Arterial hypertension in cats. Diagnosis and treatment of hypertension in cats

Cats don't smoke, don't eat excessive amounts of salt, and their lives are generally calm and stress-free, so why should we worry about their blood pressure? For a long time, most veterinarians did not know or even consider that cats could have high blood pressure or hypertension, and they did not know how to measure this pressure. Subtle, subtle signs that indicate high blood pressure in a cat are more frequent and louder meows throughout the day and a "dazed", sleepy state of the pet, as if under the influence of alcohol.

Veterinarians now know, based on numerous examinations, that high blood pressure is quite common in older cats and, fortunately, responds well to treatment. It is quite difficult to measure the pressure of a cat and get accurate and reliable data at the same time, because very few animals remain completely calm and relaxed when visiting a veterinarian. There are several types of instrumentation used to measure blood pressure, but they all have a cuff placed on the patient's paw and a mechanism for detecting when blood can flow through partially occluded blood vessels. It is necessary to take 3-5 measurements to accurately assess the value of systolic blood pressure. With a systolic pressure above 180, the risk of damage to organs and tissues is high.

High blood pressure causes problems with the heart and circulation throughout the body. In cats, one of the main organs affected by high blood pressure is the eyes. Tiny blood vessels in the eye can burst when too much pressure is applied to them. When this happens, retinal detachments and hemorrhages begin, and blindness may occur. If the owner immediately detects sudden blindness in a cat and is diagnosed with high blood pressure, immediate treatment can lead to restoration of vision. If high blood pressure is not treated within a few days, the chances that the retina will heal and vision will be restored are extremely small.

Most people develop hypertension without a specific medical problem. In cats, high blood pressure is always a secondary disease that occurs with chronic, (hyperfunction thyroid gland) or diabetes. If you have a cat suffering from these diseases, it is necessary to check it arterial pressure at least 1-2 times a year. If the cat is diagnosed with arterial hypertension, it is important to do all the necessary tests and undergo an examination to find possible reasons and underlying disease.

The initial treatment for high blood pressure in cats is medicine like amlodipine. It is produced in the form of tablets for humans, and is very difficult to cut into smaller doses, so it is recommended to purchase a special tablet knife for more accurate dosing. Amlodipine is a calcium channel blocker. Cats usually need to take it orally (by mouth) once or twice a day. If amlodipine does not help lower blood pressure, other drugs are added.

Unfortunately, studies have not shown a significant effect of diet on feline blood pressure, but diets for older cats, like those intended for cats with kidney disease, tend to have lower sodium and are also recommended for cats. arterial hypertension. Blood pressure usually stabilizes within 1-2 weeks of treatment, but cats almost always need ongoing treatment for the rest of their lives. The exception is high blood pressure caused by hyperthyroidism, if this disease is eliminated, the pressure also normalizes.

It is helpful for owners to know how cats develop hypertension. Pressure checks should be an integral part of the next veterinary visit for older cats and for younger cats with suspicious clinical signs(symptoms).

Hypertension is primary due to the pathology of the vessels themselves (idiopathic or essential) and secondary, which has arisen against the background of problems from some organ or system (for example, the kidneys or the hormonal system), and sometimes it can occur due to the use of certain drugs. Secondary hypertension in cats and dogs is more common than primary. AH more often develops in animals of older age groups (After 6-7 years).

How is blood pressure regulated in dogs and cats and why does hypertension occur?

Blood pressure (BP) depends on two quantities: the volume of blood that the heart pumps per unit time (varies depending on the heart rate and cardiac output) and the total vascular resistance (the elasticity of the vascular walls).

Simply put, the pressure of a liquid in any pipe system is regulated by the pumped volume of this very liquid and the diameter of the pipes through which it flows. An increase in the volume of liquid and / or a decrease in the lumen of the pipe (vessel) leads to an increase in pressure.

The mechanisms of blood pressure regulation are complex. Normally, the relative constancy of blood pressure is maintained by well-coordinated work nervous (central and peripheral) and hormonal systems.

The kidneys are one of the main organs that affect blood pressure. The kidneys perform several functions that help regulate blood pressure: these are the filtration of salts and water, and they also take part in the work of the renin-angiotensin-aldoside system (RAAS).

One of the endocrine glands that affect the amount of blood pressure is the adrenal glands (due to catecholamines and aldosterone).

Scheme of the work of the renin-angiotensin-aldoside system (RAAS)

Participation Example nervous system in the process of regulating blood pressure is shown in the figure below: impulses from baroreceptors (which respond to pressure changes and are located in the vessels) along the afferent nerve fiber go to the central nervous system to the centers that process these impulses (vasomotor) and return along the efferent nerve fiber to the receptors / tissues / organs responsible for changing pressure.

Scheme of the participation of the nervous system in the regulation of blood pressure

The main mechanisms leading to the development of hypertension

• violation of the filtration of sodium salts by the kidneys and their retention in the body (i.e., an increase in the amount of sodium salts leads to an influx of water into the bloodstream, which is necessary to maintain a stable concentration of the latter, which increases the total blood volume and pressure);
• disruption of the sympathetic nervous system;
• disruption of the RAAS;
• disruption of the work of endothelial cells (- cells lining the vessels from the inside, take part in the expansion and narrowing of blood vessels, they directly affect elasticity);
• vascular hypertrophy (thickened walls, unable to respond mobilely and expand the lumen of the vessel to changes, for example, blood volume or an increase in cardiac output).

