats determined by an indirect Doppler method in a clinical setting." J Vet Med Sci 68(8): 827-32.
>> Free, full text article

More on cat health: Winn Feline Foundation Library

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Levetiracetam for Epilepsy in Cats

Bailey, K. S., C. W. Dewey, et al. (2008). "Levetiracetam as an adjunct to phenobarbital treatment in cats with suspected idiopathic epilepsy." J Am Vet Med Assoc 232(6): 867-72.

Levetiracetam (Keppra, UCB Pharma) is an anticonvulsant medication licensed for the treatment of epilepsy in humans. Anecdotally, it has been used as adjunctive therapy for epilepsy in dogs and cats. The goal of this study was to assess the pharmacokinetics, efficacy and adverse effects of oral levetiracetam administered in conjunction with phenobarbital in cats with poorly controlled epilepsy. The study was designed as an open-label, noncomparative clinical trial. Twelve cats with epilepsy poorly controlled by phenobarbital or that had unacceptable adverse effects from phenobarbital were enrolled in the study. The cats were treated with levetiracetam at 20 mg/kg every 8 hours. Serum drug levels were measured after at least 1 week of treatment. Seizure frequency before and after initiation of therapy were compared, and any adverse effects were recorded. The median serum half-life for levetiracetam was 2.9 hours. Seizure frequency was significantly higher prior to treatment with levetiracetam (2.1 seizures/month versus 0.42 seizures/month). Seven of 10 cats had reduction in seizure frequency of equal to or greater than 50%. Two cats had transient lethargy and anorexia. The researchers conclude that levetiracetam is well tolerated in cats, and may be a useful adjunct therapy to phenobarbital for cats with idiopathic epilepsy.
>> PubMed abstract

Related articles:
Dewey, C. W. (2006). "Anticonvulsant therapy in dogs and cats." Vet Clin North Am Small Anim Pract 36(5): 1107-27, vii.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

Bailey, K. S., C. W. Dewey, et al. (2008). "Levetiracetam as an adjunct to phenobarbital treatment in cats with suspected idiopathic epilepsy." J Am Vet Med Assoc 232(6): 867-72.

Levetiracetam (Keppra, UCB Pharma) is an anticonvulsant medication licensed for the treatment of epilepsy in humans. Anecdotally, it has been used as adjunctive therapy for epilepsy in dogs and cats. The goal of this study was to assess the pharmacokinetics, efficacy and adverse effects of oral levetiracetam administered in conjunction with phenobarbital in cats with poorly controlled epilepsy. The study was designed as an open-label, noncomparative clinical trial. Twelve cats with epilepsy poorly controlled by phenobarbital or that had unacceptable adverse effects from phenobarbital were enrolled in the study. The cats were treated with levetiracetam at 20 mg/kg every 8 hours. Serum drug levels were measured after at least 1 week of treatment. Seizure frequency before and after initiation of therapy were compared, and any adverse effects were recorded. The median serum half-life for levetiracetam was 2.9 hours. Seizure frequency was significantly higher prior to treatment with levetiracetam (2.1 seizures/month versus 0.42 seizures/month). Seven of 10 cats had reduction in seizure frequency of equal to or greater than 50%. Two cats had transient lethargy and anorexia. The researchers conclude that levetiracetam is well tolerated in cats, and may be a useful adjunct therapy to phenobarbital for cats with idiopathic epilepsy.
>> PubMed abstract

Related articles:
Dewey, C. W. (2006). "Anticonvulsant therapy in dogs and cats." Vet Clin North Am Small Anim Pract 36(5): 1107-27, vii.
>> PubMed abstract

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New Antiviral Treatment for Feline Calicivirus

Smith, A. W., P. L. Iversen, et al. (2008). "Virus-specific antiviral treatment for controlling severe and fatal outbreaks of feline calicivirus infection." Am J Vet Res 69(1): 23-32.

During the past decade, several outbreaks of severe systemic disease associated with feline calicivirus (FCV) have occurred with high mortality in the affected animals. This study details evaluation of a virus-specific antiviral phosphorodiamidate morpholino oligomer (PMO) for treating 112 kittens involved in 3 natural outbreaks of disease in the United States. PMOs are molecules used to modify gene expression. This novel treatment modality has not previously been tested in cats. A calicivirus strain was isolated from a cat that died of natural hemorrhagic calicivirus disease and a PMO was synthesized. The PMO was administered on day 1 of clinical signs and continued for up to 7 days. Various antiviral doses were evaluated by comparing survival times, clinical recovery, and virus shedding. In the natural outbreaks, 47 of 59 treated cats survived, but only 3 of 31 untreated cats survived. PMO treatment reduced calicivirus shedding and improved clinical recovery. Virus-specific PMOs may be an effective modality for treatment of severe disease associated with feline calicivirus.
>> PubMed abstract

Related blog posts:
Virulent systemic calicivirus
Feline caliciviruses causing virulent systemic disease are genetically distinct


More on PMOs


More on cat health: Winn Feline Foundation Library

Smith, A. W., P. L. Iversen, et al. (2008). "Virus-specific antiviral treatment for controlling severe and fatal outbreaks of feline calicivirus infection." Am J Vet Res 69(1): 23-32.

