Experienced and professional animal trainer provide their insights in answering this question :
A. Try to encourage him to drink water. He may have a urinary tract infection or a stone. If he is otherwise acting normal, you can bring him to the vet tomorrow. If he seems more tired than usual or will not eat, or had other signs of illness, he may need to be evaluated by a vet sooner.

How to Identify Common Pet Problems ?

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There are no known effective home remedies for peeing blood in dogs. In some cases, a preventative dose of cranberry extract may help dogs with recurrent infections.
Bladder infection, or a UTI (this of course is the most common cause of blood in dog`s urine). The prostate (this would be an issue for male dogs who pee blood, which possibly indicates an issue with the prostate). Bladder stones could also be a culprit, due to nutrition, genetics, or persistent infection.
The age and sex of a dog may give some clues as to what is causing the bleeding. A female dog peeing blood (but acting normal) is more likely to have a urinary tract infection or inflammation, whereas a male dog peeing blood (but acting normal) is more likely to have bladder stones or a prostate problem.
Causes – Lower urinary tract bleeding

FLUTD has been linked to stress and anxiety. Prostate – the most common causes of bleeding from the prostate in an unneutered dog are prostatitis (infection) and benign hyperplasia.

Antibiotics are the treatment of choice for bladder, kidney, urinary tract, and other infections. Specific antibiotics that your vet may prescribe will depend on your dog`s history with antibiotics and the site of the infection.
Typically, green urine indicates late-stage kidney failure, cancer of the kidneys, or extremely severe urinary tract infection. Urine may turn green because bilirubin makes its way into the kidneys, where it is not supposed to be.
Antibiotics are the typical treatment for UTIs in dogs, and the vet may also prescribe pain medication, because UTIs can be very uncomfortable for dogs.
Typically when there is blood in your dog`s urine, this is due to inflammation or infection in the urinary tract which could include the upper or lower urinary tract. However, it`s important to contact a veterinarian or emergency vet as soon as possible to rule out any serious medical issues.
If you have a female dog that has not been spayed, you may see some blood when your dog urinates during her heat cycle. This is not necessarily an indication of a problem.
The clinical signs of more advanced kidney failure include loss of appetite, lethargy, vomiting, diarrhea, and very bad breath. Occasionally, ulcers will be found in the mouth.
Bloody urine may be due to a problem in your kidneys or other parts of the urinary tract, such as: Cancer of the bladder or kidney. Infection of the bladder, kidney, prostate, or urethra. Inflammation of the bladder, urethra, prostate, or kidney (glomerulonephritis)
Mix a one-to-one solution of white vinegar and water. Using a sponge, rub the solution onto the stain. Let it sit for 5-to-10 minutes, and then wipe it up with a clean, dry towel. Some experts advise using a more diluted formulation of 1/2-cup vinegar to one gallon of warm water.
One of the main treatments for kidney or bladder stones that cause blood in urine is to drink water.
Treatment might involve: Taking antibiotic medicines to clear a urinary tract infection. Trying a prescription medicine to shrink an enlarged prostate. Having a treatment that uses sound waves to break up bladder or kidney stones.
Some of the earliest signs of kidney disease in dogs may include subtle weight loss, urinating/peeing more often and drinking a lot more water. Therefore, if you notice your dog is peeing on the floor or asking to go out more, or if your dog is always thirsty, it`s time to visit your veterinarian.
Milk is a safe treat in small quantities. A few tablespoons of cow`s milk or goat`s milk on an occasional basis can be a nice reward for your dog. But, you should probably hold off on offering your dog an entire bowl in one sitting, as it can cause unpleasant reactions, including diarrhea, vomiting, and loose stools.
Ignoring signs of a UTI can lead to bigger, more serious issues like a kidney infection, not to mention discomfort or pain for your dog.
Recovery and management of UTIs in dogs

Recovery time depends on the severity of the infection. Most cases clear up pretty quickly without any complications once treatment begins, but in other situations it may take longer.

Bananas and other high-fiber foods can be good for urinary tract health and preventing urinary tract infections (UTIs) by encouraging regular bowel movements and relieving pressure on urine flow.
For males, blood in the urine may come from prostatic disease. For female dogs, it may come from pyometra, a discharge of pus and blood. This discharge goes for unspayed female dogs 2-8 weeks after the heat cycle. (In some cases, hematuria can be a symptom of more serious issues.)
The only way to stop the bleeding from a UTI is to treat the UTI. Antibiotics are the best course of action. Your doctor can provide you with a prescription for an antibiotic to treat your UTI.
The food your dog eats also impacts on the development of calcium oxalate stones. To decrease the chances of your dog developing bladder stones, you should avoid feeding foods that contain high levels of oxalate such as spinach, sweet potatoes, organ meat and brown rice.
What are the clinical signs of bladder stones? The most common signs that a dog has bladder stones are hematuria (blood in the urine) and dysuria (straining to urinate). Hematuria occurs because the stones rub against the bladder wall, irritating and damaging the tissue and causing bleeding.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. Has not eaten in 2 days. Noticed a little blood on the fur on her butt. What can I do?
ANSWER : A. Blood near the rear can be caused by a number of things. Bright red blood in the stool or around the anus can indicate a problem with the colon or anal region such as constipation, tears, illness or problems with the anal glands.