Diseases that can cause secondary hypertension

• kidney disease (they are in the first place in both cats and dogs);
• hyperthyroidism (more common in cats);
• hyperadenocorticism;
• diabetes;
• hypothyroidism;
• acromegaly;
• pheochromocytoma;
• hyperaldesteronism;
• hyperkinesis of the heart and arrhythmias;
• intracranial problems (for example, increased intracranial pressure);
• hyperestrogenism.

The mechanisms underlying the development of primary hypertension in cats and dogs (as well as in humans in general) are not yet fully known and understood. That is, what causes the thickening of the walls of blood vessels or leads to disruption of the endothelium (in the absence of other causes of hypertension) has not been fully studied.

Why is AG dangerous?

Any disease has its target organs (the ones that suffer the most during the development of pathology). In AH, these are: kidneys, heart, brain, eyes.

• kidneys: with a constantly high blood pressure in the vessels of the nephron, a gradual change in the structure of the tissue of this unit of the kidney (an increase in the number of fibrous fibers) occurs, leading first to a violation, and then to total loss ability to filter urine. When there are more than 75% of such nephrons, irreversible renal failure occurs.
• Heart: constantly increased pressure makes the heart muscle work with more force, this leads over time to its thickening, complicating the nutrition of the heart muscle and increasing the risk of arrhythmias.
• Brain: the trophism (nutrition) of individual parts of the brain is disturbed as a result of tissue edema (due to high pressure, part of the liquid component of the blood “sweats” into the surrounding tissues) or hemorrhages (as a result of vascular ruptures). In some cases, these changes can lead to irreversible changes in the functioning of the central nervous system. Hydrocephalus (stagnation of fluid in the ventricles of the brain) also sometimes develops.
• Eyes: due to increased pressure in the vessels of the eye, hemorrhages can occur in different departments eyeball, retinal detachment, glaucoma develops. These changes often lead to partial or complete loss of vision.

As a rule, in the presence of hypertension, not one, but all of the listed organs suffer. And it doesn’t matter for what reason AH arose. It is important how long and how much the pressure rises.

What are the symptoms of hypertension in cats and dogs?

Symptoms of hypertension vary in manifestation and strength. They depend, of course, on which, and how much, the target organ has suffered. Symptoms that owners of animals with AH usually pay attention to:

• impaired/loss of vision (more common in cats);
• pendulum eye movements;
• hemorrhages (redness) in the anterior chamber of the eye;
• causeless vocalization (in cats);
• dyspnea;
• fainting;
• epileptiform seizures;
• lethargy, apathy;
• violation of appetite and water consumption;
• arena movements (movement in a circle).

Symptoms of high blood pressure in cats and dogs (changes) that can only be detected by specific methods in a veterinary clinic

• proteinuria and hematuria (urinalysis);
• concentric hypertrophy of the left ventricle of the heart (only echo kg);
• arrhythmia (via ECG);
• systolic murmur (during auscultation);
• detachment of the retina or hemorrhage in the fundus (ophthalmoscopy);
• changes in the structure of the central nervous system (according to CT or MRI).

These symptoms are nonspecific, often found in other diseases. And this greatly complicates the early diagnosis of AH disease.

How to detect high blood pressure?

There are not many options for measuring pressure: they are direct when placing sensors directly into the central vessels (traumatic method), but more accurate than indirect. In human medicine and veterinary medicine, it is used in the intensive care unit and during complex operations.

The indirect method is the measurement of pressure with tonometers known to all of us. However, in veterinary medicine, conventional medical blood pressure monitors often give too large an error or it is not possible to use them at all, for example, in cats and dogs of toy breeds.

In small animal veterinary medicine, it is recommended to use Doppler devices - one of them is PetMAP. Pressure is measured by placing the cuff on the foot or tail. It is recommended to carry out up to 3-5 changes in one place and display the average.

AT veterinary center"Constellation" can measure the pressure of a cat and a dog using such a device. The price for measuring pressure in dogs and cats is indicated in the corresponding section.

For dogs, pressure rates range from 100/65mmHg - 160/100mmHg (systole/diastole). For cats - 110/70 - 180/110mmHg. Systolic pressure close to 200 always requires medical correction, and above 280 may require emergency measures.

However, in some pets, a pressure of 185/110 may already require therapeutic intervention. Unfortunately, finding out the presence of high blood pressure is not enough; it is important to understand whether primary or secondary hypertension is present. And for this, additional studies are always required, which are prescribed by the doctor based on clinical symptoms noticed by the owner and identified during the inspection of deviations.

This is important, because in the presence of secondary hypertension, therapeutic correction (if possible) of the primary disease, removes the symptom of hypertension. If this is not possible, the doctor selects a drug to lower blood pressure. Dose adjustment of the drug often occurs during the first 1-2 weeks of treatment and is then applied for life.

