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Veterinary Definitions and Resources

As I write about Athena’s FIP diagnosis and treatment, there are terms that don’t have plain language equivalents. So, I created this page to house explanations and definitions to avoid cluttering my posts any more than necessary.

Overview of FIP, updated 7/1/2024

NOTE: I’ve only included terms for which I can’t find easy links.

Terminology Definitions

Alanine Transaminase (ALT) is also important in the metabolism of nitrogen and is most often associated with the liver. High levels indicate liver damage, toxin ingestion, Cushing’s disease and various metabolic disorders. Low levels indicate starvation or malnutrition. | Source: PetPlace.com

Albumin is the major protein found in the body. It carries various substances through the blood and is important in maintaining pressure within the vessels. High levels indicate dehydration. Low levels indicate chronic inflammation, liver disease, kidney disease, starvation and blood loss. | Source: PetPlace.com

Cerenia (maropitant citrate) can be used as a mild form of pain relief. It is sometimes used in surgery, reducing the pain felt during manipulation of internal organs during procedures such as spaying, and hence reducing the amount of general anaesthetic agent needed (this is known as an “anaesthetic sparing effect”). | Source: Cats.com

Chloride is responsible in part for metabolism (turning food into energy), and keeping the body’s acid base balanced. | Source: PetMD

Compounded animal drugs are typically made by pharmacists or veterinarians. Animal drug compounding is the process of combining, mixing, or altering ingredients to create a medication tailored to the needs of an individual animal or a small group of animals, and these drugs can play a critical role in veterinary medicine. | Source: FDA

Creatinine is a muscle enzyme that is excreted by the kidneys and builds up in the blood when kidney function decreases. It will increase with dehydration and decrease in very thin cats but your veterinarian will take these factors into account when staging your cat. | Source: Scottsdale Cat Clinic

Dorzolamide and Timolol are both prescribed to cats as eye drops. Timolol is in a class of medications called topical beta blockers which reduce intraocular pressure preventing damage to the optic nerve and the subsequent loss of vision. Dorzolamide is in a class of medications called topical carbonic anhydrase inhibitors which reduce intraocular pressure similar to beta-blockers. Dorzolamide and timolol lower pressure in the eye by decreasing the production of natural fluids in the eye. | Sources: MedlinePlus.gov, PubMed.gov, Topical Ophthalmic Beta Blockers: A Comparative Review.

The Fever of Unknown Origin (FUO) Blood Panel our local vet ran is through Idexx. While not much information is available about the panel, the submitted blood is checked for the following:

(Globulin is a class of protein.) There are many types of globulin, each of which has a specific function… Globulins play an important role in the body’s defense system; some are ‘first responders’, like firefighters, and appear in the blood stream quickly after any tissue injury. Others, called antibodies, are produced by lymphoid cells, a type of white blood cell, and appear in the blood stream more slowly following injury. Antibodies are essential to the body’s ability to defend against invading bacteria and other disease-causing organisms. | Source: VCA Animal Hospitals

A granuloma is a tiny cluster of white blood cells and other tissue that can be found in the lungs, head, skin or other parts of the body in some people. Granulomas are not cancerous. They form as a reaction to infections, inflammation, irritants or foreign objects. | Source: HealthDirect

Hematocrit (HCT) (also often called Packed Cell Volume, or PCV) is the most common way to measure anemia and refers to the percentage of blood volume that is taken up by red blood cells. The normal HCT for a cat is 25-45%, and any HCT below 25% is considered anemic. | Source: Cornell Feline Health Center

An immune mediated disease is a disease of unknown cause, but one which is thought to be modulated by an aberrant immune response. Unlike autoimmune diseases, the antibody causing this group of diseases has not been identified. [Basically, it’s an autoimmune disease without the scientific data to prove it.] | Source: The Schwarzman Animal Medical Center

