Oxygen Therapy-When in CHF and at the Vet-How to Restore Oxygen Levels and Why

When your cat is in CHF-congestive heart failure-or has any other illness or issue, the cat likely will need oxygen therapy. When in CHF, oxygen and injected lasix at the vet/vet ER works fast to restore the cat. HCM depletes oxygen over time especially with CHF (read previous posts for explanations.) A body depleted of oxygen isn't just weak but isn't functioning well at all. Read this link for more information on the necessity of oxygen therapy.

https://bluepearlvet.com/library-articles/cardiology/oxygen-delivery-methods/

Lethargy Causes and Solutions

Let's review possible causes of lethargy, when it is common and when it is not common and the cat should see the vet.

Lethargy can be due to the difficulty of HCM-difficulty getting oxygen to the body from the lungs into the blood stream when the heart cannot pump enough blood due to swelling and heart failure.

Lethargy is also due to a lack of electrolytes-a lack of potassium, sodium, glucose, magnesium, potassium, calcium, phosphate, chloride, and bicarb-caused by the necessary use of diuretics which, when pulling fluid from the body, takes the electrolytes with the fluid. Low electrolytes leads to low heart rate, low blood pressure, a lack of what makes the heart beat and the kidneys work, etc. This makes one feel weak and faint. A cat owner can supplement electrolytes by giving the cat a potassium supplement (Renal K powder or gel, or human potassium pills such as Nature Made or Sundown), or some mashed banana or sweet potato-or baby food banana or sweet potato-and by giving sweetened condensed milk or corn syrup 1/8 tsp cut with 2 oz of water, added to food or fed by mouth a couple times a day. Sodium should not be given unless a cat has been vomiting or had diarrhea a few times a day for more than two days.

Lethargy is due to dehydration, caused by the necessity of diuretics. Dehydration lowers the heart rate and blood pressure, making one feel weak and faint. A cat owner can give water by mouth using a 3ml syringe (gently give 9mls or more this way), by adding it to wet food, and by providing many bowls of fresh water to encourage intake of fluid.

Lethargy can be caused by the use of medications for heart disease. These meds lower the heart rate and blood pressure in order to help the heart and may make one feel weak and faint. The cat may need time to get used to the meds but a cat owner can discuss the possibility of adjusting meds with the vet.

Lethargy can be caused by any number of issues or complications of heart disease, especially CHF-congestive heart failure-or the buildup of fluid in or around the lungs, making breathing difficult and painful.

Lethargy can be caused by any procedure or vet visit that has worn the cat out. The cat may take a day or two to recover but should be eating enough and using the litter box.

Lethargy can be caused by a lack of intake of food-a lack of nutrients and electrolytes found in foods. If a cat is not eating enough, hand feeding may be necessary. Hills AD is a good choice. It's high in calories and blends well with little water, and can easily be syringed up into a 3ml syringe and fed by mouth to the cat. Stimulants can also be used. Cyproheptadine, an antihistamine, increases appetite but does not wind up a cat. 1/4 tab once a day may be enough to help the cat eat enough. Mirtazapine is another stimulant which I use when the cat is terribly ill and cypro is not strong enough to spur eating. 1/4 of a tab once or twice a day may be needed. Further hand feeding may be necessary if the cat is very run down. Try using baby sweet potato for potassium, corn syrup in water for glucose, protein from tuna juice or homemade beef/chicken broth (plain-no salt or spices) or peanut butter are good protein choices. These should be fed a few times a day, giving the cat about 9-15mls at each feeding.

Whenever your HCM cat is lethargic, note it in your notebook; track what the cat eats, if the cat is moving about; track when the cat had meds and if you hand fed. Then if the cat is not improved after a day, take the cat to the vet and review your notes with the vet. Have the cat examined and blood work drawn to test for electrolyte levels, dehydration, kidney and liver values, and overall health.

Fluid In the Cat's Heart-Pericardial Effusion

What about fluid in the heart? That is known as pericardial effusion, caused by pericarditis, which is an inflammation of the pericardium, a double-layered membrane sac that surrounds the heart. This is NOT the same as CHF but it can lead to CHF. Pericardial effusion affects the right side of the heart more, compressing and restricting, and damaging the heart. The lower heart rate means the heart cannot be strong enough to pump fluid in and out, leading to the fluid backing into the lungs causing CHF. Fluid retention throughout the body typically follows ascites, swelling of the limbs, and weakness or collapse. While PE is possible, it is not always present or the cause of CHF in a typical pet.

Symptoms include those for any HCM issue or other disease:

Lethargy
Vomiting
Anorexia
Pale gums
Abdominal distention
Exercise intolerance
Fainting or collapse
Respiratory distress
Increased breathing rate and/or increased heart beat rat

Fluid IN the Lungs, Fluid Around the Lungs, and Chylothorax

Let's discuss congestion or CHF a bit more. Fluid in the body is comprised of fluid-water from food and drinking, things digested that the body breaks down, and blood. HCM, which is the enlarging of the heart valves, can lead to fluid build up in the lungs, known as CHF-congestive heart failure. The heart is unable to handle the fluid in the body, is unable to pump it out or take it all into the valves. The leftover fluid then backs up into the lungs. This is called pulmonary edema. When the drainage system in the body goes awry-various reason due to heart disease:

Increased hydrostatic pressure as a result of congestive heart failure (CHF)
Hypoalbuminemia (low levels of protein in the blood)
Changes in blood vessels-hey become "leaky"
Obstruction of lymphatic drainage/abnormal lymphatic function
Chylothorax (accumulation of chyle, a lymphatic fluid that originates in the intestines and has a high concentration of fat).
Diaphragmatic hernia
Hemothorax (bleeding into the pleural space)
Pulmonary thromboembolism (a blood clot in the lungs)
Bacterial, viral or fungal infection of the lungs
Cancer

-fluid can gather outside the lungs in the area between the lungs and chest, called the pleural sac, leading to pleural effusion. Regardless where is the fluid in or around the lungs, a diuretic is necessary to get rid of congestion. BUT fluid in the pleural sac can be drained if the diuretic is not working effectively. However, the necessity to drain the lungs often damages the lungs over time, creating pockets from the needle where fluid can gather and not be reached by draining, making breathing difficult and CHF still likely. Increasing the diuretic dosage is often necessary to further fight CHF.

It is possible for HCM cats, with advanced heart disease, to have the thoracic system fail and allow the buildup of chylothorax, a fatty white fluid that builds up in the pleural sac, causing CHF. This is an added complication and almost impossible to fight. It must be drained with a needle. Myrna developed this the last year of her life and lived 8 months with it. We had fluid drained every other week, increased the lasix, changed the diuretic to a harder one called Torsemide, and tried a supplement called Rutin which is supposed to help. Either she needed more or it wasn't working but it did not seem to end the chylothorax. A low fat diet is recommended also for this condition but I'm not sure what foods are low in fat; we didn't try that with Myrna. Chylothorax further damages the lungs because it is a caustic substance. You can read more here: https://vcahospitals.com/know-your-pet/chylothorax-in-cats
Chylothorax and the necessity to constantly drain the lungs due to pleural effusion, can lead to death-damage to the lungs and increased CHF; and because it is a sign of the heart system failing. Myrna lived eight months with pleural effusion/chylothorax which surprised her cardiologist and the vet hospital where we took her for her necropsy (animal autopsy.)