Differential diagnosis of blood-red urine in dogs and cats
The color of urine in healthy animals, affected by urine pigment and urine volume, usually appears from light yellow to amber. Urine is affected by various substances and exhibits abnormal colors. Among them, red urine is the most common and is mostly related to important diseases. The red urine defined in this article is a broad definition, including from red, yellowish-brown to black-brown.
The main reasons for the appearance of red urine are in Table 1, the most important of which are red blood cells, hemoglobin and bilirubin, but also various other substances are included. When diagnosing, it is necessary to first understand the causes of red urine, and then explore the causes of the disease.
Diagnosis Steps The diagnosis of red urine has three steps:
① Collection of initial data (lnitial database)
② Identification of red urine
③ Determination of etiology
1. Collection of initial data
Initial data include understanding the previous medical history, grasping the current situation, observing the urination status, performing a comprehensive physical examination and urine examination.
(1) Understand past medical history
Inquiry in detail about the past history of cystitis, urinary tract stones, trauma, chronic prostatitis, anemia, hemolytic diseases, bleeding tendencies, liver diseases, etc.
(2) Grasp the status quo
Inquiry in detail about the period, degree and process of the diseased animal's diseased animal's red urine, the strength of the red urine color during urination, recent treatment experience, food content, and whether there are signs of urination disorders such as difficulty in urination, frequent urination.
(3) Observe the urination status
If there is a urination disorder, it is necessary to actually observe the patient's urination status. Difficulty in urination refers to urethra stenosis or compression, which can be suspected of tumors, blood clots, urinary stones, etc. If frequent urination, prostatitis and cystitis can be suspected of.
(4) Comprehensive physical examination
In addition to general physical examinations, special palpation of the kidneys, bladder, prostate, urethra, uterus, and uterus, pay attention to their shape, size, hardness and pain. In addition, it is necessary to check whether there is bleeding, inflammation or tumor in the penis, foreskin, vagina and other areas. In addition, it is necessary to observe whether other surface mucosa tend to have bleeding tendencies, such as point-shaped bleeding, bleeding spots, and black stools.
(5) Urine examination
Usual examination is required before the initiation of treatment. For urine collection, you can use natural urination, hand compression, insertion catheter, bladder puncture, etc. However, natural urination is easily contaminated. Among the three methods described later, especially hand compression method and catheter insertion method, it is easy to have iatrogenic hematuria. In addition, catheter insertion method and bladder puncture method are also prone to secondary infection of bacteria, which have advantages and disadvantages. According to actual conditions, appropriate methods must be selected to combine them.
If bladder puncture is performed using a 22-digit needle, it will basically not cause a large amount of bleeding; if hematuria is suspected, natural urination is preferred to avoid iatrogenic hematuria. However, natural urination will also mix into the blood, white blood cells, and bacteria from the genitals, which needs to be considered.
After urine collection, conduct examinations as quickly as possible. If the examination cannot be performed immediately, the examination should be placed in the refrigerator to store; during the examination, the urine sample must be restored to body temperature. Low-temperature urine samples are prone to precipitation of crystals, resulting in misdiagnosis.
urine samples should be divided into three parts, and physical examinations, chemical examinations and urine sediment examinations are performed separately. Usually, it is easier to use test strips for general examination, but the urine samples must be centrifuged and the sediment should be taken for microscopic examination. The quantitative examination and evaluation method of urine sediment is to take a certain amount of urine (usually 5ml), rotate at a speed of 1,000 ~ 1,500 rpm, and centrifuge it for 5 minutes. Normal urine should not exceed 4-5 red bloods in each field of vision under high power microscope (400 times).