During the past decade, several outbreaks of severe systemic disease associated with feline calicivirus (FCV) have occurred with high mortality in the affected animals. This study details evaluation of a virus-specific antiviral phosphorodiamidate morpholino oligomer (PMO) for treating 112 kittens involved in 3 natural outbreaks of disease in the United States. PMOs are molecules used to modify gene expression. This novel treatment modality has not previously been tested in cats. A calicivirus strain was isolated from a cat that died of natural hemorrhagic calicivirus disease and a PMO was synthesized. The PMO was administered on day 1 of clinical signs and continued for up to 7 days. Various antiviral doses were evaluated by comparing survival times, clinical recovery, and virus shedding. In the natural outbreaks, 47 of 59 treated cats survived, but only 3 of 31 untreated cats survived. PMO treatment reduced calicivirus shedding and improved clinical recovery. Virus-specific PMOs may be an effective modality for treatment of severe disease associated with feline calicivirus.
>> PubMed abstract

Related blog posts:
Virulent systemic calicivirus
Feline caliciviruses causing virulent systemic disease are genetically distinct


More on PMOs


More on cat health: Winn Feline Foundation Library

Read More

New FIV Test Developed

Levy, J. K., P. C. Crawford, et al. (2008). "Differentiation of feline immunodeficiency virus vaccination, infection, or vaccination and infection in cats." J Vet Intern Med 22(2): 330-4.


Diagnosis of feline immunodeficiency virus (FIV) is complicated by the fact that no commercially available tests can differentiate between naturally infected cats and cats that have been vaccinated against FIV. After vaccination, cats produce antibodies that to date have been indistinguishable from those induced by natural infection. A discriminant enzyme-linked immunosorbent assay (ELISA) was developed that detects antibodies against formalin-treated FIV whole virus and untreated transmembrane peptide. In this study, blood samples from 73 uninfected and unvaccinated cats, 89 uninfected FIV-vaccinated cats, 99 unvaccinated FIV-infected cats, and 3 FIV-infected and vaccinated cats were tested. The discriminate ELISA correctly identified all uninfected cats, giving a specificity of 100%. Of the FIV-infected cats, 99 were correctly identified, giving a sensitivity of 97.1%. Other than virus isolation, which is not widely available and is time-consuming and expensive, this discriminate ELISA is the most reliable test for diagnosis of FIV. When this test becomes available at referral diagnostic laboratories, a new strategy for FIV testing would be to use the existing patient-side antibody assay as a screening test, and confirm positive results with the discriminant ELISA.
>> PubMed abstract


Related articles:
Kusuhara, H., T. Hohdatsu, et al. (2007). "Serological differentiation of FIV-infected cats from dual-subtype feline immunodeficiency virus vaccine (Fel-O-Vax FIV) inoculated cats." Vet Microbiol 120(3-4): 217-25.
>> PubMed abstract


More on cat health: Winn Feline Foundation Library

Levy, J. K., P. C. Crawford, et al. (2008). "Differentiation of feline immunodeficiency virus vaccination, infection, or vaccination and infection in cats." J Vet Intern Med 22(2): 330-4.


Diagnosis of feline immunodeficiency virus (FIV) is complicated by the fact that no commercially available tests can differentiate between naturally infected cats and cats that have been vaccinated against FIV. After vaccination, cats produce antibodies that to date have been indistinguishable from those induced by natural infection. A discriminant enzyme-linked immunosorbent assay (ELISA) was developed that detects antibodies against formalin-treated FIV whole virus and untreated transmembrane peptide. In this study, blood samples from 73 uninfected and unvaccinated cats, 89 uninfected FIV-vaccinated cats, 99 unvaccinated FIV-infected cats, and 3 FIV-infected and vaccinated cats were tested. The discriminate ELISA correctly identified all uninfected cats, giving a specificity of 100%. Of the FIV-infected cats, 99 were correctly identified, giving a sensitivity of 97.1%. Other than virus isolation, which is not widely available and is time-consuming and expensive, this discriminate ELISA is the most reliable test for diagnosis of FIV. When this test becomes available at referral diagnostic laboratories, a new strategy for FIV testing would be to use the existing patient-side antibody assay as a screening test, and confirm positive results with the discriminant ELISA.
>> PubMed abstract


Related articles:
Kusuhara, H., T. Hohdatsu, et al. (2007). "Serological differentiation of FIV-infected cats from dual-subtype feline immunodeficiency virus vaccine (Fel-O-Vax FIV) inoculated cats." Vet Microbiol 120(3-4): 217-25.
>> PubMed abstract


More on cat health: Winn Feline Foundation Library

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Hemangiosarcoma in Cats

Johannes, C. M., C. J. Henry, et al. (2007). "Hemangiosarcoma in cats: 53 cases (1992-2002)." J Am Vet Med Assoc 231(12): 1851-6.