OPHTHALMOLOGY

OPHTHALMIC MANIFESTATIONS OF SYSTEMIC HYPERTENSION IN CATS

OCULAR MANIFESTATIONS OF SYSTEMIC

HYPERTENSION IN CATS

UDC 617.7:616.12-008.331.1:636.8

L.A. SOLOMAKHINA, chief physician of the Voronezh veterinary complex "Kot M @ Troskin", member of the Rovo and ESVO l. solomakhina, DVM, Chief doctor, Member of the RSVO and of the ESVO, Voronezh Veterinary Complex "Cat [email protected]»

KEY WORDS / KEY woRDS:

ocular manifestations, systemic hypertension, cats

ABBREVIATIONS:

CKD - ​​chronic renal insufficiency of CHF- chronic heart failure BP - arterial hypertension AH - arterial hypertension CCC - the cardiovascular system PCG - anterior chamber of the eye ONH - disc optic nerve CNS - central nervous system

ANNOTATION

Systemic hypertension occurs in both dogs and cats. Hypertension is most common in cats because this species has a relatively high predisposition to developing CKD. ocular lesions in systemic hypertension include retinal and optic disc edema, tortuous retinal blood vessels, and preretinal, intraretinal, subretinal hemorrhages. Secondary retinal degeneration, probably due to ischemia and/or inflammation, is a common continuation of the disease (Figure 16). Animals with systemic hypertension may present with acute blindness (with fixed, dilated pupils) caused by bullous retinal detachment due to subretinal effusion (Figure 13).

Systemic hypertension occurs in both dogs and cats. It is more common in cats because this species has a relatively higher incidence of chronic kidney disease. The ocular lesions in systemic hypertension include retinal and papillary edema, tortuous retinal blood vessels, and preretinal, intraretinal and subretinal hemorrhage. Secondary retinal degeneration, probably due to ischemia and/or inflammation, is a common sequel (Fig. 16). Animals with systemic hypertension may be presented with a complaint of acute blindness (with fixed, dilated pupils) caused by bullous retinal detachment due to subretinal effusion (Fig. 13).

Arterial (systemic) hypertension occurs in cats and dogs, but is most common in cats. This is due to the high incidence of CRF in this species. Cats may have primary and secondary systemic hypertension.

more prone to this disease cats from 5 to 20 years old, but more often it occurs at the age of 8-10 years.

Causes of secondary systemic hypertension

Chronic and acute kidney disease. Statistically, 19-65% of cats with CKD have hypertension. Cause-

we hypertension most often are diseases such as chronic interstitial nephritis, amyloidosis, glomerulonephritis, pyelonephritis, polycystic kidney disease, renal dysplasia;

CHF (HKMP, etc.);

Diabetes;

Hyperthyroidism (87% of cats);

Hypothyroidism (dogs);

Hyperadrenocorticism (60% of dogs);

Pheochromocytoma (50% of dogs);

Primary hyperaldosteronism (dogs);

Obesity (hyperlipidemia) has been described as a risk factor for dogs (77% males);

OPHTHALMOLOGY

EDITOR'S COLUMN

Doctor, my old cat went blind...

Lyubov SOLOMAKHINA

Usually this is the phrase of the owners of elderly cats who have lost their sight, who come to see me. The pupils of these cats are fixed and dilated (Fig. 1). In addition, there is a feeling that in the pupil, just behind the lens, translucent "sheets", usually with a reddish tint, are floating (Fig. 2-5). This is nothing more than a detached retina, which, due to the accumulation of subretinal effusion, is raised upward and is thus viewed through the pupil directly behind the lens using a conventional focal light source, even without ophthalmoscopy. I call this picture "scarlet sails" ... This is the association I have when I see a bullous retinal detachment with hemorrhages that give a reddish tint when viewed from dilated pupils. However, in cats, even with complete bilateral retinal detachment, striking compensation is observed. In such cases, blindness can be detected when the animal enters an unfamiliar environment. Usually, there is a history of symptoms of systemic disorders in the form of polyuria-polydipsia, disorders of the urinary system and the gastrointestinal tract, weight loss, and seizures (which are often mistaken for epilepsy). Most often the reason given state in older cats, there is chronic renal failure and arterial hypertension secondary to it, which can also manifest itself as a convulsive syndrome. In addition, the cause of arterial hypertension may be related to heart failure, feline hyperthyroidism, etc. Sometimes in cats, arterial hypertension can be primary (idiopathic). It is important to remember that changes in the fundus appear already in the early stages. Initially, this may be increased tortuosity of the arterioles (Fig. 6) or the appearance of small retinal hemorrhages (Fig. 7), local retinal detachments without loss of visual function (Fig. 8-12). Owners at this stage usually do not notice vision problems in their pet. Given that cats are excellent at orienting themselves in familiar surroundings, owners usually notice loss of vision when there are already catastrophic changes in the fundus in the form of complete retinal detachment or extensive hemorrhages (Fig. 13-15). Therefore, veterinarians need to examine the fundus of all cats older than 5 years 2 times a year!

Elderly cats with AH (fixed and dilated pupils)

chronic anemia, polycythemia, fever, arteriovenous fistula;

Hypercalcemia (dogs);

Hyperestrogenism;

Food high in salt.