Immunoflorescence staining is a method that uses a fluorescent dye to color antibodies that have bound to specific antigens, usually proteins or glycoproteins. | Source: Stanford Anatomic Pathology & Clinical Laboratories

Immunoperoxidase staining is a method that uses the enzyme peroxidase to cause a chemical reaction that colors antibodies that have bound to specific antigens, usually proteins or glycoproteins. | Source: Wikipedia

Lymphocytes are produced in lymph nodes throughout the body. They also help fight infection and produce antibodies against viruses, bacteria, etc. Lymphocytes may be increased with an infection, they can be decreased in cats that are severely stressed, and they might be lost in some types of diarrhea. | Source: Just Cats Clinic

MCV is an abbreviation for mean corpuscular volume. This is the average size of the red blood cells. A high MCV usually indicates certain vitamin deficiencies. A low MCV indicates iron deficiency. | Source: Pet Place

Neutrophils help fight infections. They can be decreased with bone marrow disease, in some viral diseases, and in some cats receiving cancer chemotherapy drugs. Neutrophils are increased with inflammation or infection of any part of the body and in cats receiving prednisolone or other cortisone-type drugs. | Source: Just Cats Clinic

Brain natriuretic peptide (BNP) is a prohormone (proBNP) — a substance that is a precursor to a hormone with minimal hormonal effect by itself — that is produced in the myocytes (smallest subunits of muscular tissues) of the atria (upper chambers of the heart). Normal stretching of the atria causes the proBNP hormone to be released. With the development of cardiac disease, the hormone is also produced and released by the myocytes of the ventricles (lower chambers of the heart) in an amount that is proportional to the severity of the disease. | Source: IDEXX

Reticulocyte hemoglobin content reflects the amount of iron available for hemoglobin production in the bone marrow. It is a useful parameter that can be confidently used in the diagnosis of iron deficiency anemia. | Source: Clinical Significance of Reticulocyte Hemoglobin Content in the Diagnosis of Iron Deficiency Anemia by Mustafa Karagülle, Eren Gündüz, […], and Meltem Olga Akay

Sodium is involved in many critical bodily functions, including maintaining blood pressure, blood volume, maintain the delicate acid/base balance in the body, as well as play a role in the transmission of nerve impulses (signals) within nerves. | Source: PetMD

Total Protein (TP) is an important substance in all parts of the body. High levels indicate dehydration, inflammation, chronic infection and certain cancers. Low levels indicate intestinal absorption problems, liver disease, Addison’s disease, severe burns and losses through the kidneys. | Source: PetPlace.com

Intraocular Pressure

In researching the “normal” range for intraocular pressure (IOP) I found that many sources disagree. I developed the “normal” range I used for my July 1 Athena post from the information below.

Normal cats exhibit a pronounced circadian rhythm in IOP, with highest values at night (by about 4- 5 mmHg) and a gradual decline in IOP occurring during the day (with IOP in the mid-to late afternoon about 1-1.5 mmHg lower than morning values). Intraocular pressure in cats is also influenced by the age of the subject, being considerably lower in geriatric cats than in young cats; higher in adolescent than in adult cats, and lower in young kittens within the first few weeks of life than in adolescent cats. In one large study involving 538 cats 7 years of age and older, normal mean IOP as measured by Tono-pen XL was 12.3 ±4.0 mmHg. In those cats in which IOP was measured on multiple occasions over time, IOP decreased progressively and it was not unusual for aged cats to have very low IOPs (≤ 7 mmHg) in the absence of any signs of anterior uveitis. This reduction in IOP may reflect reduction in active secretion of aqueous humor associated with declining systemic health. Marked asymmetry in IOPs, with a difference of 12mmHg or more between eyes, or an IOP of 25mmHg or more in older cats (measured with a Tono-pen XL), should prompt a thorough evaluation for ocular abnormalities including glaucoma. | Source

Normal IOP in cats is 15-25 mmHg. Any IOP above normal is considered glaucoma. Sustained elevations in IOP will cause blindness due to damage to the optic nerve and retina. | Source

