Reddit reviews Obligate Carnivore: Cats, Dogs, and What it Really Means to be Vegan

You're right that a human going vegan has a bigger impact than a cat, but why not both?

• Vegetarian versus Meat-Based Diets for Companion Animals (2016) - "Cats and dogs maintained on vegetarian diets may be healthy—including those exercising at the highest levels—and indeed may experience a range of health benefits."
  
• VEGAN NUTRITION OF DOGS AND CATS (2014) - "It is the intention of this paper to provide general information on vegan nutrition of dogs and cats and furthermore to deal with how an adequate nutrient intake can be met with only plant based feeds" - Master's thesis from the Veterinary University of Vienna (translated from German).
  
• Evaluation of cats fed vegetarian diets and attitudes of their caregivers (2006)
  
  

  What about Taurine (and other essential nutrients)?
  

  
  Many people are concerned vegan diets lack essential nutrients for cats and dogs that can only be found in meat, like Taurine. Without Taurine, cats will suffer from retinal degeneration, cardiomyopathy, birth defects, and eventually death. This fear is heightened by anecdotal reports of owners who naively and cruelly feed an incomplete plant-based diet to their pets. However, many nutritionally complete dog and cat foods exist.
  
  Evolution is one such vegan dog & cat food brand, you can see their ingredients here. Both dog and cat food contain (ethical & sustainable) synthetic Taurine, Lysine, Carnitine, and more. This is not unique to Evolution. Any AAFCO compliant vegan pet food brand will have all essential nutrients and healthy carb/protein/fat macro-nutrient ratios as laid out by the guidelines.
  
  Some people worry that synthetic nutrients are less healthy than "natural" meat, or cost prohibitive. A common saying in the pet food industry is that "pets need nutrients, not ingredients". Almost all meat-based pet foods are just supplemented as vegan foods. The low-quality rendered meat is heavily processed in order to become edible flavoring, which denatures most amino acids and destroys other nutrients. You can see synthetic Taurine, amino acids, vitamins, and other nutrients in the labels of almost any pet food.
  
  

• Purina One
  
• Petcurean - Endless Valley Adult Dog
  
• And so on.
  
  

  Can cats be vegan?
  

  
  

• Arguments for trialing vegan food with cats.
  
  Yes. Cats require many nutrients that typically come from meat. In regular kibble, many of these nutrients are stripped away during processing and added back in from synthetic sources. These same sources are used to fulfill missing nutrients in vegan diets. Studies and anecdotal evidence support vegan diets as a healthy diet for cats.
  
  Vegan dog and cat food has the same amount of carbs, protein, and fat.
  
  There is one point of concern though. Vegan diets are typically more alkaline/basic (high pH) than meat based diets. Basic diets can cause FLUTD (feline lower urinary tract disease), especially in male cats. To combat this their food must be acidified.
  
  Most vegan and non-vegan cat kibble is acidified to prevent this condition. It's still a good idea to monitor your cat as it transitions foods to ensure its best health. On his website, Dr Andrew Knight says
  
  > Based on his experiences with thousands of vegan cats Gillen (2003) states that 85-90% of vegetarian cats do not require attention to dietary content; however, for the remaining 10-15%, urinary pH and dietary magnesium concentrations (see following) require monitoring
  
  The most relevant research has this to say on the matter
  
  > The normal pH of a cat’s urine is 5.5–7, and the normal range for a dog’s urine is pH 5–7 [85]. A pH > 7 indicates alkalinity. A variety of dietary products (e.g., “Vegeyeast” from Harbingers of a New Age—see [26]) and additives can correct alkalinization, should it occur. Asparagus, peas, brown rice, oats, lentils, corn, brussel sprouts and yeast may be included in feline and canine diets, and are all urinary acidifiers [27]. Vitamin C (ascorbic acid) is also a urinary acidifier. The British Small Animal Veterinary Association (BSAVA) Small Animal Formulary [86] recommends a dosage of 50–80 mg/kg every 24 h for cats and dogs. And for more serious cases, the amino acids methionine and cysteine may be used [13]. The BSAVA Small Animal Formulary [86] recommends a dosage of 200 mg/cat every 8 h. More detailed advice about urinary alkalinisation and corrective strategies is available via www.vegepets.info, or within veterinary medical texts.
  