Diagnosis of arterial hypertension

requires measurement of systolic blood pressure, ideally measurement of systolic and diastolic blood pressure is required. It must be remembered that in shy and aggressive animals, blood pressure can be erroneously high. In this case, adaptation of the animal and several repeated measurements. In cats, systolic pressure is over 160-170 mm Hg. and diastolic pressure over 100 mm Hg. considered elevated. That is, blood pressure over 180/100 mm Hg. considered abnormally high. Values ​​above 200/110 mmHg Art. accompanied by characteristic clinical manifestations, incl. hypertensive retinopathy.

Blood pressure devices

Doppler veterinary 811. Frequency - from 8 MHz to 9.7 MHz. Doppler is designed to measure systolic blood pressure in cats and dogs.

Doppler veterinary Vet Dop BF1. Frequency 9.4 MHz, focussed transducer, convenient for fixing limb and transducer with one hand. The kit includes

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OPHTHALMOLOGY

sphygmomanometer, headphones, instructions for English language and video instruction, five cuffs 25x6, 21x5, 17x4, 14x3 and 11x2.5 (length and width are indicated in cm).

Veterinary tonometer PetMa (oscillographic method). Designed to measure systolic and diastolic pressure, heart rate. Measurement area: 30-260 mmHg, accuracy: +/- 2 mmHg, heart rate: 40 to 220 bpm. The set includes 7 cuffs up to 5 cm wide.

target organs

with arterial hypertension

Hypertension is the most common disease in aging cats, affecting the eyes, kidneys, heart (CVS), and CNS.

Hypertensive kidney disease:

Progression of renal failure;

Elevated creatinine in 65% of cats with hypertension and ophthalmic manifestations.

Required research:

Checking the level of serum creatinine and urea;

Analysis of urine;

Urine protein/creatinine ratio;

Ultrasound of the kidneys, etc.

Hypertensive lesion of the CCC:

Left ventricular hypertrophy;

gallop rhythm;

Arrhythmia;

systolic murmur;

Signs of heart failure;

Nose bleed.

Required research:

radiograph chest;

Auscultation;

Hypertension of the CNS:

encephalopathy;

Stroke;

TABLE 1. Normal Blood Pressure (mmHg) in Dogs and Cats

Dogs Cats

Systolic 148±16 171±22

Diastolic 87±8 123±17

Outbred cat, 19 years old, with hypertension against the background of CRF (fixed and dilated pupils)

Appearance anterior segment of the right eye of a purebred cat (fundus camera and slit lamp)

Appearance of the anterior segment of the left eye of a purebred cat (fundus camera and slit lamp)

Visualization of a detached retina in the pupil just behind the lens in a mongrel cat

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OPHTHALMOLOGY

Increased tortuosity of arterioles in cats with hypertension

Appearance of small retinal hemorrhages (indicated by arrows) in a cat with hypertension

Appearance of the anterior segment of the eyes and the fundus of a 15-year-old cat with hypertensive retinopathy

Appearance of the anterior segment of the eyes and the fundus of a 21-year-old cat with hypertensive retinopathy

TABLE 2. Risk of target organ damage

i Minimum Less than 150 Less than 95

2 Light 150-159 95-99

3 Medium 160-179 100-119

4 Heavy Greater than or equal to 180 Greater than or equal to 120

Weakness;

Ataxia;

Disorientation;

Vestibular disorders;

Neck flexion;

Paraparesis;

convulsions;

Required research:

neurological examination;

Eye lesions in systemic hypertension

Many studies show that eye lesions occur in 80-100% of cases with hypertension.

Hemorrhages in the PCG (Fig. 17);

Hyphema (Fig. 18);

Hemorrhages in the vitreous body;

Hypertensive retinopathy:

Edema of the retina and optic disc;

Pathological tortuosity of arterioles, thickening of their walls, reduction of their lumen (there may be focal constriction of arterioles);

Arterioles diverge at right angles (“buffalo horns”);

Preretinal, intraretinal and subretinal hemorrhages (Fig. 19, 20, 21, 22);

Animals with arterial hypertension often present with complaints of acute blindness (with fixed, dilated pupils) as a result of bullous retinal detachment due to subretinal effusion;

Secondary retinal degeneration (resulting from ischemia and/or inflammation) is a common consequence.

Clinical signs of retinal detachment:

The appearance of a floating sheet (retinal detachment) can be seen behind the lens without the use of an ophthalmoscope;

The sheet may be transparent, white, or bloody, depending on the type of fluid (exudative or hemorrhagic, respectively) involved in the pathogenesis of the detachment;

Retinal vessels are clearly visible;

The retina is out of focus on ophthalmoscopy;

If the posterior segment of the eye cannot be visualized, for example because of a hyphema, an ultrasound should be done;

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OPHTHALMOLOGY

The classic manifestation of retinal detachment on ultrasound is the "seagull sign" - retinal detachment, which remains fixed to the back wall of the eye, to the head of the optic nerve and to the dentate line of the retina (Fig. 24, 25);

The presence of subretinal fluid and vitreal inflammation are also seen on ultrasound.

Retinal hemorrhages

Based on their ophthalmoscopic appearance, the position of hemorrhages in the involved layer can be localized. Localization helps to identify the source of blood:

Subretinal hemorrhages originate from the choroidal vessels.