Normal eye pressure is on average 15-20 mm Hg for the dog and cat. | Source

…normal intraocular range is 10-25 mmHg in cats | Source

In dogs and cats, normal IOP values are between 10 and 20 mm Hg; elevated IOP is indicative of glaucoma. | Source

The normal IOP range in cats has been reported to be between 15 and 25 mm Hg (mean, ~20 mm Hg). | Source

The often cited normal range of intraocular pressure (IOP) for dogs and cats is 10 to 25 mm Hg… In my experience, for example, a normal IOP range is usually 8 to 20 mm Hg when using an applanation or rebound tonometer. | Source

An overview of glaucoma in cats

Schirmer Tear Test

In researching the “normal” range for the Schirmer Tear Test, I found that sources disagree. I developed the “normal” range I used for my July 1 Athena post from the information below.

Schirmer Tear Test overview

The average STT for the right eyes was 12.16 ± 4.04 mm/minute, and for the left eyes, it was 12.76 ± 4.41 mm/minute (for both eyes: 12.46 ± 4.20 mm/minute), with a median of 13.50 for both eyes (Table 1). Reference values were calculated, and they ranged from 11.27 to 13.65 mm/minute. No significant differences were recorded in the STT for the right and left eyes of the cats (p > 0.05). Our results were slightly lower than in our previous observations (15.8 ± 6.1 mm/minute in the right eye and 17.3 ± 5.6 mm/minute in the left eye) (Kovalcuka and Nikolajenko, 2020). In other studies, STT-1 has ranged between 11.00 ± 1.41 and 20.80 ± 2.25 mm/minute (Aftab et al., 2018; Rajaei et al., 2018; Sebbag et al., 2020)… in cats, where it ranges from 13.7 ± 4.6 to 15.7 ± 3.7 mm/minute (Sebbag et al., 2020). | Source

A mean STT 14.9±4.8 mm/min was calculated for the eyes of all cats. There was a significant difference between STT values in kittens (≤6 months old) and cats of other age groups (P<0.001). A substantial number of cats with clinically normal eyes had STT values less than 10 mm/min. No significant difference was found between males (14.7±5.0 mm/min) and females (15.1±4.5 mm/min) in STT values (P=0.46). Significant differences were found between entire (14.4±4.2 mm/min) and neutered (16.2±4.1 mm/min) cats (P=0.001), and between STT values of DSH (14.6±5.0 mm/min) and Persian (16.5±3.1 mm/min) cats in the study population (P=0.001). | Source

The median STT-1 at 60 seconds was 14.3mm (8.2-22.3mm). This is largely in accordance with previously published data. | Source

Resources

Published Studies

While I’m sure there are many published studies on FIP treatment, I’m providing links to those that I’ve read and have found useful

Retrospective study and outcome of 307 cats with feline infectious peritonitis treated with legally sourced veterinary compounded preparations of remdesivir and GS-441524 (2020–2022). Journal of Feline Medicine and Surgery, Volume 25, Issue 9. September 2023.

Long-term follow-up of cats in complete remission after treatment of feline infectious peritonitis with oral GS-441524. Journal of Feline Medicine and Surgery. August 2023

2022 AAFP/EveryCat Feline Infectious Peritonitis Diagnosis Guidelines. Journal of Feline Medicine and Surgery. August 2022.

History of Feline infectious Peritonitis 1963-2022 – First description to Successful Treatment. Unknown publication. April 2022.

A retrospective study of clinical and laboratory features and treatment on cats highly suspected of feline infectious peritonitis in Wuhan, China. Scientific Reports. March 2021.

Sequence Analysis of Feline Coronaviruses and the Circulating Virulent/Avirulent Theory. National Library of Medicine, PubMed Central. April 2011.

Diagnostic features of clinical neurologic feline infectious peritonitis. National Library of Medicine, PubMed. November–December 1998

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