Blood that is dark or black in the stool can indicate a problem with the upper intestines such as the stomach or small intestine. This is usually considered more serious than bright red stool, however any blood seen is cause for concern. If the blood is seen more than once or twice, making a vet appointment is a must.

If your dog is not eating and is having blood in either her stool or vomit, making an appointment with your local vet is best. Illness, digestive upset or problems with internal organs can all cause these symptoms. In the mean time, a bland diet of plain boiled chicken and plain white rice may help to soothe minor digestive upset until you can get into the vet.

Q. Male neutered cat [1 1/2 years old] has just started trying to spray everywhere around the house. Nothing is coming out. No recent changes.
ANSWER : A. Changes in urinary habits can be caused by a number of things, especially in neutered male cats. Attempting to urinate or have accidents in places other than the litter box can often be a sign of a urinary tract infection, or crystals and debris in the bladder causing problems. Pets may need to go more frequently, may dribble or urinate in small amounts more often, may have accidents or may have blood-tinged or cloudy urine.Infections are usually treated with medications and changes to the diet, however in some cases of large stones or crystals surgery may be needed.

Male cats can also experience urinary blockage. This is due to a unique anatomical part or the urethra that forms a U-shape before exiting the body in male cats. If a cat has crystals or other debris in the urine, it can block at this point preventing urine from being able to exit. Cats may attempt to urinate without producing anything, may become very vocal (indicating pain) or may have a hunched back, full abdomen or pain in the abdomen (protecting the very full bladder). Urinary blockage IS a medical emergency so if suspected, your vet or local emergency clinic should be contacted immediately. Treatment usually involves a hospital stay and catheterization of the bladder to remove the blockage and allow urine to drain followed by medications and a change in diet to prevent further problems.

It is best to try and collect a sample of urine and make an appointment for your cat if he has had a change in urinary habits. If you do suspect a blockage, then contact your vet ASAP is best.

Q. I just noticed red color (blood?) In my dogs urine, not when she first goes but after when she is “marking” her area. ? She is rhodesian ridgeback-
ANSWER : A. If she has come into season you can sometimes see blood passing with the urine. If not it could be cystitis. You normally notice the dog urinating more often but smaller amounts. If this is the case you should see your vet to get appropriate medications. Other possibilities are kidney infection or kidney or bladder tumours but these are no where near as common as cystitis

Q. I found a large amount of pee from my unfixed male cat and it had blood in it. I notice later what looked similar to crystals in the same puddle. Help
ANSWER : A. You should have your cat examined and a urinalysis done immediately. Some cats do form crystals in their urine which leads to bladder inflammation,look in the urine, pain and in creased frequency of urination. The specific problem with male cats is the narrow width of the urethra through which the urine passes. Make cats have a very narrow urethra unlike female cats. The crystals, blood and other “sludge” that forms in the bladder when a cat has cystitis can cause a blockage in male cats and this is an emergency. A urinalysis can determine the extent of the problem and allow your vet to recommend appropriate treatment before it becomes an emergency. Your cat should be seen today.

Read Full Q/A … : Causes of Blood in Cat Urine

Q. My female dog urinates well and then she will squat in different places
ANSWER : A. If your dog is having accidents in the house, or is attempting to urinate frequently, going small amounts often, or has cloudy or blood-tinged urine, it may indicate a Urinary Tract Infection. Bringing her in along with a sample of her urine is best to check for this common issue and rule out any other causes of the constant urination. Your vet can then provide treatment such as antibiotics or a urine-friendly diet to help her feel better.

Q. 7 yr lab female blood in urine excess drinking some coughing my vet gone till Mon. Is this emergency or can it wait till next week?
ANSWER : A. I definitely would not wait. There are several concerning symptoms going on – blood in urine, coughing, excess drinking – and 4 days from now whatever is going on could be much worse. I would seek emergency care. An exam is the first thing that should be done, then blood work and a urinalysis to try to determine the reason for the excessive drinking and the blood in the urine. She made need chest x-rays as well depending on how her lungs sound when examined with the stethoscope.

Read Full Q/A … : Vetinfo

Q. My 20lb dog has trouble urinating. Painful urination blood in the urine low urine production. Urination in the house. And what seams like diarrhea.
ANSWER : A. The diarrhoea might be the result of straining to urinate, he could have an obstruction or an infection . It’ s very important that you have him checked.

Q. Cat is over 13 years old, blood test show anemia, weight loss, increase appetite, thick nails, very vocal, blood test did not show thyroid disease,tre
ANSWER : A. It is possible another metabolic issue could be causing the anemia and weight loss, or a more in-depth thyroid test is needed beyond the basic panel. Anemia can be caused by a number of things including blood loss from internal or external bleeding, failure to produce enough blood cells, or destruction of the blood cells by the immune system. Looking for causes of anemia may help you to find the underlying cause causing your cat’s symptoms. Additional tests such as ultrasound, further blood work and more may be beneficial.