Preretinal hemorrhages originate from ophthalmoscopically visible vessels of the inner retina.

The mechanism of occurrence of hypertensive retinopathy

The vessels of the choroid and retina are most often damaged. There is a violation of vascular autoregulation of retinal arterioles. An increase in blood pressure causes narrowing of the arterioles, which leads to compensatory hypertrophy and hyperplasia of the smooth muscles of the vascular wall.

Due to changes in the content of fibrin in smooth muscle fibers, plasma seeps into the vessel wall, causing hyalinization, accompanied by necrosis. The result of plasma diffusion is retinal edema, hemorrhages, retinal detachment.

Treatment of arterial hypertension is aimed primarily at the underlying disease. Early initiation of medical treatment is necessary.

Antihypertensive drugs:

Amlodipine (calcium channel blocker) is the drug of first choice. It is especially important for the protection of the eyes and the central nervous system.

Amlodipine 0.1-0.5 mg/kg, once a day;

0.625-1.25 mg per cat every 12-24 hours (1/8 to 1/4 tablet per cat per day).

Amlodipine causes a drop in blood pressure within acceptable limits and the elimination of retinopathy. Clinically expressed adverse reactions missing. In cats, it is often used as monotherapy (without ACE inhibitors). In a study with amlodipine, retinal lesions were reduced in one or both eyes in 18 of 26 cats. Approximately 50% of cases with retinal detachment showed a decrease in the amount of subretinal fluid,

Appearance of the anterior segment of the eyes and the fundus of a 16-year-old cat with hypertensive retinopathy

Appearance of the anterior segment of the eyes and the fundus of a 14-year-old cat with hypertensive retinopathy

The appearance of the anterior segment of the eyes and the fundus of the cat in Fig. 11 after 1 month of treatment

bullous retinal detachment and hemorrhages in the right eye, extensive hemorrhages with subretinal effusion in the left eye in a cat from Fig. 2

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External view of the fundus in a cat with Fig. 2 through 8 days of treatment

The appearance of the anterior segment of the eyes and the fundus of the cat in Fig. 2 through 3 weeks of treatment

TABLE 3. Antihypertensive drugs

Generic name Dosage

ANGIOTENSIN-CONVERTING ENZYME INHIBITORS

EnaLapriL 0.5 mg/kg PO q12-24h 0.25-0.5 mg/kg PO q12-24h

CaptopriL 0.5-2.0 mg/kg PO q8-12h 3.1-6.25 mg/cat PO q8-12h

LisinopriL 0.5 mg/kg PO q24h -

Benazepril 0.25-0.5 mg/kg PO q24h 0.25-0.5 mg/kg PO q24h

CALCIUM CHANNEL BLOCKERS

DiLtiazem 0.5-1.5 mg/kg PO q8-12h to maximum of 200 mg/day 1.75-2.4 mg/kg PO q8h

DiLtiazem sustained release 10 mg/kg PO q24h 10 mg/kg PO q24h

AmLodipine 0.1 mg/kg PO q24h or 2.5 mg/dog 0.625-1.25 mg/cat PO q24h

G-ADRENERGIC BLOCKERS

PropranoLoL 0.2-1 mg/kg PO q8h to maximum of 200 mg/day 0.4-1.2 mg/kg PO q8 or 2.5-5 mg/cat PO q8-12h

AtenoLoL 0.2-2 mg/kg PO q12-24h or 6.25-12.5 mg/dog PO q12h 2-3 mg/kg PO q12h or 6.25-12.5 mg/cat PO q12h

G-ADRENERGIC BLOCKERS

Prazosin 0.065 mg/kg (1 mg/15 kg) PO q 8-12h 0.065 mg/kg (1 mg/15 kg) PO q 8-12h

Phenoxybenzamine 0.2-1.5 mg/kg PO q8-12h 2.5-7.5 mg/cat PO q8-12h or 0.5 mg/kg PO q12h

HydraLazine 0.5-2.0 mg/kg PO q12h 2.5 mg/cat PO q12-24h

Nitroprusside 1-10 Mg/kg/min IV CRI 1-10 Mg/kg/min IV CRI

Chlorothiazide 20-40 mg/kg PO q12-24h 20-40 mg/kg PO q12-24h

Hydrochlorothiazide 2-4 mg/kg PO q12h 2-4 mg/kg PO q12h

Furosemide 1-4 mg/kg PO, IM, IV or SC q8-12h (or as needed) 1-4 mg/kg PO, IM, IV or SC q8-24h

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Retinal degeneration in a cat with Fig. 2

Hemorrhage in Pkg

partial or complete replantation of the retina, or both. With retinal edema or hemorrhage without retinal detachment, 14 of 26 cats had partial or complete resolution of retinal lesions. Two cats with bilateral complete retinal detachment showed retinal replantation and some visual recovery after treatment with amlodipine.

ACE inhibitors (vasotope, etc.). Combined use of amlodipine with ACE inhibitors for cats with insufficiency of amlodipine monotherapy. As a rule, a combination of these 2 groups is used for dogs. Vasotop (rami-pril) 0.125-0.25 mg/kg, 1 time per day in the morning on an empty stomach with dose titration.