  > Increased urinary acidity, decreased urinary magnesium and increased water consumption all help to keep the urinary pH within a healthy acidic range, and help to prevent the formation of struvite crystals. However, acidifying nutrients, agents, or products should be used carefully, as excessive levels can lead to metabolic acidosis. Increased urinary acidity may also promote higher urinary excretion of calcium and lower excretion of magnesium, and magnesium is a natural inhibitor to the formation of urinary stones associated with calcium [87].
  
  
• source
  
  > "Urinary pH is the most important factor in determining the SAP [struvite activity product, which can lead to FLUTD]. Acidification of urine causes deprotonation of phosphates and increases the total proportion of urine phosphate existing as trivalent anions, reducing the SAP.6 Urinary pH and SAP have been reduced with both dietary modification and administration of urinary acidifiers.7 The solubility of struvite is maximized when the urinary pH is <6.4 ... acidification of the urine to <6.29 may increase the risk of calcium oxalate urolith formation...[Urinary acidifiers] should be considered only when the urine pH is >6.5 with ad libitum feeding conditions...A general recommendation for prevention of urolithiasis is to increase water consumption...Diets with reduced magnesium that maintain a urine pH between 6 and 6.3 are recommended despite lack of evidence of efficacy...Monitoring urine pH is recommended to assess dietary compliance and efficacy. Values between 6.0 and 6.5 may reduce the incidence of calcium oxalate and struvite crystal formation. "
  
  
• source
  
  So what should you do?
  
  
• Always soak a cat's food in water for at least 30 minutes before feeding
  
• Buy vegan cat foods that have been acidified to lower pH. pH 6.3-6.4 is optimal, though exact pH will not likely be advertised. You can check for acidifiers by looking in the ingredient list for sodium bisulfate, dl-methionine, ammonium chloride, Vitamin C and the others discussed in the above study. These are already commonly added to regular pet foods.
  
• Check your cat's urine pH 1-2 weeks after switching to vegan and then twice a year. pH > 7 is a problem.
  
• For cats the target food pH is 6.3-6.5. Urine should be 6.0-6.5. Below or above this range is unhealthy. Acidifiers are only needed if the urine is above 6.5.
  
• If your cat appears to be in pain when using the litter box, immediately contact your vet. FLUTD is a serious condition that can lead to death.
  
• If you make your own food, which is not recommended, it is extremely important to check pH after it is thoroughly blended and mixed, and that the pH is 6.3-6.5. The author of Obligate Carnivore recommends taking these steps in the following order
  

1. For minor cases, enzyme supplements which include methionine, vitamin C, and/or cranberry extract will be sufficient. These limit both urinary alkalinisation and inflammation. They also aid digestion, and can result in increased vitality.
   
2. For moderate cases, Gillen states that Vegecat pH, with added sodium bisulfate, may be sufficient.
   
3. For severe cases Gillen recommends methionine pills. Severe cases also require a visit to the vet and possibly removing them from a vegan diet. Gillen estimates 85-90% of cats will never experience even a minor case.

Wowowow. I can't believe what I'm hearing! I wouldn't be surprised to hear that vegans were aware that cats could be vegan and yet chose to still feed them meat food for fear of the complications some vegan cats experience, but it sounds like neither of you are aware of the alternative and even buy into the "obligate carnivore" thing.

Jed Gillan who originally started vegancats.com (which has since been sold) wrote a book aptly titled Obligate Carnivore in which he argues that cats can be fed vegan diets if the humans put in a little extra effort. Female cats have an easier time being vegan than male cats (I can explain if anyone wishes), but for both you'd want to monitor their urine pH for a while after switching to a vegan diet because the main complication is that if their urine isn't acidic enough they can develop crystals in their bladders which may block them from urinating and can kill them rather quickly if it's not caught... but all this really means for the human is they need to add taurine and arachidonic acid to the food to make it acidic and monitor the pH. I know several people who have had vegan cats for the cats' lifetimes with no problems. It's entirely possible; meat isn't necessary.

Really I don't see the difference in argument between cats and humans. Humans did evolve as omnivores, yes, but we also can't deny that we evolved eating some meat--the amount being contested. Still, that's why vegans today need to make sure to take a b12 supplement and, really, often other supplements like zinc, taurine, carnitine... The point being that we realize we're not getting these things from a vegan diet because a vegan diet isn't quite exactly what we evolved eating--so we add in some chemicals to complete it. Same for cats... everything we all eat is just chemicals, and cats can get the same chemicals they get from meat from other non-meat sources, too. Pangea and Vegan Essentials even sell pre-made vegan cat food if you don't feel like putting it all together yourself.