Hemangiosarcoma is a cancer arising from blood vessels and is considered rare in cats. Traditionally, feline hemangiosarcoma is classified as either dermal or visceral, with no distinction between cutaneous and subcutaneous dermal tumors. The purpose of this study was to characterize feline hemangiosarcoma and determine the signalment, clinical signs, biological behavior, treatment outcomes, and prognostic indicators associated with this type of tumor. In a retrospective case series, data from 53 cats with hemangiosarcoma was evaluated. Cutaneous and subcutaneous locations were more common than abdominal and thoracic locations. In 47 of the cats, surgery was the primary treatment. Tumor-free surgical margins were associated with longer survival times and were more likely to be obtained in cutaneous than subcutaneous tumors. Local recurrence was experienced in 6 of the 12 cats with subcutaneous tumors for which follow-up was available. Metastic disease was experienced by several cats. Of the 21 known deaths or euthanasias, 18 were directly related to the tumor. Subcutaneous hemangiosarcoma was more aggressive than the cutaneous form, and it was more likely to recur locally and result in death or euthanasia. Visceral hemangiosarcoma is associated with a grave prognosis.
>> PubMed abstract

Related articles:
Culp, W. T., K. J. Drobatz, et al. (2008). "Feline visceral hemangiosarcoma." J Vet Intern Med 22(1): 148-52.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

Johannes, C. M., C. J. Henry, et al. (2007). "Hemangiosarcoma in cats: 53 cases (1992-2002)." J Am Vet Med Assoc 231(12): 1851-6.

Hemangiosarcoma is a cancer arising from blood vessels and is considered rare in cats. Traditionally, feline hemangiosarcoma is classified as either dermal or visceral, with no distinction between cutaneous and subcutaneous dermal tumors. The purpose of this study was to characterize feline hemangiosarcoma and determine the signalment, clinical signs, biological behavior, treatment outcomes, and prognostic indicators associated with this type of tumor. In a retrospective case series, data from 53 cats with hemangiosarcoma was evaluated. Cutaneous and subcutaneous locations were more common than abdominal and thoracic locations. In 47 of the cats, surgery was the primary treatment. Tumor-free surgical margins were associated with longer survival times and were more likely to be obtained in cutaneous than subcutaneous tumors. Local recurrence was experienced in 6 of the 12 cats with subcutaneous tumors for which follow-up was available. Metastic disease was experienced by several cats. Of the 21 known deaths or euthanasias, 18 were directly related to the tumor. Subcutaneous hemangiosarcoma was more aggressive than the cutaneous form, and it was more likely to recur locally and result in death or euthanasia. Visceral hemangiosarcoma is associated with a grave prognosis.
>> PubMed abstract

Related articles:
Culp, W. T., K. J. Drobatz, et al. (2008). "Feline visceral hemangiosarcoma." J Vet Intern Med 22(1): 148-52.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

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The Best Age to Spay and Neuter

Kustritz, M. V. (2007). "Determining the optimal age for gonadectomy of dogs and cats." J Am Vet Med Assoc 231(11): 1665-75.

Spaying female cats and castrating male cats, also called gonadectomy, are among the most commonly performed surgeries in veterinary medicine. Increasingly, both pet owners and veterinarians are questioning the best age to perform gonadectomy. Most veterinarians in the U.S. recommend gonadectomy for cats and dogs between 6 and 9 months of age. However, there is no scientific evidence to document that this is the optimal age. In fact, the age for gonadectomy of cats and dogs has varied tremendously over time and by geographic location. This article is a review of the scientific evidence on optimal ages for gonadectomy.
>> Free full text article available

Related articles:
Howe, L. M. (2006). "Surgical methods of contraception and sterilization." Theriogenology 66(3): 500-9.
>> PubMed abstract

Olson, P., M. Kustritz, et al. (2001). "Early-age neutering of dogs and cats in the United States (a review)." J Reprod Fertil Suppl 57: 223-232.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

Kustritz, M. V. (2007). "Determining the optimal age for gonadectomy of dogs and cats." J Am Vet Med Assoc 231(11): 1665-75.

Spaying female cats and castrating male cats, also called gonadectomy, are among the most commonly performed surgeries in veterinary medicine. Increasingly, both pet owners and veterinarians are questioning the best age to perform gonadectomy. Most veterinarians in the U.S. recommend gonadectomy for cats and dogs between 6 and 9 months of age. However, there is no scientific evidence to document that this is the optimal age. In fact, the age for gonadectomy of cats and dogs has varied tremendously over time and by geographic location. This article is a review of the scientific evidence on optimal ages for gonadectomy.
>> Free full text article available

Related articles:
Howe, L. M. (2006). "Surgical methods of contraception and sterilization." Theriogenology 66(3): 500-9.
>> PubMed abstract

Olson, P., M. Kustritz, et al. (2001). "Early-age neutering of dogs and cats in the United States (a review)." J Reprod Fertil Suppl 57: 223-232.
>> PubMed abstract

More on cat health: Winn Feline Foundation Library

Read More