Diuretics are needed to reduce sodium and water retention in the body. Accelerate fluid resorption under the retina in animals with severe blistering detachment.

Furosemide is a loop diuretic (1-2-4 mg/kg, IV, IM, orally, 8-24 hours or 6.25-12.5 mg/cat/day in the table);

Trigrimm 2.5 mg (Diuver 5 mg) - torasemide 0.060.125 mg/kg per day.

Beta-blockers slow heart rate and inhibit the effect of triiodothyronine (T3) in hyperthyroidism.

Propranolol 2.5-5.0 mg/cat, 3 times a day;

Atenolol 6.25-12.5 mg/cat per day.

In addition, it is necessary to apply a diet with reduced content salt (up to 0.1-0.3%).

Monitoring of blood pressure and urine output is necessary, as a sharp drop in blood pressure and glomerular filtration can occur, as well as monitoring of BHAK and clinical condition animal.

deep intraretinal hemorrhages

Subretinal hemorrhages between retina and choroid

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OPHTHALMOLOGY

Local retinal detachments of the left eye in a cat with Fig. 2

II a Mil II !1 pg

MP ChK1 and □ nil

"Sign of the seagull" during an ultrasound of the right eye in a cat in Fig. 2

Blood pressure indicators are examined 5-10 days after the start of therapy. A favorable response to treatment is achieved with a decrease in systolic blood pressure by 20% or below 170 mm Hg.

Antihypertensive therapy should lower blood pressure to a level that is not associated with the appearance of new lesions and at which the animal will feel well.

Stabilization of blood pressure can occur within 1 month. Positive dynamics for treatment can develop from 1 week to 6 months. A 20% increase in blood pressure is considered a relapse of hypertension.

Eye Treatment required to prevent secondary glaucoma and uveitis. It is administered with topical corticosteroids (oftan dexamethasone/maxitrol/garazon). In addition, antioxidant therapy (emoxipin) is carried out.

Systemic anti-inflammatory therapy is often not possible due to the underlying disease. NSAIDs are not used due to their effect on platelets and blood clotting.

Uveitis due to hyphema but without glaucoma

Iridocycloplegics (atropine 1%) to keep the pupil dilated to prevent synechia.

Secondary glaucoma due to hyphema

Topical corticosteroids (0.1% dexamethasone/1% prednisolone), 6-8 hours later (3-4 times a day topically);

Beta blockers local action(0.5% timolo-la maleate / betoptic 0.5%), after 12 hours.

With a decrease in IOP, short-acting mydriatics - 1% tropicamide (midriacil) to prevent the formation of synechia, which can later impair vision.

For dissolution of clots - intracameral administration of tissue plasminogen activator tPA (actilyse) 30 μg / ml.

Forecasts

Recovery of visual function in cats with retinal detachment depends on several factors. On the-

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OPHTHALMOLOGY

The most important factor is the duration of detachment before diagnosis and treatment. If detachment continues for 2-4 weeks, retinal degeneration often occurs.

Approximately 50% of cats with multifocal retinal edema, hemorrhages and hypertension treated with amlodipine either did not progress to these lesions or partially resolved them.

The prognosis of vision recovery depends on changes in the vitreous body. Hemorrhages in the vitreous body resolve very slowly. Also, the prognosis depends on secondary eye diseases such as hyphema and glaucoma. The final assessment of the state of vision and ocular clinical signs should be carried out after 1.5-2 months.

In some cats, vision can be restored even if blood pressure is not reduced to the required level. In other cats, vision is not restored even after stabilization of blood pressure due to severe total atrophy retina.

With severe blistering, characteristic of cats with hypertensive retinopathy, degenerative

retinal movement can be strong and fast. Uremia in CRF causes toxic changes inside the retina.

Early detection of hypertensive retinopathy with the appointment of antihypertensive treatment before retinal detachment gives the best prognosis for maintaining vision. ■

LITERATURE

1. Ronald K. Rees. Ophthalmology of small animals. Aquarium-Print, 2006.

2. Barnett K.S., Crispin S.M. Feline Ophthalmology: An Atlas and Text. Phila-delphia, W.B. Saunders, 1998.

3. Kirk N. Gelatt. Veterinary Ophthalmology: John Wiley & Sons, 2013.

4. Rubin L.F: Atlas of Veterinary Ophthalmoscopy. Philadelphia, Lea and Febiger, 1974.

5. Slatter's Fundamentals of Veterinary Ophthalmology, edition 4.

MASTER CLASSES IN OPHTHALMOLOGY

Online school of webinars on ophthalmology by Dr. Solomakhina L.A.

"Ophthalmic manifestations of systemic diseases of dogs and cats"

“Basic ophthalmology for beginners. Medications for the treatment of ophthalmological patients” (tentatively beginning of February 2016, a group is being recruited)

http://vk.com/eyevets (VKontakte group) 89066710408 [email protected]

Sourced from www.icatcare.org

hypertension(hypertension) is medical term used for high blood pressure. This disease is quite common in older cats.

Feline hypertension usually develops as a result of other medical problems (so-called 'secondary hypertension'), although primary hypertension (hypertension without other, 'underlying' diseases) can also occur in cats. Unlike humans, who are more likely to have primary hypertension (also known as 'essential hypertension'), secondary hypertension is more common in cats. In most cases, secondary hypertension in cats is caused by chronic diseases kidney disease, but other diseases can also lead to its development. An association has also been established between hypertension and hyperthyroidism (an overactive thyroid gland) in cats.

Hypertension is dangerous for the entire body of a cat. The following organs are the most vulnerable:

Eyes. Bleeding in the eye and retinal disorders such as swelling and detachment are possible. As a result of these disorders, the cat's vision can suffer, and even blindness, often irreversible, can develop. In some cases, hemorrhages in the anterior chamber of the eye can be seen without the use of special equipment.

Brain and nervous system. Bleeding in these areas of the cat's body can be caused by neurological signs such as odd behavior, wobbly or drunken gait, seizures, dementia, and coma.

Heart. Gradually, the muscles in one of the heart's main chambers (the left ventricle) thicken as it becomes harder for the heart to perform its "pumping" tasks when pumping blood at elevated pressure. In very severe cases, this can lead to the development of chronic heart failure. The cat may experience shortness of breath and lethargy.

Kidneys. Over time, high blood pressure increases the risk of developing kidney problems. In cats with kidney problems, hypertension can significantly complicate the disease over time.

Diagnosis of hypertension in cats.

Because hypertension is often the result of other conditions, cats may show symptoms of the underlying disease. For example, in hyperthyroid cats with high blood pressure, the main clinical signs may be weight loss (despite excellent appetite) and hyperactivity.

Many cats may not show any specific signs of hypertension at all until the disease reaches a stage where eye hemorrhages or retinal detachments begin - such cats are often brought to the veterinarian for sudden blindness. That's why, early detection hypertension is very important to alleviate the disease and reduce the danger to the eyes and other organs of the cat's body.

Some cats suffering from hypertension appear depressed, lethargic, and withdrawn, even if there are no signs of damage to other organs. Many owners report a return to their cat's normal behavior after starting treatment for hypertension. It appears that when severely hypertensive, cats, like humans, can suffer from headaches.

To detect hypertension early, regular blood pressure measurements are recommended in cats older than 7 years of age, as hypertension is more common in older cats. Initially, this can be done once a year, but as the cat gets older, blood pressure should be checked at least twice a year, and blood pressure should be checked at every visit to the veterinarian.

Constant monitoring of pressure should be carried out for cats suffering from kidney disease, hyperthyroidism, heart disease, sudden blindness, as well as cats with other visual impairments and neurological disorders, in order to prevent the development of hypertension in time.

To measure blood pressure in cats, many clinics have the appropriate equipment. Often such devices are similar to those used by humans, with an inflatable cuff worn over a cat's paw or tail. The process of measuring pressure takes a couple of minutes, does not cause pain and is easily tolerated by most cats.

A detailed eye examination is also important in diagnosing hypertension in cats. In the initial stage of the disease, small changes in the blood vessels of the fundus and retina can be detected. In more severe cases, changes can be significant, including retinal detachment and bleeding in the eye. Typically, abnormalities are seen in both eyes of a cat, but (rarely) may be found in only one.

In the absence of blood pressure devices, it is possible to diagnose hypertension during eye examination, especially considering the dynamics of changes after the start of treatment. However, with the help of special devices for measuring pressure in cats, diagnosis and monitoring of the results of therapy is much more efficient.

Treatment of hypertension in cats.

Once hypertension is confirmed, cats are treated in two ways:

The first is treatment aimed at lowering blood pressure with antihypertensive drugs. Many drugs are now available, usually based on amlodipine and benazepril.

The second is to identify and treat the underlying disease, such as kidney disease, that causes hypertension. In some cases (for example, with hyperthyroidism), the treatment of the underlying disease can also solve the problem of high blood pressure. Urine and blood tests are usually done to identify the underlying disease.

It is also important to assess which complications of hypertension are present in the cat (eg eye disease) in order to properly manage them during therapy. Cats are characterized by very wide variability in response to antihypertensive drugs, in addition, pressure stabilization can occur at different times. It may be necessary to change medications, change the dose and / or frequency of administration, the use of more than one drug.

Response to therapy is best monitored by regular blood pressure measurements and eye examinations. In cats with kidney disease, it is important to constantly monitor kidney function during treatment.

Prognosis for treatment of hypertension in cats.

In cats with primary hypertension(without the underlying disease that caused the increase in pressure), it is usually possible to control the disease and prevent complications, for example, that are dangerous to the eye.

In the case of secondary hypertension, the long-term prognosis directly depends on the nature and severity of the disease causing the increase in pressure. In all cases, it is important to monitor blood pressure carefully and on a regular basis to avoid complications.

Arterial hypertension in cats is a persistent increase in systemic blood pressure, which has a detrimental effect on the walls of both large vessels and on the walls of blood vessels. microvasculature. The range of normal systolic blood pressure in cats is 115-160 mm. rt. Art.

The result of tonometry is affected by: the type of recording device, the size of the cuff, the behavior of the animal (in a state of stress, the indicators may be falsely high).

Today, tonometry, like thermometry, auscultation and palpation, is an integral part of the examination of an animal over the age of 7 years. This makes it possible to detect hypertension early stages, to prevent the development of irreversible processes in the body of the animal. We can observe hypertension in animals with kidney disease, cardiomyopathies, endocrine disorders and changes in the nervous system, as well as some other pathological conditions.

Causes of Hypertension in Cats

1. Hypertension "at the sight of a white coat" (an increase in blood pressure under stress. During tonometry, cats in an excited state may have falsely high blood pressure readings.). It is not a pathology.

2. Secondary hypertension develops against the background of systemic diseases.

There are many reasons leading to an increase in blood pressure in cats, for example, with such a pathological process, chronic kidney failure, hyperthyroidism, Cushing's syndrome, diabetes mellitus, are also recorded against the background of acromegaly, polycythemia, pheochromocytoma.

3. Idiopathic (primary, essential) is not associated with a systemic disease, characterized by an increase in peripheral vascular resistance and endothelial dysfunction.

In animals, hypertension in most cases is secondary!

Symptoms of hypertension in cats

Persistent systemic hypertension in cats in most cases is a symptom of the underlying disease, but in itself entails the development of pathological processes in target organs.

These organs include: kidneys, visual apparatus, heart, nervous system.

The main symptoms of kidney damage are progressive dysfunction associated with a steady increase in glomerular filtration pressure and microalbuminuria. High blood pressure is recorded at any stage of kidney disease.

As a result of hypertension, cardiac activity also suffers. Auscultation of these cats reveals a systolic murmur, a galloping rhythm, and echocardiography often reveals moderate left ventricular hypertrophy and diastolic dysfunction. During an electrocardiographic (ECG) study, ventricular and supraventricular arrhythmias, expansion of the atrial and ventricular complex, and conduction disturbances can be detected.

Against the background of high blood pressure, eye pathologies such as retinopathy and choroidopathy can develop, sometimes leading to visual impairment and acute blindness.

Neurological symptoms are dysfunction of the forebrain and vestibular apparatus. Damage to the forebrain is manifested by convulsions, a change in the mental state. The violation of the vestibular apparatus is evidenced by the tilt of the head, abnormal nystagmus, vestibular ataxia.

Also, neurological signs include: blindness, weakness, ataxia, tremor, decerebrate posture, episodic paraparesis.

In chronic hypertension, hypertrophy and hyperplasia of the smooth muscles of cerebral vessels with chronic vasoconstriction are noted. Such vascular degeneration is a predisposing factor to the appearance of microscopic hemorrhages. Cases of multiple arteriosclerosis with hemorrhage in cats with spontaneous hypertension have been reported in the veterinary literature.

Diagnosis of hypertension in cats

Diagnosing the causes of feline hypertension will include:

Routine tests:

1. Blood tests (clinical and biochemical analysis blood)

2. Blood test for T4

3. Urinalysis with the ratio of protein and creatinine

4. Tonometry

5. Ophthalmoscopy

Additional diagnostics may also be required, such as:

6. Ultrasound survey of the abdominal cavity

7. Eye ultrasound

8. Cardiological examination (ECHOCG, ECG)

How is tonometry performed in cats?

There are several ways to measure blood pressure in animals.

The most common and reliable is the indirect oscillometric method. Medical tonometers are not suitable for measuring blood pressure in animals, so our clinics are equipped with special electronic veterinary tonometers "Pet Map", which are convenient in veterinary practice.

To conduct tonometry, the cuff of the device is applied to the animal in a calm environment in the area of ​​​​the forearm, hock joint, lower leg, or at the base of the tail. Air is pumped into the cuff and fluctuations are measured as blood passes through the clamped section of the artery. To obtain the most reliable results, several measurements are taken. This procedure takes only a couple of minutes and, as a rule, does not cause any discomfort to the animal.

What is included in an eye examination?

When cat owners come to the clinic with complaints of poor eyesight, loss of vision, disorientation in space, hemorrhage in the retina, anterior chamber of the eye or vitreous body, the veterinarian will definitely check the pupillary reactions, reaction to light, reaction to threat, and conduct ophthalmoscopy. Ultrasound of the eyeball is performed with massive hemorrhage in the vitreous body, with cataracts and some other eye pathologies.

Indications for MRI/CT

If in persistent hypertension prevail neurological symptoms, after a series of studies, the veterinarian will refer your pet for additional diagnostics - computed tomography(CT) or magnetic resonance imaging (MRI).

These non-invasive methods will allow you to get a detailed image of the brain of good quality and detect signs of pathologies on different stages. They help to assess the condition of the smooth muscles of the cerebral vessels, detect aneurysm, neoplasm, and also confirm or refute some other pathologies of the nervous system.

Treatment of hypertension in cats

The first task of the attending veterinarian is to find the cause of hypertension. Early diagnosis and treatment can help prevent negative consequences illness. By treating the underlying cause with medication, hypertension can sometimes be completely cured. Symptomatic therapy is aimed at reducing systemic arterial pressure and preventing damage to the microvasculature of target organs, and improving blood circulation in them.

Prognosis for hypertension in cats

The prognosis depends on the reversibility of the primary disease, the degree of damage to target organs, and the response to antihypertensive therapy.